Constituent Screening for

Coal Combustion Wastes

Work Assignment 3-43

Contract No. 68-W-98-085

Prepared for:

 U.S. Environmental Protection Agency

Office of Solid Waste

Research Triangle Park, NC 27709

Prepared by:

RTI

P.O. Box 12194

Research Triangle Park, NC 27709

October 2002
Constituent Screening for 

Coal Combustion Wastes

Work Assignment No. 3-43

Contract No. 68-W-98-085

Prepared for:

 U.S. Environmental Protection Agency

Office of Solid Waste

Research Triangle Park, NC 27709

Prepared by:

RTI

P.O. Box 12194

Research Triangle Park, NC 27709

October 2002
iii

Table of Contents

Section Page

1.0 Problem Formulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

2.0 Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1

2.1 Waste Constituents of Concern . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2

2.1.1 Selection and Grouping of Waste Types of Concern . . . . . . . . . . . . . . . 2-3

2.1.2 Selection of Appropriate Analyte Data for Screening . . . . . . . . . . . . . . 2-4

2.1.3 Development of Waste Constituent Concentrations for Screening . . . . 2-5

2.2 Human Health Benchmarks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-7

2.3 Ecological Receptors, Endpoints, and Benchmarks . . . . . . . . . . . . . . . . . . . . 2-11

2.4 Exposure Assessment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-12

2.4.1 Human Health-Based Numbers (HBNs) . . . . . . . . . . . . . . . . . . . . . . . 2-12

2.4.2 Ecological Chemical Stressor Concentration Limits (CSCLs) . . . . . . 2-13

2.4.3 Media-Specific Exposure Concentrations . . . . . . . . . . . . . . . . . . . . . . 2-15

2.5 Risk Calculations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-17

3.0 Risk Characterization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1

3.1 Human Health Results—Groundwater Pathways . . . . . . . . . . . . . . . . . . . . . . . 3-1

3.1.1 Groundwater-to-Drinking-Water Pathway . . . . . . . . . . . . . . . . . . . . . . 3-1

3.1.2 Groundwater-to-Surface-Water Pathway . . . . . . . . . . . . . . . . . . . . . . . 3-4

3.1.3 Summary and Conclusions: Groundwater Pathway Analysis . . . . . . . . 3-7

3.2 Human Health Results—Aboveground Pathways . . . . . . . . . . . . . . . . . . . . . . . 3-7

3.3 Ecological Risk Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-10

3.3.1 Soil Pathways . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-10

3.3.2 Surface Water Pathways . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-12

3.3.3 Ecological Risk Conclusions and Recommendations . . . . . . . . . . . . . 3-16

3.4 Conclusions and Recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-17

3.4.1 Aboveground Pathways . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-17

3.4.2 Groundwater Pathways . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-19

3.4.3 Constituents Not Addressed in the Screening Analysis . . . . . . . . . . . . 3-20

4.0 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1

Appendix A–CCW Constituent Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-1

Appendix B–Human Health Benchmarks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-1

Appendix C–Chemical Stressor Concentration Limits (CSCLs) for Ecological Screening . . . C-1

Appendix D–Calculation of Health-Based Numbers (HBNs) . . . . . . . . . . . . . . . . . . . . . . . . . D-1

Appendix E–Chemical-Specific Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . E-1

Appendix F–Biota Factors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . F-1

Appendix G–Human Exposure Factors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . G-1

Appendix H–Site Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . H-1

Appendix I–Tabulated Human Health Screening Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I-1

Appendix J–Tabulated Ecological Risk Screening Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . J-1
iv

List of Figures

Figure Page

1-1. Conceptual model of CCW risk assessment for landfills and surface impoundments . 1-3

2-1. Comparison of 1998 and 2002 CCW porewater concentration data . . . . . . . . . . . . . . . 2-8

2-2. Comparison of 1998 and 2002 CCW TCLP data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-9

2-3. Comparison of 1998 and 2002 CCW landfill whole waste concentration data . . . . . . 2-10

2-4. Soil dilution factors from the 1998 aboveground risk analysis for CCW landfills. . . 2-17

3-1. CCW surface impoundment porewater screening risk levels for the 

groundwater-to-drinking-water pathway . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2

3-2 CCW landfill leachate screening risk levels for the groundwater-todrinking-water pathway . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3

3-3. CCW surface impoundment porewater screening risk levels for the

surface water (fish consumption) and drinking water pathways . . . . . . . . . . . . . . . . . . 3-5

3-4. CCW landfill leachate screening risk levels for the surface water 

(fish consumption) and drinking water pathways. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-6

3-5. Comparison of 1998 and 2002 aboveground human health risk results for the 

soil pathway . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-9

3-6. CCW landfill aboveground ecological screening risks: Soil pathway . . . . . . . . . . . . 3-11

3-7. CCW surface impoundment ecological screening risks: Groundwater-to-surfacewater pathway . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-13

3-8. CCW landfill (TCLP) ecological screening risks: Groundwater-to-surfacewater pathway . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-14

3-9. CCW landfill aboveground ecological screening risks: Sediment pathway . . . . . . . . 3-15
v

List of Tables

Table Page

2-1. Constituents Addressed in the Screening Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2

2-2. Waste Types in CCW Constituent Database . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3

2-3. Comparison/Hierarchy of Leaching Methods Represented in CCW 

Constituent Database . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5

2-4. Ecological Receptors Assessed in Each Medium . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-11

2-5. CSCL Exposure Assumptions for Mammals and Birds . . . . . . . . . . . . . . . . . . . . . . . 2-15

2-6. Comparison of IWEM and CCW Landfill Areas . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-16

2-7. Comparison of IWEM and CCW Surface Impoundment Areas . . . . . . . . . . . . . . . . . 2-16

3-1 Summary of Screening Results: Constituents Exceeding Human Health

Screening Criteria for Groundwater Pathways . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-8

3-2. CCW Screening Results Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-18

3-3. Summary of CCW Screening Results: Groundwater Pathway Exceedances . . . . . . . 3-19

3-4. CCW Constituents/Measurements Not Addressed in Screening Because of

Lack of Benchmarks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-21
Section 1.0 Problem Formulation

1-1

Constituent Screening for 

Coal Combustion Wastes

This report presents the methodology and results from RTI's screening and selection of

constituents of concern for the coal combustion wastes (CCW) risk assessment. RTI developed

and applied a risk-based methodology for selecting CCW chemical constituents, waste types,

receptors, and exposure pathways for detailed modeling or additional study. Screening was

conducted for the following receptors and pathways of concern:

# Human health impacts from groundwater contamination

# Human health impacts from aboveground contamination

# Ecological impacts from groundwater contamination

# Ecological impacts from aboveground contamination.

Previous risk assessment results for CCW (U.S. EPA, 1998) indicated concern for the

groundwater pathway and limited concern for aboveground pathways for human and ecological

receptors. The primary purpose of this risk assessment is to update those results by

incorporating new waste characterization data received since 1998 and by applying current data

and methodologies to the risk assessment. The initial step in this process is screening and

constituent selection for a more detailed analysis. 

1.0 Problem Formulation

For more than 10 years, the U.S. Environmental Protection Agency (EPA) has conducted

risk assessments to assist regulators, industry, and the public in evaluating the environmental

risks associated with CCW landfills, surface impoundments, other disposal procedures, and

beneficial uses. In April 2000, the Agency determined that certain coal combustion waste would

be subject to Resource Conservation and Recovery Act (RCRA) Subtitle D regulation, but did

not specify the regulatory options at that time. This screening analysis is a first step toward

identifying and quantifying human health and ecological risks that may be associated with

current management practices for high-volume CCW: fly ash, bottom ash, boiler slag, flue gas

desulfurization (FGD) sludge, and wastes from fluidized-bed combustion (FBC) units. These

CCW risk assessments will assist the Agency in developing specific CCW regulatory options for

these waste streams under RCRA Subtitle D regulation. Details on EPA's CCW project,

including work conducted to date, can be found at

http://www.epa.gov./epaoswer/other/fossil/index.htm.
Section 1.0 Problem Formulation

1-2

The goal of screening is to identify CCW constituents, waste types, receptors, and

exposure pathways with risks below the level of concern and eliminate those combinations from

further analysis. The scope of screening is utility coal combustion wastes. EPA’s Report to

Congress on Wastes from the Combustion of Fossil Fuels (U.S. EPA, 1999) reports that there are

440 coal-fired utility power plants in the United States. Although they are concentrated in the

East, the plants are found in nearly every state, with facility settings ranging from urban to rural. 

The large volumes of wastes generated by these plants are typically managed onsite in landfills

and surface impoundments. The screening analysis must be designed to be appropriate for and

protective of this national waste management setting.

Risk-based screening analyses are, by design, intended to be protective. The objective is

to focus attention to the constituents, exposure pathways, and receptors of concern so that EPA

can begin to formulate appropriate regulatory options and undertake the additional analyses

needed to determine the best approach. To accomplish this objective, screening criteria must be

set to be protective of all CCW management scenarios across the United States. An appropriate

level of conservatism will result in confident identification of de minimis risks but will only

indicate a potential for significant risks for constituents, waste management scenarios, exposure

pathways, and receptors that do not pass the screen. This potential for risk can be examined

through less conservative analyses of conditions at CCW facilities, such as detailed site-based

modeling or analysis of damage cases at specific facilities. 

Screening should also be comprehensive in coverage of exposure pathways and receptors

of potential concern. Figure 1-1 provides a conceptual model of exposure pathways associated

with the management of CCW in surface impoundments and landfills. Key features of this

model include

# Contaminant release from landfills through water and wind erosion and leaching

# Contaminant release from surface impoundments through infiltration through the

bottom of the impoundment

# Transport of contaminants through air, overland runoff, surface water, and

groundwater

# Uptake and accumulation of contaminants by plants and animals

# Human exposure through direct contact with or ingestion of contaminated air,

water, soil, produce, beef, milk, and fish

# Ecological exposure through direct contact with contaminated media and

ingestion of contaminated organisms.

The design of the screening analysis used this conceptual model to ensure that screening is

comprehensive with respect to releases, exposure pathways, and receptors of potential concern.
1-3

SOURCE RELEASE MECHANISMS MEDIA EXPOSURE SCENARIOS EXPOSURE ROUTES 

Erosion & Runoff Soil Leaching/Infiltration Groundwater Residence Postclosure Surface Impoundment Ingestion of drinking 

Agricultural Field/ Home Garden/ Backyard Terrestrial Habitat Surface Water Habitat Ingestion of produce

meat, and milk Contact with soil 

Surface Water Ingestion of fish Inhalation of particu

Ingestion of soil 

Particulate Emissions Air Note: 1. Resident, recreational fisher, and resident farmer include one adult and four child age groups Ingestion of terrestria

soil, and soil inverteb

Contact with water 

Ingestion of aquatic p and invertebrates 

Sediment Contact with sediment 

Ingestion of sedimen invertebrates 

Active Surface Impoundment Landfill Sediment Habitat Figure 1-1. Conceptual model of CCW risk assessment for landfills and surface impoundme
Section 2.0 Analysis

1

For the groundwater-to-surface-water pathway, the analysis assumes human exposure occurs through the

consumption of contaminated fish. Ecological exposure occurs through direct contact to contaminated surface water

and sediment and consumption of aquatic organisms.

2-1

2.0 Analysis

The screening risk analysis is designed to identify CCW constituents for possible

full-scale exposure modeling of the groundwater and aboveground exposure pathways by

estimating exposure and risk that may occur from the constituents and comparing these risk

estimates with target risk criteria. The groundwater pathway screening evaluates exposure

through drinking water ingestion and surface water contamination1 from groundwater; the

aboveground pathway screening evaluates exposure through ingestion of media and food items

from a contaminated area adjacent to the waste management unit. The analysis considers risks to

both human and ecological receptors. Waste constituents that pass the screen (i.e., are below

target risk/hazard criteria) are assumed to pose de minimis risks and will not be addressed in the

full-scale modeling.

RTI’s approach to CCW screening is to compare protective concentrations in each

medium of concern for human and ecological receptors with estimated offsite media

concentrations of CCW constituents. Health-based numbers (HBNs) are media concentrations

developed to protect human health, and chemical stressor concentration limits (CSCLs) are

developed to protect ecological receptors. HBNs are calculated based on the target risk criteria

for the screening analysis: a hazard quotient (HQ) of 1 (for noncarcinogens) or an excess cancer

risk level of 10-5. CSCLs are calculated based on a HQ of 1.

The analysis phase for screening involves developing these HBNs and CSCLs, as well as

preparing the waste constituent or media concentrations to be used in the comparison and

estimating the risk associated with these concentrations. Pathways and waste streams evaluated

in the analysis include

# Groundwater-to-drinking water, by comparing drinking water HBNs directly with

landfill leachate and surface impoundment porewater concentrations

# Groundwater-to-surface water, by comparing surface water HBNs and CSCLs

directly with landfill leachate and surface impoundment porewater concentrations

# Aboveground soil, by comparing soil HBNs and CSCLs to offsite soil

contaminant concentrations from the erosion and overland transport of landfill

waste
Section 2.0 Analysis

2-2

# Aboveground sediments, by comparing sediment CSCLs to sediment contaminant

concentrations from the erosion and overland transport of landfill waste and

contaminated soil.

Direct ecological exposure to surface impoundment waters was not considered because no new

data were available. Results for this pathway from the 1998 CCW ecological risk assessment are

provided in the summary table and figures in Section 3.0. 

2.1 Waste Constituents of Concern

The CCW screening analysis addresses metals and inorganic compounds identified by

EPA as potential constituents of concern in CCW (Table 2-1). RTI derived waste concentrations

for most of these constituents from a waste characterization database prepared for EPA by

Science Applications International Corporation (SAIC). This CCW constituent database

includes analyte concentration data in three tables representing different types of waste samples:

landfill leachate analyses (in mg/L), surface impoundment and landfill porewater analyses (in

mg/L), and analyses of whole waste samples (in mg/kg). Each table specifies, for most samples,

the type of waste sampled and the type of coal burned at the facility. 

Table 2-1. Constituents Addressed in the Screening Analysis

Constituent CAS ID Constituent CAS ID

Metals Inorganic Anions

Aluminum 7429-90-5 Chloride 16887-00-6

Antimony 7440-36-0 Cyanide 57-12-5

Arsenic 7440-38-2 Fluoride 16984-48-8

Barium 7440-39-3 Total Nitrate Nitrogen 14797-55-8

Beryllium 7440-41-7 Phosphate 14265-44-2

Boron 7440-42-8 Silicon 7631-86-9

Cadmium 7440-43-9 Sulfate 14808-79-8

Chromium 7440-47-3 Sulfide 18496-25-8

Cobalt 7440-48-4 Inorganic Cations

Copper 7440-50-8 Ammonia 7664-41-7

Iron 7439-89-6 Calcium 7440-70-2

Lead 7439-92-1 pH 12408-02-5

Magnesium 7439-95-4 Potassium 7440-09-7

Manganese 7439-96-5 Sodium 7440-23-5

Mercury 7439-97-6 Nonmetallic Elements

Molybdenum 7439-98-7 Inorganic Carbon 7440-44-0

Nickel 7440-02-0 Total Elemental Sulfur 7704-34-9

Selenium 7782-49-2 Measurements

Silver 7440-22-4 Total Dissolved Solids none

(continued)
Table 2-1. (Continued)

Section 2.0 Analysis

Constituent CAS ID Constituent CAS ID

2-3

Strontium 7440-24-6 Total Organic Carbon none

Thallium 7440-28-0 Dissolved Organic Carbon none

Vanadium 7440-62-2

Zinc 7440-66-6

Table 2-2 lists the waste types evaluated in the screening analysis along with the number

of sites representing each waste type in the database. Key steps in preparing these data for

screening include (1) selection and grouping of waste types to be addressed, (2) selection of the

analyte data to be used, and (3) processing of these data to develop the analyte concentrations for

the screening analysis. 

2.1.1 Selection and Grouping of Waste Types of Concern

The CCW constituent database contains a variety of waste types. Some selection and

grouping of these types was necessary to produce a consistent and simple screening analysis. 

Table 2-2. Waste Types in CCW Constituent Database1

Waste Type

Number of Sites by Waste Type

Landfill

Leachate

Landfill

Porewater

Surface

Impoundment

Porewater

Whole

Waste

Conventional Combustion Waste 92 5 16 57

Ash (not otherwise specified) 33 1 0 25

Fly ash 62 2 2 34

Bottom ash & slag 23 1 4 22

Combined fly & bottom ash 9 0 5 4

FGD sludge 5 1 6 5

Combined ash & coal waste 4 0 4 1

Fluidized-Bed Combustion Waste 55 1 0 53

Ash (not otherwise specified) 15 1 0 9

Fly ash 34 0 0 33

Bottom and bed ash 25 0 0 25

Combined fly & bottom ash 20 0 0 22

1

Counts by waste type from leachate, porewater, and whole waste data tables in 7/08/02 SAIC database
Section 2.0 Analysis

2-4

The analysis excludes coal waste (e.g., mill rejects, coal gob, storage pile runoff) because

it is not coal combustion waste and, therefore, is out of scope for the analysis. Mixed ash and

coal waste are included. Mine-filled waste is included under the assumption that it is

representative of wastes destined for mine waste disposal and that similar waste could be

disposed of in landfills and surface impoundments. However, porewater from mine waste

disposal sites is excluded from the analysis because acidic conditions characteristic of mine

disposal sites are not characteristic of the CCW landfills and surface impoundments that are the

subject of this analysis.

 Combustion ash types in the CCW constituent database include fly ash, bottom ash, bed

ash, slag, combined fly and bottom ash, and coal ash not otherwise specified. The analysis

combines data for these ash types, as appropriate, for landfills and surface impoundments at the

same site. However, units holding FBC wastes, FGD sludges, and codisposed ash and coal

waste are addressed separately because the composition and chemistry of these wastes are likely

to be different from those of coal combustion ash. That is, the analyte concentration data for

FBC wastes, FGD sludges, and combined ash and coal waste are not mixed with analyte

concentration data for ash from conventional coal combustion units.

2.1.2 Selection of Appropriate Analyte Data for Screening

CCW analyte concentration data represent (1) leachate from landfills and surface

impoundments and (2) whole waste in landfills, as follows. 

# Whole waste analyte concentrations (in mg/kg) represent landfill waste

concentrations for screening the aboveground pathways.

# Analyte concentrations (in mg/L) in porewater sampled from surface

impoundment sediments represent surface impoundment leachate affecting the

groundwater pathways. 

# To represent landfill leachate, the leachate table in the CCW constituent

concentration database includes analyte concentrations from several leaching

methods. Data are also available from landfill porewater analyses at six sites in

the porewater data table. Table 2-3 describes the method types included in the

database, along with the decision hierarchy used when several types of leaching

data are available for a disposal site.

As shown in Table 2-3, the methods thought to best represent long-term waste monofill

porewater composition (i.e., methods with long equilibration times and low liquid-to-solid ratios)

represent only a few sites, with most sites having toxic characteristic leaching procedure (TCLP)

and/or synthetic precipitation leaching procedure (SPLP) measurements. To best represent CCW

landfill waste concentration at a wide variety of sites, the hierarchy rank shown in Table 2-3 is

used to select the best method for a particular site. For sites where two or more methods are

available in the same rank (which often occurs for SPLP and TCLP analyses), the screening

analysis uses the method with the highest analyte concentrations. This ensures that the data used

in the screening analysis are the best that are available and represent a broad variety waste

disposal conditions.
Section 2.0 Analysis

2-5

Table 2-3. Comparison/Hierarchy of Leaching Methods

Represented in CCW Constituent Database

Method (Rank) Description Pros Cons

Landfill porewater (1) Direct porewater

samples from landfill

Most representative of

leachate chemistry

Low number of sites represented

High retention time and

low L:S methods (2)

Waste extractions with

long equilibration times

(days to weeks) and low

liquid-to-solid ratios

(L:S)

Better representation of

landfill equilibration

times and L:S

Low number of sites represented

Low L:S methods (3) Waste extractions with

low liquid-to-solid ratios

Better representation of

landfill L:S

Low number of sites represented;

equilibrium times relatively short

High retention time

methods (3)

Waste extractions with

long equilibration times

(days to weeks)

Better representation of

landfill equilibration

times

Low number of sites represented; L:S

relatively high

TCLP (4) Toxicity Characteristic

Leaching Procedure

waste extractions

Most representative in

terms of number of

sites, waste types

covered 

High L:S (20:1) can dilute leachate

concentrations; short equilibration

time (18 hr) may not allow

equilibrium to develop; Na-acetate

buffer can overestimate leaching for

some constituents (e.g., Pb)

SPLP (4) Synthetic Precipitation 

Leaching Procedure and

other dilute water waste

extractions

More representative in

terms of number of

sites, waste types

covered; extract similar

to precipitation

High L:S (20:1) can dilute leachate

concentrations; short equilibration

time (18 hr) may not allow

equilibrium to develop

2.1.3 Development of Waste Constituent Concentrations for Screening

To allow screening decisions to be made by waste constituent, waste stream, and

exposure pathway, CCW data are processed to produce a single concentration per analyte and

waste stream (surface impoundment porewater, landfill leachate, and landfill whole waste) for

comparison with HBNs and CSCLs. Data processing to create these analyte concentrations

involves two steps:

1. Calculation of average constituent concentrations by site for landfill leachate,

surface impoundment porewater, and total ash concentrations. Site averaging

avoids potential bias toward sites with many analyses per analyte. During site

averaging, separate waste disposal scenarios at a site (e.g., non-FBC and FBC

ash; FGD sludge and ash) are treated as separate "sites" and are averaged

independently. This approach is consistent with that used in the 1998 CCW risk
Section 2.0 Analysis

2

 Appendix A contains figures showing how site-averaged 90th percentile concentrations and 90th percentile

concentrations taken across all analyses (nonaveraged concentrations) compare with HBNs for surface impoundment

porewater, TCLP leachate, and whole waste concentrations.

3

Although 90th percentile concentrations are used for screening, 95th percentile concentrations are presented

in these figures for purposes of comparison to the available data from the 1998 risk analysis.

2-6

analysis. As in 1998, nondetects are averaged at one-half the reported detection

limit.2

2. Selection of screening concentrations from site-averaged values. For the

screening calculations, the analysis uses the 90th percentile of the site-averaged

concentrations across all sites for landfill leachate, surface impoundment

porewater, and total ash concentrations. 

Figures 2-1 through 2-3 compare the 1998 and 2002 95th percentile constituent

concentrations for the porewater, landfill leachate (TCLP), and whole waste data sets.3 The 2002

data set includes all of the 1998 data sets along with additional analyses that EPA has received

from industry and state sources since 1998. Although the 2002 porewater data set includes only

surface impoundment porewater, the smaller 1998 data set includes a few landfill leachate and

mine waste leachate porewater samples. The mine waste porewater samples were excluded in

2002 because this disposal environment tends to produce acidic leachate not characteristic of the

onsite landfills and surface impoundments that are the subject of this analysis. 

SAIC prepared the waste characterization database for EPA in 2002. The 2002 waste

characterization database includes all of the coal combustion waste characterization data used by

EPA in its risk assessments supporting the March 1999 Report to Congress (RTC) on Wastes

from the Combustion of Fossil Fuels. In addition to the data set from the March 1999 RTC,

SAIC supplemented the database in 2002 with the following:

# Data submitted with public comments to EPA on the 1999 RTC

# Data submitted with public comments to EPA concerning the May 22, 2002, Final

Regulatory Determination

# Data collected by and provided to EPA since the end of the public comment

period on the Final Regulatory Determination

# Data identified from literature searches.

The primary sources of these additional data include the electric power industry, state

regulatory agencies, and scientific literature. The additional data represent a significant

expansion in the quantity and scope of characterization data available to EPA for analysis. For

example, the data set used for the risk assessments supporting the RTC covered approximately

50 coal combustion waste generation and/or disposal sites. With the addition of the

supplemental data, the 2002 waste characterization database now covers approximately 140

sites.
Section 2.0 Analysis

2-7

Although comparable for many constituents, the larger 2002 data set has several distinct

differences from the 1998 data set: 

# Porewater data in 2002 are consistently lower than 1998 values (Figure 2-1).

Barium concentrations are almost 2 orders of magnitude lower in 2002. All other

analytes show less than an order-of-magnitude difference, with the largest

differences occurring for arsenic, molybdenum, nickel, and zinc. Only cadmium

shows a slightly higher value in 2002. Porewater data are limited for antimony,

beryllium, mercury, and thallium to a few nondetect analyses in both data sets.

Although silver has a larger data set, all values are below detection in 1998 and

2002.

# TCLP data were limited to four metals in 1998 (Figure 2-2). Concentrations of

arsenic, nickel, and chromium are an order of magnitude or more higher in 2002,

while selenium shows lower concentrations in the more recent data set.

# Whole waste data do not show a consistent pattern from 1998 to 2002 and tend to

agree more closely than porewater or TCLP data (Figure 2-3). The largest

differences can be seen for barium, selenium, and strontium, which have higher

1998 concentrations, and nickel and vanadium, which have higher 2002

concentrations.

Barium, selenium, and strontium show consistently lower 1998 values for all three waste

categories. 

2.2 Human Health Benchmarks

HBNs for the residential well screening are based on human health benchmarks from

approved EPA sources selected based on the following order of preference (which is consistent

with previous EPA Office of Solid Waste [OSW] risk assessments):

# Integrated Risk Information System (IRIS)

# Superfund Technical Support Center Provisional Benchmarks

# Health Effects Assessment Summary Tables (HEAST)

# EPA health assessment documents

# Various other EPA health benchmark sources

# Agency for Toxic Substances and Disease Registry (ATSDR) minimal risk levels

(MRLs)

# California Environmental Protection Agency (CalEPA) chronic inhalation

reference exposure levels (RELs) and cancer potency factors

# Drinking water maximum contaminant levels (MCLs) or action levels.

Note that the hierarchy uses non-EPA sources as a last resort. MCLs are used for constituents

lacking human health benchmarks from other sources. Where MCLs are lower than HBNs (e.g.,

for nitrate), the MCL is used for screening. Appendix B provides a more detailed discussion of

the rationale, data sources, and human health benchmark values used for CCW screening. 
Section 2.0 Analysis

2-8

0.0001 0.001 0.01 0.1 1 10 100 1000 10000

Zn

V

Tl

Sr

Ag

Se

NO2

NO3

Ni

Mo

Hg

Mn

Pb

FCu

Co

Cr

Cd

B

Be

Ba

As

Sb

Al

Analytes

95th Percentile Concentration (mg/L)

2002 SI Porewater 1998 Porewater

(not detected in 1998; 11 nondetects in 2002)

(insufficient data in 1998; 1 detection, 10 nondetects in 2002)

(one nondetect analysis in 2002)

(not detected in 1998; 49 nondetects in 2002)

(insufficient data in 1998; 11 nondetects in 2002)

Figure 2-1. Comparison of 1998 and 2002 CCW porewater concentration data.
Section 2.0 Analysis

2-9

0.001 0.01 0.1 1 10 100

Zn

V

Tl

Sr

Ag

Se

NO3

Ni

Mo

Hg

Mn

Pb

FCN

Cu

Co

Cr

Cd

B

Be

Ba

As

Sb

Al

Analytes

95th Percentile Concentration (mg/L)

2002 TCLP/EP 1998 TCLP

Figure 2-2. Comparison of 1998 and 2002 CCW TCLP data.
Section 2.0 Analysis

2-10

1 10 100 1000 10000 100000 1000000

Zn

V

Tl

Sr

Ag

Se

Pb

Ni

Mo

Mn

Cu

Co

Cr

Cd

B

Be

Ba

Sb

As

Al

Analyte

95th Percentile Total Waste Concentration (mg/kg)

1998 2002

Figure 2-3. Comparison of 1998 and 2002 CCW whole waste concentration data.
Section 2.0 Analysis

2-11

2.3 Ecological Receptors, Endpoints, and Benchmarks

Ecological CSCLs are taken directly from the 1998 fossil fuel combustion risk analysis,

Non-groundwater Pathways, Human Health and Ecological Risk Analysis for Fossil Fuel

Combustion Phase 2 (FFC2) (U.S. EPA, 1998). The receptors and endpoints selected for the

1998 analysis were evaluated and are considered appropriate for the goals of this screening

analysis. As summarized in Table 2-4, the analysis considers both direct contact and ingestion

endpoints and benchmarks. 

Ecological receptors are exposed through direct contact with contaminants in surface

water, sediment, and soil. The receptors selected to assess the direct contact exposure route for

each medium are shown in Table 2-4 and are described in Appendix C, along with the endpoints

and benchmarks used to develop direct-contact CSCLs. 

The derivation of ingestion CSCLs begins with the selection of appropriate

ecotoxicological data based on a hierarchy of data sources. The assessment endpoint for the

ecological screening analysis was population viability; therefore, the analysis develops

benchmarks from measures of reproductive-developmental success or, if unavailable, from other

effects that could conceivably impair population dynamics. Population-level benchmarks are

preferred over benchmarks for individual organisms; however, very few population-level

benchmarks have been developed. Therefore, the ecological screening analysis uses benchmarks

derived from individual organism studies, and protection is inferred at the population level. 

Table 2-4. Ecological Receptors Assessed in Each Medium

Receptor Type

Surface Water

(Leachate,

Porewater)

Sediment

(Whole Waste)

Soil

(Whole Waste)

Direct Contact Exposure

Aquatic Community U

Sediment Community U

Soil Community U

Amphibians U

Aquatic Plants and Algae U

Terrestrial Plants U

Ingestion Exposure

Mammals U U

Birds U U
Section 2.0 Analysis

2-12

2.4 Exposure Assessment

Exposure assessment for CCW screening involves both deriving protective HBNs and

CSCLs for human and ecological receptors and selecting conservative exposure concentrations

in the media of concern for the analysis.

The exposure scenarios assumed for CCW management (see Figure 1) define the media

of concern for the analysis. Human exposure scenarios include:

# Drinking of groundwater contaminated by leachate from CCW landfills and

surface impoundments

# Consumption of fish by recreational fishers fishing in streams and lakes

contaminated by CCW leachate through the groundwater-to-surface-water

pathway

# Exposure to a farmer through the consumption of soil, produce, beef, and milk

contaminated with constituents eroded by wind and water from a CCW landfill

and deposited on an adjacent agricultural field and home garden 

# Inhalation (by the farmer) of airborne particulates eroded from a CCW landfill by

wind.

Ecological exposure scenarios occurring near CCW landfills or surface impoundments include

direct contact and ingestion exposure routes and follows:

# Direct contact with soil and sediment contaminated by erosion and overland

transport from a CCW landfill

# Ingestion of plants, soil, and soil invertebrates contaminated with constituents

eroded by wind and water from a CCW landfill and deposited on an adjacent

terrestrial habitat

# Direct contact with surface water contaminated by CCW leachate through the

groundwater-to-surface-water pathway

# Ingestion of aquatic organisms in streams and lakes contaminated by CCW

leachate through the groundwater-to-surface-water pathway.

The screening analysis calculates HBNs and CSCLs for the contaminated media in each of these

exposure scenarios.

2.4.1 Human Health-Based Numbers (HBNs)

HBNs represent media concentrations that are protective of human health from exposure

pathways that are relevant to that particular medium. The CCW screening analysis uses HBNs

calculated for groundwater and surface water exposure, as well as for the aboveground exposure
Section 2.0 Analysis

2-13

pathways described above. The CCW HBNs represent reasonable maximum exposure (RME)

scenarios for an offsite receptor: 

# Groundwater HBNs are protective for residential drinking water exposure from a

domestic well immediately downgradient from a CCW landfill or surface

impoundment.

# Surface water HBNs are protective for fish caught (and consumed) by a

recreational fisher from a river, lake, or stream adjacent to a CCW landfill or

surface impoundment.

# Aboveground HBNs are protective for a farmer living just downslope of an CCW

landfill. Exposure pathways for the farmer include inhalation of air contaminated

with waste particulate matter blowing off the landfill; soil ingestion; consumption

of produce grown in contaminated soil and contaminated via air deposition; and

consumption of beef and milk from cattle eating grain, forage, and silage grown

in contaminated soil and contaminated via air deposition.

Key features and assumptions of the HBN calculations include the following:

# HBNs are calculated based on a target cancer risk of 10-5 or target HQ of 1. 

# The source size for estimating landfill particulate emissions is set at the 95th

percentile for landfill areas identified in the Electric Power Research Institute

(EPRI) database (EPRI, 1997).

# The analysis considers exposures for one adult and three child receptor cohorts;

exposure for each cohort is assumed to start at ages 3, 8, 15, and 20.

# Chemical properties (biouptake and bioaccumulation factors) are collected from

best available literature values (see Appendix E). 

# Human exposure factors (e.g., body weight, exposure duration, exposure

frequency, consumption rates) are set at central-tendency values (see

Appendix G).

Appendix D provides details on the HBN calculations, including all assumptions and equations. 

Appendices E through H provide the input data used in the calculations and all data sources. 

2.4.2 Ecological Chemical Stressor Concentration Limits (CSCLs)

The CCW ecological screening analysis parallels the human health screening analysis

and addresses two routes of exposure for ecological receptors: direct contact with contaminated

media and ingestion of contaminated food items. Screening CSCLs incorporate chemicalspecific assumptions protective of ecological receptors of concern. These media concentrations

are analogous to HBNs used in the human health screening. As with the HBNs, CSCLs can be

compared directly with concentrations of constituents found in CCW, leachate, and porewater, or

with conservative offsite media concentrations to estimate risk. 
Section 2.0 Analysis

2-14

The analysis derives CSCLs for each chemical and receptor to the extent that supporting

data are available. The lowest (most sensitive) CSCL for each chemical in each medium is used

to calculate HQs in the screening analysis. For example, several receptors (soil invertebrates,

terrestrial plants, mammals, and birds) can be exposed to chemicals in soils; the analysis uses the

lowest (most conservative) soil CSCL for these receptors. 

The CCW CSCLs come from a compilation of data from sources meeting predetermined

data quality objectives. The analysis uses the lowest CSCL for each receptor in each medium,

and different CSCLs reflect different effects levels.

# Mammal and bird CSCLs are all based on no-observed-adverse-effects-level

(NOAEL) dose benchmarks.

# Soil CSCLs are mostly based on low effects levels (i.e., they are concentrations at

which adverse effects would be expected, but these effects would not be expected

to impair the receptor’s ability to maintain its function in the ecosystem). 

# Sediment CSCLs are based on lowest observed effects levels (LOAELs, which

are less conservative than NOAELs) for some chemicals, and on threshold effects

levels (TELs) for others. TELs are the geometric mean of the 15th percentile

effects data and the 50th percentile no effects data and can be thought of as an

intermediate value between a NOAEL and a LOAEL. 

# Surface water CSCLs are National Ambient Water Quality Criteria (NAWQC),

secondary chronic values (SCVs) derived using methods similar to the NAWQC, 

or Great Lake Initiative final chronic values (FCVs). As such, they generally

reflect low effects values. 

# Amphibian CSCLs consist of the geometric mean of LC50 data. They are based

on the only data available: acute exposure data. Although this is a departure

from the methods used for other CSCLs, amphibians are generally sensitive

receptors and need to be addressed with the best data available. 

The CSCLs for mammals and birds are calculated based on several assumptions about

exposure (see Table 2-5). In general, the assumptions used for this analysis are representative

(as opposed to conservative) with the exception of the percentage of diet that is contaminated;

the analysis assumes that 100 percent of each receptor’s diet is contaminated. 
Section 2.0 Analysis

4

Although the 95th percentile was used in 1998, the 90th percentile is used in this analysis as a reasonably

conservative value considering the protective screening analysis assumptions and the larger 2002 data set. 

2-15

Table 2-5. CSCL Exposure Assumptions for Mammals and Birds

Assumption Potential Bias

Ingestion rates and diet composition are for

adults.

Does not account for different susceptibility for

young.

Body weights are mean adult values, including

male and female data.

Does not account for different susceptibility

among young.

Dietary composition includes a representative

variety of items when appropriate and a single

item in cases where one item is preponderant

(e.g., makes up more than 90% of the diet)

Representative

100% of diet is contaminated. Conservative assumption; unlikely except for

species with small home ranges (e.g., salamanders

and other amphibians, small mammals)

Appendix B summarizes the methodology used to develop the CSCLs and provides the

CSCLs used in the analysis. Both direct contact and ingestion CSCLs were developed for the

1998 risk analysis. For direct contact CSCLs, ecological receptors that live in close contact with

contaminated media are considered potentially at risk. These receptors are exposed through

direct contact with contaminants in surface water, sediment, and soil. The ingestion route of

exposure addresses the exposure of terrestrial mammals and birds through ingestion of plants

and prey and incidental soil ingestion. Thus, ingestion CSCLs express media concentrations

that, based on certain assumptions about receptor diet and foraging behavior, are expected to be

protective of populations of mammals and birds that feed and forage in contaminated areas. 

2.4.3 Media-Specific Exposure Concentrations

The screening analysis requires media concentrations for soil, groundwater, surface

water, and sediment to compare with the HBNs and CSCLs. The simple scope of the screening

analysis does not allow for media-specific modeling to be conducted. Instead, the analysis uses

waste concentrations as protective estimates of offsite media concentrations. For soil and

sediment, simple dilution factors, based on modeling conducted for the 1998 CCW risk

assessment, are used to adjust whole waste concentrations to better represent offsite soil.

For groundwater-to-drinking-water exposures, the analysis uses the 90th percentile waste

porewater4

 and leachate concentrations to represent groundwater contamination from the surface

impoundment and landfill, respectively. No dilution or attenuation is assumed between the

waste management unit and the drinking water well because the large size range of CCW units

precludes the use of dilution attenuation factors (DAFs) greater than 1, such as those that were

developed for the industrial waste management scenarios addressed by the Industrial Waste

Management Evaluation Model (IWEM). Tables 2-6 and 2-7 compare the size distribution of
Section 2.0 Analysis

2-16

landfills and surface impoundments for CCWs with the industrial waste management units used

to develop the IWEM DAFs, showing that CCW units are much larger than industrial waste

management units. A DAF of 1 was also used for constituent screening in the 1998 risk analysis. 

Table 2-6. Comparison of IWEM and CCW Landfill Areas

Percentile IWEM (acres) CCW (acres)

min 0.01 3

10 0.12 16

25 0.6 27

50 3 68

75 13 176

90 35 300

95 55 351

max 770 900

Table 2-7. Comparison of IWEM and CCW 

Surface Impoundment Areas

Percentile IWEM (acres) CCW (acres)

min 0.002 5

10 0.04 22

25 0.1 43

50 0.4 100

75 1.7 195

90 7 310

95 13 412

max 1,200 1,500

To represent soil concentrations for aboveground exposures, the analysis divides the 90th

percentile whole waste concentration by a conservative dilution factor to represent the offsite

transport to downslope soils adjacent to the landfill. This dilution factor is based on the

modeling results for soil exposure scenarios from the 1998 CCW risk analyses. Figure 2-4 plots

the ratio of 1998 whole waste concentrations to soil concentrations for several constituents as a

function of the soil-water partition coefficient. The graph illustrates that the lowest waste-to-soil

ratio is 20, and this ratio appears to meet a minimum value at close to 20. This minimum value

(20) is used to represent soil concentrations for the characterization of risks for ecological

receptors. The aboveground analysis of human risks use a dilution factor of 10, because

exposures include direct soil ingestion and plant uptake from soil along with deposition of

particulate matter onto leafy vegetation. The more conservative value (10) was used in this case
Section 2.0 Analysis

2-17

21935

4170 2945

297

192

99

42

28

20

1

10

100

1000

10000

100000

1000000

1 10 100 1000 10000 100000

1998 Soil DF (Total Waste Concentration/Offsite Soil Concentration) 

Kd (L/kg)

Ag

B

Se

Co

Tl

Cd

Ba

Al

Pb

2002 FFCW Soil DAF (10)

Figure 2-4. Soil dilution factors from the 1998 aboveground risk

analysis for CCW landfills.

to allow some soil dilution without overly diluting the contribution from aerial deposition of dust

from the landfill.

2.5 Risk Calculations

The analysis estimates human-health risk for CCW constituents by calculating the ratio

between the 90th percentile constituent concentrations (numerator) and the HBNs (denominator)

developed for the aboveground and groundwater pathways. Because HBNs are derived for the

target risk criteria set for the analysis—an excess cancer risk of 10-5 or a HQ of 1—the ratio of

the 90th percentile concentration and the HBN represents the screening risk estimate (HQ for

noncarcinogens or cancer risk for carcinogens): 

HQ (or cancer risk) = 90th percentile concentration / HBN.

Similarly, the analysis screens constituents for adverse ecological effects by calculating

the ratio between the 90th percentile concentrations (numerator) and the CSCLs (denominator). 

Because the CSCLs are derived for a target HQ of 1 for relevant ecological endpoints, the ratio

of a 90th percentile constituent concentration to its CSCL represents the HQ for that constituent: 

HQ = 90th percentile concentration / CSCL.
Section 3.0 Risk Characterization

3-1

3.0 Risk Characterization

Risk characterization for the CCW risk assessment involved estimating the risks to

human health and ecological receptors associated with exposure to CCW through the exposure

pathways pictured in Figure 1-1 and described in Section 2.3. Consistent with the goals of the

screening analysis, screening results are used primarily to identify, with a high level of

confidence, CCW constituents, waste streams, and exposure pathways of no further concern for

the CCW risk analysis. Constituents with risk levels that exceed the target risk criteria (10-5

excess cancer risk or an HQ of 1) cannot be eliminated from concern and will be investigated

further by EPA. However, the screening risk estimates for these constituents should not be

considered accurate estimates of the risks currently posed to human and ecological receptors by

CCW. The highly protective assumptions (e.g., RME scenarios, waste concentrations as media

concentrations) needed for protective screening of constituents of further concern have likely

resulted in overestimates of the actual risks posed by CCW constituents managed in landfills and

surface impoundments.

As described in Section 2.4, the screening analysis estimates risk by dividing media (or

waste) chemical concentrations by HBNs (for human health) or CSCLs (for ecological risks).

This section characterizes these results with respect to the target risk criteria for humans and

ecological receptors, compares results with the results of the 1998 CCW risk assessment (U.S.

EPA, 1998a,b), and evaluates differences. Although 95th percentile waste concentrations were

used in 1998, this analysis uses 90th percentile concentrations for screening decisions because of

the conservatism of the screening assumptions and the larger, more comprehensive data set

available to evaluate 2002 risks. The 95th percentile 2002 concentrations are also presented for

comparison with 90th percentile values and 1998 risk results.

3.1 Human Health Results—Groundwater Pathways

The screening analysis evaluates groundwater pathways for both landfills and surface

impoundments. Groundwater pathways screened for human health risks include the

groundwater-to-drinking water pathway for domestic wells and the groundwater-to-surfacewater pathway for exposure through fish consumption by recreation fishers. The latter pathway

is significant because coal-fired power plants are often located adjacent to large bodies of water

that are used for recreational fishing. 

3.1.1 Groundwater-to-Drinking-Water Pathway

Figures 3-1 and 3-2 show the groundwater-to-drinking-water pathway screening results

for surface impoundments and landfills, respectively. Based on the screening criteria—HQ of 1

for noncancer risk and a 10-5 cancer risk—16 of 24 constituents fail the screen for surface 
Section 3.0 Risk Characterization

3-2

0.001 0.01 0.1 1 10 100 1000 10000

As, Cancer

As

NO3 (MCL)

B

Tl

Pb (MCL)

Co

Cd

Mo

Mn

Sb

FCr VI

Se

V

NO2

Ni

Sr

Al

Cu (MCL)

Ba

Be

Zn

Ag

Hg

Cr III

Analytes

Hazard Quotient (Risk Level)

2002 SI Porewater 90th percentile 2002 SI Porewater 95th percentile 1998 Porewater 95th percentile

(10-6) (10-5 (10 ) -7 (10 ) -8) (10-4) (10-3) (10-2) (10-1)

Figure 3-1. CCW surface impoundment porewater screening risk levels for the 

groundwater-to-drinking-water pathway.
Section 3.0 Risk Characterization

3-3

0.001 0.01 0.1 1 10 100 1000

As, Cancer

As

Sb

Tl

Pb (MCL)

Mo

B

Cd

Cr VI

V

FSe

NO2

Mn

Ba

Sr

Ni

Hg

NO3 (MCL)

Be

Ag

Zn

Al

Co

Cu (MCL)

CN

Cr III

Analytes

Hazard Quotient (Risk Level)

2002 Leachate 90th percentile 2002 Leachate 95th percentile 1998 TCLP 95th percentile

(10-5 (10 ) -6 (10 ) -7 (10 ) -8) (10-4) (10-3) (10-2)

Figure 3-2. CCW landfill leachate screening risk levels for the groundwater-todrinking-water pathway.
Section 3.0 Risk Characterization

5

 Manganese and hexavalent chromium also show lower HBNs in 2002 because of lower health benchmarks

than those used in 1998. Fluoride has a slightly higher HBN in 2002 because of EPA’s decision to use the adjusted

reference dose (RfD) for skeletal fluorosis instead of the RfD for dental fluorosis. 

3-4

impoundment porewater (Figure 3-1). These results are generally consistent with the 1998 CCW

groundwater risk analysis. Cobalt was not addressed in porewater in 1998, but does show a

screening exceedance in the 2002 results. Barium and zinc, which showed exceedances in 1998,

do not exceed the screening criteria in 2002 because the waste concentrations in the 2002

database are lower than in the 1998 database (see Figure 2-1).

Antimony and thallium surface impoundment porewater concentrations are all below

detection limits in the 2002 data, as they were in 1998. However, because the detection limit is

more than twice the HBN for most of the analyses in the 2002 database, the 90th percentile of the

nondetect values is above the screening criteria for these constituents. EPA elected not to

consider these nondetects quantitatively in the 1998 risk analysis. Although concentrations set at

one-half of the detection limit do exceed the risk criteria in 2002, the values could be less than

this assumed value. 

Figure 3-2 shows the 2002 landfill leachate screening risks and compares them with the

risk results for the few constituents with TCLP leachate data in 1998. Constituents failing the

landfill leachate screen are similar to those failing the screen for surface impoundment

porewater, with 12 of 25 constituents failing the screen. Exceptions include nitrate, cobalt, and

nickel, which fail for surface impoundment porewater only. Antimony and thallium, which have

detectable concentrations in the landfill leachate data set, fail the screen for both landfills.

Appendix D includes a comparison of the 1998 and 2002 drinking water HBNs. 

Aluminum and cobalt were not evaluated in 1998 because health benchmarks were not available. 

Aluminum screens out for both landfills and surface impoundments for the 2002 data set; cobalt

screens out in landfill leachate, but not in surface impoundment porewater. Most of the

remaining constituents show lower HBNs in 2002 by a factor of 1.8, primarily because of the

differences in exposure factors between the adult-only scenario assumed in 1998 and the child

age cohorts used in 2002.5

 However, the changes in HBNs from 1998 to 2002 did not affect the

results (in terms of number of exceedances).

3.1.2 Groundwater-to-Surface-Water Pathway

The ground-water-to-surface-water pathway screening analysis considers risks to human

health from the migration of contaminants from the landfill or surface impoundment, through

groundwater, and into surface water, where contaminants can accumulate in fish. Recreational

fishers who consume their catch are the receptors of concern. This pathway was not addressed

in the 1998 risk analysis.

Figures 3-3 and 3-4 summarize the 90th percentile groundwater-to-surface-water

screening results for surface impoundments and landfills, respectively. In each case, five metals

show screening risks of concern: arsenic, cadmium, mercury, selenium, and thallium. 

Comparing these results with the 90th percentile groundwater-to-drinking-water results shows

that arsenic, cadmium, selenium, and thallium show screening exceedances for both pathways.
Section 3.0 Risk Characterization

3-5

0.00001 0.0001 0.001 0.01 0.1 1 10 100 1000 10000

Hg

As, Cancer

Se

As

Tl

Cd

Cu

Mo

Zn

Sb

Cr VI

Be

Ni

Cr III

Analytes

Hazard Quotient (Risk Level)

Surface water (fish) Drinking-water

(10-6) (10-5 (10 ) -7 (10 ) -8) (10-4) (10-3) (10-2) (10-1 (10 ) -10) (10-9)

Figure 3-3. CCW surface impoundment porewater screening risk levels for the

surface water (fish consumption) and drinking water pathways.
Section 3.0 Risk Characterization

3-6

0.000001 0.00001 0.0001 0.001 0.01 0.1 1 10 100 1000

Hg

Tl

Se

As, Cancer

Cd

As

Zn

Cu

Sb

Mo

Be

Cr VI

Ni

CN

Cr III

Analytes

Hazard Quotient (Risk Level)

Surface-water (fish) Drinking Water

(10-5 (10 ) -6 (10 ) -7 (10 ) -8) (10-4) (10-3) (10-2 (10 ) -11) (10-9 (10 ) -10)

Figure 3-4. CCW landfill leachate screening risk levels

for the surface water (fish consumption) and drinking water pathways.
Section 3.0 Risk Characterization

Mercury, which tends to bioconcentrate in fish tissue, only exceeds the screening criterion for

the groundwater-to-surface-water pathway.

3.1.3 Summary and Conclusions: Groundwater Pathway Analysis

Table 3-1 summarizes the results of the groundwater pathway screening analysis for

drinking water ingestion and fish consumption, listing the 17 constituents found to exceed the

screening criteria for either landfill leachate or surface impoundment porewater, along with their

relative rank in the landfill and surface impoundment results. More detailed results are tabulated

in Appendix I. Key findings of the groundwater pathway human health screening analysis

include the following:

# Sixteen chemicals exceed screening criteria for the groundwater-to-drinking water

pathway. Most of these chemicals showed exceedances in the 1998 risk analysis

as well (cobalt was not evaluated in 1998).

# Although they exceeded risk criteria in 1998, barium and zinc do not exceed risk

criteria in the 2002 screening analysis because of lower waste concentrations in

the more comprehensive surface impoundment porewater database. 

# Arsenic, cadmium, selenium, and thallium exceeded risk criteria for both

pathways in landfills and surface impoundments.

# Six chemicals exceeded screening criteria for the groundwater-to-surface-water

pathway, with mercury exceeding for this pathway only. Mercury and selenium

show higher screening risks for this pathway than for the drinking water pathway

because of their tendency to accumulate in fish tissues. 

3.2 Human Health Results—Aboveground Pathways

Figure 3-5 summarizes the 2002 aboveground human health screening risk results for the

offsite soil scenario and compares them with 1998 aboveground risk results. The 2002

aboveground risks are calculated by first dividing waste concentrations by a dilution factor of 10

to represent a conservative offsite soil concentration for a farm immediately downslope from a

CCW landfill. That is, the soil is assumed to be 5 percent CCW eroded from the landfill and

deposited on the field by wind and water. The ratio between this offsite soil concentration and

the soil HBN provides the screening level risk/hazard estimates.

For constituents addressed in both 1998 and 2002, screening results differ somewhat

from 1998 aboveground risk analysis; arsenic, barium, and thallium showed risks at or above the

screening criteria in 1998 and no risk exceedances in 2002. Although the complexity of the

aboveground risk assessment makes it difficult to identify all of the factors that result in these

differences, the lower concentration of these analytes in the 2002 data is a primary factor (see

Figure 2-3). 
3-8

Table 3-1. Summary of Screening Results: Constituents Exceeding Human Healt

Screening Criteria for Groundwater Pathways Chemical Hazard Quotient or Cancer Risk Number of Sites with Analyses (Number of Sites Exceeding Screening Criteria)2 

SI Porewater Landfill Leachate SI Porewater Landfill Leachate GW->DW GW->SW GW->DW GW->SW GW->DW GW->SW GW->DW GW->SW 

Carcinogenic Constituents (screening risk criterion = 10-5 cancer risk) Arsenic, cancer 1.81E-02 2.24E-04 1.38E-03 1.71E-05 17 (17) 17 (6) 119 (113) 119 (22) 

Noncarcinogenic Constituents (screening risk criterion = HQ of 1) Antimony 5.45 0.02 22.20 0.06 2 (1) 2 (0) 60 (37) 60 (0) 

Arsenic 588.00 7.28 44.80 0.55 17 (15) 17 (4) 119 (99) 119 (8) 

Boron 28.40 -- 4.00 -- 18 (11) - 72 (28) - Cadmium 8.91 3.73 3.37 1.41 17 (5) 17 (3) 117 (39) 117 (22) Chromium VI 4.15 0.01 2.27 < 0.01 18 (6) 18 (0) 118 (35) 118 (0) 

Cobalt 10.70 -- 0.14 -- 4 (1) - 51 (0) - Fluoride 5.42 -- 1.80 -- 15 (4) - 33 (6) - 

Lead 11.80 -- 15.90 -- 14 (6) - 116 (78) - 

Manganese 5.56 -- 0.99 -- 16 (4) - 72 (8) - Mercury 0.03 65.00 0.31 700.00 1 (0) 1 (1) 97 (6) 97 (97) 

Molybdenum 6.81 0.08 4.20 0.05 18 (13) 18 (0) 49 (29) 49 (1) 

Nickel 1.27 < 0.01 0.53 < 0.01 17 (3) 17 (0) 80 (3) 80 (0) 

Nitrate 60.20 -- 0.28 -- 13 (3) - 17 (1) - Nitrite 1.78 -- 1.18 -- 15 (2) - 5 (1) - Selenium 2.43 9.50 1.20 4.69 15 (5) 15 (9) 119 (14) 119 (69) Thallium 19.30 5.69 21.30 6.29 2 (2) 2 (1) 40 (32) 40 (20) 

Vanadium 2.33 -- 2.19 -- 15 (6) - 40 (8) - 

1 Percent of sites with no detections of chemical in any sample. 2 Number of sites exceeding screening criteria are given in parentheses. Bold indicates values/pathways exceeding screening risk criteria (HQ of 1 or 10-5 cancer risk). GW->DW = groundwater-to-drinking-water pathway; GW->SW = groundwater-to-surface-water pathway (fish ingestion); SI 

PW = porewater; TCLP = Toxicity Characteristic Leaching Procedure -- = no HBN available for constituent/pathway combination
Section 3.0 Risk Characterization

3-9

0.00000001 0.0000001 0.000001 0.00001 0.0001 0.001 0.01 0.1 1 10

As, cancer

Tl

B

Ag

Sb

As

Hg

Sr

Zn

Cr VI, cancer

Mo

Cr VI

V

Cd

Ni

Ba

Al

Se

Pb (SSL/PRG)

Mn

Co

Co, cancer

Be

Be, cancer

FCd, cancer

Cr III

CN

NO3

Analytes

Hazard Quotient (Risk Level)

2002 90th percentile 2002 95th percentile 1998 95th percentile

(10-5) (10-4 (10 ) -6 (10 ) -7 (10 ) -8 (10 ) -9 (10 ) -10 (10 ) -11 (10 ) -12 (10 ) -13)

1

 Offsite soil = total waste concentrations/10

Figure 3-5. Comparison of 1998 and 2002 aboveground

 human health risk results for the soil pathway.
Section 3.0 Risk Characterization

6

 The HQs shown in Figure 3-6 reflect a soil dilution factor of 20 applied to whole waste concentrations. 

The dilution factor was derived from the 1998 analysis by comparing whole waste concentrations to modeled offsite

soil concentrations (see Section 2.3.3).

3-10

More detailed results for the aboveground human health screening analysis are tabulated

in Appendix I. For human exposure through aboveground pathways, no exceedances occur for

soil concentrations based on the 90th percentile whole waste concentrations, with only slight

exceedances (HQ at or less than 1.5) at the 95th percentile concentrations for mercury, thallium,

boron, and silver (which did not exceed the risk criteria in 1998). Based on these results and

considering the highly protective assumptions of the aboveground screening analysis, EPA does

not believe that additional modeling or evaluation of aboveground human exposure pathways is

necessary. 

3.3 Ecological Risk Results 

Ecological screening assesses risks for soil and surface water pathways, considering

exposure through direct contact and ingestion. The surface water analysis includes exposure to

both contaminated water and sediments. Results for each pathway are discussed below. 

3.3.1 Soil Pathways

In general, the soil pathway for ecological receptors addresses exposure through direct

contact with soil and ingestion of terrestrial (i.e., soil-based) food and prey items. Figure 3-6

shows ecological screening estimates calculated for soil pathways by dividing the 90th percentile

offsite soil concentrations by ecological CSCLs. The screening criterion for soil ecological risk

is an HQ of 10. This is consistent with the approach used in 1998 bounding risk analysis and

justified as "strongly suggestive of de minimis ecological impacts” because of the highly

conservative nature of the screening ecological risk analysis. The 1998 CSCLs are conservative

both in terms of the benchmark selection and the assumption of direct exposures. Moreover, the

spatial scale of potential ecological effects based on the screening results is highly conservative

(i.e., the area affected by landfills may be of limited significance ecologically). Because the

2002 analysis uses the 1998 CSCLs along with protective assumptions about offsite soil

concentrations,6 the HQ of 10 was considered to be an appropriate criterion for this analysis. 

As in 1998, all constituents except boron passed the ecological risk screen for soil. Boron was

excluded in 1998 because its soil CSCL (based on toxicity to plants) is lower than typical

background soil levels across the United States. It is included for discussion in these results

because boron is an important component of coal ash and because previous work (e.g., Carlson

and Adriano, 1993) indicates that the boron in coal ash is in a more available and toxic form for

plant uptake than it is in typical soils. Aluminum also may be of concern (draft CSCLs are well

below whole waste concentrations), but the chemical form is especially important for this metal

because of its widespread occurrence in aluminosilicate minerals in soil and CCW. The

screening results indicate that chemicals other than boron and aluminum are not of potential

concern for terrestrial wildlife exposed through these pathways.
Section 3.0 Risk Characterization

3-11

0.0001 0.001 0.01 0.1 1 10 100

B

Se

Hg

Ni

Cu

As

V

Zn

Cd

Sb

Pb

Cr

Ba

Mo

Co

Analytes

Ecological Hazard Quotient (HQ)

2002 90th percentile 2002 95th percentile 1998 95th percentile

Boron CSCL < typical background

1

 Offsite soil = total waste concentrations/20

Figure 3-6. CCW landfill aboveground ecological screening risks: Soil pathway.
Section 3.0 Risk Characterization

7

 The 2002 CCW constituent database does not include impoundment water samples, and the direct

exposure pathway was not addressed.

3-12

3.3.2 Surface Water Pathways 

The screening analysis assesses ecological receptor exposure to surface water and

sediments for the groundwater-to-surface-water pathway. Porewater analyses for surface

impoundments and leachate analyses for landfills are used to assess groundwater-to-surfacewater contamination. The screening analysis calculates HQs by dividing the 90th percentile

waste concentration by the appropriate CSCL. No dilution factor is applied in these results

because this pathway was not assessed in the 1998 study, and data are therefore lacking to

support estimation of a dilution factor.

Figures 3-7 and 3-8 show the respective screening results for the groundwater-to-surfacewater pathway. At the HQ criterion limit of 1, none of the constituents of concern are below the

screening criterion for landfills or for surface impoundments. However, considering the

conservative nature of the CSCLs and the use of waste leachate and porewater concentrations to

represent surface water concentrations, a target HQ of 10 can be applied and a few metals (4

surface impoundment porewater and 5 for landfill leachate) are below the screening criterion.

In the 1998 study, all but seven metals were below the risk criterion for the surface water

pathway—aluminum, arsenic, boron, cadmium, lead, mercury, selenium. (Aluminum and boron

HQs greater than 1 were based on amphibian CSCLs derived from acute effects data.) However,

the 1998 study estimated surface water exposure for ecological receptors based on surface water

concentrations from aboveground transport (where risks were negligible) and concentrations in

the waters of the surface impoundments themselves (where risks were significant). While

surface impoundments may be used by mammals and birds in the area for feeding and foraging,

there is no expectation that surface impoundments support aquatic communities (e.g., fish,

aquatic invertebrates), and therefore risks to aquatic receptors were not considered in 1998 for

exposures within surface impoundments. 

The current surface water screening addresses exposure to receptors in offsite surface

waterbodies impacted by groundwater, where both the aquatic communities and upper trophic

level terrestrial receptors would need to be protected.7

 Figures 3-7 and 3-8 show the 1998

impoundment water results for comparison. If data were available to reassess ecological risks

for exposure in surface impoundment waters, we would follow a similar approach to the 1998

study and restrict the analysis to terrestrial receptors that obtain food and prey from the surface

impoundments and exclude aquatic receptors living in the water column. However, in the

absence of new analytical data for impoundment water, the 1998 results are used for this 2002

screening analysis.

Results for the sediment pathway are shown in Figure 3-9. Sediment HQs are calculated

by dividing 90th percentile whole-waste concentrations by sediment CSCLs. All chemicals for

which CSCLs are available screen out for the sediment pathway. The sediment HQs in

Figure 3-9 reflect a sediment concentration equivalent to 95th percentile whole waste

concentrations diluted by a factor of 1,000. In a comparison, based on the 1998 waste

concentrations and modeled sediment concentrations, the lowest dilution factor was 13,000 (i.e.,
Section 3.0 Risk Characterization

3-13

0.1 1 10 100 1000 10000 100000 1000000

B

Hg

As IV

Pb

Co

Al

Ba

Se, total

Cd

Se VI

As III

Cr VI

Cu

V

Ni

Ag

Se IV

Be

Zn

Cr III

Tl

Mo

Sb

Analytes

Ecological Hazard Quotient (HQ)

2002 SI Porewater (GW-to-SW exposure pathway) 1998 SI Wastewater (direct exposure)

Figure 3-7. CCW surface impoundment ecological screening risks:

Groundwater-to-surface-water pathway.
Section 3.0 Risk Characterization

3-14

0.1 1 10 100 1000 10000 100000 1000000

Hg

B

Pb

Ba

Al

Ag

As IV

Se, total

Be

V

Cd

Se VI

Cr VI

Zn

Cu

Sb

Se IV

Ni

Tl

Co

As III

Cr III

Mo

Analytes

Ecological Hazard Quotient (HQ)

2002 Landfill leachate (GW-to-SW exposure pathway) 1998 SI wastewater (direct exposure)

Figure 3-8. CCW landfill (TCLP) ecological screening risks:

Groundwater-to-surface-water pathway.
Section 3.0 Risk Characterization

3-15

0.00001 0.0001 0.001 0.01 0.1 1

Pb

As

V

Sb

Ni

Ag

Hg

Cu

Cr

Cd

Ba

Zn

Mo

Analytes

Ecological Hazard Quotient (HQ)

2002 90th percentile 2002 95th percentile 1998 95th percentile

Figure 3-9. CCW landfill aboveground ecological screening risks:

Sediment pathway.
Section 3.0 Risk Characterization

3-16

the factor of 1,000 is clearly conservative). These results indicate no potential concern for the

sediment pathway with respect to aboveground transport pathways. However, the potential for

sediment contamination from groundwater-to-surface water discharge has not been assessed. 

Furthermore, eight potentially significant metals (aluminum, beryllium, boron, cobalt,

molybdenum, selenium, thallium, and vanadium) are not assessed for the sediment pathway

because of a lack of toxicological benchmarks.

3.3.3 Ecological Risk Conclusions and Recommendations

As described above, the CCW screening analysis calculates ecological HQs as the media

concentration (soil, sediment, and surface water) divided by the chemical- and receptor-specific

CSCL. For CCW screening, both the numerator (waste concentration) and the denominator

(CSCL) are conservative. CSCLs are taken from a compilation of data sources meeting

predetermined data quality objectives, with the lowest value for each receptor in each medium

being selected (see Section 2.3). 

The analysis also uses protective assumptions to estimate media concentrations.

Porewater and leachate concentrations are used to represent surface water concentrations

contaminated through the groundwater pathway. A conservative dilution factor of 20, based on

the 1998 CCW exposure modeling results (see Section 2.4), is used to adjust whole waste

concentrations to represent offsite soil concentrations. Generally speaking, these concentrations

are conservative and it is unlikely that ecological receptors are exposed to these concentrations

for most CCW exposure scenarios. 

However, the surface impoundment scenario may be an exception. It is probable that

ecological receptors eat and drink from surface impoundments in some settings. In addition,

ecological receptors, particularly amphibians who may lay their eggs in surface impoundments,

are probably exposed through chronic contact with wastewater. Because amphibians are prey to

a large variety of animals (e.g., raptors; wading birds; mammalian omnivores, such as foxes,

raccoons, and weasels), this exposure is transferred up the food chain. Aquatic plants, although

not often a focus of ecological risk assessment, are directly exposed in surface impoundments. 

Plants, in turn, may be ingested by vertebrates and invertebrates at higher trophic levels. 

Similarly, in landfills, there is a chance that receptors could incidentally ingest some

whole waste. For example, a white-tailed deer or a vole could ingest whole waste as it browses

or forages in the landfill. Small mammals, such as voles, are preyed upon by higher trophic

levels.

The ecological screening results indicate some areas of potential concern for ecological

risks. In particular,

# Boron may represent a risk for terrestrial plants exposed to contaminated soil.

# Aluminum may be of concern for various receptors and pathways, but impacts are

highly dependent on the chemical speciation of the metal.
Section 3.0 Risk Characterization

3-17

# For the groundwater-to-surface-water pathway, all but five chemicals of potential

concern are above the risk criterion for aquatic receptors.

# The sediment pathway is not of concern with respect to aboveground

contamination. However, surface water sediments can be contaminated by

groundwater discharge, and this pathway was not evaluated in this screening

analysis.

# Risks to organisms in the hyporheic zone (the transition zone between

groundwater and surface water) were not evaluated in this analysis but could be

significant for the groundwater-to-surface-water pathway.

# Based on the 1998 CCW risk assessment results, direct exposure to surface

impoundment waters may pose risks of concern to mammals and birds for seven

metals. 

3.4 Conclusions and Recommendations

This screening analysis addressed constituents of concern in CCW for which the human

health or ecological benchmarks were available to apply the risk-based methodology described

in Section 2. Table 3-2 lists these constituents and shows the results, by pathway and receptor

type, in terms of the risk criteria used in the analysis; values of 1 or above indicate risks of

concern that will be investigated further by EPA. Recommendations are described by pathway

in the following sections.

3.4.1 Aboveground Pathways

All constituents evaluated were below the screening criteria for human exposure through

the aboveground pathways evaluated (inhalation, soil ingestion, and ingestion of contaminated

produce, beef, and milk). This confirms the findings of the 1998 risk assessment, and supports

the conclusion that no additional analysis is needed with respect to human health impacts

through aboveground exposure pathways. 

The analysis also evaluated ecological impacts from exposure to soils and sediments

contaminated through aboveground overland transport. No screening exceedances occur for

surface water sediment contaminated through erosion and overland transport of soil. Only boron

exceeds the risk criteria for direct exposure to contaminated soil. This agrees with previous

studies noting plant toxicity to boron in coal ash (e.g., Carlson and Adriano, 1993). Because of

the magnitude of this screening exceedance (3.5 times the risk criteria) and the existence of

documented damage cases, we do not believe additional modeling of this pathway is needed to

confirm that boron is of concern to plants grown in soil contaminated with coal ash.

Consequently, additional full-scale modeling will not be conducted for human or ecological

aboveground exposure pathways. 
Section 3.0 Risk Characterization

3-18

Table 3-2. CCW Screening Results Summary

Analyte

Human Health Risk/Risk Criteria1 Ecological Risk/Risk Criteria2

GW-toDWGW-toSW AG-SoilGW-toSW AG-SoilAGSedimentSI-direct

(1998)3

Aluminum 0.39 -- 0.03 26.50 -- -- 10.00

Antimony 2.22 0.06 0.28 0.87 0.02 < 0.01 0.46

Arsenic 1,811.00 22.40 0.80 63.90 0.05 0.02 19.00

Barium 0.78 -- 0.04 40.10 0.01 < 0.01 < 0.01

Beryllium 0.27 0.02 < 0.01 2.40 -- -- NA

Boron 28.40 -- 0.72 4,699.00 3.46 -- 16.00

Cadmium 8.91 3.73 0.07 5.23 0.03 < 0.01 23.00

Chromium 4.15 0.01 0.10 3.33 0.01 < 0.01 0.10

Cobalt 10.70 -- 0.01 27.30 < 0.01 -- 0.20

Copper 0.22 0.22 -- 3.05 0.05 < 0.01 0.34

Cyanide 0.11 < 0.01 < 0.01 -- -- -- NA

Fluoride 5.42 -- < 0.01 -- -- -- NA

Lead 15.90 -- 0.02 79.40 0.01 0.04 830.00

Manganese 5.56 -- 0.02 -- -- -- NA

Mercury 0.31 700.00 0.24 1,418.00 0.08 < 0.01 4,500.00

Molybdenum 6.81 0.08 0.09 0.27 < 0.01 < 0.01 0.14

Nickel 1.27 < 0.01 0.05 1.44 0.06 < 0.01 0.28

Nitrate 60.20 -- < 0.01 -- -- -- NA

Nitrite 1.78 -- -- -- -- -- NA

Selenium 2.43 9.50 0.03 7.13 0.11 -- 30,000.00

Silver 0.27 -- 0.52 11.00 -- < 0.01 0.15

Strontium 0.55 -- 0.17 -- -- -- NA

Thallium 21.30 6.29 0.07 0.42 -- -- 0.45

Vanadium 2.33 -- 0.08 2.39 0.04 0.01 0.31

Zinc 0.22 0.24 0.12 1.61 0.03 < 0.01 0.10

1 Human health risk criteria are an HQ of 1 for noncarcinogens and a 10-5 excess cancer risk for carcinogens 2 Ecological risk criteria are an HQ of 10 for soil, surface water, and sediment and an HQ of 1 for direct surface

impoundment exposure. 3 Results from 1998 ecological risk analysis (U.S. EPA, 1998a), which considered only risks to mammals, birds,

and amphibians frequenting the impoundment. Effects on aquatic biota within the impoundment were not

considered to be indicative of ecological risk because surface impoundments are not designed to serve as aquatic

habitats.

Bold indicates values over the risk criteria; the highest of landfill and surface impoundment results are shown

in the table.

GW = groundwater, SW = surface water, AG = aboveground, SI = surface impoundment

-- = no health benchmark available to conduct the analysis

NA = not addressed in 1998
Section 3.0 Risk Characterization

3-19

3.4.2 Groundwater Pathways

With respect to exposure through groundwater transport, 23 CCW constituents showed

risk above the screening criteria for human or ecological exposure. The screening analysis

confirms the results of the 1998 risk analysis that showed significant risks through the

groundwater-to-drinking-water pathway and suggests that risks are also significant for exposure

to human and ecological receptors through the groundwater-to-surface-water pathway (which

was not evaluated in 1998). The screening results support a full-scale modeling effort to

characterize the nationwide distribution of risks through groundwater transport.

Table 3-3 summarizes the groundwater pathway screening results for these constituents

by showing the risk ranking, by pathway, for each constituent. This table also prioritizes the 23

constituents of concern for the groundwater pathways by risk rank and number of pathways/

receptors with screening exceedances. These priorities are intended to help plan and implement

the full-scale modeling effort. Full-scale modeling will address both groundwater impacts on

drinking water wells (for human receptors) and groundwater impacts on surface water quality

(for human and ecological receptors). Waterbodies of concern include fishable streams, rivers,

and lakes adjacent to CCW landfills and surface impoundments, as well as nearby groundwaterfed wetlands where sensitive ecological receptors may be present.

Table 3-3. Summary of CCW Screening Results: Groundwater Pathway Exceedances

Analyte

Human Health -

Drinking Water

Human Health -

Surface Water1

Ecological Risk -

Surface Water Modeling

LF Rank SI Rank LF Rank SI Rank LF Rank SI Rank Priority

Arsenic 1 1 2 5 7 3 1

Boron 6 3 - - 2 1 1

Cadmium 7 7 5 4 11 9 1

Lead 4 5 - - 3 4 1

Mercury - - 1 1 1 2 1

Selenium 11 13 3 3 8 8 1

Thallium 3442- - 1

Aluminum - - - - 5 6 2

Antimony 2 10 - - - - 2

Barium - - - - 4 7 2

Cobalt 6 - - - 5 2

Molybdenum 5 8 ---- 2

Chromium 8 12 - - 12 10 3

Fluoride 10 11 - - - - 3

Manganese 13 9 - - - - 3

Vanadium 9 14 - - 10 12 3

(continued)
Table 3-3. (Continued)

Section 3.0 Risk Characterization

3-20

Analyte

Human Health -

Drinking Water

Human Health -

Surface Water1

Ecological Risk -

Surface Water Modeling

LF Rank SI Rank LF Rank SI Rank LF Rank SI Rank Priority

Beryllium ----9- 4

Copper - - - - 14 11 4

Nickel - 16 - - - 13 4

Nitrate - 2 - - - - 4

Nitrite 12 15 - - - - 4

Silver - - - - 6 14 4

Zinc - - - - 13 - 4

1

 Fish-consumption pathway

LF = landfill

SI = surface impoundment

3.4.3 Constituents Not Addressed in the Screening Analysis

Table 3-4 lists the constituents not addressed in the screening analysis; they are not

addressed primarily because there are no suitable human health or ecological benchmarks to

conduct the risk-based screening described in this report. Ammonia was not addressed because

data in the CCW constituent database are limited to a few pilot project sites; EPA is in the

process of collecting additional analyte data for facilities that implement this new technology. 

Several of the constituents that were not screened are of actual or potential concern with

respect to environmental impacts. Perhaps the most significant of these is porewater or leachate

pH, which ranges from the acidic conditions (pH 3 to 4) that occur when ash is codisposed with

coal wastes, to the very alkaline conditions (a pH of up to 12.5 or higher) that are characteristic

of FBC wastes and certain FGD sludges and conventional combustion ash. Carlson and Adriano

(1993) cite damage incidents resulting from alkaline CCW effluent discharge to surface

waterbodies. The potential for negative impacts on groundwater chemistry is possible as well.

Public comments to the 1999 RTC also mention environmental damages by excessively high pH

as an area of concern.

Similarly, several metals and ions (calcium, chloride, iron, potassium, sodium, sulfate,

and sulfur) occur at concentrations in ash leachate and porewater that are high enough to be of

concern because of their potential to change aquatic chemistry and have a negative impact on

ecosystems.
Section 3.0 Risk Characterization

3-21

Table 3-4. CCW Constituents/Measurements Not Addressed in 

Screening Because of Lack of Benchmarks 

Constituent Comment

Potential concern because of high concentrations

Calcium Values range from 1 to more than 1,000 mg/L; could affect surface or groundwater chemistry

Chloride Values range from < 1 to more than 23,000 mg/L (in FGD sludge); could affect surface or

groundwater chemistry

Iron Values range from below detection to 48,000 mg/L; could affect surface or groundwater

chemistry

pH Values range from < 3 to more than 12; most wastes are very alkaline, with ash mixed with coal

waste tending to be acidic. Damage cases show toxicity to aquatic life. 

Potassium Values range from < 1 to more than 5,000 mg/L; could affect surface or groundwater chemistry

Sodium Values range from < 2 to more than 10,000 mg/L; could affect surface or groundwater chemistry

Sulfate Values range from < 1 to more than 50,000 mg/L in ash mixed with coal waste; could affect

surface or groundwater chemistry 

Total Sulfur Values range from < 1 to more than 25,000 mg/L; could affect surface or groundwater chemistry

Not of concern because of generally low concentrations

Carbon

Cyanide

Dissolved

Organic Carbon

Magnesium

Phosphate

Silicon

Sulfide

Total Organic

Carbon

Insufficient data to determine concern

Ammonia EPA is in the process of obtaining additional data

Total Dissolved

Solids
Section 4.0 References

4-1

4.0 References

Carlson, C. L., and D. C. Adriano. 1993. Environmental impacts of coal combustion residues. J.

Environ. Qual. 22:227-247.

EPRI (Electric Power Research Institute). 1997. Coal Combustion By-Products and LowVolume Wastes Comanagement Survey. Palo Alto, CA. June.

U.S. EPA (Environmental Protection Agency). 1998a. Non-groundwater Pathways, Human

Health and Ecological Risk Analysis for Fossil Fuel Combustion Phase 2 (FFC2): Draft

Final Report. Office of Solid Waste, Washington, DC. June. 

U.S EPA (Environmental Protection Agency). 1998b. Technical Background Document for the

Supplemental Report to Congress on Remaining Fossil Fuel Combustion Wastes:

Ground-Water Pathway Human Health Risk Assessment. Revised Draft Final. Office of

Solid Waste, Washington, DC. June.

U.S. EPA (Environmental Protection Agency). 1999. Report to Congress: Wastes from the

Combustion of Fossil Fuels. EPA 530-5-99-010. Office of Solid Waste and Emergency

Response, Washington, DC. March.
Appendix A

FFCW Constituent Data

Appendix A

A-3

Table A-1. FFCW Landfill Waste Analyte Concentrations: Total Waste Analyses (mg/kg)

Analyte Sites1 ND Sites2

2002 FFCW Total Waste Concentrations 1998 Total

Waste

Minimum Maximum 50th 75th 90th 95th 95th

Aluminum 71 0 1.45E+01 1.37E+05 2.53E+04 4.17E+04 8.57E+04 9.76E+04 1.43E+05

Antimony 64 19 1.25E-01 3.10E+02 1.56E+01 2.94E+01 4.62E+01 7.93E+01 4.67E+01

Arsenic 111 3 4.70E-02 3.70E+02 2.79E+01 6.18E+01 1.05E+02 1.25E+02 1.54E+02

Barium 94 1 4.76E+00 7.14E+03 2.22E+02 4.49E+02 1.05E+03 2.59E+03 8.38E+03

Beryllium 37 6 1.19E-01 2.85E+01 4.10E+00 1.00E+01 1.76E+01 2.25E+01 1.56E+01

Boron 70 4 2.50E-02 2.47E+03 5.35E+01 1.50E+02 3.46E+02 5.54E+02 4.17E+02

Cadmium 102 21 1.65E-04 7.60E+02 1.08E+00 2.26E+00 5.43E+00 1.12E+01 2.37E+01

Chromium 108 2 5.00E-03 1.38E+03 4.45E+01 7.62E+01 1.66E+02 1.81E+02 2.91E+02

Cobalt 67 8 5.00E-03 1.35E+02 1.02E+01 3.26E+01 6.22E+01 7.93E+01 4.16E+01

Copper 95 3 5.00E-03 8.90E+02 3.61E+01 8.24E+01 2.28E+02 2.99E+02 1.55E+02

Cyanide 2 1 1.25E-01 2.48E-01 1.86E-01 2.17E-01 2.35E-01 2.41E-01 -

Fluoride 8 0 2.50E+00 7.61E+02 1.08E+01 2.07E+01 2.49E+02 5.05E+02 -

Lead 107 6 1.30E-02 1.37E+03 2.87E+01 4.97E+01 8.06E+01 1.25E+02 1.52E+02

Manganese 87 2 5.00E-02 9.81E+03 1.11E+02 2.41E+02 5.10E+02 6.37E+02 8.17E+02

Mercury 86 12 6.00E-04 6.43E+01 3.28E-01 6.00E-01 1.63E+00 8.22E+00 -

Molybdenum 73 7 4.43E-02 1.26E+02 1.20E+01 2.23E+01 3.47E+01 5.38E+01 4.31E+01

Nickel 106 5 4.90E-02 5.41E+04 4.23E+01 1.30E+02 3.29E+02 6.79E+02 1.55E+02

Nitrate 1 1 2.43E-01 2.43E-01 2.43E-01 2.43E-01 2.43E-01 2.43E-01 -

Nitrite 0 0 - - - - - - -

Selenium 94 11 5.05E-03 6.73E+02 5.12E+00 1.03E+01 2.14E+01 4.79E+01 3.24E+02

Silver 69 26 5.00E-02 1.90E+03 1.72E+00 3.30E+00 1.37E+01 2.66E+01 1.36E+01

Strontium 15 1 5.60E+00 1.23E+03 2.63E+02 7.63E+02 1.05E+03 1.20E+03 4.76E+03

Thallium 20 10 9.00E-02 1.00E+02 3.23E+00 1.05E+01 2.08E+01 4.21E+01 4.80E+01

Vanadium 43 1 3.30E+00 4.55E+03 2.24E+02 3.48E+02 9.07E+02 2.95E+03 3.46E+02

Zinc 98 1 3.40E-02 1.82E+04 4.58E+01 1.44E+02 2.93E+02 1.43E+03 8.56E+02

1 Number of sites with analyte data (2002)

2

 Number of sites with only nondetect analyte data (2002)
Appendix A

A-4

Table A-2. FFCW Surface Impoundment Waste Analyte Concentrations: 

Porewater Analyses (mg/L)

Analyte Sites1 ND Sites2

2002 SI Porewater Concentrations 1998

Porewater

95th Minimum Maximum 50th 75th 90th 95th 3

Aluminum 17 2 1.50E-02 8.91E+01 1.18E+00 4.68E+00 2.30E+01 5.02E+01 2.70E+02

Antimony 2 2 1.00E-02 7.00E-02 4.00E-02 5.50E-02 6.40E-02 6.70E-02 -

Arsenic 17 2 7.50E-03 6.77E+00 1.80E-01 4.94E-01 5.18E+00 5.65E+00 9.64E+00

Barium 17 2 1.00E-03 5.50E-01 1.10E-01 1.59E-01 3.02E-01 4.88E-01 2.74E+01

Beryllium 2 1 1.00E-03 6.20E-03 3.60E-03 4.90E-03 5.68E-03 5.94E-03 -

Boron 18 1 2.50E-02 3.37E+02 5.01E+00 2.92E+01 7.52E+01 1.44E+02 3.42E+02

Cadmium 17 9 1.00E-03 2.50E-01 2.50E-03 1.56E-02 1.31E-01 1.90E-01 1.56E-01

Chromium 18 8 9.00E-04 5.78E-01 3.56E-02 1.13E-01 3.66E-01 5.29E-01 7.46E-01

Cobalt 4 2 5.00E-03 8.87E+00 1.07E-01 2.37E+00 6.27E+00 7.57E+00 -

Copper 16 5 6.40E-04 7.22E-01 3.63E-02 1.26E-01 2.84E-01 4.90E-01 6.90E-01

Cyanide 0 0 - - - - - - -

Fluoride 15 2 5.05E-02 4.10E+02 8.96E-01 4.99E+00 1.91E+01 1.39E+02 4.10E+02

Lead 14 5 1.23E-03 2.28E-01 5.90E-03 4.53E-02 1.77E-01 2.16E-01 4.68E-01

Manganese 16 2 4.24E-03 1.82E+02 1.69E-01 1.20E+00 7.67E+00 5.15E+01 1.03E+02

Mercury 1 1 2.50E-04 2.50E-04 2.50E-04 2.50E-04 2.50E-04 2.50E-04 7.96E-04

Molybdenum 18 6 1.79E-02 1.14E+01 4.73E-01 6.55E-01 1.00E+00 2.70E+00 1.14E+01

Nickel 17 4 5.00E-03 1.23E+01 4.61E-02 2.75E-01 7.49E-01 3.09E+00 8.33E+00

Nitrate 13 3 8.05E-02 1.17E+03 1.85E+00 4.73E+00 6.02E+02 9.17E+02 1.17E+03

Nitrite 15 4 7.00E-03 4.61E+02 1.89E-01 1.39E+00 5.22E+00 1.43E+02 4.61E+02

Selenium 15 3 2.50E-03 1.03E+00 6.97E-02 1.93E-01 3.56E-01 5.92E-01 1.03E+00

Silver 8 8 5.00E-05 5.00E-03 2.06E-03 4.25E-03 5.00E-03 5.00E-03

Strontium 17 0 4.20E-01 1.61E+01 4.25E+00 7.00E+00 8.74E+00 1.06E+01 1.61E+01

Thallium 2 2 2.50E-03 5.00E-02 2.63E-02 3.81E-02 4.53E-02 4.76E-02

Vanadium 15 1 1.25E-03 6.61E-01 1.03E-01 3.15E-01 4.78E-01 5.81E-01 8.00E-01

Zinc 17 5 1.16E-02 2.34E+01 1.00E-01 1.20E-01 6.70E-01 5.40E+00 2.31E+01

1

 Number of sites with analyte data (2002)

2

 Number of sites with only nondetect analyte data (2002)

3

 Includes both landfill and surface impoundment (SI) porewater data
Appendix A

A-5

Table A-3. FFCW Landfill Waste Analyte Concentrations: TCLP Analyses (mg/L)

Analyte Sites1 ND Sites2

TCLP Concentrations 1998

TCLP

Minimum Maximum 50th 75th 90th 95th 95th

Aluminum 54 3 3.00E-02 2.86E+01 2.06E+00 4.47E+00 1.05E+01 1.36E+01 -

Antimony 60 27 6.50E-04 7.87E-01 2.19E-02 7.50E-02 2.61E-01 2.98E-01 -

Arsenic 119 26 1.00E-03 1.80E+00 3.65E-02 1.31E-01 3.94E-01 1.01E+00 2.40E-01

Barium 115 7 2.00E-02 4.20E+01 3.04E-01 5.71E-01 1.60E+00 2.55E+00 -

Beryllium 47 15 5.00E-05 2.80E-01 2.14E-03 5.37E-03 1.58E-02 2.96E-02 -

Boron 72 3 1.00E-02 2.79E+01 1.07E+00 4.57E+00 1.06E+01 2.07E+01 -

Cadmium 117 38 1.50E-04 6.00E-01 1.00E-02 2.24E-02 4.94E-02 9.00E-02 -

Chromium 118 17 1.00E-03 7.64E-01 3.40E-02 1.00E-01 2.00E-01 3.50E-01 5.90E-02

Cobalt 51 10 1.92E-03 2.46E-01 1.52E-02 2.55E-02 8.25E-02 1.31E-01 -

Copper 72 13 1.60E-03 3.27E+00 4.14E-02 9.46E-02 1.50E-01 4.55E-01 -

Cyanide 24 14 3.50E-03 1.20E-01 7.23E-03 2.03E-02 6.32E-02 8.67E-02 -

Fluoride 33 1 8.00E-02 5.99E+01 8.19E-01 1.90E+00 6.34E+00 3.09E+01 -

Lead 116 38 1.00E-03 3.61E+00 3.23E-02 7.23E-02 2.39E-01 2.90E-01 -

Manganese 72 13 1.25E-03 3.27E+00 1.63E-01 4.39E-01 1.37E+00 1.56E+00 -

Mercury 97 60 5.00E-06 2.90E-01 2.89E-04 1.00E-03 2.69E-03 1.32E-02 -

Molybdenum 49 5 1.00E-02 3.09E+01 1.77E-01 3.40E-01 6.16E-01 1.27E+00 -

Nickel 80 19 2.00E-03 3.88E+00 5.17E-02 1.41E-01 3.09E-01 5.70E-01 5.00E-02

Nitrate 17 3 1.75E-02 2.60E+01 1.59E+00 2.50E+00 2.83E+00 7.72E+00 -

Nitrite 5 4 5.00E-02 5.00E+00 8.33E-01 1.17E+00 3.47E+00 4.23E+00 -

Selenium 119 23 1.00E-03 1.05E+00 4.87E-02 8.74E-02 1.76E-01 2.06E-01 4.40E-01

Silver 109 60 0.00E+00 2.50E-01 8.70E-03 1.75E-02 3.95E-02 5.02E-02 -

Strontium 20 0 6.35E-02 4.28E+01 2.95E+00 4.87E+00 9.70E+00 1.36E+01 -

Thallium 40 18 1.00E-03 1.97E-01 8.29E-03 2.34E-02 5.00E-02 6.54E-02 -

Vanadium 40 5 1.00E-03 1.20E+01 1.07E-01 1.82E-01 4.50E-01 1.50E+00 -

Zinc 75 9 2.00E-03 5.83E+01 1.30E-01 6.09E-01 1.94E+00 1.01E+01 -

1

 Number of sites with analyte data (2002)

2

 Number of sites with only nondetect analyte data (2002)

TCLP = Toxicity Characteristic Leaching Procedure
Appendix A

A-6

0.001 0.01 0.1 1 10 100 1000 10000

As, Cancer

As

NO3 (MCL)

B

Tl

Pb (MCL)

Co

Cd

Mo

Mn

Sb

FCr VI

Se

V

NO2

Ni

Sr

Al

Cu (MCL)

Ba

Be

Zn

Ag

Hg

Cr III

Analytes

90th percentile concentration/health-based number (HBN)

Non-averaged Site-averaged

Figure A-1. Comparison of site-averaged and nonaveraged results for surface impoundment

porewater screening, groundwater-to-drinking-water pathway.
Appendix A

A-7

0.001 0.01 0.1 1 10 100 1000

As, Cancer

As

Sb

Tl

Pb (MCL)

B

V

FCd

Cr VI

Mo

Mn

Se

Ba

Zn

Hg

Ni

Be

Ag

Cu (MCL)

NO3 (MCL)

Co

Sr

Al

CN

Cr III

Analytes

95th percentile concentration/health-based number (HBN)

Non-averaged Site-averaged

Figure A-2. Comparison of site-averaged and nonaveraged results for landfill leachate

(TCLP) screening, groundwater-to-drinking-water pathway.
Appendix A

A-8

0.0000001 0.000001 0.00001 0.0001 0.001 0.01 0.1 1 10

As, Cancer

Tl

B

Ag

Sb

As

Hg

Sr

Zn

Mo

Cr VI

V

Cd

Ni

Ba

Al

Se

Pb (SSL/PRG)

Mn

Co

Cr VI, Cancer

Be

FCo, Cancer

Be, Cancer

Cr III

Cd, Cancer

CN

NO3

Analytes

90th percentile concentration/health-based number (HBN)

Non-averaged Site-averaged

Figure A-3. Comparison of site-averaged and nonaveraged results for landfill

total waste screening, aboveground pathways.
Appendix B

Human Health Benchmarks

Appendix B September 2002

B-3

Appendix B 

Human Health Benchmarks

The fossil fuel combustion waste (FFCW) risk assessment will require human health

benchmarks to assess potential risks from chronic oral and inhalation exposures. The U.S.

Environmental Protection Agency (EPA) uses reference doses (RfDs) and reference concentrations

(RfCs) to evaluate noncancer risk from oral and inhalation exposures, respectively. Oral cancer slope

factors (CSFs), inhalation unit risk factors (URFs), and inhalation CSFs are used to evaluate risk for

carcinogens. 

This appendix provides the human health benchmarks used in the FFCW screening and risk

analyses. Section B.1 describes the data sources and general hierarchy that RTI used to collect these

benchmarks. Section B.2 provides the benchmarks along with discussions of individual human health

benchmarks extracted from a variety of sources.

B.1 Methodology and Data Sources

Several sources of health benchmarks are available. RTI used health benchmarks developed

by EPA to the extent that they were available. For chemicals for which EPA benchmarks were not

available, we used available benchmarks from non-EPA sources. RTI obtained human health

benchmarks from sources in the following order of preference:

# Integrated Risk Information System (IRIS)

# Superfund Technical Support Center Provisional Benchmarks

# Health Effects Assessment Summary Tables (HEAST)

# EPA health assessment documents

# Various other EPA health benchmark sources

# Agency for Toxic Substances and Disease Registry (ATSDR) minimal risk levels

(MRLs)

# California Environmental Protection Agency (CalEPA) chronic inhalation reference

exposure levels (RELs) and cancer potency factors.

Integrated Risk Information System (IRIS)

Benchmarks in IRIS are prepared and maintained by EPA, and RTI used values from IRIS

whenever available. IRIS is EPA’s electronic database containing information on human health effects

(U.S. EPA, 2002). Each chemical file contains descriptive and quantitative information on potential

health effects. Health benchmarks for chronic noncarcinogenic health effects include RfDs and RfCs. 

Cancer classification, oral CSFs, and inhalation URFs are included for carcinogenic effects. IRIS is the

official repository of Agency-wide consensus of human health risk information. 
Appendix B September 2002

B-4

Inhalation CSFs are not available from IRIS, so we calculated them from inhalation URFs

(which are available from IRIS) using the following equation:

In this equation, 70 kg represents average body weight; 20 m3/d represents average inhalation rate; and

1000 :g/mg is a units conversion factor (U.S. EPA, 1997). EPA uses these standard estimates of

body weight and inhalation rate in the calculation of the URF; therefore, we used these values to

calculate inhalation CSFs.

Superfund Provisional Benchmarks

The Superfund Technical Support Center (EPA’s National Center for Environmental

Assessment [NCEA]) derives provisional RfCs, RfDs, and CSFs for certain chemicals. These

provisional health benchmarks can be found in Risk Assessment Issue Papers. Some of the provisional

values have been externally peer reviewed. These provisional values have not undergone EPA’s formal

review process for finalizing benchmarks and do not represent Agency-wide consensus information.

Health Effects Assessment Summary Tables (HEAST)

HEAST is a listing of provisional noncarcinogenic and carcinogenic health toxicity values (RfDs,

RfCs, URFs, and CSFs) derived by EPA (U.S. EPA, 1997). Although the health toxicity values in

HEAST have undergone review and have the concurrence of individual EPA program offices, either

they have not been reviewed as extensively as those in IRIS or their data set is not complete enough to

be listed in IRIS. HEAST benchmarks have not been updated in several years and do not represent

Agency-wide consensus information.

Other EPA Health Benchmarks

EPA has also derived health benchmark values in other risk assessment documents, such as

Health Assessment Documents (HADs), Health Effect Assessments (HEAs), Health and Environmental

Effects Profiles (HEEPs), Health and Environmental Effects Documents (HEEDs), Drinking Water

Criteria Documents, and Ambient Water Quality Criteria Documents. Evaluations of potential

carcinogenicity of chemicals in support of reportable quantity adjustments were published by EPA’s

Carcinogen Assessment Group (CAG) and may include cancer potency factor estimates. Health

benchmarks derived by EPA for listing determinations (e.g., solvents) or studies (e.g., Air

Characteristic Study) are also available. Health toxicity values identified in these EPA documents are

usually dated and are not recognized as Agency-wide consensus information or verified benchmarks.
Appendix B September 2002

B-5

ATSDR Minimal Risk Levels

The ATSDR MRLs are substance-specific health guidance levels for noncarcinogenic

endpoints (ATSDR, 2002). An MRL is an estimate of the daily human exposure to a hazardous

substance that is likely to be without appreciable risk of adverse noncancer health effects over a

specified duration of exposure. MRLs are based on noncancer health effects only and are not based on

a consideration of cancer effects. MRLs are derived for acute, intermediate, and chronic exposure

durations for oral and inhalation routes of exposure. Inhalation and oral MRLs are derived in a manner

similar to EPA’s RfCs and RfDs, respectively (i.e., ATSDR uses the no observed adverse effect

level/uncertainty factor [NOAEL/UF] approach); however, MRLs are intended to serve as screening

levels and are exposure duration-specific. Also, ATSDR uses EPA’s (1994) inhalation dosimetry

methodology in the derivation of inhalation MRLs.

CalEPA Cancer Potency Factors and Reference Exposure Levels 

CalEPA has developed cancer potency factors for chemicals regulated under California’s Hot

Spots Air Toxics Program (CalEPA, 1999a). The cancer potency factors are analogous to EPA’s oral

and inhalation CSFs. CalEPA has also developed chronic inhalation RELs, analogous to EPA’s RfC,

for 120 substances (CalEPA, 1999b, 2000). CalEPA used EPA’s (1994) inhalation dosimetry

methodology in the derivation of inhalation RELs. The cancer potency factors and inhalation RELs

have undergone internal peer review by various California agencies and have been the subject of public

comment.

Surrogate Health Benchmarks

If no human health benchmarks were available from EPA or alternative sources, then RTI

sought benchmarks for similar chemicals to use as surrogate data. For example, the health benchmark

of a mixture could serve as the surrogate benchmark for its components or a benchmark of a metal salt

could serve as the surrogate for an elemental metal.

B.2 Human Health Benchmarks

The chronic human health benchmarks used to calculate the health-based numbers (HBNs) in

the FFCW screening analysis are summarized in Table B-1, which provides the Chemical Abstract

Service Registry Number (CASRN), constituent name, RfD (mg/kg-d), RfC (mg/m3), oral CSF

(mg/kg-d-1), inhalation URF [(:g/m3)

-1], inhalation CSF (mg/kg-d-1), and reference for each

benchmark. A key to the references cited and abbreviations used is provided at the end of the table.

For a majority of constituents, human health benchmarks were available from IRIS (U.S. EPA,

2002), Superfund Provisional Benchmarks, or HEAST (U.S. EPA, 1997). Benchmarks also were

obtained from ATSDR (2002) or CalEPA (1999a, 1999b, 2000). This section describes benchmarks

obtained from other sources, along with the Superfund Provisional values and special uses of IRIS

benchmarks.
Appendix B September 2002

B-6

Provisional inhalation health benchmarks were developed in the Air Characteristic Study (U.S.

EPA, 1999) for several constituents lacking IRIS, HEAST, alternative EPA, or ATSDR values. For

vanadium, the study on which the ATSDR acute inhalation MRL is based was used but was adjusted

for chronic exposure. Additional details on the derivation of this inhalation benchmark can be found in

the Revised Risk Assessment for the Air Characteristic Study (U.S. EPA, 1999).

The provisional RfD of 0.02 mg/kg-d developed by NCEA for the Superfund Technical

Support Center (U.S. EPA, 2001) was used for cobalt.
B-7

Table B-1. Human Health Benchmarks Used in FFCW Screening Analysis Constituent Name CASRN RfD (mg/kg-d) Ref RfC (mg/m3) Ref CSFo (per mg/kg-d) Ref URF (per ug/m3) Ref CSFi (per mg/kg-d) Ref MCL (mg/L) 

Aluminum 7429-90-5 2.0E+00 A RfD Ammonia 7664-41-7 9.7E-01 H 1.0E-01 I RfDAntimony 7440-36-0 4.0E-04 I 2.0E-04 I RfC Arsenic, inorganic 7440-38-2 3.0E-04 I 3.0E-05 Cal00 1.5E+0 I 4.3E-3 I 1.5E+1 calc Barium 7440-39-3 7.0E-02 I 5.0E-04 H Beryllium 7440-41-7 2.0E-03 I 2.0E-05 I 2.4E-3 I 8.4E+0 calc Boron 7440-42-8 9.0E-02 I 2.0E-02 H Cadmium 7440-43-9 5.0E-04 I 2.0E-05 Cal00 1.8E-3 I 6.3E+0 calc RfD 

Chloride 16887-00-6 250 Chromium (III), insoluble salts 16065-83-1 1.5E+00 I Chromium (VI) 18540-29-9 3.0E-03 I 1.0E-04 I 1.2E-2 I 4.2E+1 calc Cobalt (and cmpds) 7440-48-4 2.0E-02 SF 1.0E-04 A 2.8E-3 SF 9.8E+0 calc Copper 7440-50-8 1.3 Cyanide (amenable) 57-12-5 2.0E-02 I Divalent mercury 3.0E-04 H RfD 

for f

Divalent mercury 1.0E-04 I RfD 

fish 

Fluoride 16984-48-8 1.2E-01 I RfD 

IRIS dent

Iron 7439-89-6 0.3 Lead and cmpds (inorganic) 7439-92-1 0.015 
 B-8Table B-1. (continued)

Constituent Name CASRN

RfD

(mg/kg-d) Ref

RfC

(mg/m3) Ref

CSFo

(per

mg/kg-d) Ref

URF

(per

ug/m3) Ref

CSFi

(per mg/kg-d) Ref

MCL

(mg/L) 

Manganese 7439-96-5 1.4E-01 I 5.0E-05 I RfD 

2 mk

Molybdenum 7439-98-7 5.0E-03 INickel, soluble salts 7440-02-0 2.0E-02 I 2.0E-04 ANitrate 14797-55-8 1.6E+00 INitrite 14797-65-0 1.0E-01 ISelenium 7782-49-2 5.0E-03 I 2.0E-02 Cal00Silver 7440-22-4 5.0E-03 IStrontium 7440-24-6 6.0E-01 ISulfate 14808-79-8 250Thallium, elemental 7440-28-0 8.0E-05 I RfD Total dissolved solids 500Vanadium 7440-62-2 7.0E-03 H 7.0E-05 ACZinc 7440-66-6 3.0E-01 I

Key: CASRN = Chemical Abstract Service registry number. CSFo = oral cancer slope factor.

RfD = reference dose. CSFi = inhalation cancer slope factor.RfC = reference concentration. URF = unit risk factor.MCL = maximum contaminant level.

a Sources:

A = ATSDR MRLs (ATSDR, 2002)AC = developed for the Air Characteristic Study (U.S. EPA, 1999)calc = calculatedCal00 = CalEPA chronic REL (CalEPA, 2000)H = HEAST (U.S. EPA, 1997)I = IRIS (U.S. EPA, 2002)SF = Superfund Risk Issue Paper (U.S. EPA, 2001a,b)
Appendix B September 2002

B-9

For several constituents, IRIS benchmarks for similar chemicals were used as surrogate data. 

The rationale for these recommendations is as follows: 

# The RfC for antimony trioxide (2E-04 mg/m3) was used as a surrogate for antimony.

# Fluoride was based on fluorine. The IRIS RfD for fluorine is based on soluble fluoride. 

The primary RfD cited in IRIS (6E-02 mg/kg-d) is for dental fluorosis, a cosmetic

effect. In this analysis, an alternative IRIS value (1.2E-01 mg/kg-d) for skeletal

fluorosis in adults was used instead.

# The RfC for mercuric chloride (9E-05 mg/m3) was used as a surrogate for elemental

mercury. The RfDs for mercuric chloride (3E-04 mg/kg-d) and methyl mercury (1E-04

mg/kg-d) were used as surrogates for elemental mercury for assessing potential risks

from food, soil, and water ingestion, and fish ingestion, respectively.

# Thallium was based on thallium chloride. There are several thallium salts that have

RfDs in IRIS. The lowest value among the thallium salts (8E-05 mg/kg-d) is routinely

used to represent thallium in risk assessments.

B.3 References

ATSDR (Agency for Toxic Substances and Disease Registry). 2002. Minimal Risk Levels (MRLs)

for Hazardous Substances. Available online at http://www.atsdr.cdc.gov/mrls.html.

CalEPA (California Environmental Protection Agency). 1999a. Air Toxics Hot Spots Program Risk

Assessment Guidelines: Part II. Technical Support Document for Describing Available

Cancer Potency Factors. Office of Environmental Health Hazard Assessment, Berkeley, CA. 

Available online at http://www.oehha.org/air/cancer_guide/hsca2.html.

CalEPA (California Environmental Protection Agency). 1999b. Air Toxics Hot Spots Program Risk

Assessment Guidelines: Part III. Technical Support Document for the Determination of

Noncancer Chronic Reference Exposure Levels. SRP Draft. Office of Environmental

Health Hazard Assessment, Berkeley, CA. Available online (in two sections) at

http://www.oehha.org/air/chronic_rels/ragsii.html,

http://www.oehha.org/air/chronic_rels/RAGSp3draft.html.

CalEPA (California Environmental Protection Agency). 2000. Air Toxics Hot Spots Program Risk

Assessment Guidelines: Part III. Technical Support Document for the Determination of

Noncancer Chronic Reference Exposure Levels. Office of Environmental Health Hazard

Assessment, Berkeley, CA. Available online (in four sections) at

http://www.oehha.org/air/chronic_rels/22RELS2k.html,

http://www.oehha.org/air/chronic_rels/42kChREL.html,

http://www.oehha.org/air/chronic_rels/Jan2001ChREL.html,

http://www.oehha.org/air/chronic_rels/1201Crels.html.
Appendix B September 2002

B-10

U.S. EPA (Environmental Protection Agency). 1994. Methods for Derivation of Inhalation

Reference Concentrations and Application of Inhalation Dosimetry. EPA/600/8-90-066F.

Environmental Criteria and Assessment Office, Office of Health and Environmental

Assessment, Office of Research and Development, Research Triangle Park, NC.

U.S. EPA (Environmental Protection Agency). 1997. Health Effects Assessment Summary Tables

(HEAST). EPA-540-R-97-036. FY 1997 Update. Office of Solid Waste and Emergency

Response, Washington, DC. 

U.S. EPA (Environmental Protection Agency). 1999. Revised Risk Assessment for the Air

Characteristic Study. EPA-530-R-99-019a. Volume 2. Office of Solid Waste,

Washington, DC.

U.S. EPA (Environmental Protection Agency). 2001a. Risk Assessment Paper for Derivation of a

Provisional RfD for Cobalt and Compounds (CASRN 7440-48-4). 00-122/3-16-01. 

National Center for Environmental Assessment. Superfund Technical Support Center,

Cincinnati, OH.

U.S. EPA (Environmental Protection Agency). 2001b. Risk Assessment Paper for Derivation of a

Provisional Carcinogenicity Assessment for Cobalt and Compounds (CASRN 7740-48-4).

00-122/3-16-01. National Center for Environmental Assessment. Superfund 

U.S. EPA (Environmental Protection Agency). 2002. Integrated Risk Information System (IRIS). 

National Center for Environmental Assessment, Office of Research and Development,

Washington, DC. Available online at http://www.epa.gov/iris/.
Appendix C

Chemical Stressor Concentration Limits

(CSCLs) for Ecological Screening

Appendix C August 2002

C-3

Appendix C

Chemical Stressor Concentration Limits

(CSCLs) for Ecological Screening

C.1 Introduction

The screening analysis for fossil fuel combustion wastes included an ecological screening

analysis (ESA) that parallels the human health screening analysis. As described in Section 2.2.2 of this

report, the ESA addressed two routes of exposure for ecological receptors, direct contact with

contaminated media and ingestion of contaminated food items. Screening hazard quotients (HQs) were

calculated using chemical-specific media concentrations assumed to be protective of ecological

receptors of concern. These media concentrations are referred to as chemical stressor concentration

limits, or CSCLs. CSCLs are analogous to health-based numbers (HBNs) used in the human health

screening. The CSCLs were compared directly with concentrations of constituents found in fossil fuel

combustion wastes, leachate, and pore water. Table C-1 shows the receptor types assessed for each

exposure route in each environmental medium and the type of waste data assumed to represent

exposure levels in each medium. 

CSCLs were taken directly from the 1998 fossil fuel combustion risk analysis, Nongroundwater Pathways, Human Health and Ecological Risk Analysis for Fossil Fuel Combustion

Phase 2 (FFC2) (U.S. EPA, 1998). The receptors and endpoints selected for the 1998 analysis were

evaluated and considered appropriate for the goals of this screening analysis. The CSCLs were

derived for each chemical and receptor to the extent that supporting data were available. 

Table C-1. Receptors Assessed in Each Medium

Receptor Type

Surface Water

(Leachate )

Sediment

(Pore Water)

Soil

(Whole Waste)

Direct Contact Exposure

Aquatic Community U

Sediment Community U

Soil Community U

Amphibians U

Aquatic Plants and Algae U

Terrestrial Plants U

Ingestion Exposure

Mammals U U

Birds U U
Appendix C August 2002

C-4

To calculate HQs in the screening analysis, the lowest (most sensitive) CSCL for each chemical in each

medium was selected. For example, several receptors (soil invertebrates, terrestrial plants, mammals,

and birds) are exposed to constituents in soils. The soil HQ for a given chemical was calculated using

whichever soil CSCL was the lowest and would thus give the highest (most conservative) HQ. Table

C-2 shows the CSCLs used to calculate HQs.

The following sections summarize methods used in the 1998 analysis to generate the CSCLs

used in the ESA. Section C2.0 summarizes the derivation of CSCLs for media contact, and Section

C3.0 summarizes the derivation of the ingestion CSCLs. 

C.2 CSCLs for the Direct Contact Exposure

 Ecological receptors that live in close contact with contaminated media are considered to be

potentially at risk. These receptors are exposed through direct contact with contaminates in surface

water, sediment, and soil. The receptors selected to assess the direct contact exposure route for each

medium are shown in Table C-1. The CSCLs for receptor communities are not truly community-level

concentration limits in that they do not consider predator-prey interactions. Rather, they are based on

the theory that protection of 95 percent of the species in the community will provide a sufficient level of

protection for the community (see, for example, Stephan et al., 1985, for additional detail). The

following sections summarize the CSCL derivation methods for each receptor assessed for the direct

contact route of exposure. 

C.2.1 Aquatic Community CSCLS

The aquatic community receptor comprises fish and aquatic invertebrates exposed through

direct contact with constituents in surface water. For the aquatic community, the Final Chronic Value

(FCV), developed either for the Great Lakes Water Quality Initiative (U.S. EPA, 1993) or the

National Ambient Water Quality Criteria (NAWQC) (U.S. EPA, 1995a, 1995b), was the preferred

source for the CSCL. If an FCV was unavailable and could not be calculated from available data, a

Secondary Chronic Value (SCV) was estimated using methods developed for wildlife criteria for the

Great Lakes Initiative (e.g., 58 FR 20802; U.S. EPA, 1993). The SCV methodology is based on the

original species data set established for the NAWQC; however, it requires fewer data points and

includes statistically derived adjustment factors. For CSCL derivation, the minimum data set required at

least one data point for doughnuts. 

C.2.2 Amphibian CSCLS

For amphibian populations, the development of CSCLs was severely limited by data

availability. After a review of several compendia presenting amphibian ecotoxicity data (e.g., U.S. EPA,

1996; Power et al., 1989), as well as primary literature sources, it was determined that the lack of

standard methods on endpoints, species, and test durations made deriving a chronic CSCL for

amphibians inappropriate. Consequently, an acute CSCL was derived for aqueous exposures in

amphibians by taking a geometric mean of LC50 (i.e., concentration lethal to 50% of test subjects) data

identified in studies with exposure durations less than 8 days. Although the use of acute effects levels is

not consistent with other benchmarks and CSCLs, the sensitivity of these receptors warrants their

inclusion even though chronic concentration limits have not yet been developed.
C-5

Table C-2. CSCLs Used to Calculate Ecological Screening Hazard Quotients Constituent Soil Criterion Terrestrial Receptor Sediment Criterion Sediment Receptor Aquatic Criterion Aquatic Receptor 

Aluminum ID -- ID -- 0.09 Aquatic Biota 1998 Antimony 14 Raccoon 2 Sediment biota 0.03 Aquatic Biota 1998 Arsenic total 10 Plants 0.51 Spotted Sandpiper ID -- 1998 Arsenic III ID -- ID -- 0.15 Aquatic Biota 1998 Arsenic IV ID -- ID -- 8.10E-03 Aquatic Biota 1998 Barium 500 Plants 190 Spotted Sandpiper 4.00E-03 Aquatic Biota 1998 Beryllium ID -- ID -- 6.60E-04 Aquatic Biota 1998 Boron 0.5 Plants ID -- 1.60E-03 Aquatic Biota 1998 Cadmium 1 Soil invertebrates 0.68 Sediment biota 2.50E-03 Aquatic Biota 1998 Chromium total 64 Soil invertebrates 16.63 Spotted Sandpiper ID -- 1998 Chromium IV ID -- ID -- 0.09 Aquatic Biota 1998 Chromium VI ID -- ID -- 0.01 Aquatic Biota 1998 Cobalt 1000 Soil invertebrates ID -- 0.02 Aquatic Biota 1998 Copper 21 Soil invertebrates 18.7 Sediment biota 9.30E-03 Aquatic Biota 1998 Lead 28 Soil invertebrates 0.22 Spotted Sandpiper 3.00E-04 River Otter 1998 Mercury 0.1 Soil invertebrates 0.11 Spotted Sandpiper 1.90E-07 Kingfisher 1998 Molybdenum 42.08 Amer. woodcock 34 Spotted Sandpiper 0.37 Aquatic Biota 1998 Nickel 30 Plants 15.9 Sediment biota 0.05 Aquatic Biota 1998 Selenium total 1 Plants ID -- 5.00E-03 Aquatic Biota 1998 Selenium IV ID -- ID -- 0.03 Aquatic Biota 1998 Selenium VI ID -- ID -- 9.50E-03 Aquatic Biota 1998 Silver ID -- 0.73 Sediment biota 3.60E-04 Aquatic Biota 1998 Thallium ID -- ID -- 0.01 Aquatic Biota 1998 Vanadium 130.00 Soil Invertebrates 18 Spotted Sandpiper 0.02 Aquatic Biota 1998 Zinc 50 Plants 120 Sediment biota 0.12 Aquatic Biota 1998 
Appendix C August 2002

C-6

C.2.3 Sediment Community CSCLs

For the sediment community, CSCLs were selected based on a complete assessment of several

sources proposing sediment benchmark values. Primary sources evaluated for developing sediment

community CSCLs are shown in Table C-3. 

Table C-3. Primary Sources Evaluated for Developing Sediment Community CSCLs

Long, E.R., and L.G. Morgan. 1991. The Potential for Biological Effects of Sediment-Sorbed

Contaminants Tested in the National Status and Trends Program. National Oceanic and

Atmospheric Administration (NOAA) Technical Memorandum NOS OMA 52.

Jones, D.S., G.W. Suter, II, and R.N. Hull. 1997. Toxicological Benchmarks for Screening

Contaminants of Potential Concern for Effects on Sediment-Associated Biota: 1997 Revision. 

Oak Ridge National Laboratory.

U.S. EPA. 1997. Protocol for Screening Level Ecological Risk Assessment at Hazardous Waste

Combustion Facilities. Office of Solid Waste.

U.S. EPA. 1995c. Technical Support Document for the Hazardous Waste Identification Rule: Risk

Assessment for Human and Ecological Receptors. Office of Solid Waste.

MacDonald, D.D. 1994. Approach to the Assessment of Sediment Quality in Florida Coastal

Waters. Vol. 1. Florida Department of Environmental Protection (FDEP), Tallahassee, FL.

C.2.4 Soil Community CSCLs

For the soil community, the preferred methods for deriving CSCLs were analogous to those

used in deriving the NAWQC. CSCL values for soil fauna were estimated to protect 95 percent of the

species found in a typical soil community, including earthworms, insects, and other various soil fauna. 

The methodology presumes that protecting 95 percent of the soil species with a 50th percentile level of

confidence will ensure long-term sustainability of a functioning soil community. The toxicity data on soil

fauna were taken from several major compendia and supplemented with additional studies identified in

the open literature. 

The approach to calculating benchmarks for the soil community is based on efforts by Dutch

scientists (i.e., the RIVM methodology) to develop hazardous concentrations (HC) at specified levels

of protection (primarily 95%) at both a 95th percentile and a 50th percentile level of confidence (Sloof,

1992). For the soil fauna benchmarks, the 50th percentile level of confidence was selected because the

95th percentile appeared to be overly conservative for a “no effects” approach. The RIVM

methodology follows two steps: (1) fitting a distribution to the log of the selected endpoints, and (2)

extrapolating to a benchmark concentration based on the mean and standard deviation of a set of

endpoints. The key assumptions in the Dutch methodology are that (1) lowest observed effects

concentration (LOEC) data are distributed logistically, and (2) the 95 percent level of protection is

ecologically significant. The following formula was used to calculate soil fauna benchmarks: 
Appendix C August 2002

C-7

HC x k s 5% 1 − − [ m m ] (Eq. C-1)

where

HC5% = soil concentration protecting 95 percent of the soil species

xm = sample mean of the log LOEC data

kl = extrapolation constant for calculating the one-sided leftmost confidence limit for a

95 percent protection level

sm = sample standard deviation of the log LOEC data.

Sufficient data were available to develop CSCLs using this methodology for four of the metals

of concern: cadmium, copper, lead, and zinc. For the remaining constituents, benchmark studies

identifying effects to earthworms and other soil biota proposed by Oak Ridge National Laboratory

(Efroymson et al., 1997a) or criteria developed by the Canadian Council of Ministers of the

Environment (CCME, 1997) were used to estimate protective soil concentrations.

C.2.5 Algae and Aquatic Plants

For algae and aquatic plants, adverse effects concentrations are identified in the open

literature or from a data compilation presented in Toxicological Benchmarks for Screening

Potential Contaminants of Concern for Effects on Aquatic Biota: 1996 Revision (Suter and Tsao,

1996). For most contaminants, studies were not available for aquatic vascular plants, and lowest

effects concentrations were identified for algae. The CSCL for algae and aquatic plants was

based on (1) a LOEC for vascular aquatic plants or (2) an effective concentration (ECxx) for a species

of freshwater algae, frequently a species of green algae (e.g., Selenastrum capricornutum). Because

of the lack of data for this receptor group and the differences between vascular aquatic plants and algae

sensitivity, the lowest value of those identified was usually chosen. 

C.2.6 Terrestrial Plant CSCLs

For the terrestrial plant community, ecotoxicological data were identified from a summary

document prepared at the Oak Ridge National Laboratory: Toxicological Benchmarks for Screening

Potential Contaminants of Concern for Effects on Terrestrial Plants: 1997 Revision (Efroymson

et al., 1997b). The measurement endpoints are generally limited to growth and yield parameters

because (1) they are the most common class of response reported in phytotoxicity studies and,

therefore, will allow for criterion calculations for a large number of constituents, and (2) they are

ecologically significant responses both in terms of plant populations and, by extension, the ability of

producers to support higher trophic levels. As presented in Efroymson et al. (1997a), CSCLs for

phytotoxicity were selected by rank ordering the LOEC values and then approximating the 10th

percentile. If there were 10 or fewer values for a chemical, the lowest LOEC was used. If there were

more than 10 values, the 10th percentile LOEC was used.
Appendix C August 2002

C-8

C.3 CSCLs for Ingestion Exposure 

The ingestion route of exposure addresses the exposure of terrestrial mammals and birds

through ingestion of plants and prey and incidental soil ingestion. Thus, the CSCLs express media

concentrations that, based on certain assumptions about receptor diet and foraging behavior, are

expected to be protective of populations of mammals and birds feeding and foraging in contaminated

areas. 

The derivation of ingestion CSCLs begins with the selection of appropriate ecotoxicological

data based on a hierarchy of data sources. The assessment endpoint for the ESA was population

viability, and therefore, the benchmarks were developed from measures of reproductive/developmental

success or, if unavailable, from other effects that could conceivably impair population dynamics. 

Population-level benchmarks are preferred over benchmarks for individual organisms; however, very

few population-level benchmarks have been developed. Therefore, the ESA used benchmarks derived

from individual organism studies, and protection was inferred at the population level. 

Once the benchmark study was identified, the CSCL was calculated using a three-step

process. The remainder of this section outlines the basic technical approach used to convert avian or

mammalian benchmarks (in daily doses) to the CSCL (in units of concentration) for surface water and

soil. The methods reflect exposure through the ingestion of contaminated plants, prey, and various

media and include parameters on accumulation (e.g., bioconcentration factors), uptake (e.g.,

consumption rates), and dietary preferences. 

STEP 1 

Scale benchmark: The benchmarks derived for test species can be extrapolated to wildlife

receptor species within the same taxon using a cross-species scaling equation (Equation 2) (Sample et

al., 1996). This is the default methodology EPA proposed for carcinogenicity assessments and

reportable quantity documents for adjusting animal data to an equivalent human dose (57 FR 24152).

(Eq. C-2)

where

Benchmarkw = scaled ecological benchmark for species w (mg/kg/d)

LOAELt = lowest observed adverse effects level for test species (mg/kg/d) 

bwt = body weight of the surrogate test species (kg)

bww = body weight of the representative wildlife species (kg).
Appendix C August 2002

C-9

( ) CSCL benchmark bw

I I BAF sw

w fish

= ×

+ ×

 

 

STEP 2

Identify BCFs/ BAFs: For metal constituents, whole-body bioconcentration factors (BCFs)

and bioaccumulation factors (BAFs) were identified for aquatic and terrestrial organisms that may be

used as food sources (e.g., fish, plants, earthworms). The Oak Ridge National Laboratory has

proposed methods and data that are useful in predicting bioaccumulation in earthworms and small

mammals (Sample et al. 1998a, 1998b). These values were typically identified in the open literature

and EPA references. 

STEP 3

Calculate CSCLs: The following equation provides the basis for calculating the CSCL

for surface water using a population-inference benchmark (e.g., endpoint on fecundity).

(Eq. C-3) [ ( )] ( ) Benchmark

I BAF C I C

bw

fish w w w

= × +×

where

Ifish = intake of contaminated fish (kg/d)

BAF = whole-body bioaccumulation factor (L/kg)

bw = weight of the representative species (kg)

Iw = intake of contaminated water (L/d)

Cw = total concentration in the water (mg/L)

For chemicals that bioaccumulate significantly in fish tissue, the ingestion of contaminated food

will tend to dominate the exposure (i.e., [Ifish × Cfish] >> [Iw Cw]), and the water term (i.e., [Iw × Cw])

can be dropped from Equation 3 resulting in Equation 4. 

(Eq. C-4) ( ) Benchmark

I BAF C

bw

fish w

= × ×

At the benchmark dose (mg/kg-day), the concentration in water is equivalent to the chemical stressor

concentration limit for that receptor as a function of body weight, ingestion rate, and the

bioaccumulation potential for the chemical of concern. Hence, Equation 5 can be rewritten to solve for

the CSCL in surface water (CSCLsw) as follows: 

 (Eq. C-5)

For wildlife populations of mammals and birds in terrestrial systems, the CSCL for a given receptor is

given by Equation 6:
Appendix C August 2002

C-10

 (Eq. C-6) ( ) CSCL benchmark bw

I BCF F xAB I

soil

food j j j soil

= ×

∑ × +

 

where

bw = body weight (kg)

Ifood = total daily food intake of species (kg/d)

Isoil = total daily soil intake of species (kg/d)

BCFj = bioaccumulation factor in food item j (assumed unitless)

Fj = fraction of consisting of food item j (unitless)

Abj = absorption of chemical in the gut from food item j.

C.4 References

CCME (Canadian Council of Ministers of the Environment). 1997. Recommended Canadian Soil

Quality Guidelines. Science Policy and Environmental Quality Branch, Ecosystem Science

Directorate, Environment Canada, Ottawa, Ontario. ISBN 1-895-925-92-4. 

Efroymson, R.A., M.E. Will, and G.W. Suter. 1997a. Toxicological Benchmarks for

Contaminants of Potential Concern for Effects on Soil and Litter Invertebrates and

Heterotrophic Process: 1997 Revision. ES/ER/TM-126/R2. Oak Ridge National

Laboratory, Oak Ridge, TN.

Efroymson, R.A., M.E. Will, G.W. Suter, and A.C. Wooten. 1997b. Toxicological Benchmarks for

Screening Contaminants of Potential Concern for Effects on Terrestrial Plants: 1997

Revision. ES/ER/TM-85/R3. Oak Ridge National Laboratory, Oak Ridge, TN.

Jones, D.S., G.W. Suter, II, and R.N. Hull. 1997. Toxicological Benchmarks for Screening

Contaminants of Potential Concern for Effects on Sediment-Associated Biota: 1997

Revision. Oak Ridge National Laboratory.

Long, E.R., and L.G. Morgan. 1991. The Potential for Biological Effects of Sediment-Sorbed

Contaminants Tested in the National Status and Trends Program. National Oceanic and

Atmospheric Administration (NOAA) Technical Memorandum, NOS OMA 52.

MacDonald, D.D. 1994. Approach to the Assessment of Sediment Quality in Florida Coastal

Waters, Volume 1. Florida Department of Environmental Protection (FDEP),

Tallahassee, FL. 

Power, T., K.L. Clark, A. Harfenist, and D.B. Peakall. 1989. A Review and Evaluation of the

Amphibian Toxicological Literature. Technical Report Series No. 61. Canadian Wildlife

Service, Environment Canada, Hull, Quebec.
Appendix C August 2002

C-11

Sample, B.E., D.M. Opresko, and G.W. Suter, II. 1996. Toxicological Benchmarks for Wildlife:

1996 Revision. ES/ER/TM-86/R3. Oak Ridge National Laboratory, Oak Ridge, TN.

Sample, B.E., J.J. Beauchamp, R.A. Efroymson, G.W. Suter, II, and T.L. Ashwood. 1998a. 

Development and Validation of Bioaccumulation Models for Earthworms. ES/ER/TM220. Oak Ridge National Laboratory, Oak Ridge, TN.

Sample, B.E., J.J. Beauchamp, R.A. Efroymson, and G.W. Suter, II. 1998b. Development and

Validation of Bioaccumulation Models for Small Mammals. ES/ER/TM-219. Oak Ridge

National Laboratory, Oak Ridge, TN.

Sloof, W. 1992. Ecotoxicological Effect Assessment: Deriving Maximum Tolerable

Concentrations (MTC) from Single Species Toxicity Data. Guidance Document. Report

No. 719102.018. National Institute of Public Health and Environmental Protection (RIVM),

Hilversum, the Netherlands.

Stephan, C.E., D.I. Mount, D.J. Hansen, J.H. Gentile, G. A. Chapman, and W.A. Brungs. 1985. 

Guidelines for Deriving Numerical National Ambient Water Quality Criteria for the

Protection of Aquatic Organisms and Their Use. Office of Research and Development,

U.S. Environmental Protection Agency. mg/l NTIS PB85-220749, Springfield, VA.

Suter, G.W., and C.L. Tsao. 1996. Toxicological Benchmarks for Screening Potential Contaminants

of Concern for Effects on Aquatic Biota: 1996 Revision. US Department of Energy, Oak

Ridge National Laboratory. Oak Ridge, TN. June.

U.S. EPA (Environmental Protection Agency). 1993. Water Quality Guidance for the Great Lakes

System and Correction. Proposed Rule. 58 FR 20802. 

U.S. EPA (Environmental Protection Agency). 1995a. Great Lakes Water Quality Initiative

Criteria Documents for the Protection of Aquatic Life in Ambient Water. EPA-820-B95-004. Office of Water, Washington, DC.

U.S. EPA (Environmental Protection Agency). 1995b. Great Lakes Water Quality Initiative

Criteria Documents for the Protection of Wildlife DOT, Mercury, 2,3,78-TCDD, and

PCBs. EPA-820-B-95-008. Office of Water, Washington, DC.

U.S. EPA (Environmental Protection Agency). 1995c. Technical Support Document for the

Hazardous Waste Identification Rule. Office of Solid Waste, Washington, DC.

U.S. EPA (Environmental Protection Agency). 1996. Water Quality Criteria Documents for the

Protection of Aquatic Life in Ambient Water: 1995 Updates. EPA-820-B-96-001. Office

of Water, Washington, DC. 
Appendix C August 2002

C-12

U.S. EPA (Environmental Protection Agency). 1997. Protocol for Screening Level Ecological Risk

Assessment at Hazardous Waste Combustion Facilities, (Volumes 1 and 2). U.S. EPA

Office of Solid Waste. Internal Review Draft. February 28, 1997.

U.S. EPA (Environmental Protection Agency). 1998. Non-groundwater Pathways, Human Health

and Ecological Risk Analysis for Fossil Fuel Combustion Phase 2 (FFC2). Office of Solid

Waste, Washington, DC. 

U.S. EPA (Environmental Protection Agency). 1999. National Recommended Water Quality

Criteria-Correction. EPA/822-Z-99-001. Office of Water, Washington, DC.
Appendix D

Calculation of Health-Based Numbers (HBNs) 

Appendix D August 2002

D-3

Appendix D

Calculation of Health-Based Numbers (HBNs) 

Management of fossil fuel combustion

waste (FFCW) can result in contaminants

moving from a waste management unit

(WMU) and contaminating nearby air, soil,

groundwater, and surface water via

mechanisms such as groundwater transport,

overland transport, wind erosion, and

subsequent deposition. Individuals living near

WMUs may then come into contact with

chemicals directly via inhalation of ambient

air, ingestion of drinking water, or ingestion of

soil. Chemicals may then contaminate food

items via chemical uptake and accumulation

in produce, animal products, or fish. 

Health-based numbers (HBNs) for

soil, groundwater (as drinking water), and

surface water are used in this analysis to

consider risks and hazards to human receptors from chemicals that are released from FFCW

management units and move through the subsurface and aboveground environments. HBNs represent

concentrations in environmental media that will not cause an exceedance of a target cancer risk of 10-5

or a hazard quotient (HQ) of 1. 

The pathways included in the HBN calculations are summarized in Table D-1. The HBNs for

soil are based on a farmer scenario with receptors living at a site adjacent to an FFCW WMU,

breathing contaminated air, ingesting contaminated soil, and raising their own crops, beef cattle, and/or

dairy cattle. The HBN for groundwater is based on domestic use of groundwater as drinking water.

Surface water HBNs are based on a recreational fisher scenario in which the receptor is assumed to

live at a different off-site location and to only be exposed to fish. 

D.1 Methodology

All HBNs consider human receptors exposed to contaminated media and/or food items at

different ages to take into account changing exposure patterns with age. The specific receptors

considered were individuals exposed starting at ages 3, 8, 15, and 20. Depending on the start age, an

appropriate exposure duration was selected for each receptor based on residency data. Each receptor

was exposed for the period of time determined by the exposure duration, and the model accounted for

Key Features of HBN Calculations

# HBNs calculated for groundwater (mg/L), surface

water (mg/L), and soil (mg/kg)

# HBNs based on a target cancer risk of 10-5 and a

HQ of 1

# Soil HBNs based on a farmer scenario, and

consider inhalation, direct ingestion, and indirect

pathways

# Groundwater HBNs based on a residential

drinking water scenario.

# Surface water HBNs based on a recreational

fisher scenario.

# Adult and child receptors first exposed at ages 3,

8, 15 and 20.

# Exposure factors set at central tendency values.

# Source size set at the 95th percentile of FFCW

landfills.
Appendix D August 2002

D-4

changes in exposure patterns as a person ages. All exposure parameters selected for this analysis were

based on 50th percentile values. Once the cancer risks and HQs were calculated for each receptor,

HBNs were calculated based on total cancer risk across all

Table D-1. Pathways Included in HBN Calculations

HBN Calculation

Drinking

Water

Ingestion

Inhalation of 

Ambient Air

Soil

Ingestion 

Ingestion of

Producea

Ingestion

of Animal

Productsb

Fish

Ingestion

Groundwater HBN T

Soil HBN TTT T

Surface water HBN T

a Includes above- and belowground produce.

b Includes beef and milk.

pathways, noncancer inhalation, and noncancer ingestion. The most conservative HBN (i.e., the lowest

across all age groups) was selected. In all cases, the HBN calculations used central tendancy exposure

factors (e.g., body weight, exposure duration, exposure frequency, consumption rates).

The equations used to calculate the HBNs are provided at the end of this appendix in Tables

D-6 through D-27; Table D-2 below lists the tables of equations by exposure pathway. Data used in

these equations to calculate the FFCW HBNs can be found in the other appendices to this report. 

Groundwater HBNs are based on standard residential exposure assumptions for drinking water

consumption, using equations from (U.S. EPA, 1998a). The surface water HBNs are based on

concentrations in fish estimated using an aquatic food chain model (see Section D.1.2). 

For the soil HBNs, concentrations in crops and animal products were estimated using the

terrestrial food chain model described in Section D.1.1. The soil HBNs also consider air concentration

above the contaminated soil to address windblown emissions off the nearby landfill. To estimate

windblown dust emissions and air concentrations, a particulate emission factor (PEF) was calculated

based on the U.S. Environmental Protection Agency’s (EPA’s) Soil Screening Guidance (U.S. EPA,

1996; 2001) using conservative assumptions (e.g., fraction of vegetative cover was set to zero). The

source size used for estimating the PEF was the 95th percentile value presented in the Electric Power

Research Institute (EPRI) database (EPRI, 1997). Waste concentrations are divided by the PEF in

order to estimate the air concentration.

D.1.1 Terrestrial Food Chain

 The methodology used for estimating concentrations in food items is based on EPA’s

Methodology for Assessing Health Risks Associated with Multiple Pathways of Exposure to

Combustor Emissions (U.S. EPA, 1998a). The terrestrial food chain is designed to predict the
Appendix D August 2002

D-5

accumulation of a contaminant in the edible parts of a plant from uptake of contaminants in soil and

through translocation and direct deposition of contaminants in air. Concentrations are predicted for

three main categories of food crops presumed to be eaten by humans: exposed 

Table D-2. Key to Tables of Equations Used to Calculate HBNs

Equations for Air Pathway: Emissions, Dispersion, Air Concentrations, and Deposition Rates

D-6 Particulate Phase Air Concentration from Soil Emissions (mg/m3

)

D-7 Particulate Emissions Factor for Unlimited Mass–Commercial/Industrial 

Scenario (m3

/kg)

D-8 Dispersion Factor (g/m2

-s)/(kg/m2)

D-9 Annual Wet Depositon from Particle Phase (g/m2

-yr)

D-10 Annual Dry Deposition from Particle Phase (g/m2

-yr)

Equations for Indirect Soil Pathways: Produce, Beef, Milk, and Fish

D-11 Total Concentration in Above-Ground Vegetation (mg/kg - WW or DW)

D-12 Aboveground Vegetation Concentration Due to Root Uptake (mg/kg - DW)

D-13 Vegetative Concentration Due to Direct Deposition (mg/kg - DW)

D-14 Concentration in Belowground Vegetation Due to Root Uptake (mg/kg - WW)

D-15 Deposition Term for Plants (mg/m2

-yr)

D-16 Concentration in Beef Due to Plant and Soil Ingestion (mg/kg - WW)

D-17 Concentration in Milk Due to Plant and Soil Ingestion (mg/kg - WW)

D-18 Concentration in Fish at Different Trophic Levels (mg/kg)

Equations for Human Exposure

D-19 Daily Intake of Contaminant from Consumption of Aboveground Produce (mg/kg BW/day)

D-20 Daily Intake of Contaminant from Consumption of Belowground Produce (mg/kg BW/day)

D-21 Daily Intake of Contaminant from Consumption of Fish (mg/kg BW/day)

D-22 Daily Intake of Contaminant from Incidental Ingestion of Soil (mg/kg BW/day) 

D-23 Daily Intake of Contaminant from Consumption of Drinking Water (mg/kg BW/day)

D-24 Daily Intake of Contaminant from Ingestion of Animal Tissue Groups (mg/kg/BW/day)

Equations for Unit Risk Calculations and Health-based Numbers

D-25 Cancer Risk and Hazard Quotient Due to Inhalation (unitless)

D-26 Cancer Risk and Hazard Quotient Due to Ingestion (unitless)

D-27 Health-Based Concentration (ppm)

fruits and vegetables, protected fruits and vegetables, and root vegetables. The terms “exposed” and

“protected” refer to whether or not the edible portion of the produce is exposed to the atmosphere. 

Examples include tomatoes (exposed vegetable), bananas (protected fruit), and potatoes (root

vegetables). 

In addition, the terrestrial food chain estimates the contaminant concentration in farm crops for

cattle. Vegetation consumed by cattle includes grain, forage, and silage. Grain is considered to be a
Appendix D August 2002

D-6

protected vegetation and forage an exposed vegetation. Silage refers to any plants harvested for animal

consumption, whether protected or exposed. Silage is calculated as exposed vegetation; however, an

empirical correction factor for silage takes into account that silage is partly protected and partly

exposed. 

Table D-3 summarizes the mechanisms by which vegetation can be exposed to contaminants. 

The three mechanisms are (1) deposition of particle-bound contaminants to exposed plant tissues, (2)

vapor-phase deposition of contaminants to exposed plant tissues, and (3) root uptake.

Table D-3. Terrestrial Food Chain Vegetation

Type of Vegetation

Particulate

Deposition

Vapor-Phase

Deposition

Root 

Uptake

Human ingestion

Exposed vegetables T TT

Exposed fruit T TT

Protected vegetables T

Protected fruit T

Root vegetables T

Beef and dairy cow ingestion

Forage T TT

Silage T TT

Grain T

Exposed vegetation is subject to contamination via particulate deposition, vapor-phase deposition, and

root uptake, while protected vegetation is contaminated only through root uptake because the edible

portion of the vegetation is not in direct contact with air. Accumulation by root uptake can occur

through the uptake of soil and water for aboveground protected vegetables and fruit, or by absorption

into the outer parts of the root vegetables.

D.1.2 Aquatic Food Chain

 The methodology used for estimating concentrations in fish is based on EPA’s Methodology

for Assessing Health Risks Associated with Multiple Pathways of Exposure to Combustor

Emissions (U.S. EPA, 1998a). An aquatic food chain model was used to estimate the concentration of

constituent that may accumulate in fish. It is assumed for this analysis that fish are a food source for a

recreational fisher. Trophic level three (T3) and four (T4) fish were considered in this analysis. T3 fish

are those that consume invertebrates and plankton. T4 fish are those that consume other fish. Most of

the fish that humans eat are T4 fish (e.g., salmon, trout, walleye, bass) and medium to large T3 fish
Appendix D August 2002

D-7

(e.g., carp, smelt, perch, catfish, sucker, bullhead, sauger). For metals other than mercury, the

calculation of contaminants in fish is based on the total concentration of contaminants in the waterbody

(i.e., dissolved and suspended solids). For mercury, the calculation of contaminants in fish is based on

the dissolved concentration of methyl mercury in the waterbody.

Fish tissue concentrations are dependent on a bioconcentration factor (BCF), which is used to

estimate the amount of constituent being transferred from the waterbody into the fish 

tissue. Specifically, BCFs reflect the ratio between the tissue concentration in fish and the appropriate

waterbody concentration. BCFs were developed for each constituent to reflect accumulation in each

trophic level considered. They were also developed to estimate the concentration in the fish filet versus

the total fish. Human receptors consume only the filet portion of the fish, which has a lower lipid

content. Because some constituents tend to accumulate in the fatty tissue, the concentration in the filet

portion of the fish is sometimes lower than the concentration in the whole fish. 

D.2 Health-Based Numbers

Table D-4 provides the HBNs for surface water and groundwater and compares the

groundwater numbers developed for the 2002 FFCW risk analysis to those developed for the 1998

FFCW risk analysis (U.S. EPA, 1998b). (Surface water HBNs were not developed in 1998.)

Constituents with groundwater HBNs in 2002 but not in 1998 include aluminum and cobalt. Most of

the remaining constituents show lower groundwater HBNs in 2002 by a factor of 1.8, which is due to

the differences in exposure factors between the adult-only scenario assumed in 1998 and the child age

cohorts used in 2002. Manganese and hexavalent chromium also show lower HBNs in 2002 because

of lower health benchmarks than those used in 1998 (see Appendix A for the human health

benchmarks used to calculate the HBNs). Fluoride shows a slightly higher HBN in 2002 because of

EPA’s decision to use the skeletal fluorosis reference dose (RfD) instead of the lower RfD for dental

fluorosis.

Table D-5 lists the 2002 soil HBNs along with the relative contribution of each exposure

pathway to the HBN. Most of the soil HBNs are driven by the soil or milk ingestion pathways, with

antimony and the noncancer beryllium HBNs mainly reflecting risk from the ingestion of contaminated

produce. The cancer HBNs for beryllium, cadmium, chromium, and cobalt and the noncancer HBN for

ammonia are based entirely on inhalation benchmarks and therefore only reflect inhalation risks.

Table D-4. Groundwater and Surface Water HBNs

Chemical

2002 Benchmark

Type

Groundwater HBN (mg/L)1

Surface Water

HBN2 2002 1998 (mg/L)

Aluminum Noncancer 58.7 NA NA

Antimony Noncancer 0.012 0.021 NA

Arsenic Cancer 0.0029 0.0029 0.23

(continued)
Table D-4. (continued)

Appendix D August 2002

Chemical

2002 Benchmark

Type

Groundwater HBN (mg/L)1

Surface Water

HBN2 2002 1998 (mg/L)

D-8

Arsenic Noncancer 0.0088 0.015 0.71

Barium Noncancer 2.1 3.6 NA

Beryllium Noncancer 0.059 NA 1.0

Boron Noncancer 2.64 4.63 NA

Cadmium Noncancer 0.015 0.026 0.035

Chromium (III) Noncancer 44 NA 23,700

Chromium (VI) Noncancer 0.088 0.26 47

Cobalt Noncancer 0.59 NA NA

Copper MCL 1.3 1.3 NA

Cyanide Noncancer 0.59 NA NA

Fluoride Noncancer 3.52 3.08 NA

Lead MCL 0.015 0.015 NA

Manganese Noncancer 1.4 7.2 NA

Mercury Noncancer 0.0088 0.015 3.85E-06

Molybdenum Noncancer 0.147 0.257 12

Nickel Noncancer 0.59 1.03 237

Nitrate MCL 10 10 NA

Nitrate Noncancer 47 NA NA

Nitrite Noncancer 2.9 10 NA

Selenium Noncancer 0.147 0.257 0.038

Silver Noncancer 0.147 0.257 NA

Strontium Noncancer 17.6 30.8 NA

Thallium Noncancer 0.0024 0.0041 0.008

Vanadium Noncancer 0.21 0.36 NA

Zinc Noncancer 8.8 15.4 8.13

1

 Based on domestic drinking water ingestion.

2

 Based on fish consumption by a recreational fisher.

MCL = maximum contaminant level or drinking water action level (for lead and copper)

NA = not available
D-9

Table D-5. Soil HBNs and Exposure Pathway Contributions Chemical HBN (mg/kg) Benchmark Type Pathway Contributions 

Soil Beef Milk Veg Root 

luminum 3.02E+05 Noncancer ingestion 69% 5.6% 21% 3.4% 0.80% NAntimony 1.64E+01 Noncancer ingestion 19% 6.2% 20% 44% 11% NArsenic 1.31E+01 Cancer 62% 15% 14% 8.2% 0.82% 0Arsenic 4.04E+01 Noncancer ingestion 62% 15% 14% 8.2% 0.82% NBarium 2.59E+03 Noncancer ingestion 17% 0.7% 49% 26% 7.4% NBeryllium 8.44E+03 Cancer 0% 0% 0% 0% 0% 1Beryllium 3.60E+02 Noncancer ingestion 83% 5.2% 0.13% 9.7% 2.4% NBoron 4.82E+01 Noncancer ingestion 0% 1.1% 74% 22% 2.8% NCadmium 1.13E+04 Cancer 0% 0% 0% 0% 0% 1Cadmium 8.01E+00 Noncancer ingestion 4% 1.2% 75% 17% 2.7% NChromium (III) 9.65E+04 Noncancer ingestion 30% 8.3% 62% 0.27% 0.08% NChromium (VI) 1.93E+02 Noncancer ingestion 30% 8.3% 62% 0.27% 0.08% NChromium (VI) 1.69E+03 Cancer 0% 0% 0% 0% 0% 1Cobalt 5.81E+02 Noncancer ingestion 13% 20% 61% 4.8% 0.77% NCobalt 7.23E+03 Cancer 0% 0% 0% 0% 0% 1Cyanide 4.35E+03 Noncancer ingestion 99.9% 0% 0% 0.07% 0.0% NFluoride 2.61E+04 Noncancer ingestion 99.9% 0% 0% 0.07% 0% NManganese 2.59E+03 Noncancer ingestion 25% 1.4% 39% 28% 6.1% NMercury (divalent) 6.90 Noncancer ingestion 1.1% 8% 89% 2% 0.1% NMolybdenum 3.96E+01 Noncancer ingestion 4% 8.8% 72% 13% 2.6% NNickel 6.90E+02 Noncancer ingestion 16% 7.6% 43% 31% 2.7% NNitrate 3.48E+05 Noncancer ingestion 99.9% 0% 0% 0.07% 0% NNitrite 2.17E+04 Noncancer ingestion 99.9% 0% 0% 0.07% 0% NSelenium 7.83E+01 Noncancer ingestion 7% 9.1% 76% 7% 0.52% NSilver 2.62E+00 Noncancer ingestion 0.2% 0.44% 98% 1.4% 0.28% NStrontium 6.22E+02 Noncancer ingestion 0.5% 0.51% 84% 12% 3.4% NThallium 2.81E+00 Noncancer ingestion 16% 35% 48% 0.7% 0.19% NVanadium 1.16E+03 Noncancer ingestion 76% 10% 2.4% 10% 1.2% NZinc 2.43E+02 Noncancer ingestion 0.4% 19% 69% 11% 0.14% N
Table D-6. Particulate-Phase Air Concentration From Soil Emissions (mg/m^3)

Appendix D

Name Description Value

Cpar

PEF

Csoil Cpar =

PEF Particulate emissions factor for unlimited mass (m^3/kg) Calculated

Csoil Soil concentration (mg/kg) Set equal to 1 for 

the HBN 

calculation

Based on Supplemental Guidance for Developing Soil Screening Levels for Superfund Sites, U.S. EPA, 

2001, OSWER 9355.4-24.

D-10
Table D-7. Particulate Emissions Factor for Unlimited Mass--Commercial/Industrial 

Scenario (m^3/kg)

Appendix D

Name Description Value

PEF

( ) Fx

ut

uw VC

QC PEF

 ×











× − ×

×

= 3

0.036 1

3600

Q/C Dispersion factor (g/m^2-s)/(kg/m^2) Calculated

Fx Function dependent on uw/ut derived using Cowherd et al. (1985) 

(unitless)

See Appendix H

ut Equivalent threshold value of windspeed at 7m (m/s) See Appendix H

uw Mean annual windspeed (m/sec) See Appendix H

VC Fraction vegetative cover (unitless) See Appendix H

Supplemental Guidance for Developing Soil Screening Levels for Superfund Sites, U.S. EPA, 2001, 

OSWER 9355.4-24, Equation 4-5.

D-11
Table D-8. Dispersion Factor (g/m^2-s)/(kg/m^2)

Appendix D

Name Description Value

Q/C

( ( ) )















 −

= ×

C

B

DF

Area DF

A QC DF e

2

ln

Area Source area (acres) See Appendix H

DF_A Constant selected based on location (unitless) See Appendix H

DF_B Constant selected based on location (unitless) See Appendix H

DF_C Constant selected based on location (unitless) See Appendix H

Supplemental Guidance for Developing Soil Screening Levels for Superfund Sites, U.S. EPA, 2001, 

OSWER 9355.4-24.

D-12
Table D-9. Annual Wet Deposition from Particle Phase (g/m^2-yr)

Appendix D

Name Description Value

Dywp

Dywp = Cpar× May ×Wp × 0.00001

1.00E-05 Conversion factor (10 -3 g/mg)(10 -2 m/cm)

Wp Volumetric washout ratio for particulates (unitless) 1.00E5 (Bidleman, 

1988)

Cpar Contaminant air concentration (mg/m^3) Calculated

May Average annual moisture (precipitation: rainfall, snowfall) (cm/yr) See Appendix H

Source: U.S. EPA (1998a) Equation 4-3 for particles and 6-16 for vapors.

D-13
Table D-10. Annual Dry Deposition from Particle Phase (g/m^2-yr)

Appendix D

Name Description Value

Dydp

Dydp = 315.36×Vdp ×Cpar

315.36 Conversion factor ([3.1536E+07 sec/yr]/[100 cm/m][1e3 mg/g])

Vdp Dry deposition velocity of particles (cm/s) 1

Cpar Particle phase air concentration (μg/m^3) Calculated

Source: U.S. EPA (1998a) Equation 4-2 for particles and 6-17 for vapors.

D-14
Table D-11. Total Concentration in Aboveground Vegetation (mg/kg - WW or DW)

Appendix D

Name Description Value

Pveg

( )

100

100 MAF P Pd Pv Pf veg−

= + + ×

100 Conversion factor to percent (unitless)

Pd Vegetative concentration due to direct deposition (mg/kg - DW) Calculated

Pr Aboveground vegetation concentration due to root uptake (mg/kg - 

DW)

Calculated

Pv Vegetative concentration due to air-to-plant transfer (mg/kg - DW) Calculated

MAF Plant tissue-specific moisture adjustment factor to convert DW 

concentration into WW (percent)

See note below

Source: U.S. EPA, 1998a.

Note: For exposed vegetation, MAF is 92, for exposed fruit 85, for protected fruit 90, and for protected 

vegetables 80. Dry weight is used for silage and feed. Wet weight is used for exposed vegetataion, 

exposed fruit, and protected fruit

D-15
Table D-12. Aboveground Vegetation Concentration Due to Root Uptake (mg/kg - DW)

Appendix D

Name Description Value

Pr

Pr = Csoil × Br

BrExfruit Soil-to-plant bioconcentration factor for exposed fruit (mg/kg DW 

plant / mg/kg soil)

See Appendix E

BrExveg Soil-to-plant bioconcentration factor for exposed vegetables (mg/kg 

DW plant / mg/kg soil)

See Appendix E

BrForage Soil-to-plant bioconcentration factor for forage (mg/kg DW plant / 

mg/kg soil)

See Appendix E

BrGrain Soil-to-plant bioconcentration factor for grain (mg/kg DW plant / 

mg/kg soil)

See Appendix E

BrProfruit Soil-to-plant bioconcentration factor for protected fruit (mg/kg DW 

plant / mg/kg soil)

See Appendix E

BrProveg Soil-to-plant bioconcentration factor for protected vegetables (mg/kg 

DW plant / mg/kg soil)

See Appendix E

BrSilage Soil-to-plant bioconcentration factor for silage (mg/kg DW plant / 

mg/kg soil)

See Appendix E

Csoil Concentration of contaminant in soil (mg/kg) Set equal to 1 for 

the HBN 

calculation

Source: U.S. EPA, 1998a.

D-16
Table D-13. Vegetative Concentration Due to Direct Deposition (mg/kg - DW)

Appendix D

Name Description Value

Pd

( )

Yp KpPar

Dp Rp e

Pd

KpPar Tp

×

× × −

=

− ×

1

Dp Deposition term for plants (mg/m^2-yr) Calculated

KpPar Plant surface loss coefficient, particulate (1/yr) See Appendix E

Rp_exfruit Interception fraction for exposed fruit (unitless) See Appendix F

Rp_exveg Interception fraction for exposed vegetables (unitless) See Appendix F

Rp_forage Interception fraction for forage (unitless) See Appendix F

Rp_silage Interception fraction for silage (unitless) See Appendix F

Tp_exfruit Length of plant exposure to deposition for exposed fruit (yr) See Appendix F

Tp_exveg Length of plant exposure to deposition for exposed vegetables (yr) See Appendix F

Tp_forage Length of plant exposure to deposition for forage (yr) See Appendix F

Tp_silage Length of plant exposure to deposition for silage (yr) See Appendix F

Yp_exfruit Crop yield for exposed fruit (kg DW/m^2) See Appendix F

Yp_exveg Crop yield for exposed vegetables (kg DW/m^2) See Appendix F

Yp_forage Crop yield for forage (kg DW/m^2) See Appendix F

Yp_silage Crop yield for silage (kg DW/m^2) See Appendix F

Source: U.S. EPA, 1998a.

D-17
Table D-14. Concentration in Belowground Vegetation Due to Root Uptake (mg/kg - WW)

Appendix D

Name Description Value

Prbg

Csoil Br DWr Prbg = × root ×

Br_root Soil-to-plant bioconcentration factor for roots (mg/kg DW plant / 

mg/kg soil)

See Appendix E

DWr Dry weight fraction for root vegetables (unitless) See Appendix F

Csoil Concentration of contaminant in soil (mg/kg) Set equal to 1 for 

the HBN 

calculation

Source: U.S. EPA, 1998a.

D-18
Table D-15. Deposition Term for Plants (mg/m^2-yr)

Appendix D

Name Description Value

Dp

Dp ( Q) ( F ) (Dydp (Fw Dywp )) = 1000 × × 1 − v × + ×

1000 Conversion factor (mg/g)

Dydp Normalized annual average dry deposition from particle phase (sm^2/m^2-yr)

Dywp Normalized annual average wet deposition from particle phase (sm^2/m^2-yr)

Fw Fraction of wet deposition adhering to plant surface (unitless) 0.6

Fv Fraction of air concentration in vapor phase (unitless) See Appendix E

Q Emission rate from source (g/s-m^2) Set to unit value of 

1

Source: U.S. EPA, 1998a.

D-19
Table D-16. Concentration in Beef Due to Plant and Soil Ingestion (mg/kg - WW)

Appendix D

Name Description Value

Abeef

( ) ( ) ( ) Fgrain Qgbs Pgrain Fforage Qfbs Pforage Fsilage Qsbs Psilage PlantIntake = × × + × × + × ×

A PlantIntake Qsoilbs Csoil BaBeef beef = ( + ( × )×

P_forage Vegetative concentration for forage (mg/kg - DW) Calculated

P_grain Vegetative concentration for grain (mg/kg - DW) Calculated

P_silage Vegetative concentration in silage (mg/kg - DW) Calculated

PlantIntake Amount of vegetation consumed by beef cattle (mg/day) (mg/day) Calculated

BaBeef Beef biotransfer factor (day/kg - WW) See Appendix E

F_forage Fraction of forage grown on contaminated soil and eaten (unitless) See Appendix F

F_grain Fraction of grain grown on contaminated soil and eaten (unitless) See Appendix F

F_silage Fraction of silage grown on contaminated soil and eaten (unitless) See Appendix F

Qfbs Quantity of forage eaten each day by beef cattle (kg - DW/day) See Appendix F

Qgbs Quantity of grain eaten each day by beef cattle (kg - DW/day) See Appendix F

Qsbs Quantity of silage eaten each day by beef cattle (kg - DW/day) See Appendix F

Qsoilbs Consumption rate of soil for beef cattle (kg/day) See Appendix F

Csoil Concentration of contaminant in soil (mg/kg) Set equal to 1 for 

the HBN 

calculation

Source: U.S. EPA, 1998a.

D-20
Table D-17. Concentration in Milk Due to Plant and Soil Ingestion (mg/kg - WW)

Appendix D

Name Description Value

Amilk

( ) ( ) ( ) Fgrain Qgbs Pgrain Fforage Qfbs Pforage Fsilage Qsbs Psilage PlantIntake = × × + × × + × ×

A PlantIntak e Qsoilbs Csoil BaMilk milk = ( + ( × )×

P_forage Vegetative concentration for forage (mg/kg - DW) Calculated

P_grain Vegetative concentration for grain (mg/kg - DW) Calculated

P_silage Vegetative concentration in silage (mg/kg - DW) Calculated

PlantIntake Amount of vegetation consumed by beef cattle (mg/day) Calculated

BaMilk Milk biotransfer factor (day/kg - WW) See Appendix E

F_forage Fraction of forage grown on contaminated soil and eaten (unitless) See Appendix F

F_grain Fraction of grain grown on contaminated soil and eaten (unitless) See Appendix F

F_silage Fraction of silage grown on contaminated soil and eaten (unitless) See Appendix F

Qfds Quantity of forage eaten each day by dairy cattle (kg - DW/day) See Appendix F

Qgds Quantity of grain eaten each day by dairy cattle (kg - DW/day) See Appendix F

Qsds Quantity of silage eaten each day by dairy cattle (kg - DW/day) See Appendix F

Qsoilds Consumption rate of soil for dairy cattle (kg/day) See Appendix F

Csoil Concentration of contaminant in soil (mg/kg) Set equal to 1 for 

the HBN 

calculation

Source: U.S. EPA, 1998a.

D-21
Table D-18. Concentration in Fish at Different Trophic Levels (mg/kg)

Appendix D

Name Description Value

Cfish_T

CfishT Cdw BCFT

ForMercury

= ×

:

Cdw = 0.05 ×Cwt

CfishT Cwt BCFT

ForNon VolatileMetals

= ×

− :

Cdw Concentration in water (dissolved) (mg/L) Calculated

Cwt Concentration in water (total) (mg/L) Calculated

0.05 Fraction of total mercury as dissolved methyl mercury Derived from 

MRTC, 1997

BCF_T3F Bioconcentration factor for trophic level 3, fish filet (L/kg) See Appendix E

BCF_T3W Bioconcentration factor for trophic level 3, fish whole (L/kg) See Appendix E

BCF_T4F Bioconcentration factor for trophic level 4, fish filet (L/kg) See Appendix E

BCF_T4W Bioconcentration factor for trophic level 4, fish whole (L/kg) See Appendix E

Source: U.S. EPA, 1998a.

D-22
Table D-19. Daily Intake of Contaminant from Consumption of Aboveground Produce 

(mg/kg BW/day)

Appendix D

Name Description Value

Iag

P ( L)

F

I = CR × × × 1 −

1,000

exfruit exveg profruit proveg Iag = I + I + I + I

1000 Conversion factor (g/kg)

I_exfruit Contaminant intake from consumption of exposed fruit (mg/kg 

BW/day)

Calculated

I_exveg Contaminant intake from consumption of exposed vegetables (mg/kg 

BW/day)

Calculated

I_profruit Contaminant intake from consumption of protected fruit (mg/kg 

BW/day)

Calculated

I_proveg Contaminant intake from consumption of protected vegetables (mg/kg 

BW/day)

Calculated

P_exfruit Exposed fruit concentration (mg/kg WW) Calculated

P_exveg Exposed vegetable concentration (mg/kg WW) Calculated

P_profruit Protected fruit concentration (mg/kg WW) Calculated

P_proveg Protected vegetable concentration (mg/kg WW) Calculated

CR_exfruit Daily human consumption rate of exposed fruit (g WW/kg BW/day) See Appendix G

CR_exveg Daily human consumption rate of exposed vegetables (g WW/kg 

BW/day)

See Appendix G

CR_profruit Daily human consumption rate of protected fruit (g WW/kg BW/day) See Appendix G

CR_proveg Daily human consumption rate of protected vegetables (g WW/kg 

BW/day)

See Appendix G

F_exfruit Fraction of exposed fruit grown in contaminated soil (unitless) See Appendix G

F_exveg Fraction of exposed vegetables grown in contaminated soil (unitless) See Appendix G

F_profruit Fraction of protected fruit grown in contaminated soil (unitless) See Appendix G

F_proveg Fraction of protected vegetables grown in contaminated soil (unitless) See Appendix G

L_exfruit Food preparation loss for exposed fruit (unitless) See Appendix G

L_exveg Food preparation loss for exposed vegetables (unitless) See Appendix G

L_profruit Food preparation loss for protected fruit (unitless) See Appendix G

L_proveg Food preparation loss for protected vegetables (unitless) See Appendix G

Source: U.S. EPA, 1998a.

D-23
Table D-20. Daily Intake of Contaminant from Consumption of Belowground Produce 

(mg/kg BW/day)

Appendix D

Name Description Value

Ibg

( ) bg bg

bg

bg F L

CR

I = × × × 1−

1,000

Prbg

1000 Conversion factor (g/kg)

Prbg Belowground vegetable concentration in whole weight (mg/kg WW) Calculated

CR_bg Daily human consumption rate of below ground vegetables (g WW/kg 

BW/day)

See Appendix G

F_bg Fraction of belowground vegetables grown in contaminated soil 

(unitless)

See Appendix G

L_bg Food preparation loss for root vegetables (unitless) See Appendix G

Source: U.S. EPA, 1998a.

D-24
Table D-21. Daily Intake of Contaminant from Consumption of Fish (mg/kg BW/day)

Appendix D

Name Description Value

Ifish

CfishT = FT 3 ×CfishT3F + FT 4 ×CfishT4F

BW

F

Ifish Cfish CR fish

T fish

×

= × ×

1,000

1000 Conversion factor (g/kg)

C_fishT3F Concentration of contaminant in fish at different trophic levels (mg/kg) Calculated

C_fishT4F Concentration of contaminant in fish at different trophic levels (mg/kg) Calculated

Cfish_T Concentration of contaminant in fish (mg/kg) Calculated

BW Body weight (kg) See Appendix G

CR_fish Consumption rate of fish (g WW/day) See Appendix G

F_fish Fraction of fish intake from contaminated source (unitless) See Appendix G

F_T3 Fraction of trophic level 3 intake, 0.36 (unitless) See Appendix G

F_T4 Fraction of trophic level 4 intake, 0.64 (unitless) See Appendix G

Source: U.S. EPA, 1998a.

D-25
Table D-22. Daily Intake of Contaminant from Incidental Ingestion of Soil (mg/kg BW/day)

Appendix D

Name Description Value

Isoil

× 0.000001 × ×=

BW

Csoil CRs F

Isoil soil

0.000001 Conversion factor (kg/mg)

Isoil Daily intake of contaminant from incidental ingestion of soil (mg/kg 

BW/day)

Calculated

BW Body weight (kg) See Appendix G

CRs Soil ingestion rate (mg/day) See Appendix G

F_soil Fraction of contaminated soil that is ingested (unitless) See Appendix G

Csoil Concentration of contaminant in soil (mg/kg) Set equal to 1 for 

the HBN 

calculation

Source: U.S. EPA, 1998a.

D-26
Table D-23. Daily Intake of Contaminant from Consumption of Drinking Water (mg/kg 

BW/day)

Appendix D

Name Description Value

Idw

BW

F

Idw C Cr dw = dw × dw ×

1000 Conversion factor (mL/L)

Cdw Concentration of contaminant in water (mg/L) Calculated

BW Body weight (kg) See Appendix G

CR_dw Consumption rate of water (L/day) See Appendix G

F_dw Fraction of drinking water ingested that is contaminated (unitless) See Appendix G

Source: U.S. EPA, 1998a.

D-27
Table D-24. Daily Intake of Contaminant from Ingestion of i-th Animal Tissue Group 

(mg/kg BW/day)

Appendix D

Name Description Value

Ianimal

Fi Li CRi Ianimal = Ai × × ×

1,000

1000 Conversion factor (g/kg)

Ai Concentration of contaminant in i-th animal tissue group (mg/kg WW) Calculated

CRi Daily human consumption rate of i-th animal tissue group (g WW/kg 

BW/day)

See Appendix G

Fi Fraction of animal tissue that is contaminated (unitless) See Appendix G

Li Contaminant loss factor (unitless) See Appendix G

Source: U.S. EPA, 1998a.

D-28
Table D-25. Cancer Risk and Hazard Quotient Due to Inhalation (unitless)

Appendix D

Name Description Value

Risk_Air

RfC

Cair HQAir =

AT BW

Cair BRi EDi EFi CSF Risk inhal

Air × ×

× × × ×

=

365

365 Conversion factor (days/yr)

Cair Concentration of contaminant in air (mg/m^3) Calculated

HQ_Air Noncancer hazard quotient for inhalation (unitless) Calculated

CSFInhal Inhalation cancer slope factor (mg/kg/day)-1 See Appendix B

RfC Noncancer reference concentration (mg/m^3) See Appendix B

AT Averaging time (yr) See Appendix G

Bri Breathing rate (m^3/day) See Appendix G

BW Body weight (kg) See Appendix G

EDi Exposure duration for inhalation (yr) See Appendix G

EFi Exposure frequency (days/yr) See Appendix G

D-29
Table D-26. Cancer Risk and Hazard Quotient Due to Ingestion (unitless)

Appendix D

Name Description Value

Risk_Oral

RfD

I

HQOral =

×365

× × ×

=

AT

I ED EF CSF Risk Oral

Oral

365 Conversion factor (days/yr)

HQ_Oral Noncancer hazard quotient for ingestion (unitless) Calculated

I Combined intake rate from soil, animal products and produce 

(mg/kg/day)

Calculated

CSFOral Oral cancer slope factor (mg/kg/day)-1 See Appendix B

RfD Noncancer reference dose (mg/kg/day) See Appendix B

AT Averaging time (yr) See Appendix G

ED Exposure duration for oral ingestion (yr) See Appendix G

EF Exposure frequency (days/yr) See Appendix G

D-30
Table D-27. Health-Based Concentration (ppm)

Appendix D

Name Description Value

CalcHBN

THQ

HQ

C

HBN

Oral

NCOral

= ×

THQ

HQ

C

HBN

Inhal

NCinhal = ×

TR

Risk

C

HBNRisk = ×

THQ Target noncancer hazard quotient (unitless) 1

TR Target cancer risk (unitless) 1.00E-5

HQ_Inhal Noncancer hazard quotient for inhalation (unitless) Calculated

HQ_Oral Noncancer hazard quotient for ingestion (unitless) Calculated

Risk Total cancer risk (unitless) Calculated

C Constituent concentration in media (mg/L or mg/kg) Value set to unit 

concentration of 1

Backcalculation assuming linearity.

D-31
Appendix D August 2002

D-32

D.3 References

Bidleman, T.F. 1988. Atmospheric Processes. Environmental Science and Technology 22(4).

EPRI (Electric Power Research Institute). 1997. Coal Combustion and Low Volume Wastes

Comanagement Survey. EPRI. Palo Alto, CA. June.

U.S. EPA (Environmental Protection Agency). 1996. Soil Screening Guidance Technical

Background Document. EPA/540/R/95/128. Office of Solid Waste and Emergency

Response, Washington, DC. May.

U.S. EPA (Environmental Protection Agency). 1998a. Methodology for Assessing Health Risks

Associated with Multiple Pathways of Exposure to Combustor Emissions. EPA 600/R98/137. National Center for Environmental Assessment, Cincinnati, OH. December.

U.S. EPA (Environmental Protection Agency). 1998b. Technical Background Document for the

Supplemental Report to Congress on Remaining Fossil-Fuel Combustion Wastes—

Ground-Water Pathway Human Health Risk Assessment. Revised Draft Final. Office of

Solid Waste, Washington, DC. June.

U.S. EPA (Environmental Protection Agency). 2001. Supplemental Guidance for Developing Soil

Screening Levels for Superfund Sites: Peer Review Draft. OSWER 9355.4-24. Office of

Solid Waste and Emergency Response. March.
Appendix E

Chemical-Specific Inputs 

Appendix E

E-3

Appendix E

Chemical-Specific Inputs

Chemical-specific inputs used to develop the FFCW HBNs include the biouptake, biotranfer,

and bioconcentration factors needed to estimate exposure concentrations in produce, beef, milk, and

fish. Values for these inputs are obtained from the best available literature source. Tables E-1 through

E-25 provide, for each chemical in the FFCW screening analysis, the values used in the analysis along

with the source of each value.
Table E-1. Chemical-Specific Inputs for Aluminum (7429905)

Parameter Value Units Reference

Appendix E

Description Comment

BaBeef 1.5E-3 (day/kg - WW) Baes et al., 1984 Beef biotransfer factor

BaMilk 2.0E-4 (day/kg - WW) Baes et al., 1984 Milk biotransfer factor

BCF_T3F NO DATA - - Bioconcentration factor for trophic level 3 fish, filet

BCF_T3W NO DATA - - Bioconcentration factor for trophic level 3 fish, whole

BCF_T4F NO DATA - - Bioconcentration factor for trophic level 4 fish, filet

BCF_T4W NO DATA - - Bioconcentration factor for trophic level 4 fish, whole

BrExfruit 6.5E-04 (ug/g DW 

plants)/(ug/g soil)

Soil-to-plant bioconcentration factor, exposed fruit Baes et al., 1984

BrExveg 4.0E-03 (ug/g DW 

plants)/(ug/g soil)

Soil-to-plant bioconcentration factor, exposed Baes et al., 1984

vegetables

BrForage 4.0E-03 (ug/g DW 

plants)/(ug/g soil)

Soil-to-plant bioconcentration factor, forage Baes et al., 1984

BrGrain 6.5E-04 (ug/g DW 

plants)/(ug/g soil)

Soil-to-plant bioconcentration factor, grain Baes et al., 1984

BrProfruit 6.5E-04 (ug/g DW 

plants)/(ug/g soil)

Soil-to-plant bioconcentration factor, protected fruit Baes et al., 1984

BrProveg 6.5E-04 (ug/g DW 

plants)/(ug/g soil)

Soil-to-plant bioconcentration factor, protected Baes et al., 1984

vegetables

BrRoot 4.0E-03 (ug/g DW 

plants)/(ug/g soil)

Soil-to-plant bioconcentration factor, roots Baes et al., 1984

BrSilage 4.0E-03 (ug/g DW 

plants)/(ug/g soil)

Soil-to-plant bioconcentration factor, silage Baes et al., 1984

Fv 0 (unitless) - Set to zero for nonvolatile 

chemicals.

Fraction of air concentration in vapor phase

KpPar 18.07 (1/yr) U.S. EPA, 1997b Plant surface loss coefficient, particulate

E-4
Table E-2. Chemical-Specific Inputs for Ammonia (7664417)

Parameter Value Units Reference

Appendix E

Description Comment

BaBeef NO DATA - - Beef biotransfer factor

BaMilk NO DATA - - Milk biotransfer factor

BCF_T3F NO DATA - - Bioconcentration factor for trophic level 3 fish, filet

BCF_T3W NO DATA - - Bioconcentration factor for trophic level 3 fish, whole

BCF_T4F NO DATA - - Bioconcentration factor for trophic level 4 fish, filet

BCF_T4W NO DATA - - Bioconcentration factor for trophic level 4 fish, whole

BrExfruit NO DATA - - Soil-to-plant bioconcentration factor, exposed fruit

BrExveg NO DATA - - Soil-to-plant bioconcentration factor, exposed 

vegetables

BrForage NO DATA - - Soil-to-plant bioconcentration factor, forage

BrGrain NO DATA - - Soil-to-plant bioconcentration factor, grain

BrProfruit NO DATA - - Soil-to-plant bioconcentration factor, protected fruit

BrProveg NO DATA - - Soil-to-plant bioconcentration factor, protected 

vegetables

BrRoot NO DATA - - Soil-to-plant bioconcentration factor, roots

BrSilage NO DATA - - Soil-to-plant bioconcentration factor, silage

Fv 0 (unitless) - Set to zero for nonvolatile 

chemicals.

Fraction of air concentration in vapor phase

KpPar 18.07 (1/yr) U.S. EPA, 1997b Plant surface loss coefficient, particulate

E-5
Table E-3. Chemical-Specific Inputs for Antimony (7440360)

Parameter Value Units Reference

Appendix E

Description Comment

BaBeef 1.0E-3 (day/kg - WW) Baes et al., 1984 Beef biotransfer factor

BaMilk 1.0E-4 (day/kg - WW) Baes et al., 1984 Milk biotransfer factor

BCF_T3F 0 (L/kg) Barrows et al., 1980 BCF_T3W was used as a 

surrogate. Species was 

sunfish.

Bioconcentration factor for trophic level 3 fish, filet

BCF_T3W 0 (L/kg) Barrows et al., 1980 Species was sunfish. Bioconcentration factor for trophic level 3 fish, whole

BCF_T4F 0 (L/kg) Barrows et al., 1980 BCF_T3W was used as a 

surrogate. Species was 

sunfish.

Bioconcentration factor for trophic level 4 fish, filet

BCF_T4W 0 (L/kg) Barrows et al., 1980 BCF_T3W was used as a 

surrogate. Species was 

sunfish.

Bioconcentration factor for trophic level 4 fish, whole

BrExfruit 3.0E-02 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, exposed fruit Baes et al., 1984

BrExveg 2.0E-01 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, exposed Baes et al., 1984

vegetables

BrForage 2.0E-01 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, forage Baes et al., 1984

BrGrain 3.0E-02 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, grain Baes et al., 1984

BrProfruit 3.0E-02 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, protected fruit Baes et al., 1984

BrProveg 3.0E-02 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, protected Baes et al., 1984

vegetables

BrRoot 2.0E-01 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, roots Baes et al., 1984

BrSilage 2.0E-01 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, silage Baes et al., 1984

Fv 0 (unitless) - Set to zero for nonvolatile 

chemicals.

Fraction of air concentration in vapor phase

KpPar 18.07 (1/yr) U.S. EPA, 1997b Plant surface loss coefficient, particulate

E-6
Table E-4. Chemical-Specific Inputs for Arsenic (7440382)

Parameter Value Units Reference

Appendix E

Description Comment

BaBeef 2.0E-3 (day/kg - WW) Baes et al., 1984 Beef biotransfer factor

BaMilk 6.0E-5 (day/kg - WW) Baes et al., 1984 Milk biotransfer factor

BCF_T3F 4.0E+00 (L/kg) Barrows et al., 1980 BCF_T3W was used as a 

surrogate. Species was 

sunfish.

Bioconcentration factor for trophic level 3 fish, filet

BCF_T3W 4.0E+00 (L/kg) Barrows et al., 1980 Species was sunfish. Bioconcentration factor for trophic level 3 fish, whole

BCF_T4F 4.0E+00 (L/kg) Barrows et al., 1980 BCF_T3W was used as a 

surrogate. Species was 

sunfish.

Bioconcentration factor for trophic level 4 fish, filet

BCF_T4W 4.0E+00 (L/kg) Barrows et al., 1980 BCF_T3W was used as a 

surrogate. Species was 

sunfish.

Bioconcentration factor for trophic level 4 fish, whole

BrExfruit 2.0E-03 (ug/g DW plant)/ 

(ug/g soil)

Calculated based on 

U.S. EPA, 1999

Soil-to-plant bioconcentration factor, exposed fruit

BrExveg 1.0E-02 (ug/g DW plant)/ 

(ug/g soil)

Calculated based on 

U.S. EPA, 1999

Soil-to-plant bioconcentration factor, exposed 

vegetables

BrForage 5.3E-02 (ug/g DW plant)/ 

(ug/g soil)

Calculated based on 

U.S. EPA, 1999

Soil-to-plant bioconcentration factor, forage

BrGrain 4.3E-03 (ug/g DW plant)/ 

(ug/g soil)

Calculated based on 

U.S. EPA, 1999

Soil-to-plant bioconcentration factor, grain

BrProfruit 2.0E-03 (ug/g DW plant)/ 

(ug/g soil)

Calculated based on 

U.S. EPA, 1999

Soil-to-plant bioconcentration factor, protected fruit

BrProveg 2.0E-03 (ug/g DW plant)/ 

(ug/g soil)

Calculated based on 

U.S. EPA, 1999

Soil-to-plant bioconcentration factor, protected 

vegetables

BrRoot 4.6E-03 (ug/g DW plant)/ 

(ug/g soil)

Calculated based on 

U.S. EPA, 1999

Soil-to-plant bioconcentration factor, roots

BrSilage 5.3E-02 (ug/g DW plant)/ 

(ug/g soil)

Calculated based on 

U.S. EPA, 1999

Soil-to-plant bioconcentration factor, silage

Fv 0 (unitless) - Set to zero for nonvolatile 

chemicals.

Fraction of air concentration in vapor phase

KpPar 18.07 (1/yr) U.S. EPA, 1997b Plant surface loss coefficient, particulate

E-7
Table E-5. Chemical-Specific Inputs for Barium (7440393)

Parameter Value Units Reference

Appendix E

Description Comment

BaBeef 1.5E-4 (day/kg - WW) Baes et al., 1984 Beef biotransfer factor

BaMilk 3.5E-4 (day/kg - WW) Baes et al., 1984 Milk biotransfer factor

BCF_T3F NO DATA - - Bioconcentration factor for trophic level 3 fish, filet

BCF_T3W NO DATA - - Bioconcentration factor for trophic level 3 fish, whole

BCF_T4F NO DATA - - Bioconcentration factor for trophic level 4 fish, filet

BCF_T4W NO DATA - - Bioconcentration factor for trophic level 4 fish, whole

BrExfruit 1.5E-02 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, exposed fruit Baes et al., 1984

BrExveg 1.5E-01 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, exposed Baes et al., 1984

vegetables

BrForage 1.5E-01 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, forage Baes et al., 1984

BrGrain 1.5E-02 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, grain Baes et al., 1984

BrProfruit 1.5E-02 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, protected fruit Baes et al., 1984

BrProveg 1.5E-02 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, protected Baes et al., 1984

vegetables

BrRoot 1.5E-01 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, roots Baes et al., 1984

BrSilage 1.5E-01 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, silage Baes et al., 1984

Fv 0 (unitless) - Set to zero for nonvolatile 

chemicals.

Fraction of air concentration in vapor phase

KpPar 18.07 (1/yr) U.S. EPA, 1997b Plant surface loss coefficient, particulate

E-8
Table E-6. Chemical-Specific Inputs for Beryllium (7440417)

Parameter Value Units Reference

Appendix E

Description Comment

BaBeef 1.0E-3 (day/kg - WW) Baes et al., 1984 Beef biotransfer factor

BaMilk 9.0E-7 (day/kg - WW) Baes et al., 1984 Milk biotransfer factor

BCF_T3F 1.9E+01 (L/kg) Barrows et al., 1980 BCF_T3W was used as a 

surrogate. Species was 

sunfish.

Bioconcentration factor for trophic level 3 fish, filet

BCF_T3W 1.9E+01 (L/kg) Barrows et al., 1980 Species was sunfish. Bioconcentration factor for trophic level 3 fish, whole

BCF_T4F 1.9E+01 (L/kg) Barrows et al., 1980 BCF_T3W was used as a 

surrogate. Species was 

sunfish.

Bioconcentration factor for trophic level 4 fish, filet

BCF_T4W 1.9E+01 (L/kg) Barrows et al., 1980 BCF_T3W was used as a 

surrogate. Species was 

sunfish.

Bioconcentration factor for trophic level 4 fish, whole

BrExfruit 1.5E-03 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, exposed fruit Baes et al., 1984

BrExveg 1.0E-02 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, exposed Baes et al., 1984

vegetables

BrForage 1.0E-02 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, forage Baes et al., 1984

BrGrain 1.5E-03 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, grain Baes et al., 1984

BrProfruit 1.5E-03 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, protected fruit Baes et al., 1984

BrProveg 1.5E-03 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, protected Baes et al., 1984

vegetables

BrRoot 1.0E-02 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, roots Baes et al., 1984

BrSilage 1.0E-02 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, silage Baes et al., 1984

Fv 0 (unitless) - Set to zero for nonvolatile 

chemicals.

Fraction of air concentration in vapor phase

KpPar 18.07 (1/yr) U.S. EPA, 1997b Plant surface loss coefficient, particulate

E-9
Table E-7. Chemical-Specific Inputs for Boron (7440428)

Parameter Value Units Reference

Appendix E

Description Comment

BaBeef 8.0E-4 (day/kg - WW) Baes et al., 1984 Beef biotransfer factor

BaMilk 1.5E-3 (day/kg - WW) Baes et al., 1984 Milk biotransfer factor

BCF_T3F NO DATA - - Bioconcentration factor for trophic level 3 fish, filet

BCF_T3W NO DATA - - Bioconcentration factor for trophic level 3 fish, whole

BCF_T4F NO DATA - - Bioconcentration factor for trophic level 4 fish, filet

BCF_T4W NO DATA - - Bioconcentration factor for trophic level 4 fish, whole

BrExfruit 2.0E+00 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, exposed fruit Baes et al., 1984

BrExveg 4.0E+00 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, exposed Baes et al., 1984

vegetables

BrForage 4.0E+00 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, forage Baes et al., 1984

BrGrain 2.0E+00 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, grain Baes et al., 1984

BrProfruit 2.0E+00 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, protected fruit Baes et al., 1984

BrProveg 2.0E+00 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, protected Baes et al., 1984

vegetables

BrRoot 4.0E+00 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, roots Baes et al., 1984

BrSilage 4.0E+00 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, silage Baes et al., 1984

Fv 0 (unitless) - Set to zero for nonvolatile 

chemicals.

Fraction of air concentration in vapor phase

KpPar 18.07 (1/yr) U.S. EPA, 1997b Plant surface loss coefficient, particulate

E-10
Table E-8. Chemical-Specific Inputs for Cadmium (7440439)

Parameter Value Units Reference

Appendix E

Description Comment

BaBeef 5.5E-4 (day/kg - WW) Baes et al., 1984 Beef biotransfer factor

BaMilk 1.0E-3 (day/kg - WW) Baes et al., 1984 Milk biotransfer factor

BCF_T3F 2.7E+02 (L/kg) Kumada et al., 1972 BCF_T3W was used as a 

surrogate. Geomean of 3 

data points in Table 2.

Bioconcentration factor for trophic level 3 fish, filet

BCF_T3W 2.7E+02 (L/kg) Kumada et al., 1972 Geomean of 3 data points 

in Table 2.

Bioconcentration factor for trophic level 3 fish, whole

BCF_T4F 2.7E+02 (L/kg) Kumada et al., 1972 BCF_T4W was used as a 

surrogate. Geomean of 3 

data points in Table 2. 

Species were doce and 

rainbow trout.

Bioconcentration factor for trophic level 4 fish, filet

BCF_T4W 2.7E+02 (L/kg) Kumada et al., 1972 Geomean of 3 data points 

in Table 2. Species were 

doce and rainbow trout.

Bioconcentration factor for trophic level 4 fish, whole

BrExfruit 2.5E-03 (ug/g DW plant)/ 

(ug/g soil)

Calculated based on 

U.S. EPA, 1999

Soil-to-plant bioconcentration factor, exposed fruit

BrExveg 6.7E-01 (ug/g DW plant)/ 

(ug/g soil)

Calculated based on 

U.S. EPA, 1999

Soil-to-plant bioconcentration factor, exposed 

vegetables

BrForage 4.0E-01 (ug/g DW plant)/ 

(ug/g soil)

Calculated based on 

U.S. EPA, 1999

Soil-to-plant bioconcentration factor, forage

BrGrain 1.1E-01 (ug/g DW plant)/ 

(ug/g soil)

Calculated based on 

U.S. EPA, 1999

Soil-to-plant bioconcentration factor, grain

BrProfruit 2.5E-03 (ug/g DW plant)/ 

(ug/g soil)

Calculated based on 

U.S. EPA, 1999

Soil-to-plant bioconcentration factor, protected fruit

BrProveg 2.5E-03 (ug/g DW plant)/ 

(ug/g soil)

Calculated based on 

U.S. EPA, 1999

Soil-to-plant bioconcentration factor, protected 

vegetables

BrRoot 2.5E-01 (ug/g DW plant)/ 

(ug/g soil)

Calculated based on 

U.S. EPA, 1999

Soil-to-plant bioconcentration factor, roots

BrSilage 4.0E-01 (ug/g DW plant)/ 

(ug/g soil)

Calculated based on 

U.S. EPA, 1999

Soil-to-plant bioconcentration factor, silage

Fv 0 (unitless) - Set to zero for nonvolatile 

chemicals.

Fraction of air concentration in vapor phase

KpPar 18.07 (1/yr) U.S. EPA, 1997b Plant surface loss coefficient, particulate

E-11
Table E-9. Chemical-Specific Inputs for Chromium(III) (16065831)

Parameter Value Units Reference

Appendix E

Description Comment

BaBeef 5.5E-3 (day/kg - WW) Baes et al., 1984 Beef biotransfer factor

BaMilk 1.5E-3 (day/kg - WW) Baes et al., 1984 Milk biotransfer factor

BCF_T3F 6.0E-01 (L/kg) Stephan, 1993 BCF_T4F was used as a 

surrogate. Geomean (as 

cited in Stephan, 1993) 

based on Buhler et al. 

(1977) and Calamari et al. 

(1982). Used chromium as 

a surrogate.

Bioconcentration factor for trophic level 3 fish, filet

BCF_T3W 6.0E-01 (L/kg) Stephan, 1993 BCF_T4F was used as a 

surrogate. Geomean (as 

cited in Stephan, 1993) 

based on Buhler et al. 

(1977) and Calamari et al. 

(1982). Used chromium as 

a surrogate.

Bioconcentration factor for trophic level 3 fish, whole

BCF_T4F 6.0E-01 (L/kg) Stephan, 1993 Geomean (as cited in 

Stephan, 1993) based on 

Buhler et al. (1977) and 

Calamari et al. (1982). 

Used chromium as a 

surrogate.

Bioconcentration factor for trophic level 4 fish, filet

BCF_T4W 6.0E-01 (L/kg) Stephan, 1993 BCF_T4F was used as a 

surrogate. Geomean (as 

cited in Stephan, 1993) 

based on Buhler et al. 

(1977) and Calamari et al. 

(1982). Used chromium as 

a surrogate.

Bioconcentration factor for trophic level 4 fish, whole

BrExfruit 1.4E-04 (ug/g DW plant)/ 

(ug/g soil)

Calculated based on 

U.S. EPA, 1999

Soil-to-plant bioconcentration factor, exposed fruit

BrExveg 5.8E-04 (ug/g DW plant)/ 

(ug/g soil)

Calculated based on 

U.S. EPA, 1999

Soil-to-plant bioconcentration factor, exposed 

vegetables

BrForage 1.9E-03 (ug/g DW plant)/ 

(ug/g soil)

Calculated based on 

U.S. EPA, 1999

Soil-to-plant bioconcentration factor, forage

BrGrain 9.0E-05 (ug/g DW plant)/ 

(ug/g soil)

Calculated based on 

U.S. EPA, 1999

Soil-to-plant bioconcentration factor, grain

BrProfruit 1.4E-04 (ug/g DW plant)/ 

(ug/g soil)

Calculated based on 

U.S. EPA, 1999

Soil-to-plant bioconcentration factor, protected fruit

BrProveg 1.4E-04 (ug/g DW plant)/ 

(ug/g soil)

Calculated based on 

U.S. EPA, 1999

Soil-to-plant bioconcentration factor, protected 

vegetables

BrRoot 9.5E-04 (ug/g DW plant)/ 

(ug/g soil)

Calculated based on 

U.S. EPA, 1999

Soil-to-plant bioconcentration factor, roots

BrSilage 1.9E-03 (ug/g DW plant)/ 

(ug/g soil)

Calculated based on 

U.S. EPA, 1999

Soil-to-plant bioconcentration factor, silage

Fv 0 (unitless) - Set to zero for nonvolatile 

chemicals.

Fraction of air concentration in vapor phase

KpPar 18.07 (1/yr) U.S. EPA, 1997b Plant surface loss coefficient, particulate

E-12
Table E-10. Chemical-Specific Inputs for Chromium(VI) (18540299)

Parameter Value Units Reference

Appendix E

Description Comment

BaBeef 5.5E-3 (day/kg - WW) Baes et al., 1984 Beef biotransfer factor

BaMilk 1.5E-3 (day/kg - WW) Baes et al., 1984 Milk biotransfer factor

BCF_T3F 6.0E-01 (L/kg) Stephan, 1993 BCF_T4F was used as a 

surrogate. Geomean (as 

cited in Stephan, 1993) 

based on Buhler et al. 

(1977) and Calamari et al. 

(1982). Used chromium as 

a surrogate.

Bioconcentration factor for trophic level 3 fish, filet

BCF_T3W 6.0E-01 (L/kg) Stephan, 1993 BCF_T4F was used as a 

surrogate. Geomean (as 

cited in Stephan, 1993) 

based on Buhler et al. 

(1977) and Calamari et al. 

(1982). Used chromium as 

a surrogate.

Bioconcentration factor for trophic level 3 fish, whole

BCF_T4F 6.0E-01 (L/kg) Stephan, 1993 Geomean (as cited in 

Stephan, 1993) based on 

Buhler et al. (1977) and 

Calamari et al. (1982). 

Used chromium as a 

surrogate.

Bioconcentration factor for trophic level 4 fish, filet

BCF_T4W 6.0E-01 (L/kg) Stephan, 1993 BCF_T4F was used as a 

surrogate. Geomean (as 

cited in Stephan, 1993) 

based on Buhler et al. 

(1977) and Calamari et al. 

(1982). Used chromium as 

a surrogate.

Bioconcentration factor for trophic level 4 fish, whole

BrExfruit 1.4E-04 (ug/g DW plant)/ 

(ug/g soil)

Calculated based on 

U.S. EPA, 1999

Soil-to-plant bioconcentration factor, exposed fruit

BrExveg 5.8E-04 (ug/g DW plant)/ 

(ug/g soil)

Calculated based on 

U.S. EPA, 1999

Soil-to-plant bioconcentration factor, exposed 

vegetables

BrForage 1.9E-03 (ug/g DW plant)/ 

(ug/g soil)

Calculated based on 

U.S. EPA, 1999

Soil-to-plant bioconcentration factor, forage

BrGrain 9.0E-05 (ug/g DW plant)/ 

(ug/g soil)

Calculated based on 

U.S. EPA, 1999

Soil-to-plant bioconcentration factor, grain

BrProfruit 1.4E-04 (ug/g DW plant)/ 

(ug/g soil)

Calculated based on 

U.S. EPA, 1999

Soil-to-plant bioconcentration factor, protected fruit

BrProveg 1.4E-04 (ug/g DW plant)/ 

(ug/g soil)

Calculated based on 

U.S. EPA, 1999

Soil-to-plant bioconcentration factor, protected 

vegetables

BrRoot 9.5E-04 (ug/g DW plant)/ 

(ug/g soil)

Calculated based on 

U.S. EPA, 1999

Soil-to-plant bioconcentration factor, roots

BrSilage 1.9E-03 (ug/g DW plant)/ 

(ug/g soil)

Calculated based on 

U.S. EPA, 1999

Soil-to-plant bioconcentration factor, silage

Fv 0 (unitless) - Set to zero for nonvolatile 

chemicals.

Fraction of air concentration in vapor phase

KpPar 18.07 (1/yr) U.S. EPA, 1997b Plant surface loss coefficient, particulate

E-13
Table E-11. Chemical-Specific Inputs for Cobalt (7440484)

Parameter Value Units Reference

Appendix E

Description Comment

BaBeef 0.020 (day/kg - WW) Baes et al., 1984 Beef biotransfer factor

BaMilk 2.0E-3 (day/kg - WW) Baes et al., 1984 Milk biotransfer factor

BCF_T3F NO DATA - - Bioconcentration factor for trophic level 3 fish, filet

BCF_T3W NO DATA - - Bioconcentration factor for trophic level 3 fish, whole

BCF_T4F NO DATA - - Bioconcentration factor for trophic level 4 fish, filet

BCF_T4W NO DATA - - Bioconcentration factor for trophic level 4 fish, whole

BrExfruit 7.0E-03 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, exposed fruit Baes et al., 1984

BrExveg 2.0E-02 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, exposed Baes et al., 1984

vegetables

BrForage 2.0E-02 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, forage Baes et al., 1984

BrGrain 7.0E-03 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, grain Baes et al., 1984

BrProfruit 7.0E-03 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, protected fruit Baes et al., 1984

BrProveg 7.0E-03 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, protected Baes et al., 1984

vegetables

BrRoot 2.0E-02 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, roots Baes et al., 1984

BrSilage 2.0E-02 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, silage Baes et al., 1984

Fv 0 (unitless) - Set to zero for nonvolatile 

chemicals.

Fraction of air concentration in vapor phase

KpPar 18.07 (1/yr) U.S. EPA, 1997b Plant surface loss coefficient, particulate

E-14
Table E-12. Chemical-Specific Inputs for Cyanide (57125)

Parameter Value Units Reference

Appendix E

Description Comment

BaBeef NO DATA - - Beef biotransfer factor

BaMilk NO DATA - - Milk biotransfer factor

BCF_T3F NO DATA - - Bioconcentration factor for trophic level 3 fish, filet

BCF_T3W NO DATA - - Bioconcentration factor for trophic level 3 fish, whole

BCF_T4F NO DATA - - Bioconcentration factor for trophic level 4 fish, filet

BCF_T4W NO DATA - - Bioconcentration factor for trophic level 4 fish, whole

BrExfruit NO DATA - - Soil-to-plant bioconcentration factor, exposed fruit

BrExveg NO DATA - - Soil-to-plant bioconcentration factor, exposed 

vegetables

BrForage NO DATA - - Soil-to-plant bioconcentration factor, forage

BrGrain NO DATA - - Soil-to-plant bioconcentration factor, grain

BrProfruit NO DATA - - Soil-to-plant bioconcentration factor, protected fruit

BrProveg NO DATA - - Soil-to-plant bioconcentration factor, protected 

vegetables

BrRoot NO DATA - - Soil-to-plant bioconcentration factor, roots

BrSilage NO DATA - - Soil-to-plant bioconcentration factor, silage

Fv 0 (unitless) - Set to zero for nonvolatile 

chemicals.

Fraction of air concentration in vapor phase

KpPar 18.07 (1/yr) U.S. EPA, 1997b Plant surface loss coefficient, particulate

E-15
Table E-13. Chemical-Specific Inputs for Fluoride (16984488)

Parameter Value Units Reference

Appendix E

Description Comment

BaBeef NO DATA - - Beef biotransfer factor

BaMilk NO DATA - - Milk biotransfer factor

BCF_T3F NO DATA - - Bioconcentration factor for trophic level 3 fish, filet

BCF_T3W NO DATA - - Bioconcentration factor for trophic level 3 fish, whole

BCF_T4F NO DATA - - Bioconcentration factor for trophic level 4 fish, filet

BCF_T4W NO DATA - - Bioconcentration factor for trophic level 4 fish, whole

BrExfruit NO DATA - - Soil-to-plant bioconcentration factor, exposed fruit

BrExveg NO DATA - - Soil-to-plant bioconcentration factor, exposed 

vegetables

BrForage NO DATA - - Soil-to-plant bioconcentration factor, forage

BrGrain NO DATA - - Soil-to-plant bioconcentration factor, grain

BrProfruit NO DATA - - Soil-to-plant bioconcentration factor, protected fruit

BrProveg NO DATA - - Soil-to-plant bioconcentration factor, protected 

vegetables

BrRoot NO DATA - - Soil-to-plant bioconcentration factor, roots

BrSilage NO DATA - - Soil-to-plant bioconcentration factor, silage

Fv 0 (unitless) - Set to zero for nonvolatile 

chemicals.

Fraction of air concentration in vapor phase

KpPar 18.07 (1/yr) U.S. EPA, 1997b Plant surface loss coefficient, particulate

E-16
Table E-14. Chemical-Specific Inputs for Manganese (7439965)

Parameter Value Units Reference

Appendix E

Description Comment

BaBeef 4.0E-4 (day/kg - WW) Baes et al., 1984 Beef biotransfer factor

BaMilk 3.5E-4 (day/kg - WW) Baes et al., 1984 Milk biotransfer factor

BCF_T3F NO DATA - - Bioconcentration factor for trophic level 3 fish, filet

BCF_T3W NO DATA - - Bioconcentration factor for trophic level 3 fish, whole

BCF_T4F NO DATA - - Bioconcentration factor for trophic level 4 fish, filet

BCF_T4W NO DATA - - Bioconcentration factor for trophic level 4 fish, whole

BrExfruit 5.0E-02 (ug/g DW 

plants)/(ug/g soil)

Soil-to-plant bioconcentration factor, exposed fruit Baes et al., 1984

BrExveg 2.5E-01 (ug/g DW 

plants)/(ug/g soil)

Soil-to-plant bioconcentration factor, exposed Baes et al., 1984

vegetables

BrForage 2.5E-01 (ug/g DW 

plants)/(ug/g soil)

Soil-to-plant bioconcentration factor, forage Baes et al., 1984

BrGrain 5.0E-02 (ug/g DW 

plants)/(ug/g soil)

Soil-to-plant bioconcentration factor, grain Baes et al., 1984

BrProfruit 5.0E-02 (ug/g DW 

plants)/(ug/g soil)

Soil-to-plant bioconcentration factor, protected fruit Baes et al., 1984

BrProveg 5.0E-02 (ug/g DW 

plants)/(ug/g soil)

Soil-to-plant bioconcentration factor, protected Baes et al., 1984

vegetables

BrRoot 2.5E-01 (ug/g DW 

plants)/(ug/g soil)

Soil-to-plant bioconcentration factor, roots Baes et al., 1984

BrSilage 2.5E-01 (ug/g DW 

plants)/(ug/g soil)

Soil-to-plant bioconcentration factor, silage Baes et al., 1984

Fv 0 (unitless) - Set to zero for nonvolatile 

chemicals.

Fraction of air concentration in vapor phase

KpPar 18.07 (1/yr) U.S. EPA, 1997b Plant surface loss coefficient, particulate

E-17
Table E-15. Chemical-Specific Inputs for Mercury (99991)

Parameter Value Units Reference

Appendix E

Description Comment

BaBeef 7.7E-03 (day/kg - WW) U.S. EPA, 1997a BTF based on divalent 

mercury.

Beef biotransfer factor

BaMilk 2.6E-03 (day/kg - WW) U.S. EPA, 1997a BTF based on divalent 

mercury.

Milk biotransfer factor

BCF_T3F 1.6E+06 (L/kg) U.S. EPA, 1997a BCF_T3W was used as a 

surrogate. BAF used with 

dissolved methylmercury 

concentrations.

Bioconcentration factor for trophic level 3 fish, filet

BCF_T3W 1.6E+06 (L/kg) U.S. EPA, 1997a BAF used with dissolved 

methylmercury 

concentrations.

Bioconcentration factor for trophic level 3 fish, whole

BCF_T4F 6.8E+06 (L/kg) U.S. EPA, 1997a BCF_T4W was used as a 

surrogate. BAF used with 

dissolved methylmercury 

concentrations.

Bioconcentration factor for trophic level 4 fish, filet

BCF_T4W 6.8E+06 (L/kg) U.S. EPA, 1997a BAF used with dissolved 

methylmercury 

concentrations.

Bioconcentration factor for trophic level 4 fish, whole

BrExfruit 1.4E-02 (ug/g DW plant)/ 

(ug/g soil)

Calculated based on 

U.S. EPA, 1999

Soil-to-plant bioconcentration factor, exposed fruit For divalent mercury.

BrExveg 1.7E-01 (ug/g DW plant)/ 

(ug/g soil)

Calculated based on 

U.S. EPA, 1999

Soil-to-plant bioconcentration factor, exposed For divalent mercury.

vegetables

BrForage 6.7E-01 (ug/g DW plant)/ 

(ug/g soil)

Calculated based on 

U.S. EPA, 1999

Soil-to-plant bioconcentration factor, forage For divalent mercury.

BrGrain 8.6E-02 (ug/g DW plant)/ 

(ug/g soil)

Calculated based on 

U.S. EPA, 1999

Soil-to-plant bioconcentration factor, grain For divalent mercury.

BrProfruit 1.4E-02 (ug/g DW plant)/ 

(ug/g soil)

Calculated based on 

U.S. EPA, 1999

Soil-to-plant bioconcentration factor, protected fruit For divalent mercury.

BrProveg 1.4E-02 (ug/g DW plant)/ 

(ug/g soil)

Calculated based on 

U.S. EPA, 1999

Soil-to-plant bioconcentration factor, protected For divalent mercury.

vegetables

BrRoot 3.6E-02 (ug/g DW plant)/ 

(ug/g soil)

Calculated based on 

U.S. EPA, 1999

Soil-to-plant bioconcentration factor, roots For divalent mercury.

BrSilage 6.7E-01 (ug/g DW plant)/ 

(ug/g soil)

Calculated based on 

U.S. EPA, 1999

Soil-to-plant bioconcentration factor, silage For divalent mercury.

Fv 0 (unitless) - Set to zero for nonvolatile 

chemicals.

Fraction of air concentration in vapor phase

KpPar 40.41 (1/yr) U.S. EPA, 1997b For divalent mercury. Plant surface loss coefficient, particulate

E-18
Table E-16. Chemical-Specific Inputs for Molybdenum (7439987)

Parameter Value Units Reference

Appendix E

Description Comment

BaBeef 6.0E-3 (day/kg - WW) Baes et al., 1984 Beef biotransfer factor

BaMilk 1.5E-3 (day/kg - WW) Baes et al., 1984 Milk biotransfer factor

BCF_T3F 4.0E+00 (L/kg) Eisler, 1989 BCF_T4F was used as a 

surrogate. Geomean of 

values found on pages 27 

and 28. Species were 

rainbow trout and 

steelhead trout.

Bioconcentration factor for trophic level 3 fish, filet

BCF_T3W 4.0E+00 (L/kg) Eisler, 1989 BCF_T4F was used as a 

surrogate. Geomean of 

values found on pages 27 

and 28. Species were 

rainbow trout and 

steelhead trout.

Bioconcentration factor for trophic level 3 fish, whole

BCF_T4F 4.0E+00 (L/kg) Eisler, 1989 Geomean of values found 

on pages 27 and 28. 

Species were rainbow trout 

and steelhead trout.

Bioconcentration factor for trophic level 4 fish, filet

BCF_T4W 4.0E+00 (L/kg) Eisler, 1989 BCF_T4F was used as a 

surrogate. Geomean of 

values found on pages 27 

and 28. Species were 

rainbow trout and 

steelhead trout.

Bioconcentration factor for trophic level 4 fish, whole

BrExfruit 6.0E-02 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, exposed fruit Baes et al., 1984

BrExveg 2.5E-01 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, exposed Baes et al., 1984

vegetables

BrForage 2.5E-01 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, forage Baes et al., 1984

BrGrain 6.0E-02 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, grain Baes et al., 1984

BrProfruit 6.0E-02 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, protected fruit Baes et al., 1984

BrProveg 6.0E-02 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, protected Baes et al., 1984

vegetables

BrRoot 2.5E-01 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, roots Baes et al., 1984

BrSilage 2.5E-01 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, silage Baes et al., 1984

Fv 0 (unitless) - Set to zero for nonvolatile 

chemicals.

Fraction of air concentration in vapor phase

KpPar 18.07 (1/yr) U.S. EPA, 1997b Plant surface loss coefficient, particulate

E-19
Table E-17. Chemical-Specific Inputs for Nickel (7440020)

Parameter Value Units Reference

Appendix E

Description Comment

BaBeef 6.0E-3 (day/kg - WW) Baes et al., 1984 Beef biotransfer factor

BaMilk 1.0E-3 (day/kg - WW) Baes et al., 1984 Milk biotransfer factor

BCF_T3F 8.0E-01 (L/kg) Stephan, 1993 BCF_T4F was used as a 

surrogate. Derived from 

Calamari et al. (1982) (as 

cited in Stephan, 1993).

Bioconcentration factor for trophic level 3 fish, filet

BCF_T3W 8.0E-01 (L/kg) Stephan, 1993 BCF_T4F was used as a 

surrogate. Derived from 

Calamari et al. (1982) (as 

cited in Stephan, 1993).

Bioconcentration factor for trophic level 3 fish, whole

BCF_T4F 8.0E-01 (L/kg) Stephan, 1993 Derived from Calamari et 

al. (1982) (as cited in 

Stephan, 1993).

Bioconcentration factor for trophic level 4 fish, filet

BCF_T4W 8.0E-01 (L/kg) Stephan, 1993 BCF_T4F was used as a 

surrogate. Derived from 

Calamari et al. (1982) (as 

cited in Stephan, 1993).

Bioconcentration factor for trophic level 4 fish, whole

BrExfruit 6.0E-02 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, exposed fruit Baes et al., 1984

BrExveg 1.0E-02 (ug/g DW plant)/ 

(ug/g soil)

Calculated based on 

U.S. EPA, 1999

Soil-to-plant bioconcentration factor, exposed 

vegetables

BrForage 2.0E-02 (ug/g DW plant)/ 

(ug/g soil)

Calculated based on 

U.S. EPA, 1999

Soil-to-plant bioconcentration factor, forage

BrGrain 6.0E-02 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, grain Baes et al., 1984

BrProfruit 6.0E-02 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, protected fruit Baes et al., 1984

BrProveg 6.0E-02 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, protected Baes et al., 1984

vegetables

BrRoot 6.0E-02 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, roots Baes et al., 1984

BrSilage 2.0E-02 (ug/g DW plant)/ 

(ug/g soil)

Calculated based on 

U.S. EPA, 1999

Soil-to-plant bioconcentration factor, silage

Fv 0 (unitless) - Set to zero for nonvolatile 

chemicals.

Fraction of air concentration in vapor phase

KpPar 18.07 (1/yr) U.S. EPA, 1997b Plant surface loss coefficient, particulate

E-20
Table E-18. Chemical-Specific Inputs for Selenium (7782492)

Parameter Value Units Reference

Appendix E

Description Comment

BaBeef 0.015 (day/kg - WW) Baes et al., 1984 Beef biotransfer factor

BaMilk 4.0E-3 (day/kg - WW) Baes et al., 1984 Milk biotransfer factor

BCF_T3F 4.9E+02 (L/kg) Lemly, 1985 Based on threadfin shad 

and blueback herring. 

Units corrected.

Bioconcentration factor for trophic level 3 fish, filet

BCF_T3W 4.9E+02 (L/kg) Lemly, 1985 BCF_T3F was used as a 

surrogate. Based on 

threadfin shad and 

blueback herring. Units 

corrected.

Bioconcentration factor for trophic level 3 fish, whole

BCF_T4F 1.7E+03 (L/kg) Lemly, 1985 Based on threadfin shad 

and blueback herring. 

Units corrected.

Bioconcentration factor for trophic level 4 fish, filet

BCF_T4W 1.7E+03 (L/kg) Lemly, 1985 BCF_T4F was used as a 

surrogate. Based on 

threadfin shad and 

blueback herring. Units 

corrected.

Bioconcentration factor for trophic level 4 fish, whole

BrExfruit 2.5E-02 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, exposed fruit Baes et al., 1984

BrExveg 2.5E-02 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, exposed Baes et al., 1984

vegetables

BrForage 2.5E-02 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, forage Baes et al., 1984

BrGrain 2.5E-02 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, grain Baes et al., 1984

BrProfruit 2.5E-02 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, protected fruit Baes et al., 1984

BrProveg 2.5E-02 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, protected Baes et al., 1984

vegetables

BrRoot 2.5E-02 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, roots Baes et al., 1984

BrSilage 2.5E-02 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, silage Baes et al., 1984

Fv 0 (unitless) - Set to zero for nonvolatile 

chemicals.

Fraction of air concentration in vapor phase

KpPar 18.07 (1/yr) U.S. EPA, 1997b Plant surface loss coefficient, particulate

E-21
Table E-19. Chemical-Specific Inputs for Silver (7440224)

Parameter Value Units Reference

Appendix E

Description Comment

BaBeef 3.0E-3 (day/kg - WW) Baes et al., 1984 Beef biotransfer factor

BaMilk 0.020 (day/kg - WW) Baes et al., 1984 Milk biotransfer factor

BCF_T3F 0 (L/kg) Barrows et al., 1980 BCF_T3W was used as a 

surrogate. Species was 

sunfish.

Bioconcentration factor for trophic level 3 fish, filet

BCF_T3W 0 (L/kg) Barrows et al., 1980 Species was sunfish. Bioconcentration factor for trophic level 3 fish, whole

BCF_T4F 0 (L/kg) Barrows et al., 1980 BCF_T3W was used as a 

surrogate. Species was 

sunfish.

Bioconcentration factor for trophic level 4 fish, filet

BCF_T4W 0 (L/kg) Barrows et al., 1980 BCF_T3W was used as a 

surrogate. Species was 

sunfish.

Bioconcentration factor for trophic level 4 fish, whole

BrExfruit 1.0E-01 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, exposed fruit Baes et al., 1984

BrExveg 4.0E-01 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, exposed Baes et al., 1984

vegetables

BrForage 4.0E-01 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, forage Baes et al., 1984

BrGrain 1.0E-01 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, grain Baes et al., 1984

BrProfruit 1.0E-01 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, protected fruit Baes et al., 1984

BrProveg 1.0E-01 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, protected Baes et al., 1984

vegetables

BrRoot 4.0E-01 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, roots Baes et al., 1984

BrSilage 4.0E-01 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, silage Baes et al., 1984

Fv 0 (unitless) - Set to zero for nonvolatile 

chemicals.

Fraction of air concentration in vapor phase

KpPar 18.07 (1/yr) U.S. EPA, 1997b Plant surface loss coefficient, particulate

E-22
Table E-20. Chemical-Specific Inputs for Strontium (7440246)

Parameter Value Units Reference

Appendix E

Description Comment

BaBeef 3.0E-4 (day/kg - WW) Baes et al., 1984 Beef biotransfer factor

BaMilk 1.5E-3 (day/kg - WW) Baes et al., 1984 Milk biotransfer factor

BCF_T3F NO DATA - - Bioconcentration factor for trophic level 3 fish, filet

BCF_T3W NO DATA - - Bioconcentration factor for trophic level 3 fish, whole

BCF_T4F NO DATA - - Bioconcentration factor for trophic level 4 fish, filet

BCF_T4W NO DATA - - Bioconcentration factor for trophic level 4 fish, whole

BrExfruit 2.5E-01 (ug/g DW 

plants)/(ug/g soil)

Soil-to-plant bioconcentration factor, exposed fruit Baes et al., 1984

BrExveg 2.5E+00 (ug/g DW 

plants)/(ug/g soil)

Soil-to-plant bioconcentration factor, exposed Baes et al., 1984

vegetables

BrForage 2.5E+00 (ug/g DW 

plants)/(ug/g soil)

Soil-to-plant bioconcentration factor, forage Baes et al., 1984

BrGrain 2.5E-01 (ug/g DW 

plants)/(ug/g soil)

Soil-to-plant bioconcentration factor, grain Baes et al., 1984

BrProfruit 2.5E-01 (ug/g DW 

plants)/(ug/g soil)

Soil-to-plant bioconcentration factor, protected fruit Baes et al., 1984

BrProveg 2.5E-01 (ug/g DW 

plants)/(ug/g soil)

Soil-to-plant bioconcentration factor, protected Baes et al., 1984

vegetables

BrRoot 2.5E+00 (ug/g DW 

plants)/(ug/g soil)

Soil-to-plant bioconcentration factor, roots Baes et al., 1984

BrSilage 2.5E+00 (ug/g DW 

plants)/(ug/g soil)

Soil-to-plant bioconcentration factor, silage Baes et al., 1984

Fv 0 (unitless) - Set to zero for nonvolatile 

chemicals.

Fraction of air concentration in vapor phase

KpPar 18.07 (1/yr) U.S. EPA, 1997b Plant surface loss coefficient, particulate

E-23
Table E-21. Chemical-Specific Inputs for Thallium (7440280)

Parameter Value Units Reference

Appendix E

Description Comment

BaBeef 0.040 (day/kg - WW) Baes et al., 1984 Beef biotransfer factor

BaMilk 2.0E-3 (day/kg - WW) Baes et al., 1984 Milk biotransfer factor

BCF_T3F 3.4E+01 (L/kg) Barrows et al., 1980 BCF_T3W was used as a 

surrogate. Species was 

sunfish.

Bioconcentration factor for trophic level 3 fish, filet

BCF_T3W 3.4E+01 (L/kg) Barrows et al., 1980 Species was sunfish. Bioconcentration factor for trophic level 3 fish, whole

BCF_T4F 1.3E+02 (L/kg) Stephan, 1993 Derived from Zitko et al. 

(1975) (as cited in 

Stephan, 1993).

Bioconcentration factor for trophic level 4 fish, filet

BCF_T4W 1.3E+02 (L/kg) Stephan, 1993 BCF_T4F was used as a 

surrogate. Derived from 

Zitko et al. (1975) (as cited 

in Stephan, 1993).

Bioconcentration factor for trophic level 4 fish, whole

BrExfruit 4.0E-04 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, exposed fruit Baes et al., 1984

BrExveg 4.0E-03 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, exposed Baes et al., 1984

vegetables

BrForage 4.0E-03 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, forage Baes et al., 1984

BrGrain 4.0E-04 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, grain Baes et al., 1984

BrProfruit 4.0E-04 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, protected fruit Baes et al., 1984

BrProveg 4.0E-04 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, protected Baes et al., 1984

vegetables

BrRoot 4.0E-03 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, roots Baes et al., 1984

BrSilage 4.0E-03 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, silage Baes et al., 1984

Fv 0 (unitless) - Set to zero for nonvolatile 

chemicals.

Fraction of air concentration in vapor phase

KpPar 18.07 (1/yr) U.S. EPA, 1997b Plant surface loss coefficient, particulate

E-24
Table E-22. Chemical-Specific Inputs for Total Nitrate Nitrogen (14797558)

Parameter Value Units Reference

Appendix E

Description Comment

BaBeef NO DATA - - Beef biotransfer factor

BaMilk NO DATA - - Milk biotransfer factor

BCF_T3F NO DATA - - Bioconcentration factor for trophic level 3 fish, filet

BCF_T3W NO DATA - - Bioconcentration factor for trophic level 3 fish, whole

BCF_T4F NO DATA - - Bioconcentration factor for trophic level 4 fish, filet

BCF_T4W NO DATA - - Bioconcentration factor for trophic level 4 fish, whole

BrExfruit NO DATA - - Soil-to-plant bioconcentration factor, exposed fruit

BrExveg NO DATA - - Soil-to-plant bioconcentration factor, exposed 

vegetables

BrForage NO DATA - - Soil-to-plant bioconcentration factor, forage

BrGrain NO DATA - - Soil-to-plant bioconcentration factor, grain

BrProfruit NO DATA - - Soil-to-plant bioconcentration factor, protected fruit

BrProveg NO DATA - - Soil-to-plant bioconcentration factor, protected 

vegetables

BrRoot NO DATA - - Soil-to-plant bioconcentration factor, roots

BrSilage NO DATA - - Soil-to-plant bioconcentration factor, silage

Fv 0 (unitless) - Set to zero for nonvolatile 

chemicals.

Fraction of air concentration in vapor phase

KpPar 18.07 (1/yr) U.S. EPA, 1997b Plant surface loss coefficient, particulate

E-25
Table E-23. Chemical-Specific Inputs for Total Nitrite Nitrogen (14797650)

Parameter Value Units Reference

Appendix E

Description Comment

BaBeef NO DATA - - Beef biotransfer factor

BaMilk NO DATA - - Milk biotransfer factor

BCF_T3F NO DATA - - Bioconcentration factor for trophic level 3 fish, filet

BCF_T3W NO DATA - - Bioconcentration factor for trophic level 3 fish, whole

BCF_T4F NO DATA - - Bioconcentration factor for trophic level 4 fish, filet

BCF_T4W NO DATA - - Bioconcentration factor for trophic level 4 fish, whole

BrExfruit NO DATA - - Soil-to-plant bioconcentration factor, exposed fruit

BrExveg NO DATA - - Soil-to-plant bioconcentration factor, exposed 

vegetables

BrForage NO DATA - - Soil-to-plant bioconcentration factor, forage

BrGrain NO DATA - - Soil-to-plant bioconcentration factor, grain

BrProfruit NO DATA - - Soil-to-plant bioconcentration factor, protected fruit

BrProveg NO DATA - - Soil-to-plant bioconcentration factor, protected 

vegetables

BrRoot NO DATA - - Soil-to-plant bioconcentration factor, roots

BrSilage NO DATA - - Soil-to-plant bioconcentration factor, silage

Fv 0 (unitless) - Set to zero for nonvolatile 

chemicals.

Fraction of air concentration in vapor phase

KpPar 18.07 (1/yr) U.S. EPA, 1997b Plant surface loss coefficient, particulate

E-26
Table E-24. Chemical-Specific Inputs for Vanadium (7440622)

Parameter Value Units Reference

Appendix E

Description Comment

BaBeef 2.5E-3 (day/kg - WW) Baes et al., 1984 Beef biotransfer factor

BaMilk 2.0E-5 (day/kg - WW) Baes et al., 1984 Milk biotransfer factor

BCF_T3F NO DATA - - Bioconcentration factor for trophic level 3 fish, filet

BCF_T3W NO DATA - - Bioconcentration factor for trophic level 3 fish, whole

BCF_T4F NO DATA - - Bioconcentration factor for trophic level 4 fish, filet

BCF_T4W NO DATA - - Bioconcentration factor for trophic level 4 fish, whole

BrExfruit 3.0E-03 (ug/g DW 

plants)/(ug/g soil)

Soil-to-plant bioconcentration factor, exposed fruit Baes et al., 1984

BrExveg 5.5E-03 (ug/g DW 

plants)/(ug/g soil)

Soil-to-plant bioconcentration factor, exposed Baes et al., 1984

vegetables

BrForage 4.9E-03 (ug/g DW plant)/ 

(ug/g soil)

Calculated based on 

U.S. EPA, 1999

Soil-to-plant bioconcentration factor, forage

BrGrain 3.0E-03 (ug/g DW 

plants)/(ug/g soil)

Soil-to-plant bioconcentration factor, grain Baes et al., 1984

BrProfruit 3.0E-03 (ug/g DW 

plants)/(ug/g soil)

Soil-to-plant bioconcentration factor, protected fruit Baes et al., 1984

BrProveg 3.0E-03 (ug/g DW 

plants)/(ug/g soil)

Soil-to-plant bioconcentration factor, protected Baes et al., 1984

vegetables

BrRoot 5.5E-03 (ug/g DW 

plants)/(ug/g soil)

Soil-to-plant bioconcentration factor, roots Baes et al., 1984

BrSilage 4.9E-03 (ug/g DW plant)/ 

(ug/g soil)

Calculated based on 

U.S. EPA, 1999

Soil-to-plant bioconcentration factor, silage

Fv 0 (unitless) - Set to zero for nonvolatile 

chemicals.

Fraction of air concentration in vapor phase

KpPar 18.07 (1/yr) U.S. EPA, 1997b Plant surface loss coefficient, particulate

E-27
Table E-25. Chemical-Specific Inputs for Zinc (7440666)

Parameter Value Units Reference

Appendix E

Description Comment

BaBeef 0.10 (day/kg - WW) Baes et al., 1984 Beef biotransfer factor

BaMilk 0.010 (day/kg - WW) Baes et al., 1984 Milk biotransfer factor

BCF_T3F 3.5E+02 (L/kg) Murphy et al., 1978 BCF_T3W was used as a 

surrogate. Geomean of 

converted dry weight 

concentration in Table 1 of 

bluegills at Site A and B.

Bioconcentration factor for trophic level 3 fish, filet

BCF_T3W 3.5E+02 (L/kg) Murphy et al., 1978 Geomean of converted dry 

weight concentration in 

Table 1 of bluegills at Site 

A and B.

Bioconcentration factor for trophic level 3 fish, whole

BCF_T4F 3.5E+02 (L/kg) Murphy et al., 1978 BCF_T3W was used as a 

surrogate. Geomean of 

converted dry weight 

concentration in Table 1 of 

bluegills at Site A and B.

Bioconcentration factor for trophic level 4 fish, filet

BCF_T4W 3.5E+02 (L/kg) Murphy et al., 1978 BCF_T3W was used as a 

surrogate. Geomean of 

converted dry weight 

concentration in Table 1 of 

bluegills at Site A and B.

Bioconcentration factor for trophic level 4 fish, whole

BrExfruit 9.0E-01 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, exposed fruit Baes et al., 1984

BrExveg 3.3E-01 (ug/g DW plant)/ 

(ug/g soil)

Calculated based on 

U.S. EPA, 1999

Soil-to-plant bioconcentration factor, exposed 

vegetables

BrForage 3.2E-01 (ug/g DW plant)/ 

(ug/g soil)

Calculated based on 

U.S. EPA, 1999

Soil-to-plant bioconcentration factor, forage

BrGrain 3.3E-01 (ug/g DW plant)/ 

(ug/g soil)

Calculated based on 

U.S. EPA, 1999

Soil-to-plant bioconcentration factor, grain

BrProfruit 9.0E-01 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, protected fruit Baes et al., 1984

BrProveg 9.0E-01 (ug/g DW plant)/ 

(ug/g soil)

Soil-to-plant bioconcentration factor, protected Baes et al., 1984

vegetables

BrRoot 1.3E-01 (ug/g DW plant)/ 

(ug/g soil)

Calculated based on 

U.S. EPA, 1999

Soil-to-plant bioconcentration factor, roots

BrSilage 3.2E-01 (ug/g DW plant)/ 

(ug/g soil)

Calculated based on 

U.S. EPA, 1999

Soil-to-plant bioconcentration factor, silage

Fv 0 (unitless) - Set to zero for nonvolatile 

chemicals.

Fraction of air concentration in vapor phase

KpPar 18.07 (1/yr) U.S. EPA, 1997b Plant surface loss coefficient, particulate

E-28
Appendix E

E-29

References

Baes, C.F., III, R.D. Sharp, A.L. Sjoreen, and R.W. Shor. 1984. A Review and Analysis of

Parameters for Assessing Transport of Environmentally Released Radionuclides Through

Agriculture. ORNL-5786. Oak Ridge National Laboratory, Oak Ridge, TN. September.

Barrows, M.E., S.R. Petrocelli, K.J. Macek, and J.J. Carroll. 1980. Chapter 24: Bioconcentration

and elimination of selected water pollutants by bluegill sunfish (Lepomis macrochirus). In: 

Dynamics, Exposure and Hazard Assessment of Toxic Chemicals, R. Haque (ed.), Ann

Arbor Science Publishers Inc., Ann Arbor, MI. pp. 379-392.

Eisler, R. 1989. Molybdenum Hazards to Fish, Wildlife, and Invertebrates: A Synoptic Review.

Contaminant Hazard Reviews, Report No. 19, Biological Report 85(1.19). Laurel, MD.

August.

Kumada, H., S. Kimura, M. Yokote, and Y. Matida. 1972. Acute and chronic toxicity, uptake, and

retention of cadmium in freshwater organisms. Bulletin of Freshwater Fisheries Research

Laboratory 22(2):157-165. December 20.

Lemly, A.D. 1985. Toxicology of selenium in a freshwater reservoir: Implications for environmental

hazard evaluation and safety. Ecotoxicology and Environmental Safety 10:314-338.

Murphy, B.R., G.J. Atchison, and A.W. McIntosh. 1978. Cadmium and zinc in muscle of bluegill

(Lepomis macrochirus) and largemouth bass (Micropterus salmoides) from an industrially

contaminated lake. Environmental Pollution 17:253-257.

Stephan, C.E. 1993. Derivation of Proposed Human Health and Wildlife Bioaccumulation

Factors for the Great Lakes Initiative (Draft). PB93-154672. Environmental Research

Laboratory, Office of Research and Development, Duluth, MN. March.

U.S. EPA (Environmental Protection Agency). 1997a. Mercury Study Report to Congress. Volume

III - Fate and Transport of Mercury in the Environment. EPA 452/R-97/005. Office of Air

Quality Planning and Standards and Office of Research and Development, Washington, DC.

U.S. EPA (Environmental Protection Agency). 1997b. The Parameter Guidance Document. A

Companion Document to the Methodology for Assessing Health Risks Associated with

Multiple Pathways Exposure to Combustor Emissions (Internal Draft). NCEA-0238. 

National Center for Environmental Assessment, Cincinnati, OH. March.

U.S. EPA (Environmental Protection Agency). 1999. Estimating Risk from the Use of Agricultural

Fertilizers (Draft Report). Office of Solid Waste, Washington, DC. August. Web site at

http://www.epa.gov/epaoswer/hazwaste/recycle/fertiliz/risk/index.htm.

Appendix F

Biota Factors 

Code Description Value

Appendix F

Table F-1. Model Parameters for Biota Data

Reference

Cattle Intake Rates

Qfbs Quantity of forage eaten each day by beef cattle (kg - DW/day) 8.8 U.S.EPA, 1997

Qfds Quantity of forage eaten each day by dairy cattle (kg - DW/day) 11 U.S.EPA, 1997

Qgbs Quantity of grain eaten each day by beef cattle (kg - DW/day) 0.47 U.S.EPA, 1997

Qgds Quantity of grain eaten each day by dairy cattle (kg - DW/day) 2.6 U.S.EPA, 1997

Qsbs Quantity of silage eaten each day by beef cattle (kg - DW/day) 2.5 U.S.EPA, 1997

Qsds Quantity of silage eaten each day by dairy cattle (kg - DW/day) 3.3 U.S.EPA, 1997

Qsoilbs Consumption rate of soil for beef cattle (kg/day) 0.39 U.S.EPA, 1997

Qsoilds Consumption rate of soil for dairy cattle (kg/day) 0.41 U.S.EPA, 1997

Fraction Contaminated

F_forage Fraction of forage grown on contaminated soil and eaten (unitless) 1 U.S.EPA, 1997

F_grain Fraction of grain grown on contaminated soil and eaten (unitless) 1 U.S.EPA, 1997

F_silage Fraction of silage grown on contaminated soil and eaten (unitless) 1 U.S.EPA, 1997

Vegetation

DWr Dry weight fraction for root vegetables (unitless) 0.13 U.S.EPA, 1997

Rp_exfruit Interception fraction for exposed fruit (unitless) 0.052 U.S.EPA, 1997

Rp_exveg Interception fraction for exposed vegetables (unitless) 0.052 U.S.EPA, 1997

Rp_forage Interception fraction for forage (unitless) 0.47 U.S.EPA, 1997

Rp_silage Interception fraction for silage (unitless) 0.44 U.S.EPA, 1997

Tp_exfruit Length of plant exposure to deposition for exposed fruit (yr) 0.123 U.S.EPA, 1997

Tp_exveg Length of plant exposure to deposition for exposed vegetables (yr) 0.123 U.S.EPA, 1997

Tp_forage Length of plant exposure to deposition for forage (yr) 0.123 U.S.EPA, 1997

Tp_silage Length of plant exposure to deposition for silage (yr) 0.164 U.S.EPA, 1997

Yp_exfruit Crop yield for exposed fruit (kg DW/m2) 0.09 U.S.EPA, 1997

Yp_exveg Crop yield for exposed vegetables (kg DW/m2) 0.18 U.S.EPA, 1997

Yp_forage Crop yield for forage (kg DW/m2) 0.31 U.S.EPA, 1997

Yp_silage Crop yield for silage (kg DW/m2) 0.31 U.S.EPA, 1997

F-3
Appendix F

F-4

References

U.S. EPA (Environmental Protection Agency). 1997. The Parameter Guidance Document. A

Companion Document to the Methodology for Assessing Health Risks Associated with

Multiple Pathways Exposure to Combustor Emissions (Internal Draft). NCEA-0238. 

National Center for Environmental Assessment, Cincinnati, OH, pp. 1-281. March.
Appendix G

Human Exposure Factors

Appendix G August 2002

G-3

Appendix G

Human Exposure Factors

Exposure factors are data that quantify human behavior patterns (e.g., ingestion rates of beef

and fruit) and characteristics (e.g., body weight) that affect their exposure to environmental

contaminants. These data can be used to construct realistic assumptions concerning an individual’s

exposure to and subsequent intake of a contaminant in the environment. The exposure factors data also

enable the U.S. Environmental Protection Agency (EPA) to determine the exposures of individuals who

have different lifestyles (e.g., a resident vs. a farmer, and a child vs. an adult). 

Most human exposure factors used in the fossil fuel combustion waste (FFCW) screening

analysis are based on national data provided in EPA’s Exposure Factors Handbook (EFH) (U.S.

EPA, 1997a, 1997b, 1997c). The EFH summarizes data from relevant studies and provides

recommendations and associated confidence estimates on the values of exposure factors. The main

sources of information on food consumption rates are the U.S. Department of Agriculture (USDA)

Nationwide Food Consumption Survey (NFCS) and the USDA Continuing Survey of Food Intakes by

Individuals (CSFII). EPA used data from the NFCS to generate consumer-only and per capita intake

rates for various food items and food groups, and data from the CSFII to generate per capita intake

rates (U.S. EPA, 1997b). 

The exposure factors parameters used in the deterministic fossil fuel combustion waste

(FFCW) screening analysis are summarized in Tables G-1a and G-1b. 
Code Description Value

Appendix G

Table G-1a. Model Parameters for Exposure Data

Reference

AT Averaging time (yr) 70 U.S. EPA, 1991.

Bri_1 Breathing rate (m3/d) Receptor Specific

Bri_2 Breathing rate (m3/d) Receptor Specific

Bri_3 Breathing rate (m3/d) Receptor Specific

Bri_4 Breathing rate (m3/d) Receptor Specific

BW_1 Body weight (kg) Receptor Specific

BW_2 Body weight (kg) Receptor Specific

BW_3 Body weight (kg) Receptor Specific

BW_4 Body weight (kg) Receptor Specific

CR_beef_1 Daily human consumption rate of beef (g WW/kg BW/day) Receptor Specific

CR_beef_2 Daily human consumption rate of beef (g WW/kg BW/day) Receptor Specific

CR_beef_3 Daily human consumption rate of beef (g WW/kg BW/day) Receptor Specific

CR_beef_4 Daily human consumption rate of beef (g WW/kg BW/day) Receptor Specific

CR_dw_1 Consumption rate of water (L/day) Receptor Specific

CR_dw_2 Consumption rate of water (L/day) Receptor Specific

CR_dw_3 Consumption rate of water (L/day) Receptor Specific

CR_dw_4 Consumption rate of water (L/day) Receptor Specific

CR_exfruit_1 Daily human consumption rate of exposed fruit (g WW/kg

BW/day)

Receptor Specific

CR_exfruit_2 Daily human consumption rate of exposed fruit (g WW/kg

BW/day)

Receptor Specific

CR_exfruit_3 Daily human consumption rate of exposed fruit (g WW/kg

BW/day)

Receptor Specific

CR_exfruit_4 Daily human consumption rate of exposed fruit (g WW/kg

BW/day)

Receptor Specific

CR_exveg_1 Daily human consumption rate of exposed vegetables (g

WW/kg BW/day)

Receptor Specific

CR_exveg_2 Daily human consumption rate of exposed vegetables (g

WW/kg BW/day)

Receptor Specific

CR_exveg_3 Daily human consumption rate of exposed vegetables (g

WW/kg BW/day)

Receptor Specific

CR_exveg_4 Daily human consumption rate of exposed vegetables (g

WW/kg BW/day)

Receptor Specific

CR_fish_1 Consumption rate of fish (g WW/day) Receptor Specific

CR_fish_2 Consumption rate of fish (g WW/day) Receptor Specific

CR_fish_3 Consumption rate of fish (g WW/day) Receptor Specific

CR_fish_4 Consumption rate of fish (g WW/day) Receptor Specific

CR_milk_1 Daily human consumption rate of milk (g WW/kg BW/day) Receptor Specific

CR_milk_2 Daily human consumption rate of milk (g WW/kg BW/day) Receptor Specific

CR_milk_3 Daily human consumption rate of milk (g WW/kg BW/day) Receptor Specific

CR_milk_4 Daily human consumption rate of milk (g WW/kg BW/day) Receptor Specific

G-4
Code Description Value

Appendix G

Table G-1a. Model Parameters for Exposure Data

Reference

CR_profruit_1 Daily human consumption rate of protected fruit (g WW/kg

BW/day)

Receptor Specific

CR_profruit_2 Daily human consumption rate of protected fruit (g WW/kg

BW/day)

Receptor Specific

CR_profruit_3 Daily human consumption rate of protected fruit (g WW/kg

BW/day)

Receptor Specific

CR_profruit_4 Daily human consumption rate of protected fruit (g WW/kg

BW/day)

Receptor Specific

CR_proveg_1 Daily human consumption rate of protected vegetables (g

WW/kg BW/day)

Receptor Specific

CR_proveg_2 Daily human consumption rate of protected vegetables (g

WW/kg BW/day)

Receptor Specific

CR_proveg_3 Daily human consumption rate of protected vegetables (g

WW/kg BW/day)

Receptor Specific

CR_proveg_4 Daily human consumption rate of protected vegetables (g

WW/kg BW/day)

Receptor Specific

CR_root_1 Daily human consumption rate of below ground vegetables (g

WW/kg BW/day)

Receptor Specific

CR_root_2 Daily human consumption rate of below ground vegetables (g

WW/kg BW/day)

Receptor Specific

CR_root_3 Daily human consumption rate of below ground vegetables (g

WW/kg BW/day)

Receptor Specific

CR_root_4 Daily human consumption rate of below ground vegetables (g

WW/kg BW/day)

Receptor Specific

CRs_1 Soil ingestion rate (mg/day) Receptor Specific

CRs_2 Soil ingestion rate (mg/day) Receptor Specific

CRs_3 Soil ingestion rate (mg/day) Receptor Specific

CRs_4 Soil ingestion rate (mg/day) Receptor Specific

ED_1 Exposure duration (yr) Receptor Specific

ED_2 Exposure duration (yr) Receptor Specific

ED_3 Exposure duration (yr) Receptor Specific

ED_4 Exposure duration (yr) Receptor Specific

EF Exposure frequency (d/yr) 350 U.S. EPA, 1991.

F_beef Fraction of animal tissue that is contaminated (unitless) Receptor Specific

F_dw Fraction of drinking water ingested that is contaminated

(unitless)

1

F_exfruit Fraction of exposed fruit grown in contaminated soil (unitless) Receptor Specific

F_exveg Fraction of exposed vegetables grown in contaminated soil

(unitless)

Receptor Specific

F_fish Fraction of fish intake from contaminated source (unitless) 1

F_milk Fraction of milk that is contaminated (unitless) Receptor Specific

F_profruit Fraction of protected fruit grown in contaminated soil

(unitless)

Receptor Specific

F_proveg Fraction of protected vegetables grown in contaminated soil

(unitless)

Receptor Specific

G-5
Code Description Value

Appendix G

Table G-1a. Model Parameters for Exposure Data

Reference

F_root Fraction of below ground vegetables grown in contaminated

soil (unitless)

Receptor Specific

F_soil Fraction of contaminated soil that is ingested (unitless) 1

F_T3 Fraction of trophic level 3 intake, 0.36 (unitless) 0.36

F_T4 Fraction of trophic level 4 intake, 0.64 (unitless) 0.64

L_exfruit Food preparation loss for exposed fruit (unitless) 0.21 U.S. EPA, 1997.

L_exveg Food preparation loss for exposed vegetables (unitless) 0.16 U.S. EPA, 1997.

L_profruit Food preparation loss for protected fruit (unitless) 0.29 U.S. EPA, 1997.

L_proveg Food preparation loss for protected vegetables (unitless) 0.13 U.S. EPA, 1997.

L_root Food preparation loss for root vegetables (unitless) 0.05 U.S. EPA, 1997.

L1_beef Cooking loss for beef (unitless) 0.27 U.S. EPA, 1997.

L2_beef Post-cooking loss for beef (unitless) 0.24 U.S. EPA, 1997.

SY Start year (yr) Receptor Specific U.S. EPA, 1997.

G-6
Parameter

Appendix G

Table G-1b. 50th Percentile Exposure Data

Value Cohort_1 Cohort_2 Cohort_3 Cohort_4

Parameters for Aboveground and Drinking Water HBN Calculation

BW (kg) 15.3 29.6 56.8 69.3

SY (yr) 3 8 15 20

Parameters for Aboveground HBN Calculation

Bri (m3/d) 7.6 11.8 14 13.3

CR_beef (g WW/kg BW/day) 2.11 2.11 1.51 1.64

CR_exfruit (g WW/kg BW/day) 1.82 1.11 0.609 1.3

CR_exveg (g WW/kg BW/day) 1.46 0.643 0.656 1.38

CR_fish (g WW/day) 2 22 2

CR_milk (g WW/kg BW/day) 69.99 38.6 14.28 12.1

CR_profruit (g WW/kg BW/day) 2.34 2.34 1.23 2.13

CR_proveg (g WW/kg BW/day) 1.397 0.791 0.583 0.599

CR_root (g WW/kg BW/day) 0.686 0.523 0.565 0.883

CRs (mg/day) 100 50 50 50

ED (yr) 5 7.5 8 10

F_beef (unitless) 0.485

F_exfruit (unitless) 0.328

F_exveg (unitless) 0.42

F_milk (unitless) 0.254

F_profruit (unitless) 0.03

F_proveg (unitless) 0.394

F_root (unitless) 0.173

Parameters for Drinking Water HBN Calculation

CR_dw (L/day) 0.6165 0.731 0.8685 1.275

ED (yr) 5 7.5 8 9

G-7
Appendix G August 2002

G-8

References

U.S. EPA (Environmental Protection Agency). 1989. Risk Assessment Guidance for Superfund.

Volume I: Human Health Evaluation Manual (Part A) (Interim Final). EPA/540/1-89/002.

Prepared by U.S. Environmental Protection Agency, Office of Emergency and Remedial

Response, Washington, DC. December.

U.S. EPA (Environmental Protection Agency). 1997a. Exposure Factors Handbook, Volume I,

General Factors. EPA/600/P-95/002Fa. Office of Research and Development, Washington,

DC. August. 

U.S. EPA (Environmental Protection Agency). 1997b. Exposure Factors Handbook, Volume II,

Food Ingestion Factors. EPA/600/P-95/002Fa. Office of Research and Development,

Washington, DC. August. 

U.S. EPA (Environmental Protection Agency). 1997c. Exposure Factors Handbook, Volume III,

Activity Factors. EPA/600/P-95/002Fa. Office of Research and Development, Washington,

DC. August.
Appendix H

Site Data 

Appendix H

H-3

Appendix H

Site Data

To estimate air dispersion and deposition, the HBN calculations require assumptions about site

meteorology, ground cover, and waste management unit (WMU) size. Default values for most of these

variables are from EPA’s Soil Screening Guidance and are designed to be protective for a nationwide

screening analysis. The WMU area used is the 95th percentile value from EPRI’s survey of FFCW

onsite landfills. The landfill is also assumed to be uncovered.
Code Description Value

Appendix H

Table H-1. Model Parameters for Site Data

Reference

Meteorology

DF_A Dispersion factor constant selected based on location 

(unitless)

16.2302 U.S. EPA, 2001

DF_B Dispersion factor constant selected based on location 

(unitless)

18.7762 U.S. EPA, 2001

DF_C Dispersion factor constant selected based on location 

(unitless)

216.108 U.S. EPA, 2001

May Average annual moisture (precipitation: rainfall, snow) 

(cm/yr)

150 U.S. EPA, 1998

ut Equivalent threshold value of windspeed at 7m (m/s) 11.32 U.S. EPA, 2001

uw Mean annual windspeed (m/s) 4.69 U.S. EPA, 2001

Source

Area Source area 95th percentile (acres) 351.2 EPRI, 1997

Csoil Soil concentration (mg/kg) 1 Set equal to 1 for the HBN 

calculation

Fx Function dependent on uw/ut derived using Cowherd 

et al. (1985) (unitless)

0.194 U.S. EPA, 2001

VC Fraction vegetative cover (unitless) 0 Assumed protective value

H-4
Appendix H

H-5

References

U.S. EPA (Environmental Protection Agency). 1998. Methodology for Assessing Health Risks

Associated with Multiple Pathways of Exposure to Combustor Emissions. Update to

EPA/600/6-90/003 Methodology for Assessing Health Risks Associated with Indirect

Exposure to Combustor Emissions. EPA 600/R-98/137. National Center for Environmental

Assessment, Cincinnati, OH. December.

U.S. EPA (Environmental Protection Agency). 2001. Supplemental Guidance for Developing Soil

Screening Levels for Superfund Sites. Office of Solid Waste, Washington DC. March.

EPRI (Electric Power Research Institute). 1997. Coal Combustion and Low Volume Wastes

Comanagement Survey. EPRI. Palo Alto, CA. June.

Appendix I

Tabulated Human Health Screening Results

Appendix I

I-3

Table I-1. FFCW Surface Impoundment (SI) Human Health Screening Results: 

Groundwater-to-Drinking-Water Pathway

Chemical

Benchmark

Type

2002

HBN

2002 SI Porewater

1998 HBN

1998 Porewater

90th

Percentile

HQ

(Cancer

Risk)

Number of

Sites (Sites

Exceeding)

95th

Percentile

HQ

(Cancer

Risk)

Analytes Exceeding Risk Criteria1

Antimony Noncancer 1.17E-02 6.40E-02 5.45E+00 2 (1) 2.10E-02 NA NA

Arsenic Cancer 2.86E-03 5.18E+00 (1.81E-02) 17 (17) 2.90E-03 9.64E+00 (3.32E-02)

Arsenic Noncancer 8.81E-03 5.18E+00 5.88E+02 17 (15) 1.50E-02 9.64E+00 6.43E+02

Boron Noncancer 2.64E+00 7.52E+01 2.84E+01 18 (11) 4.63E+00 3.42E+02 7.39E+01

Cadmium Noncancer 1.47E-02 1.31E-01 8.91E+00 17 (5) 2.60E-02 1.56E-01 6.00E+00

Chromium (VI) Noncancer 8.81E-02 3.66E-01 4.15E+00 18 (6) 2.60E-01 7.46E-01 2.87E+00

Cobalt Noncancer 5.87E-01 6.27E+00 1.07E+01 4 (1) NA NA NA

Fluoride Noncancer 3.52E+00 1.91E+01 5.42E+00 15 (4) 3.08E+00 4.10E+02 1.33E+02

Lead MCL 1.50E-02 1.77E-01 1.18E+01 14 (6) 1.50E-02 4.68E-01 3.12E+01

Manganese Noncancer 1.38E+00 7.67E+00 5.56E+00 16 (4) 7.20E+00 1.03E+02 1.43E+01

Molybdenum Noncancer 1.47E-01 1.00E+00 6.81E+00 18 (13) 2.57E-01 1.14E+01 4.44E+01

Nickel Noncancer 5.87E-01 7.49E-01 1.27E+00 17 (3) 1.03E+00 8.33E+00 8.09E+00

Nitrate MCL 1.00E+01 6.02E+02 6.02E+01 13 (3) 1.00E+01 1.17E+03 1.17E+02

Nitrite Noncancer 2.94E+00 5.22E+00 1.78E+00 15 (2) 1.00E+01 4.61E+02 4.61E+01

Selenium Noncancer 1.47E-01 3.56E-01 2.43E+00 15 (5) 2.57E-01 1.03E+00 4.01E+00

Thallium Noncancer 2.35E-03 4.52E-02 1.93E+01 2 (2) 4.10E-03 NA NA

Vanadium Noncancer 2.06E-01 4.78E-01 2.33E+00 15 (6) 3.60E-01 8.00E-01 2.22E+00

Analytes Below Risk Criteria1

Aluminum Noncancer 5.87E+01 2.30E+01 3.92E-01 17 (1) NA 2.70E+02 NA

Barium Noncancer 2.06E+00 3.02E-01 1.47E-01 17 (0) 3.60E+00 2.74E+01 7.61E+00

Beryllium Noncancer 5.87E-02 5.68E-03 9.67E-02 2 (0) 1.00E-04 NA NA

Chromium (III) Noncancer 4.40E+01 3.66E-01 8.31E-03 18 (0) NA 7.46E-01 NA

Copper MCL 1.30E+00 2.84E-01 2.18E-01 16 (0) 1.30E+00 6.90E-01 5.31E-01

Mercury Noncancer 8.81E-03 2.50E-04 2.84E-02 1 (0) 1.50E-02 7.96E-04 5.31E-02

Silver Noncancer 1.47E-01 5.00E-03 3.41E-02 8 (0) 2.57E-01 NA NA

Strontium Noncancer 1.76E+01 8.74E+00 4.96E-01 17 (0) 3.08E+01 1.61E+01 5.23E-01

Zinc Noncancer 8.81E+00 6.70E-01 7.60E-02 17 (1) 1.54E+01 2.31E+01 1.50E+00

1

 Risk criteria are 1E-05 cancer risk or a hazard quotient (HQ) of 1E+00 for noncancer endpoints.

HBN = health-based number

90th percentile = 90th percentile SI porewater concentration

HQ = hazard quotient

MCL = maximum contaminant level

NA = not available in 1998
Appendix I

I-4

Table I-2. FFCW Surface Impoundment (SI) Human Health Screening Results:

Groundwater-to-Surface-Water (Fish Ingestion) Pathway

Chemical Benchmark Type 2002 HBN

2002 SI Porewater

90th Percentile

HQ

(Cancer Risk)

Number of Sites

(sites exceeding)

Analytes Exceeding Risk Criteria1

Arsenic Cancer 0.23 5.18E+00 (2.24E-04) 17 (6)

Arsenic Noncancer 0.71 5.18E+00 7.28E+00 17 (4)

Cadmium Noncancer 0.035 1.31E-01 3.73E+00 17 (3)

Mercury Noncancer 3.85E-06 2.50E-04 6.50E+01 1 (1)

Selenium Noncancer 0.038 3.56E-01 9.50E+00 15 (9)

Thallium Noncancer 0.008 4.52E-02 5.69E+00 2 (1)

Analytes Below Risk Criteria1

Antimony AWQ 4.3 6.40E-02 1.49E-02 2 (0)

Beryllium Noncancer 1.00 5.68E-03 5.69E-03 2(0)

Chromium (III) Noncancer 23,700 3.66E-01 1.54E-05 18 (0)

Chromium (VI) Noncancer 47 3.66E-01 7.72E-03 18 (0)

Copper AWQ 1.3 2.84E-01 2.18E-01 16 (0)

Molybdenum Noncancer 12 1.00E+01 8.43E-02 18 (0)

Nickel Noncancer 237 7.49E-01 3.16E-03 17 (0)

Zinc Noncancer 8.13 6.70E-01 8.24E-02 17 (1)

1 Risk criteria are 1E-05 cancer risk or a hazard quotient (HQ) of 1E+00 for noncancer endpoints.

HBN = health-based number

90th percentile = 90th percentile SI porewater concentration

HQ = hazard quotient

AWQ = National Ambient Water Quality Criteria

MCL = maximum contaminant level

NA = not available in 1998
Appendix I

I-5

Table I-3. FFCW Landfill Leachate Human Health Screening Results: 

Groundwater-to-Drinking-Water Pathway

Chemical

Benchmark

Type 2002 HBN

2002 Landfill Leachate

1998 HBN

1998 TCLP

90th

Percentile

HQ

(Cancer

Risk)

Number of

Sites

(Sites

Exceeding)

95th

Percentile

HQ

(Cancer

Risk)

Analytes Exceeding Risk Criteria1

Antimony Noncancer 1.17E-02 2.61E-01 2.22E+01 60 (37) 2.10E-02 NA NA

Arsenic Cancer 2.86E-03 3.94E-01 (1.38E-03) 119 (113) 2.90E-03 2.40E-01 (8.28E-04)

Arsenic Noncancer 8.81E-03 3.94E-01 4.48E+01 119 (99) 1.50E-02 2.40E-01 1.60E+01

Boron Noncancer 2.64E+00 1.06E+01 4.00E+00 72 (28) 4.63E+00 NA NA

Cadmium Noncancer 1.47E-02 4.94E-02 3.37E+00 117 (39) 2.60E-02 NA NA

Chromium (VI) Noncancer 8.81E-02 2.00E-01 2.27E+00 118 (35) 2.60E-01 5.90E-02 2.27E-01

Fluoride Noncancer 3.52E+00 6.34E+00 1.80E+00 33 (6) 3.08E+00 NA NA

Lead MCL 1.50E-02 2.39E-01 1.59E+01 116 (78) 1.50E-02 NA NA

Molybdenum Noncancer 1.47E-01 6.16E-01 4.20E+00 49 (29) 2.57E-01 NA NA

Nitrite Noncancer 2.94E+00 3.47E+00 1.18E+00 5 (1) 1.00E+01 NA NA

Selenium Noncancer 1.47E-01 1.76E-01 1.20E+00 119 (14) 2.57E-01 4.40E-01 1.71E+00

Thallium Noncancer 2.35E-03 5.00E-02 2.13E+01 40 (32) 4.10E-03 NA NA

Vanadium Noncancer 2.06E-01 4.50E-01 2.19E+00 40 (8) 3.60E-01 NA NA

Analytes Below Risk Criteria1

Aluminum Noncancer 5.87E+01 1.05E+01 1.79E-01 54 (0) NA NA NA

Barium Noncancer 2.06E+00 1.60E+00 7.80E-01 115 (10) 3.60E+00 NA NA

Beryllium Noncancer 5.87E-02 1.58E-02 2.70E-01 47 (1) 1.00E-04 NA NA

Chromium (III) Noncancer 4.40E+01 2.00E-01 4.54E-03 118 (0) NA NA NA

Cobalt Noncancer 5.87E-01 8.25E-02 1.40E-01 51 (0) NA NA NA

Copper MCL 1.30E+00 1.50E-01 1.15E-01 72 (2) 1.30E+00 NA NA

Cyanide Noncancer 5.87E-01 6.32E-02 1.08E-01 24 (0) NA NA NA

Manganese Noncancer 1.38E+00 1.37E+00 9.92E-01 72 (8) 7.20E+00 NA NA

Mercury Noncancer 8.81E-03 2.69E-03 3.06E-01 97 (6) 1.50E-02 NA NA

Nickel Noncancer 5.87E-01 3.09E-01 5.27E-01 80 (3) 1.03E+00 5.00E-02 4.85E-02

Nitrate MCL 1.00E+01 2.83E+00 2.83E-01 17 (1) 1.00E+01 NA NA

Silver Noncancer 1.47E-01 3.95E-02 2.69E-01 109 (2) 2.57E-01 NA NA

Strontium Noncancer 1.76E+01 9.70E+00 5.51E-01 20 (1) 3.08E+01 NA NA

Zinc Noncancer 8.81E+00 1.94E+00 2.20E-01 75 (5) 1.54E+01 NA NA

1

 Risk criteria are 1E-05 cancer risk or a hazard quotient (HQ) of 1E+00 for noncancer endpoints, applied to 90th

percentile concentrations.

HBN = health-based number

90th percentile = 90th percentile concentration

HQ = hazard quotient

MCL = maximum contaminant level

NA = not available in 1998
Appendix I

I-6

Table I-4. FFCW Landfill Leachate Human Health Screening Results: 

Groundwater-to-Surface-Water Pathway

Chemical Benchmark Type 2002 HBN

2002 Landfill Leachate

90th Percentile

HQ

(Cancer Risk)

Number of Sites

(sites exceeding)

Analytes Exceeding Risk Criteria1

Arsenic Cancer 0.23 3.94E-01 (1.71E-05) 119 (22)

Cadmium Noncancer 0.035 4.94E-02 1.41E+00 117 (22)

Mercury Noncancer 3.85E-06 2.69E-03 7.00E+02 97 (97)

Selenium Noncancer 0.038 1.76E-01 4.69E+00 119 (69)

Thallium Noncancer 0.008 5.00E-02 6.29E+00 40 (20)

Analytes Below Risk Criteria1

Antimony AWQ 4.3 2.61E-01 6.07E-02 60 (0)

Arsenic Noncancer 0.71 3.94E-01 5.54E-01 119 (8)

Beryllium Noncancer 1.00 1.58E-02 1.59E-02 47(0)

Chromium (III) Noncancer 23,700 2.00E-01 8.44E-06 118 (0)

Chromium (VI) Noncancer 47 2.00E-01 4.22E-03 118 (0)

Copper AWQ 1.3 1.50E-01 1.15E-01 72 (2)

Cyanide AWQ 222 6.32E-02 2.85E-04 24 (0)

Molybdenum Noncancer 12 6.16E-01 5.20E-02 49 (1)

Nickel Noncancer 237 3.09E-01 1.30E-03 80 (0)

Zinc Noncancer 8.13 1.94E+00 2.38E-01 75 (5)

1

 Risk criteria are 1E-05 cancer risk or a hazard quotient (HQ) of 1E+00 for noncancer endpoints, applied to 90th

percentile concentrations.

HBN = health-based number

90th percentile = 90th percentile concentration

HQ = hazard quotient

AWQ = National Ambient Water Quality Criteria

MCL = maximum contaminant level

NA = not available in 1998
Appendix I

I-7

Table I-5. FFCW Landfill Human Health Screening Results: 

Aboveground Inhalation and Ingestion Pathways

Chemical

Benchmark

Type 2002 HBN

2002 Aboveground Results 1998

Aboveground

Cancer Risk or

HQ

90th

Percentile2

HQ (Cancer

Risk)

Driving

Pathway3

Number of

Sites (Sites

Exceeding)

Analytes Below Risk Criteria1

Aluminum Noncancer 3.02E+05 8.57E+03 2.84E-02 Soil 71 (0) NA

Antimony Noncancer 1.64E+01 4.62E+00 2.81E-01 Produce 64 (3) NA

Arsenic Cancer 1.31E+01 1.05E+01 (8.05E-06) Soil 111 (4) 1.70E+00

Arsenic Noncancer 4.04E+01 1.05E+01 2.60E-01 Soil 111 (0) NA

Barium Noncancer 2.59E+03 1.05E+02 4.05E-02 Milk 94 (0) 1.00E+00

Beryllium Noncancer 3.60E+02 1.76E+00 4.88E-03 Soil 37 (0) NA

Beryllium Cancer 8.44E+03 1.76E+01 (2.08E-08) Air 37 (0) NA

Boron Noncancer 4.82E+01 3.46E+01 7.18E-01 Milk 70 (5) 5.00E-04

Cadmium Noncancer 8.01E+00 5.42E-01 6.77E-02 Milk 102 (2) 1.00E-01

Cadmium Cancer 1.13E+04 5.42E+00 (4.82E-09) Air 102 (0) NA

Chromium (III) Noncancer 9.65E+04 1.66E+01 1.72E-04 Milk 108 (0) NA

Chromium (VI) Cancer 1.69E+03 1.66E+02 (9.83E-07) Inhalation 108 (0) 3.50E-01

Chromium (VI) Noncancer 1.93E+02 1.66E+01 8.60E-02 Milk 108 (0) 3.10E-02

Cobalt Noncancer 5.81E+02 6.22E+00 1.07E-02 Milk 67 (0) 2.00E-03

Cobalt Cancer 7.23E+03 6.22E+01 (8.60E-08) Inhalation 67 (0) NA

Cyanide Noncancer 4.35E+03 2.35E-02 5.41E-06 Soil 2 (0) NA

Fluoride Noncancer 2.61E+04 2.49E+01 9.56E-04 Soil 8 (0) NA

Lead SSL/PRG 4.00E+02 8.06E+00 2.01E-02 Soil 107 (0) NA

Manganese NoncancEr 2.59E+03 5.10E+01 1.97E-02 Milk 87 (0) NA

Mercury

(divalent) Noncancer 6.90E-01 1.63E-01 2.37E-01 Milk 86 (5) NA

Molybdenum Noncancer 3.96E+01 3.47E+00 8.76E-02 Milk 73 (0) NA

Nickel Noncancer 6.90E+02 3.29E+01 4.77E-02 Milk 106 (1) 2.10E-02

Nitrate Noncancer 3.48E+05 2.42E-02 6.97E-08 Soil 3 (0) NA

(continued)
Table I-5. (continued)

Appendix I

Chemical

Benchmark

Type 2002 HBN

2002 Aboveground Results 1998

Aboveground

Cancer Risk or

HQ

90th

Percentile2

HQ (Cancer

Risk)

Driving

Pathway3

Number of

Sites (Sites

Exceeding)

I-8

Selenium Noncancer 7.83E+01 2.14E+00 2.74E-02 Milk 94 (0) 9.30E-03

Silver Noncancer 2.62E+00 1.37E+00 5.23E-01 Milk 69 (4) 8.00E-04

Strontium Noncancer 6.22E+02 1.05E+02 1.69E-01 Milk 15 (0) NA

Thallium Noncancer 2.81E+00 2.08E+00 7.39E-01 Milk 20 (2) 1.10E+00

Vanadium Noncancer 1.16E+03 9.07E+01 7.85E-02 Soil 43 (0) NA

Zinc Noncancer 2.43E+02 2.93E+01 1.21E-01 Milk 98 (3) NA

1

 Risk criteria are 1.0E-05 cancer risk or a hazard quotient (HQ) of 1.0E+00 for noncancer endpoints, applied to 90th

 percentile concentrations

2

 Soil concentrations (total waste/10) or total waste concentrations (for Be, Cd, Cr VI, and Co inhalation cancer risk) 

3

 See Appendix D, Table D-5 for relative contributions of ingestion pathways to risk estimates

HBN = health-based number

90th percentile = 90th percentile concentration

HQ = hazard quotient

MCL = maximum contaminant level

NA = not available
Appendix J

Tabulated Ecological Risk 

Screening Results

Appendix J

J-3

Table J-1. Landfill Ecological Screening Results: Aboveground Soil Pathway

Chemical CSCL

2002 Soil 1998 Soil

Soil (mg/kg)1 HQ

Number of

Sites (Sites

Exceeding) Soil (mg/kg) HQ

Analytes Exceeding Risk Criterion2

Boron 5.00E-01 1.73E+01 3.46E+01 70 (25) 1.00E-01 -

Analytes Not Exceeding Risk Criterion2

Antimony 1.40E+01 2.31E+00 1.65E-01 64 (0) - -

Arsenic 1.00E+01 5.26E+00 5.26E-01 111 (0) - -

Barium 5.00E+02 5.26E+01 1.05E-01 94 (0) 2.00E+02 3.90E-01

Cadmium 1.00E+00 2.71E-01 2.71E-01 102 (2) 2.40E-01 2.40E-01

Chromium 6.40E+01 8.30E+00 1.30E-01 108 (0) - -

Cobalt 1.00E+03 3.11E+00 3.11E-03 67 (0) 1.40E-01 1.40E-04

Copper 2.10E+01 1.14E+01 5.44E-01 95 (0) - -

Lead 2.80E+01 4.03E+00 1.44E-01 107 (0) 7.60E+00 2.70E-01

Mercury 1.00E-01 8.17E-02 8.17E-01 86 (2) - -

Molybdenum 4.21E+01 1.74E+00 4.12E-02 73 (0) - -

Nickel 3.00E+01 1.65E+01 5.49E-01 106 (1) - -

Selenium 1.00E+00 1.07E+00 1.07E+00 94 (2) 1.10E-01 1.10E-01

Vanadium 1.30E+02 4.53E+01 3.49E-01 43 (0) - -

Zinc 5.00E+01 1.47E+01 2.93E-01 98 (2) - -

1

 90th percentile total waste concentration / 20 (dilution factor) 2

Risk criterion is a hazard quotient (HQ) of 10

CSCL = chemical stressor concentration level
Appendix J

J-4

Table J-2. Surface Impoundment Ecological Screening Results: Direct Surface Impoundment

and Groundwater-to-Surface-Water Pathways

CSCL 2002 SI Porewater 1998 SI Water

Chemical (mg/L) 

90th

Percentile

(mg/L) HQ

Number of

Sites (Sites

Exceeding)

95th

Percentile

(mg/L) HQ

Analytes Exceeding Risk Criterion1

Aluminum 8.70E-02 2.30E+01 2.65E+02 17 (11) 5.11E+00 5.87E+01

Arsenic III 1.50E-01 5.18E+00 3.45E+01 17 (3) 5.50E-01 3.67E+00

Arsenic IV 8.10E-03 5.18E+00 6.39E+02 17 (11) 5.50E-01 6.79E+01

Barium 4.00E-03 3.02E-01 7.54E+01 17 (13) 7.12E-01 1.78E+02

Boron 1.60E-03 7.52E+01 4.70E+04 18 (18) 4.60E+02 2.88E+05

Cadmium 2.50E-03 1.31E-01 5.23E+01 17 (3) 2.50E-01 1.00E+02

Chromium VI 1.10E-02 3.66E-01 3.33E+01 18 (5) 2.67E-02 2.43E+00

Cobalt 2.30E-02 6.27E+00 2.73E+02 4 (1) 1.00E-02 4.35E-01

Copper 9.30E-03 2.84E-01 3.05E+01 16 (5) 3.90E-01 4.19E+01

Lead 3.01E-04 1.77E-01 5.88E+02 14 (10) 2.50E-01 8.31E+02

Mercury 1.90E-07 2.50E-04 1.32E+03 1 (1) 1.50E-03 7.89E+03

Nickel 5.20E-02 7.49E-01 1.44E+01 17 (3) 6.00E-01 1.15E+01

Selenium IV 2.80E-02 3.56E-01 1.27E+01 15 (3) 7.80E+00 2.79E+02

Selenium total 5.00E-03 3.56E-01 7.13E+01 15 (8) 7.80E+00 1.56E+03

Selenium VI 9.50E-03 3.56E-01 3.75E+01 15 (6) 7.80E+00 8.21E+02

Silver 3.60E-04 5.00E-03 1.39E+01 8 (3) 5.00E-03 1.39E+01

Vanadium 2.00E-02 4.78E-01 2.39E+01 15 (6) 8.00E-01 4.00E+01

Analytes Not Exceeding Risk Criterion1

Antimony 3.00E-02 6.40E-02 2.13E+00 2 (0) 1.37E-01 4.57E+00

Beryllium 6.60E-04 5.68E-03 8.61E+00 2 (0) 1.00E-03 1.52E+00

Chromium III 8.60E-02 3.66E-01 4.26E+00 18 (0) 4.00E-01 4.65E+00

Molybdenum 3.70E-01 1.00E+00 2.70E+00 18 (1) 5.00E-01 1.35E+00

Thallium 1.20E-02 4.52E-02 3.77E+00 2 (0) 5.00E-02 4.17E+00

Zinc 1.20E-01 6.70E-01 5.58E+00 17 (1) 6.70E-01 5.58E+00

1

 Risk criterion is a hazard quotient (HQ) of 10 (for direct exposure to impoundment waters).

SI = surface impoundment

CSCL = chemical stressor concentration level
Appendix J

J-5

Table J-3. Landfill Ecological Screening Results: 

Groundwater-to-Surface-Water Pathway

Chemical

CSCL

(mg/L)

2002 - Landfill Leachate

90th Percentile

(mg/L) HQ

Number of Sites

(Sites Exceeding)

Analytes Exceeding Risk Criterion1

Aluminum 8.70E-02 1.05E+01 1.21E+02 54 (36)

Arsenic IV 8.10E-03 3.94E-01 4.87E+01 119 (40)

Barium 4.00E-03 1.60E+00 4.01E+02 115 (112)

Beryllium 6.60E-04 1.58E-02 2.40E+01 47 (11)

Boron 1.60E-03 1.06E+01 6.61E+03 72 (71)

Cadmium 2.50E-03 4.94E-02 1.98E+01 117 (25)

Chromium VI 1.10E-02 2.00E-01 1.82E+01 118 (27)

Copper 9.30E-03 1.50E-01 1.61E+01 72 (19)

Lead 3.01E-04 2.39E-01 7.94E+02 116 (102)

Mercury 1.90E-07 2.69E-03 1.42E+04 97 (97)

Selenium total 5.00E-03 1.76E-01 3.52E+01 119 (54)

Selenium VI 9.50E-03 1.76E-01 1.85E+01 119 (27)

Silver 3.60E-04 3.95E-02 1.10E+02 109 (77)

Vanadium 2.00E-02 4.50E-01 2.25E+01 40 (9)

Zinc 1.20E-01 1.94E+00 1.61E+01 75 (12)

Analytes Not Exceeding Risk Criterion1

Antimony 3.00E-02 2.61E-01 8.70E+00 60 (3)

Arsenic III 1.50E-01 3.94E-01 2.63E+00 119 (2)

Chromium III 8.60E-02 2.00E-01 2.33E+00 118 (0)

Cobalt 2.30E-02 8.25E-02 3.59E+00 51 (1)

Molybdenum 3.70E-01 6.16E-01 1.67E+00 49 (1)

Nickel 5.20E-02 3.09E-01 5.95E+00 80 (5)

Selenium IV 2.80E-02 1.76E-01 6.28E+00 119 (5)

Thallium 1.20E-02 5.00E-02 4.17E+00 40 (1)

1

Risk criterion is a hazard quotient (HQ) of 10

CSCL = chemical stressor concentration level
Appendix J

J-6

Table J-4. Landfill Aboveground Ecological Screening Results:

Surface Water Sediment Pathways

2002 Sediment Results 1998 Sediment Results

Chemical CSCL

90th

Percentile

Total Waste

(mg/kg)

Sediment1

(mg/kg) HQ

Number of

Sites (Sites

Exceeding)

95th

Percentile

Total

Waste

(mg/kg)

Sediment

(mg/kg) HQ

Analytes Not Exceeding Risk Criterion3

Antimony 2.00E+00 4.62E+01 4.62E-02 2.31E-02 64 (0) 4.67E+01

Arsenic 5.12E-01 1.05E+02 1.05E-01 2.05E-01 111 (0) 1.54E+02

Barium 1.90E+02 1.05E+03 1.05E+00 5.54E-03 94 (0) 8.38E+03 2.40E-01 1.30E-03

Cadmium 6.80E-01 5.42E+00 5.42E-03 7.98E-03 102 (0) 2.37E+01 3.50E-04 5.20E-04

Chromium 1.66E+01 1.66E+02 1.66E-01 9.98E-03 108 (0) 2.91E+02

Copper 1.87E+01 2.28E+02 2.28E-01 1.22E-02 95 (0) 1.55E+02

Lead 2.18E-01 8.06E+01 8.06E-02 3.69E-01 107 (0) 1.52E+02 1.20E-02 5.40E-02

Mercury 1.04E-01 1.63E+00 1.63E-03 1.56E-02 86 (0) -

Molybdenu

m 3.40E+01 3.47E+01 3.47E-02 1.02E-03 73 (0) 4.31E+01

Nickel 1.59E+01 3.29E+02 3.29E-01 2.07E-02 106 (0) 1.55E+02

Silver 7.30E-01 1.37E+01 1.37E-02 1.88E-02 69 (0) 1.36E+01 6.90E-05 9.40E-05

Vanadium 1.80E+01 9.07E+02 9.07E-01 5.04E-02 43 (0) 3.46E+02

Zinc 1.20E+02 2.93E+02 2.93E-01 2.44E-03 98 (0) 8.56E+02

CSCL = chemical stressor concentration level

1

 90th percentile total waste concentration diluted by 1,000 (lowest 1998 sediment dilution factor / 10) 2

 1998 modeled sediment concentration from aboveground pathways using 95th percentile total waste concentration 3

 Risk criterion is a hazard quotient (HQ) of 10