United States
Environmental Protection
Agency
Office of Water
Regulations and Standards
Washington. DC 20460
Water
June, 1985
Environmental Profiles
and Hazard Indices
for Constituents
of Municipal Sludge:
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PREFACE
This document is one of a series of preliminary assessments dealing
with chemicals of potential concern in municipal sewage sludge. The
purpose of these documents is to: (a) summarize the available data for
the constituents of potential concern, (b) identify the key environ-
mental pathways for each constituent related to a reuse and disposal
option (based on hazard indices), and (c) evaluate the conditions under
which such a pollutant may pose a hazard. Each document provides a sci-
entific basis for making an initial determination of whether a pollu-
tant, at levels currently observed in sludges, poses a likely hazard to
human health or the environment when sludge is disposed of by any of
several methods. These methods include landspreading on food chain or
nonfood chain crops, distribution and marketing programs, landfill ing,
incineration and ocean disposal.
These documents are intended to serve as a rapid screening tool to
narrow an initial list of pollutants to those of concern. If a signifi-
cant hazard is indicated by this preliminary analysis, a more detailed
assessment will be undertaken to better quantify the risk from this
chemical and to derive criteria if warranted. If a hazard is shown to
be unlikely, no further assessment will be conducted at this time; how-
ever, a reassessment will be conducted after initial regulations are
finalized. In no case, however, will criteria be derived solely on the
basis of information presented in this document.
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TABLE OF CONTENTS
Page
PREFACE i
1. INTRODUCTION 1-1
2. PRELIMINARY CONCLUSIONS FOR BENZO(A)PYRENE IN MUNICIPAL SEWAGE
SLUDGE 2-1
Landspreading and Distribution-and-Marketing 2-1
Landfilling 2-2
Incineration 2-2
Ocean Disposal 2-3
3. PRELIMINARY HAZARD INDICES FOR BENZO(A)PYRENE IN MUNICIPAL
SEWAGE SLUDGE 3-1
Landspreading and Distribution-and-Marketing 3-1
Effect on soil concentration of benzo(a)pyrene
(Index 1) 3-1
Effect on soil biota and predators of soil biota
(Indices 2-3) 3-2
Effect on plants and plant tissue
concentration (Indices 4-6) 3-4
Effect on herbivorous animals (Indices 7-8) 3-7
Effect on humans (Indices 9-13) 3-9
Landf illing .' 3-16
Index of groundwater concentration resulting
from landfilled sludge (Index 1) 3-16
Index of human cancer risk resulting from
groundwater contamination (Index 2) 3-23
Incineration 3-24
Index of air concentration increment resulting
from incinerator emissions (Index 1) 3-24
Index of human cancer risk resulting from
inhalation of incinerator emissions (Index 2) 3-28
Ocean Disposal 3-29
Index of seawater concentration resulting from
initial mixing of sludge (Index 1) 3-30
Index of seawater concentration representing a
24-hour dumping cycle (Index 2) 3-33
11
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TABLE OP CONTENTS
(Continued)
Page
Index of toxicity to aquatic life (Index 3) 3-34
Index of human toxicity risk resulting from
seafood consumption (Index 4) 3-36
4. PRELIMINARY DATA PROFILE FOR BENZO(A)PYRENE IN MUNICIPAL SEWAGE
SLUDGE 4-1
Occurrence 4-1
Sludge 4-1
Soil - Unpolluted 4-1
Water - Unpolluted 4-1
Air 4-2
Food 4-2
Human Effects 4-4
Ingestion 4-4
Inhalation 4-6
Plant Effects 4-7
Phytotoxicity 4-7
Uptake 4-7
Domestic Animal and Wildlife Effects 4-7
Toxicity 4-7
Uptake 4-7
Aquatic Life Effects 4-7
Toxicity 4-7
Uptake 4-8
Soil Biota Effects 4-8
Physicochemical Data for Estimating Fate and Transport 4-8
5. REFERENCES 5-1
APPENDIX. PRELIMINARY HAZARD INDEX CALCULATIONS FOR
BENZO(A)PYRENE IN MUNICIPAL SEWAGE SLUDGE A-l
111
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SECTION 1
IHTRODUCTION
This preliminary data profile is one of a series of profiles
dealing with chemical pollutants potentially of concern in municipal
sewage sludges. Benzo(a)pyrene (BaP) was initially identified as being
of potential concern when sludge is landspread (including distribution
and marketing), placed in a landfill, incinerated or ocean disposed.*
This profile is a compilation of information that may be useful in
determining whether BaP poses an actual hazard to human health or the
environment when sludge is disposed of by these methods.
The focus of this document is the calculation of "preliminary
hazard indices" for selected potential exposure pathways, as shown in
Section 3. Each index illustrates the hazard that could result from
movement of a pollutant by a given pathway to cause a given effect
(e.g., sludge -* soil * plant uptake * animal uptake -» human toxicity).
The values and assumptions employed in these calculations tend to
represent a reasonable "worst case"; analysis of error or uncertainty
has been conducted to a limited degree. The resulting value in most
cases is indexed to unity; i.e., values >1 may indicate a potential
hazard, depending upon the assumptions of the calculation.
The data used for index calculation have been selected or estimated
based on information presented in the "preliminary data profile",
Section 4. Information in the profile is based on a compilation of the
recent literature. An attempt has been made to fill out the profile
outline to the greatest extent possible. However, since this is a pre-
liminary analysis, the literature has not been exhaustively perused.
The "preliminary conclusions" drawn from each index in Section 3
are summarized in Section 2. The preliminary hazard indices will be
used as a screening tool to determine which pollutants and pathways may
pose a hazard. Where a potential hazard is indicated by interpretation
of these indices, further analysis will include a more detailed exami-
nation of potential risks as well as an examination of site-specific
factors. These more rigorous evaluations may change the preliminary
conclusions presented in Section 2, which are based on a reasonable
"worst case" analysis.
The preliminary hazard indices for selected exposure routes
pertinent to landspreading and distribution and marketing, landfilling,
incineration and ocean disposal practices are included in this profile.
The calculation formulae for these indices are shown in the Appendix.
The indices are rounded to two significant figures.
* Listings were determined by a series of expert workshops convened
during March-May, 1984 by the Office of Water Regulations and
Standards (OWRS) to discuss landspreading, landfilling, incineration,
and ocean disposal, respectively, of municipal sewage sludge.
1-1
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SECTION 2
PRELIMINARY CONCLUSIONS FOR BENZO(A)PYRENE IN MUNICIPAL SEWAGE SLUDGE
The following preliminary conclusions have been derived from the
calculation of "preliminary hazard indices", which represent conserva-
tive or "worst case" analyses of hazard. The indices and their basis
and interpretation are explained in Section 3. Their calculation
formulae are shown in the Appendix.
I. LANDSPREADING AND DISTRIBUTION-AND-MARKETING
A. Effect on Soil Concentration of Benzo(a)pyrene
Landspreading of sludge may slightly increase che soil concen-
tration of BaP when sludge containing a high concentration of
BaP is applied at the 50 and 500 me/ha rates (see Index 1).
B. Effect on Soil Biota and Predators of Soil Biota
Conclusions were not drawn because index values could not be
calculated due to lack of data.
C. Effect on Plants and Plant Tissue Concentration
The potential toxicity of increased soil concentrations of BaP
to plants could not be determined due to lack of data (see
Index 4).
Landspreading of sludge containing a high concentration of BaP
is expected to slightly increase the tissue concentration of
BaP in plants in the animal and human diet (see Index 5).
The maximum plant tissue concentration which is permitted by
phytotoxicity could not be determined due to lack of data
(see Index 6).
D. Effect on Herbivorous Animals
The concentration of BaP in plants grown on sludge-amended
soil is not expected to exceed the dietary concentration which
is toxic to herbivorous animals (see Index 7).
Landspreading of sludge is not expected to pose a toxic hazard
due to BaP for grazing animals that incidentally ingest
sludge-amended soil (see Index 8).
E. Effect on Humans
For toddlers who consume plants grown in sludge-amended soil,
an increase in the risk of cancer due to BaP is expected when
sludges containing the worst-case concentration of BaP are
landspread. For adults, an increase in the risk of cancer is
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expected when sludges containing a typical concentration of
BaP are applied at the rates of 50 and 500 mt/ha, and when
sludges containing a worst-case concentration are applied at
any rate (5 to 500 mt/ha) (see Index 9).
A conclusion was not drawn as to the cancer risk resulting
from consumption of animal products derived from animals feed-
ing on plants because the index values could not be calculated
due to lack of data (see Index 10).
A conclusion was not drawn as to the cancer risk resulting
from consumption of animal products derived from animals
ingesting soil because the index values could not be calcu-
lated due to lack of data (see Index 11).
An increase in the risk of cancer is expected to occur for
toddlers who ingest sludge-amended soil when sludges
containing atypically high concentrations of BaP are applied
to soil at high rates (50 and 500 mt/ha) (see Index 12).
The aggregate human cancer risk due to BaP resulting from
landspreading of sludge could not be evaluated due to lack of
data (see Index 13).
II. LAHDFILLING
The concentration of BaP in groundwater at the well is expected to
increase when sludge is disposed in landfills. The greatest
increase in the groundwater concentration is expected when worst-
case conditions exist in. both the unsaturated and saturated zones
(see Index 1).
The risk of cancer due to BaP in groundwater is expected to
atypically increase above the pre-existing risk due to dietary
sources only when sludges with atypically high concentrations of
BaP are disposed in landfills which are characterized by the worst-
case conditions (see Index 2).
III. INCINERATION
The concentration of BaP in air is expected to increase as the
sludge feed rate and concentration of BaP in sludge increase. An
exception is found when sludge containing a typical concentration
of BaP is burned at a low rate (2660 kg/hr DW); in this case no
increase is expected (see Index 1).
Incineration of sludge is expected to increase the cancer risk due
to inhalation of BaP above the risk posed by background urban air
concentrations of BaP. This increase may be substantial when
sludge containing a high concentration of BaP is incinerated at a
high feed rate and a large fraction of the pollutant is emitted
through the stack (see Index 2).
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IV. OCEAN DISPOSAL
Only slight increases of BaP occur after the dumping of sludges and
initial mixing (see Index 1). Only slight increases of seawater
BaP concentrations occur after a 24-hour dumping cycle (see
Index 2). Only slight increases in the incremental hazard to
aquatic life are evident for worst-concentration sludges dumped at
the typical and worst sites. No increase is apparent for typical
sludges dumped at typical sites (see Index 3). Increases in human
health risk are apparent from consuming seafood taken from typical
or worst sites after dumping of sludges containing worst
concentrations of BaP (see Index 4).
2-3
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SECTION 3
PRELIMINARY HAZARD INDICES FOR BENZO(A)PYRENE
IN MUNICIPAL SEWAGE SLUDGE
LANDSPREADING AND DISTRIBUTION-AND-MARKETING
A. Effect on Soil Concentration of Benzo(a)pyrene
1. Index of Soil Concentration (Index 1)
a. Explanation - Calculates concentrations in Ug/g DW
of pollutant in sludge-amended soil. Calculated for
sludges with typical (median, if available) and
worst (95 percentile, if available) pollutant con-
centrations, respectively, for each of four applica-
tions. Loadings (as dry matter) are chosen and
explained as follows:
0 mt/ha No sludge applied. Shown for all indices
for purposes of comparison, to distin-
guish hazard posed by sludge from pre-
existing hazard posed by background
levels or other sources of the pollutant.
5 mt/ha Sustainable yearly agronomic application;
i.e., loading typical of agricultural
practice, supplying >^50 kg available
nitrogen per hectare.
50 mt/ha Higher single application as may be used
on public lands, reclaimed areas or home
gardens.
500 mt/ha Cumulative loading after 100 years of
application at 5 mt7ha/year.
b. Assumptions/Limitations - Assumes pollutant is
incorporated into the upper 15 cm of soil (i.e., the
plow layer), which has an approximate mass (dry
matter) of 2 x 10^ mt/ha and is then dissipated
through first order processes which can be expressed
as a soil half-life.
c. Data Used and Rationale
i. Sludge concentration of pollutant (SC)
Typical 0.143 Ug/g DW
Worst 1.937 Ug/g DW
The typical and worst sludge concentrations are
the median and 95th percentile values
3-1
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statistically derived from sludge concentration
data from a survey of 40 publicly-owned
treatment works (POTWs) (U.S. EPA, 1982). (See
Section 4, p. 4-1.)
ii. Background concentration of pollutant in soil
(BS) =0.1 Ug/g DW
In agricultural and forest conditions
reasonably removed from industrial and urban
influence, the levels of BaP are approximately
0 to 10 ppb (Kolan et al., 1975 and Hites et
al., 1977 as cited by Overcash, 1984).
iii. Soil half-life of pollutant (t^) = 0.18986 years
The value given was derived from a degradation
rate of 0.01 day"1 (Herbes and Schwall, 1978).
(See Section 4, p. 4-8.)
d. Index 1 Values (ug/g DW)
Sludge Application Rate (mt/ha)
Sludge
Concentration 0 5 50 500
Typical 0.10 0.10 0.10 0.10
Worst 0.10 0.10 0.14 0.11
e. Value Interpretation - Value equals the expected
concentration in sludge-amended soil.
f. Preliminary Conclusion - Landspreading of sludge may
slightly increase the soil concentration of BaP when
sludge containing a high concentration of BaP is
applied at the 50 and 500 mt/ha rates.
Effect on Soil Biota and Predators of Soil Biota
1. Index of Soil Biota Toxicity (Index 2)
a. Explanation - Compares pollutant concentrations in
sludge-amended soil with soil concentration shown to
be toxic for some soil organism.
b. Assumptions/Limitations - Assumes pollutant form in
sludge-amended soil is equally bioavailable and
toxic as form used in study where toxic effects were
demonstrated.
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c. Data Used and Rationale
i. Concentration of pollutant in sludge-amended
soil (Index 1)
See Section 3, p. 3-2.
ii. Soil concentration toxic to soil biota (TB) -
Data not immediately available.
d. Index 2 Values - Values were not calculated due to
lack of data.
e. Value Interpretation - Value equals factor by which
expected soil concentration exceeds toxic concentra-
tion. Value > 1 indicates a toxic hazard may exist
for soil biota.
f. Preliminary Conclusion - Conclusion was not drawn
because index values could not be calculated.
2. Index of Soil Biota Predator Toxicity (Index 3)
a. Explanation - Compares pollutant concentrations
expected in tissues of organisms inhabiting sludge-
amended soil with food concentration shown to be
toxic to a predator on soil organisms.
b. Assumptions/Limitations - Assumes pollutant form
bioconcentrated by soil biota is equivalent in
toxicity to form used to demonstrate toxic effects
in predator. Effect level in predator may be
estimated from that in a different species.
c. Data Used and Rationale
i. Concentration of pollutant in sludge-amended
soil (Index 1)
See Section 3, p. 3-2.
ii. Uptake factor of pollutant in soil biota (UB) -
Data not immediately available.
iii. Peed concentration toxic to predator (TR) -
Data not immediately available.
d. Index 3 Values - Values were not calculated due to
lack of data.
e. Value Interpretation - Values equals factor by which
expected concentration in soil biota exceeds that
which is toxic to predator. Value > 1 indicates a
toxic hazard may exist for predators of soil biota.
3-3
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f. Preliminary Conclusion - Conclusion was not drawn
because index values could not be calculated.
C. Effect on Plants and Plant Tissue Concentration
1. Index of Phytotozic Soil Concentration (Index 4)
a. Explanation - Compares pollutant concentrations in
sludge-amended soil with the lowest soil
concentration shown to be toxic for some plants.
b. Assumptions/Limitations - Assumes pollutant form in
sludge-amended soil is equally bioavailable and
toxic as form used in study where toxic effects were
demonstrated.
c. Data Used and Rationale
i. Concentration of pollutant in sludge-amended
soil (Index 1)
See Section 3, p. 3-2.
ii. Soil concentration toxic to plants (TP) - Data
not immediately available.
d. Index 4 Values - Values were not calculated due to
lack, of data.
e. Value Interpretation - Value equals factor by which
soil concentration exceeds phytotoxic concentration.
Value > 1 indicates a phytotoxic hazard may exist.
f. Preliminary Conclusion - Conclusion was not drawn
because index values could not be calculated.
2. Index of Plant Concentration Caused by Uptake (Index 5)
a. Explanation - Calculates expected tissue
concentrations, in Ug/g DW, in plants grown in
sludge-amended soil, using uptake data for the most
responsive plant species in the following
categories: (1) plants included in the U.S. human
diet; and (2) plants serving as animal feed. Plants
used vary according to availability of data.
b. Assumptions/Limitations - Assumes an uptake factor
that is constant over all soil concentrations. The
uptake factor chosen for the human diet is assumed
to be representative of all crops (except fruits) in
the human diet. The uptake factor chosen for the
animal diet is assumed to be representative of all
crops in the animal diet. See also Index 6 for
consideration of phytotoxicity.
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d.
Diet
Data Used and Rationale
i. Concentration of pollutant in sludge-amended
soil (Index 1)
See Section 3, p. 3-2;
ii. Uptake factor of pollutant in plant tissue (UP)
Animal Diet:
Spinach 0.42 Ug/g tissue DW (ug/g soil DW)1
Human Diet:
Carrot 1.8 Ug/g tissue DW (ug/g soil DW)"1
Spinach was selected to represent a plant
consumed by herbivorous animals because no data
were immediately available for crops normally
fed to animals. It is assumed that the uptake
factor for spinach is similar to uptake factors
for more representative plants. Connor (1984)
reported uptake factors of 0.02 to 0.05 (ratio
of plant to soil concentration, fresh
weight:fresh weight). Since it was noted by
Connor that conversion from dry-dry ratios to
fresh-fresh ratios had been done by multiplying
by 0.12, the inverse was assumed for conversion
of fresh-fresh to dry-dry weights. When con-
verted to a dry-dry ratio, the highest, and
thus most conservative, uptake factor for
spinach was 0.42.
Carrots were selected to represent a plant con-
sumed by humans. The uptake factor for carrot
roots ranged from 0.09 to 0.22 (fresh-fresh
ratio) when grown in sand and was 0.01 when
grown in compost (Connor, 1984). As in the
case of spinach, ratios for fresh weights were
converted to ratios of dry weights by dividing
by a factor of 0.12. The uptake factor
selected was the highest, and thus the most
conservative, value. (See Section 4, p. 4-9.)
Index 5 Values (yg/g DW)
Sludge Application Rate (mt/ha)
Sludge
Concentration 0 5 50 500
Animal
Human
Typical
Worst
Typical
Worst
0.042
0,042
0.18
0.18
0.042
0.044
0.18
0.19
0.042
0.061
0.18
0.26
0.043
0.045
0.18
0.19
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e. Value Interpretation - Value equals the expected
concentration in tissues of plants grown in sludge-
amended soil. However, any value exceeding the
value of Index 6 for the same or a similar plant
species may be unrealistically high because it would
be precluded by phytoxicity.
f. Preliminary Conclusion - Landspreading of sludge
containing a worst concentration of BaP is expected
to slightly increase the tissue concentration of BaP
in plants in the animal and human diet.
3. Index of Plant Concentration Permitted by Pbytotoxicity
(Index 6)
a. Explanation - The index value is the maximum tissue
concentration, in Ug/g DW, associated with phyto-
toxicity in the same or similar plant species used
in Index 5. The purpose is to determine whether the
plant tissue concentrations determined in Index 5
for high applications are realistic, or whether such
concentrations would be precluded by phytotoxicity.
The maximum concentration should be the highest at
which some plant growth still occurs (and thus con-
sumption of tissue by animals is possible) but above
which consumption by animals is unlikely.
b. Assumptions/Limitations - - Assumes that tissue
concentration will be a consistent indicator of
phytotoxicity.
c. Data Used and Rationale
i. Maximum plant tissue concentration associated
with phytoxicity (PP) - Data not immediately
available.
d. Index 6 Values (ug/g DW) - Values were not
calculated due to lack of data.
e. Value Interpretation - Value equals the maximum
plant tissue concentration which is permitted by
phytotoxicity. Value is compared with values for
the same or similar plant species given by Index 5.
The lowest of the two indices indicates the maximal
increase that can occur at any given application
rate.
f. Preliminary Conclusion - Conclusion was not drawn
because index values could not be calculated.
3-6
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D. Effect on Herbivorous Animals
1. Index of Animal Toxicity Resulting from Plant Consumption
(Index 7)
a. Explanation - Compares pollutant concentrations
expected in plant tissues grown in sludge-amended
soil with feed concentration shown to be toxic to
wild or domestic herbivorous animals. Does not con-
sider direct contamination of forage by adhering
sludge.
b. Assumptions/Limitations - Assumes pollutant form
taken up by plants is equivalent in toxicity to form
used to demonstrate toxic effects in animal. Uptake
or toxicity in specific plants or animals may be
estimated from other species.
c. Data Used and Rationale
i. Concentration of pollutant in plant grown in
sludge-amended soil (Index 5)
The pollutant concentration values used are
those Index 5 values for an animal diet (see
Section 3, p. 3-5).
ii. Peed concentration toxic to herbivorous animal
(TA) = 40 ug/g DW
A concentration of 40 Ug/g was the lowest
dietary concentration associated with adverse
effects. This concentration was associated
with carcinogenic effects in mice after oral
administration for 110 days (National Academy
of Sciences (NAS), 1977). No tumors were found
in mice fed up to 30 ppm in the diet for 110
days, while mice fed diets containing 50 to
250 Ug/g for 100 to 197 days showed greater
than 702 incidence of stomach tumors (U.S. EPA,
1980). (See Section 4, p. 4-10.)
d. Index 7 Values
Sludge Application Rate (mt/ha)
Sludge
Concentration 0 5 50 500
Typical 0.0011 0.0011 0.0011 0.0011
Worst 0.0011 0.0011 0.0015 0.0011
e. Value Interpretation - Value equals factor by which
expected plant tissue concentration exceeds that
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which is toxic to animals. Value > 1 indicates a
toxic hazard may exist for herbivorous animals.
f. Preliminary Conclusion - The concentration of BaP in
plants grown on sludge-amended soil is not expected
to exceed the dietary concentration toxic to
herbivorous animals.
2. Index of Animal Toxicity Resulting from Sludge Ingestion
(Index 8)
a. Explanation - Calculates the amount of pollutant in
a grazing animal's diet resulting from sludge adhe-
sion to forage or from incidental ingestion of
sludge-amended soil and compares this with the
dietary toxic threshold concentration for a grazing
animal.
b. Assumptions/Limitations - Assumes that sludge is
applied over and adheres to growing forage, or that
sludge constitutes 5 percent of dry matter in the
grazing animal's diet, and that pollutant form in
sludge is equally bioavailable and toxic as form
used to demonstrate toxic effects. Where no sludge
is applied (i.e., 0 mt/ha), assumes diet is 5 per-
cent soil as a basis for comparison.
c. Data Used and Rationale
i. Sludge concentration of pollutant (SC)
Typical 0.143 ug/g DW
Worst 1.937 Ug/g DW
See 'Section 3, p. 3-1.
ii. Fraction of animal diet assumed to be soil (CS)
= 5%
Studies of sludge adhesion to growing forage
following applications of liquid or filter-cake
sludge show that when 3 to 6 mt/ha of sludge
solids is applied, clipped forage initially
consists of up to 30 percent sludge on a dry-
weight basis (Chaney and Lloyd, 1979; Boswell,
1975). However, this contamination diminishes
gradually with time and growth, and generally
is not detected in the following year's growth.
For example, where pastures amended at 16 and
32 mt/ha were grazed throughout a growing sea-
son (168 days), average sludge content of for-
age was only 2.14 and 4.75 percent, respec-
tively (Bertrand et al., 1981). It seems
reasonable to assume that animals may receive
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Long-term dietary exposure to 5 percent sludge
if maintained on a forage to which sludge is
regularly applied. This estimate of 5 percent
sludge is used regardless of application rate,
since the above studies did not show a clear
relationship between application rate and ini-
tial contamination, and since adhesion is not
cumulative yearly because of die-back.
Studies of grazing animals indicate that soil
ingestion, ordinarily <10 percent of dry weight
of diet, may reach as high as 20 percent for
cattle and 30 percent for sheep during winter
months when forage is reduced (Thornton and
Abrams, 1983). If the soil were sludge-
amended, it is conceivable that up to 5 percent
sludge may be ingested in this manner as'well.
Therefore, this value accounts for either of
these scenarios, whether forage is harvested or
grazed in the field.
iii. Peed concentration toxic to herbivorous animal
(TA) = 40 ug/g DW
See Section 3, p. 3-7.
Index 8 Values
Sludge Application Rate (mt/ha)
Sludge
Concentration 0 5 50 500
Typical
Worst
0
0
0.00018
0.0024
0.00018
0.0024
0.00018
0.0024
Value Interpretation - Value equals factor by which
expected dietary concentration exceeds toxic concen-
tration. Value > 1 indicates a toxic hazard may
exist for grazing animals.
Preliminary Conclusion - Landspreading of sludge is
not expected to pose a toxic hazard due to BaP for
grazing animals that incidentally ingest sludge-
amended soil.
B. Effect on Humans
Index of Human Cancer Risk Resulting from Plant
Consumption (Index 9)
a. Explanation - Calculates dietary intake expected to
result from consumption of crops grown on sludge-
amended soil. Compares dietary intake with the
cancer risk-specific intake (RSI) of the pollutant.
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b. Assumptions/Limitations - Assumes that all crops are
grown on sludge-amended soil and that all those con-
sidered to be affected take up the pollutant at the
same rate. Divides possible variations in dietary
intake into two categories: toddlers (18 months to
3 years) and individuals over 3 years old.
c. Data Used and Rationale
i. Concentration of pollutant in plant grown in
sludge-amended soil (Index 5)
The pollutant concentration values used are
those Index 5 values for a human diet (see
Section 3, p. 3-5).
ii. Daily human dietary intake of affected plant
tissue (DT)
Toddler 74.5 g/day '
Adult 205 g/day
The intake value for adults is based on daily
intake of crop foods (excluding fruit) by vege-
tarians (Ryan et al., 1982); vegetarians were
chosen to represent the worst case. The value
for toddlers is based on the FDA Revised Total
Diet (Pennington, 1983) and food groupings
listed by the U.S. EPA (1984a). Dry weights
for individual food groups were estimated from
composition data given by the U.S. Department
of Agriculture (USDA) (1975). These values
were composited to estimate dry-weight consump-
tion of all non-fruit crops.
iii. Average daily human dietary intake of pollutant
(DI)
Toddler 0.29 Ug/day
Adult 0.88 Ug/day
U.S. EPA (1980) reported that daily intake of
BaP from food ranged from 0.16 to 1.6 Ug/day.
The daily intake was obtained by averaging the
two values at the extremes of the range. The
value for toddlers was calculated by assuming
that daily intake of BaP is one third of the
adult daily intake. (See Section 4, p. 4-3.)
iv. Cancer potency = 11.5 (mg/kg/day)"*
Cancer potency for ingestion of BaP was
calculated by U.S. EPA (1980). The slope was
based on a study by Meal and Rigdon (1967, as
3-10
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cited in U.S. EPA, 1980) in which BaP was fed
to mice at concentrations ranging from 1 to 250
ppm in the diet for approximately 110 days.
Results showed a significant increase in the
incidence of stomach tumors at several doses.
In the four highest dose groups receiving 5.85,
6.5, 13.0, and 13.5 mg/kg body weight (bw)/day,
tumors developed in 4 of 40, 24 of 34, 19 of
23, and 66 of 73 mice, respectively, compared
to 0 of 289 in controls. (See Section 4,
p. 4-5.)
v. Cancer risk-specific intake (RSI) =
0.00607 ug/day
The RSI is the pollutant intake value which
results in an increase in cancer risk of 10~°
(1 per 1,000,000). The RSI is calculated from
the cancer potency using the following formula:
RSI =
10
i~6 x 70 kg x 103 Ug/mg
Cancer potency
Index 9 Values
Group
Sludge
Concentration
Sludge Application
Rate (nit/ha)
5 50
500
Toddler
Typical
Worst
2300
2300
2300
2400
2300
3200
2300
2400
Adult Typical 6200 6200 6300 6400
Worst 6200 6500 8900. 6700
Value Interpretation - Value > 1 indicates a
potential increase in cancer risk of > 10~~° (1 per
1,000,000). Comparison with the null index value at
0 mt/ha indicates the degree to which any hazard is
due to sludge application, as opposed to pre-
existing dietary sources.
Preliminary Conclusion - For toddlers who consume
plants grown in sludge-amended soil, an increase in
the risk of cancer due to BaP is expected when
sludges containing the worst-case concentration of
BaP are landspread. For adults, an increase in the
risk of cancer is expected when sludges containing a
typical concentration of BaP are applied at the
rates of 50 and 500 mt/ha, and when sludges
containing a worst-case concentration are applied at
any rate (5 to 500 mt/ha).
3-11
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Index of Human Cancer Risk Resulting from Consumption of
Animal Products Derived from Animals Feeding on Plants
(Index 10)
a. Explanation - Calculates human dietary intake
expected to result from pollutant uptake by domestic
animals given feed grown on sludge-amended soil
(crop or pasture land) but not directly contaminated
by adhering sludge. Compares expected intake with
RSI.
b. Assumptions/Limitations - Assumes that all animal
products are from animals receiving all their feed
from sludge-amended soil. Assumes that all animal
products consumed take up the pollutant at the
highest rate observed for muscle of any commonly
consumed species or at the rate observed for beef
liver or dairy products (whichever is higher).
Divides possible variations in dietary intake into
two categories: toddlers (18 months to 3 years) and
individuals over 3 years old.
c. Data Used and Rationale
i. Concentration of pollutant in plant grown in
sludge-amended soil (Index 5)
The pollutant concentration values used are
those Index 5 values for an animal diet (see
Section 3, p. 3-5).
ii. Uptake factor of pollutant in animal tissue
(UA) - Data not immediately available.
iii. Daily human dietary intake of affected animal
tissue (DA)
y Toddler 43.7 g/day
Adult ' 88.5 g/day
The fat intake values presented, which comprise
meat, fish, poultry, eggs and milk products,
are derived from the FDA Revised Total Diet
(Pennington, 1983), food groupings listed by
the U.S. EPA (1984a) and food composition data
given by USDA (1975). Adult intake of meats is
based on males 25 to 30 years of age and that
for milk products on males 14 to 16 years of
age, the age-sex groups with the highest daily
intake. Toddler intake of milk products is
actually based on infants, since infant milk
consumption is the highest among that age group
(Pennington, 1983).
3-12
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iv. Average daily human dietary intake of pollutant
(DI)
Toddler 0.29 pg/day
Adult 0.88 pg/day
See Section 3, p. 3-10.
v. Cancer risk-specific intake (RSI) =
0.00607 ug/day
See Section 3, p. 3-11.
d. Index 10 Values - Values were not calculated due to
lack, of data.
e. Value Interpretation - Same as for Index 9.
f. Preliminary Conclusion - Conclusion was not drawn
because index values could not be calculated.
3. Index of Human Cancer Risk Resulting from Consumption of
Animal Products Derived from Animals Ingesting Soil
(Index 11)
a. Explanation - Calculates human dietary intake
expected to result from consumption of animal prod-
ucts derived from grazing animals incidentally
ingesting sludge-amended soil. Compares expected
intake with RSI.
b. Assumptions/Limitations - Assumes that all animal
products are from animals grazing sludge-amended
soil, and that all animal products consumed take up
the pollutant at the highest rate observed for
muscle of any commonly consumed species or at the
rate observed for beef liver or dairy products
(whichever is higher). Divides possible variations
in dietary intake into two categories: toddlers
(18 months to 3 years) and individuals over 3 years
old.
c. Data Used and Rationale
i. Animal tissue - Data not immediately available.
ii. Sludge concentration of pollutant (SC)
Typical 0.143 Ug/g DW
Worst 1.937 yg/g DW
See Section 3, p. 3-1.
3-13
-------
ill. Background concentration of pollutant in soil
(BS) = 0.1 Ug/g DW
See Section 3, p. 3-2.
iv. Fraction of animal diet assumed to be soil (CS)
= 52
See Section 3, p. 3-8.
v. Uptake factor of pollutant in animal tissue
(UA) - Data not immediately available.
vi. Daily human dietary intake of affected animal
tissue (DA)
Toddler ' 39.4 g/day
Adult 82.4 g/day
The affected tissue intake value is assumed to
be from the fat component of meat only (beef,
pork, lamb, veal) and milk products
(Pennington, 1983). This is a slightly more
limited choice than for Index 10. Adult intake
of meats is based on males 25 to 30 years of
age and the intake for milk products on males
14 to 16 years of age, the age-sex groups with
the highest daily intake. Toddler intake of
milk products is actually based on infants,
since infant milk consumption is the highest
among that age group (Pennington, 1983).
vii. Average daily human dietary intake of pollutant
(DI)
Toddler 0.29 Ug/day
Adult 0.88 Ug/day
See Section 3, p. 3-10.
viii. Cancer risk-specific intake (RSI) =
0.00607 ug/day
See Section 3, p. 3-11.
d. Index 11 Values - Values were not calculated due to
lack of data.
e. Value Interpretation - Same as for Index 9.
f. Preliminary Conclusion - Conclusion was not drawn
because index values could not be calculated.
3-14
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4. Index of Human Cancer Risk from Soil Ingestion (Index 12)
a. Explanation - Calculates the amount of pollutant in
the diet of a child who ingests soil (pica child)
amended with sludge. Compares this amount with RSI.
b. Assumptions/Limitations - Assumes that the pica
child consumes an average of 5 g/day of sludge-
amended soil. If the RSI specific for a child is
not available, this index assumes the RSI for a
10 leg child is the same as that for a 70 k.g adult.
It is thus assumed that uncertainty factors used in
deriving the RSI provide protection for the child,
taking into account the smaller body size and any
other differences in sensitivity.
c. Data Used and Rationale
i. Concentration of pollutant in sludge-amended
soil (Index 1)
See Section 3, p. 3-2.
ii. Assumed amount of soil in human diet (DS)
Pica child 5 g/day
Adult 0.02 g/day
The value of 5 g/day for a pica child is a
worst-case estimate employed by U.S. EPA's
Exposure Assessment Group (U.S. EPA, 1983a).
The value of 0.02 g/day for an adult is an
estimate from U.S. EPA, 1984a.
iii. Average daily human dietary intake of pollutant
(DI)
Toddler 0.29 Ug/day
Adult 0.88 Ug/day
See Section 3, p. 3-10.
iv. Cancer risk-specific intake (RSI) =
0.00607 Ug/day
See Section 3, p. 3-11.
3-15
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d. Index 12 Values
Sludge Application
Rate (mt/ha)
Group
Toddler
Adult
Sludge
Concentration
Typical
Worst
Typical
Worst
0
130
130
150
150
5
130
130
150
150
50
130
170
150
150
50
130
140
150
150
e. Value Interpretation - Same as for Index 9.
f. Preliminary Conclusion - An increase in the risk of
cancer is expected to occur for toddlers who ingest
sludge-amended soil when sludges containing
atypically high concentrations of BaP are applied to
soil at high rates (50 and 500 mt/ha).
5. Index of Aggregate Human Cancer Risk (Index 13)
a. Explanation - Calculates the aggregate amount of
pollutant in the human diet resulting from pathways
described in Indices 9 to 12. Compares this amount
with RSI.
b. Assumptions/Limitations - As described for Indices 9
to 12.
c. Data Used and Rationale - As described for Indices 9
to 12.
d. Index 13 Values - Values were not calculated due to
lack of data.
e. Value Interpretation - Same as for Index 9.
f. Preliminary Conclusion - Conclusion was not drawn
because index values could not be calculated.
II. LANDFILLINC
A. Index of Groundwater Concentration Resulting from Landfilled
Sludge (Index 1)
1. Explanation - Calculates groundwater contamination which
could occur in a potable aquifer in the landfill vicin-
ity. Uses U.S. EPA's Exposure Assessment Group (EAG)
model, "Rapid Assessment of Potential Groundwater Contam-
ination Under Emergency Response Conditions" (U.S. EPA,
1983b). Treats landfill leachate as a pulse input, i.e.,
the application of a constant source concentration for a
3-16
-------
short time period relative to the time frame of the anal-
ysis. In order to predict pollutant movement in soils
and groundwater, parameters regarding transport and fate,
and boundary or source conditions are evaluated. Trans-
port parameters include the interstitial pore water
velocity and dispersion coefficient. Pollutant fate
parameters include the degradation/decay coefficient and
retardation factor. Retardation is primarily a function
of the adsorption process, which is characterized by a
linear, equilibrium partition coefficient representing
the ratio of adsorbed and solution pollutant concentra-
tions. This partition coefficient, along with soil bulk
density and volumetric water content, are used to calcu-
late the retardation factor. A computer program (in
FORTRAN) was developed to facilitate computation of the
analytical solution. The program predicts pollutant con-
centration as a function of time and location in both the
unsaturated and saturated zone. Separate computations
and parameter estimates are required for each zone. The
prediction requires evaluations of four dimensionLess
input values and subsequent evaluation of the result,
through use of the computer program.
2. Assumptions/Limitations - Conservatively assumes that the
pollutant is 100 percent mobilized in the leachate and
that all leachate leaks out of the landfill in a finite
period and undiluted by precipitation. Assumes that all
soil and aquifer properties are homogeneous and isotropic
throughout each zone; steady, uniform flow occurs only in
the vertical direction throughout the unsaturated zone,
and only in the horizontal (longitudinal) plane in the
saturated zone; pollutant movement is considered only in
direction of groundwater flow for the saturated zone; all
pollutants exist in concentrations that do not signifi-
cantly affect 'water movement; for organic chemicals, the
background concentration in the soil profile or aquifer
prior to release from the source is assumed to be zero;
the pollutant source is a pulse input; no dilution of the
plume occurs by recharge from outside the source area;
the leachate is undiluted by aquifer flow within the
saturated zone; concentration in the saturated zone is
attenuated only by dispersion.
3. Data Used and Rationale
a. Unsaturated zone
i. Soil type and characteristics
(a) Soil type
Typical Sandy loam
Worst Sandy
3-17
-------
These two soil types were used by Gerritse et
al. (1982) to measure partitioning of elements
between soil and a sewage sludge solution
phase. They are used here since these parti-
tioning measurements (i.e., K^ values) are con-
sidered the best available for analysis of
metal transport from landfilled sludge. The
same soil types are also used for nonmetals for
convenience and consistency of analysis.
(b) Dry bulk density
Typical 1.53 g/mL
Worst 1.925 g/mL
Bulk density is the dry mass per unit volume of
the medium (soil), i.e., neglecting the mass of
the water (CDM, 1984a).
(c) Volumetric water content (0).
Typical 0.195 (unitless)
Worst 0.133 (unitless)
The volumetric water content is the volume of
water in a given volume of media, usually
expressed as a fraction or percent. It depends
on properties of the media and the water flux
estimated by infiltration or net recharge. The
volumetric water content is used in calculating
the water movement through the unsaturated zone
(pore water velocity) and the retardation
coefficient. Values obtained from CDM, 1984a.
(d) Fraction of organic carbon (fOc^
Typical 0.005 (unitless)
Worst 0.0001 (unitless)
Organic content of soils is described' in terms
of percent organic carbon, which is required in
the estimation of partition coefficient, K^.
Values, obtained from R. Griffin (1984) are
representative values for subsurface soils.
ii. Site parameters
(a) Landfill leaching time (LT) = 5 years
Sikora et al. (1982) monitored several sludge
entrenchment sites throughout the United States
and estimated time of landfill leaching to be 4
or 5 years. Other types of landfills may leach
for longer periods of time; however, the use of
3-18
-------
a value for entrenchment sites is conservative
because it results in a higher leachate
generation rate.
(b) Leachate generation rate (Q)
Typical 0.8 m/year
Worst 1.6 m/year
It is conservatively assumed that sludge
leachate enters the unsaturated zone undiluted
by precipitation or other recharge, that the
total volume of liquid in the sludge leaches
out of the landfill, and that leaching is com-
plete in 5 years. Landfilled sludge is assumed
to be 20 percent solids by volume, and depth of
sludge in the landfill is 5 m in the typical
case and 10 m in the worst case. Thus, the
initial depth of liquid is 4 and 8 m, and
average yearly leachate generation is 0.8 and
1.6 m, respectively.
(c) Depth to groundwater (h)
Typical 5 m
Worst 0 m
Eight landfills were monitored throughout the
United States and depths to groundwater below
them were listed. A typical depth to ground-
water of 5 m was observed (U.S. EPA, 1977).
For the worst case, a value of 0 m is used to
represent the situation where the bottom of the
landfill is occasionally or regularly below the
water table. The depth to groundwater must be
estimated in order to evaluate the likelihood
that pollutants moving -through the unsaturated
soil will reach the groundwater.
(d) Dispersivity coefficient (a)
*
Typical 0.5 m
Worst Not applicable
The dispersion process is exceedingly complex
and difficult to quantify, especially for the
unsaturated zone. It is sometimes ignored in
the unsaturated zone, with the reasoning that
pore water velocities are usually large enough
so that pollutant transport by convection,
i.e., water movement, is paramount. As a rule
of thumb, dispersivity may be set equal to
10 percent of the distance measurement of the
analysis (Gelhar and Axness, 1981). Thus,
3-19
-------
based on depth to groundwater Listed above, the
value for the typical case is 0.5 and that for
the worst case does not apply since leachate
moves directly to the unsaturated zone.
iii. Chemical-specific parameters
(a) Sludge concentration of pollutant (SC)
Typical 0.143 mg/kg DW
Worst 1.937 mg/kg DW
See Section 3, p. 3-1.
(b) Soil half-life of pollutant (t^.) = 69.3 days
The value given in days is the same as that
reported in years (0.18986) in Section 3,
p. 3-2.
(c) Degradation rate (u) = 0.01 day'l
The unsaturated zone can serve as an effective
medium for reducing pollutant concentration
through a variety of chemical and biological
decay mechanisms which transform or attenuate
the pollutant. While these decay processes are
usually complex, they are approximated here by
a first-order rate constant. The degradation
rate is calculated using the following formula:
0.693
(d) Organic carbon partition coefficient (Koc) =
630,000 mL/g
The organic carbon partition coefficient is
multiplied by the percent organic carbon
content of soil (fOc^ to derive a partition
coefficient (Kj), which represents the ratio of
absorbed pollutant concentration to the
dissolved (or solution) concentration. The
equation (Koc x foc) assumes that organic
carbon in the soil is the primary means of
adsorbing organic compounds onto soils. This
concept serves to reduce much of the variation
in Kj values for different soil types. The
value of Koc is from Lyman (1982).
3-20
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b. Saturated zone
i. Soil type and characteristics
(a) Soil type
Typical Silty sand
Worst Sand
A silty sand having the values of aquifer por-
osity and hydraulic conductivity defined below
represents a typical aquifer material. A more
conductive medium such as sand transports the
plume more readily and with less dispersion and
therefore represents a reasonable worst case.
(b) Aquifer porosity (0)
Typical 0.44 (unitless)
Worst 0.389 (unitless)
Porosity is that portion of the total volume of
soil that is made up of voids (air) and water.
Values corresponding to the above soil types
are from Pettyjohn et al. (1982) as presented
in U.S. EPA (1983b).
(c) Hydraulic conductivity of the aquifer (K)
Typical 0.86 m/day
Worst 4.04 m/day
The hydraulic conductivity (or permeability) of
the aquifer is needed to estimate flow velocity
based on Darcy's Equation. It is a measure of
the volume of liquid that can flow through a
unit area or media with time; values can range
over nine orders of magnitude depending on the
nature of the media. Heterogenous conditions
produce large spatial variation in hydraulic
conductivity, making estimation of a single
effective value extremely difficult. Values
used are from Freeze and Cherry (1979) as
presented in U.S. EPA (1983b).
(d) Fraction of organic carbon (foc) ~
0.0 (unitless)
Organic carbon content, and therefore adsorp-
tion, is assumed to be 0 in the saturated zone.
3-21
-------
ii. Site parameters
(a) Average hydraulic gradient between landfill and
well (i)
Typical 0.001 (unitless)
Worst 0.02 (unitless)
The hydraulic gradient is the slope of the
water table in an unconfined aquifer, or the
piezometric surface for a confined aquifer.
The hydraulic gradient must be known to deter-
mine the magnitude and direction of groundwater
flow. As gradient increases, dispersion is
reduced. Estimates of typical and high
gradient values were provided by Donigian
(1985).
(b) Distance from well to landfill (Ail)
Typical 100 m
Worst 50 m
This distance is the distance between a
landfill and any functioning public or private
water supply or livestock water supply.
(c) Dispersivity coefficient (a)
Typical 10 m
Worst 5 m
These values are 10 percent of the distance
from well to landfill (AZ), which is 100 and
50 m', respectively, for typical and worst
conditions.
(d) Minimum thickness of saturated zone (B) = 2 m
The minimum aquifer thickness represents the
assumed thickness due to preexisting flow;
i.e., in the absence of leachate. It is termed
the minimum thickness because in the vicinity
of the site it may be increased by leachate
infiltration from the site. A value of 2 m
represents a worst case assumption that
preexisting flow is very limited and therefore
dilution of the plume entering the saturated
zone is negligible.
(e) Width of landfill (W) = 112.8 m
The landfill is arbitrarily assumed to be
circular with an area of 10,000 m^.
3-22
-------
iii. Chemical-specific parameters
(a) Degradation rate (y) = 0 day"1
Degradation is assumed not to occur in the
saturated zone.
(b) Background concentration of pollutant in
groundwater (BC) = 0 ug/L
It is assumed that no pollutant exists in the
soil profile or aquifer prior to release from
the source.
4. Index Values - See Table 3-1.
5. Value Interpretation - Value equals the maximum expected
groundwater concentration of pollutant, in JJg/L, at the
well.
6. Preliminary Conclusion - The concentration of BaP in
groundwater at the well is expected to increase when
sludge is disposed in landfills. The greatest increase
in the groundwater concentration is expected when worst-
case conditions exist in both the unsaturated and
saturated zones.
B. Index of Human Cancer Risk Resulting from Groundwater
Contamination (Index 2)
1. Explanation - Calculates human exposure which could
result from groundwater contamination. Compares exposure
with cancer risk-specific intake (RSI) of pollutant.
2. Assumptions/Limitations - Assumes long-term exposure to
maximum concentration at well at a rate of 2 L/day.
3. Data Used and Rationale
a. Index of groundwater concentration resulting from
landfilled sludge (Index 1)
See Section 3, p. 3-25.
b. Average human consumption of drinking water (AC) =
2 L/day
The value of 2 L/day is a standard value used by
U.S. EPA in most risk assessment studies.
c. Average daily human dietary intake of pollutant (DI)
= 0.88 lag/day
See Section 3, p. 3-10.
3-23
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d. Cancer potency = 11.5 (mg/kg/day)"^-
See Section 3, p. 3-11.
e. Cancer risk-specific intake (RSI) =
0.00607 ug/day
See Section 3, p. 3-11.
4. Index 2 Values - See Table 3-1.
5. Value Interpretation - Value >1 indicates a potential
increase in cancer risk of 10~6 (1 in 1,000,000). The
null index value should be used as a basis for comparison
to indicate the degree to which any risk is due to land-
fill disposal, as opposed to preexisting dietary sources.
6. Preliminary Conclusion - The risk of cancer due to BaP in
groundwater is expected to increase above the pre-
existing risk due to dietary sources only when sludges
with atypically high concentrations of BaP are disposed
in landfills which are characterized by worst-case
conditions.
III. INCINERATION
A. Index of Air Concentration Increment Resulting from
Incinerator Emissions (Index 1)
1. Explanation - Shows the degree of elevation of Che
pollutant concentration in the air due to the incinera-
tion of sludge. An input sludge with thermal properties
defined by the energy parameter (EP) was analyzed using
the BURN model (COM, 1984a). This model uses the thermo-
dynamic and mass balance relationships appropriate for
multiple hearth incinerators to relate the input sludge
characteristics to the stack gas parameters. Dilation
and dispersion of these stack gas releases were described
by the U.S. EPA's Industrial Source Complex Long-Term
(ISCLT) dispersion model from which normalized annual
ground level concentrations were predicted (U.S. EPA,
1979). The predicted pollutant concentration can then be
compared to a ground level concentration used to assess
risk.
2. Assumptions/Limitations - The fluidized bed incinerator
was not chosen due to a paucity of available data.
Gradual plume rise, stack tip downwash, and building wake
effects are appropriate for describing plume behavior.
Maximum hourly impact values can be translated into
annual average values.
3-24
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Site Characteristics
Condition of Analysisa»k»c
345
Sludge concentration
Unsaturated Zone
W
W
N
Soil type and charac-
teristics**
Site parameters6
Saturated Zone
Soil type and charac-
teristics^
Site parameters^
Index 1 Value (pg/L)
Index 2 Value
T
T
T
T
1.3xlO-4
150
T
T
T
T
LBxlO'3
150
W
T
T
T
3.3x10-4
150
NA
W
T
T
3.9xlO-3
150
T
T
W
T
4.3x10-4
150
T
T
T
W
4.6x10-4
150
NA
W
W
W
11
3800
N
N
N
N
0
150
aT - Typical values used; W = worst-case values used; N - null condition, where no landfill exists, used as
basis for comparison; NA = not applicable for this condition.
"Index values for combinations other than those shown may be calculated using the formulae in the Appendix.
cSee Table A-l in Appendix for parameter values used.
"Dry bulk density (Pjjry), volumetric water content (0), and fraction of organic carbon (foc).
eLeachate generation rate (Q), depth to groundwater (h), and dispersivity coefficient (a).
'-Aquifer porosity (0) and hydraulic conductivity of the aquifer (K).
^Hydraulic gradient (i), distance from well to landfill (AS,), and dispersivity coefficient (a).
-------
Data Used and Rationale
a. Coefficient to correct for mass and time units (C) =
2.78 x 10~7 hr/sec x g/mg
b. Sludge feed rate (DS)
i. Typical = 2660 kg/hr (dry solids input)
A feed rate of 2660 kg/hr DW represents an
average dewatered sludge feed rate into the
furnace. This feed rate would serve a commun-
ity of approximately 400,000 people. This rate
was incorporated into the U.S. EPA-ISCLT model
based on the following input data:
EP = 360 Ib H20/mm BTU
Combustion zone temperature - 1400°F
Solids content - 28%
Stack height - 20 m
Exit gas velocity - 20 m/s
Exit gas temperature - 356.9°K (183°F)
Stack diameter - 0.60 m
ii. Worst = 10,000 kg/hr (dry solids input)
A feed rate of 10,000 kg/hr DW represents a
higher feed rate and would serve a major U..S.
city. This rate was incorporated into the U.S.
EPA-ISCLT model based on the following input
data:
EP = 392 Ib H20/mm BTU
. Combustion zone temperature - 1400°F
Solids content - 26.6Z
Stack height - 10 m
Exit gas velocity - 10 m/s
Exit gas temperature - 313.8°K (105°F)
Stack diameter - 0.80 m
c. Sludge concentration of pollutant (SC)
Typical 0.143 mg/kg DW
Worst 1.937 mg/kg DW
See Section 3, p. 3-1.
d. Fraction of pollutant emitted through stack (FM)
Typical 0.05 (unitless)
Worst 0.20 (unitless)
These values were chosen as best approximations of
the fraction of pollutant emitted through stacks
3-26
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(Farrell, 1984). No data was available to validate
these values; however, U.S. EPA is currently testing
incinerators for organic emissions.
e. Dispersion parameter for estimating maximum annual
ground level concentration (DP)
Typical 3.4
Worst 16.0
The dispersion parameter is derived from the U.S.
EPA-ISCLT short-stack model.
f. Background concentration of pollutant in urban
air (BA) = 0.0005 Ug/m3
Average concentrations of BaP in urban areas of the
United States were 0.0032 Ug/m3 in 1966, 0.0021
Ug/m3 in 1970, and 0.0005 in 1976 (U.S. EPA,
1980). These data indicate a declining trend.
Therefore, the value selected to represent the back-
ground concentration of BaP in urban air is the most
recent of these three values. (See Section 4,
p. 4-2.)
4. Index 1 Values
Sludge Feed
Fraction of Rate (kg/hr DW)a
Pollutant Emitted Sludge
Through Stack Concentration 0 2660 10,000
Typical
Typical
Worst
1.0
1.0
1.0
1.5
1.6
9.6
Worst Typical 1.0 1.1 3.5
Worst 1.0 2.9 35
a The typical (3.4 ug/m3) and worst (16.0 Ug/m3) disper-
sion parameters will always correspond, respectively,
to the typical (2660 kg/hr DW) and worst (10,000 kg/hr
DW) sludge feed rates.
Value Interpretation - Value equals factor by which
expected air concentration exceeds background levels due
to incinerator emissions.
Preliminary Conclusion - The concentration of BaP in air
is expected to increase as the sludge feed rate and con-
centration of BaP in sludge increase. An exception is
found when sludge containing a typical concentration of
BaP is burned at a low rate (2660 kg/hr DW); in this case
no increase is expected.
3-27
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B. Index of Human Cancer Risk Resulting from Inhalation
of Incinerator Emissions (Index 2)
1. Explanation - Shows the increase in human intake expected
to result from the incineration of sludge. Ground level
concentrations for carcinogens typically were developed
based upon assessments published by the U.S. EPA Carcino-
gen Assessment Group (GAG). These ambient concentrations
reflect a dose level which, for a lifetime exposure,
increases the risk of cancer by 10~^.
2. Assumptions/Limitations - The exposed population is
assumed to reside within the impacted area for 24
hours/day. A respiratory volume of 20 m3/day is assumed
over a 70-vear lifetime.
3. Data Used and Rationale
a. Index of air concentration increment resulting from
incinerator emissions (Index 1)
See Section 3, p. 3-27.
b. Background concentration of pollutant in urban air
(BA) = 0.0005 Ug/m3
See Section 3, p. 3-27.
c. Cancer potency = 4.3 (mg/kg/day)~*
The cancer potency for inhalation of BaP was derived
by U.S. EPA (1984b) based on a study by Thyssen et
al. (1981, as cited in U.S. EPA, 1984b) in which
Syrian golden hamsters were exposed to BaP by
inhalation. Dose levels of 2.2, 9.5, and 46.5 mg/m3
produced tumors in 0 of 27, 9 of 26, and 13 of 25
animals, respectively. No tumors were found in the
27 controls. (See Section 4, p. 4-6.)
d. Exposure criterion (EC) = 0.00081 Ug/m3
A lifetime exposure level which would result in a
10~° cancer risk was selected as ground level con-
centration against which incinerator emissions are
compared. The risk estimates developed by CAG are
defined as the lifetime incremental cancer risk in a
hypothetical population exposed continuously
throughout ' their lifetime to the stated con-
centration of the carcinogenic agent. The exposure
criterion is calculated using the following formula:
Pf, 10"6 x 103 Ug/mg x 70 kg
C.L. ^'~" ^~~~'~~~
Cancer potency x 20 m-Vday
3-28
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4. Index 2 Values
Sludge Feed
Fraction of Rate (kg/hr DW)a
Pollutant Emitted Sludge
Through Stack. Concentration 0 2660 10,000
Typical
Typical
Worst
0.62
0.62
0.64
0.92
1.0
5.9
Worst Typical 0.62 0.71 2.2
Worst 0.62 1.8 22
a The typical (3.4 ug/m^) and worst (16.0 yg/m^) disper-
sion parameters will always correspond, respectively,
to the typical (2660 kg/hr DW) and worst (10,000 kg/hr
DW) sludge feed rates.
5. Value Interpretation - Value > 1 indicates a potential
increase in cancer risk of > 10~6 (1 per 1,000,000).
Comparison with the null index value at 0 kg/hr DW
indicates the degree to which any hazard is due to sludge
incineration, as opposed to background urban air
concentration.
6. Preliminary Conclusion - Incineration of sludge is
expected to increase the cancer risk due to inhalation of
BaP above the risk posed by background urban air concen-
trations of BaP. This increase may be substantial when
sludge containing a high concentration of BaP is inciner-
ated at a high feed rate and a large fraction of the
pollutant is emitted through the stack.
IV. OCEAN DISPOSAL
For the purpose of evaluating pollutant effects upon and/or
subsequent uptake by marine life as a result of sludge disposal,
two types of mixing were modeled. The initial mixing or dilution
shortly after dumping of a single load of sludge represents a high,
pulse concentration to which organisms may be exposed for short
time periods but which could be repeated frequently; i.e., every
time a recently dumped plume is encountered. A subsequent addi-
tional degree of mixing can be expressed by a further dilution.
This is defined as the average dilution occurring when a day's
worth of sludge is dispersed by 24 hours of current movement and
represents the time-weighted average exposure concentration for
organisms in the disposal area. This dilution accounts for 8 to 12
hours of the high pulse concentration encountered by the organisms
during daylight disposal operations and 12 to 16 hours of recovery
(ambient water concentration) during the night when disposal
operations are suspended.
3-29
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A. Index of Seawater Concentration Resulting from Initial Mixing
of Sludge (Index 1)
1. Explanation - Calculates increased concentrations in ug/L
of pollutant in seawater around an ocean disposal site
assuming initial mixing.
2. Assumptions/Limitations - Assumes that the background
seawater concentration of pollutant is unknown or zero.
The index also assumes that disposal is by tanker and
that the daily amount of sludge disposed is uniformly
distributed along a path transversing the site and
perpendicular to the current vector. The initial
dilution volume is assumed to be determined by path
length, depth to the pycnocline (a layer separating
surface and deeper water masses), and an initial plume
width defined as the width of the plume four hours after
dumping. The seasonal disappearance of the pycnocline is
not considered.
3. Data Used and Rationale
a. Disposal conditions
Sludge Sludge Mass Length
Disposal Dumped by a of Tanker
Rate (SS) Single Tanker (ST) Path (L)
Typical 825 mt DW/day 1600 mt WW 8000 m
Worst 1650 mt DW/day 3AOO mt WW 4000 m
The typical value for the sludge disposal rate
assumes that 7.5 x 10^ mt WW/year are available for
dumping from a metropolitan coastal area. The con-
version to dry weight assumes 4 percent solids by
weight. The worst-case value is an arbitrary
doubling of the typical value to allow for potential
future increase.
The assumed disposal practice to be followed at the
model site representative of the typical case is a
modification of that proposed for sludge disposal at
the formally designated 12-mile site in the New York
Bight Apex (City of New York, 1983). Sludge barges
with capacities of 3400 mt WW would be required to
discharge a load in no less than 53 minutes travel-
ing at a minimum speed of 5 nautical miles (9260 m)
per hour. Under these conditions, the barge would
enter the site, discharge the sludge over 8180 m and
exit the site. Sludge barges with capacities of
1600 mt WW would be required to discharge a load in
no less than 32 minutes traveling at a minimum speed
of 8 nautical miles (14,816 m) per hour. Under
these conditions, the barge would enter the site,
3-30
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discharge the sludge over 7902 m and exit the site.
The mean path length for the large and small tankers
is 8041 m or approximately 8000 m. Path length is
assumed to lie perpendicular to the direction of
prevailing current flow. For the typical disposal
rate (SS) of 825 mt DW/day, it is assumed that this
would be accomplished by a mixture of four 3400 mt
WW and four 1600 mt WW capacity barges. The overall
daily disposal operation would last from 8 to 12
hours. For the worst-case disposal rate (SS) of
1650 mt DW/day, eight 3400 mt WW and eight 1600 mt
WW capacity barges would be utilized. The overall
daily disposal operation would last from 8 to 12
hours. For both disposal rate scenarios, there
would be a 12 to 16 hour period at night in which no
sludge would be dumped. It is assumed that under
the above described disposal operation, sludge
dumping would occur every day of the year.
The assumed disposal practice at the model site
representative of the worst case is as stated for
the typical site, except that barges would dump half
their load along a track, then turn around and
dispose of the balance along the same track in order
to prevent a barge from dumping outside of the site.
This practice would effectively halve the path
length compared to the typical site.
b. Sludge concentration of pollutant (SC)
Typical 0.143 mg/kg DW
Worst 1.937 mg/kg DW
See Section 3, p. 3-1.
c. Disposal site characteristics
Average
current
Depth to velocity
pycnocline (D) at site (V)
Typical 20 m 9500 m/day
Worst 5 m 4320 m/day
Typical site values are representative of a Large,
deep-water site with an area of about 1500 km^
located beyond the continental shelf in the New York
Bight. The pycnocline value of 20 m chosen is the
average of the 10 to 30 m pycnocline depth range
occurring in the summer and fall; the winter and
spring disappearance of the pycnocline is not consi-
dered and so represents a conservative approach in
evaluating annual or long-term impact. The current
3-31
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velocity of 11 cm/sec (9500 m/day) chosen is based
on the average current velocity in this area (COM,
1984b).
Worst-case values are representative of a near-shore
New York Bight site with an area of about 20 km^.
The pycnocline value of 5 m chosen is the minimum
value of the 5 to 23 ra depth range of the surface
mixed layer and is therefore a worst-case value.
Current velocities in this area vary from 0 to
30 cm/sec. A value of 5 cm/sec (4320 m/day) is
arbitrarily chosen to represent a worst-case value
(COM, 1984c).
4. Factors Considered in Initial Mixing
When a load of sludge is dumped from a moving tanker, an
immediate mixing occurs in the turbulent wake of the
vessel, followed by more gradual spreading of the plume.
The entire plume, which initially constitutes a narrow
band the length of the tanker path, moves more-or-less as
a unit with the prevailing surface current and, under
calm conditions, is not further dispersed by the current
itself. However, the current acts to separate successive
tanker loads, moving each out of the immediate disposal
path before the next load is dumped.
Immediate mixing volume after barge disposal is
approximately equal to the length of the dumping track
with a cross-sectional area about four times that defined
by the draft and width of the discharging vessel
(Csanady, 1981, as cited in NOAA, 1983). The resulting
plume is initially 10 m deep by 40 m wide (O'Connor and
Park, 1982, as cited in NOAA, 1983). Subsequent
spreading of plume band width occurs at an average rate
of approximately 1 cm/sec (Csanady et al., 1979, as cited
in NOAA, 1983). Vertical mixing is limited by the depth
of the pycnocline or ocean floor, whichever is shallower.
Four hours after disposal, therefore, average plume width
(W) may be computed as follows:
W = 40 m + 1 cm/sec x 4 hours x 3600 sec/hour x 0.01 m/cm
= 184 m - approximately 200 m
Thus the volume of initial mixing is defined by the
tanker path, a 200 m width, and a depth appropriate to
the site. For the typical (deep water) site, this depth
is chosen as the pycnocline value of 20 m. For the worst
(shallow water) site, a value of 10 m was chosen. At
times the pycnocline may be as shallow as 5 m, but since
the barge wake causes initial mixing to at least 10 m,
the greater value was used.
3-32
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5. Index 1 Values (ug/L)
Disposal Sludge Disposal
Conditions and Rate (mt DW/day)
Site Charac- Sludge
teristics Concentration 0 825 1650
Typical Typical 0.0 0.00029 0.00029
Worst 0.0 0.0039 0.0039
Worst Typical 0.0 0.0024 0.0024
Worst 0.0 0.033 0.033
6. Value Interpretation - Value equals the expected increase
.in BaP concentration in seawater around a disposal site
as a result of sludge disposal after initial mixing.
7. Preliminary Conclusion - Only slight increases of BaP
occur after the dumping of sludges and initial mixing.
B. Index of Seawater Concentration Representing a 24-Hour Dumping
Cycle (Index 2)
1. Explanation - Calculates increased effective concentra-
tions in Ug/L of pollutant in seawater around an ocean
disposal site utilizing a time weighted average (TWA)
concentration. The TWA concentration is that which would
be experienced by an organism remaining stationary (with
respect to the ocean floor) or moving randomly within the
disposal vicinity. The dilution volume is determined by
the tanker path length and depth to pycnocline or, for
the shallow water site, the 10 m effective mixing depth,
as before, but the effective width is now determined by
current movement perpendicular to the tanker path over 24
hours.
2. Assumptions/Limitations - Incorporates all of the assump-
tions used to calculate Index 1. In addition, it is
assumed that organisms would experience high-pulsed
sludge concentrations for 8 to 12 hours per day and then
experience recovery (no exposure to sludge) for 12 to 16
hours per day. This situation can be expressed by the
use of a TWA concentration of sludge constituent.
3. Data Used and Rationale
See Section 3, pp. 3-30 to 3-32.
4. Factors Considered in Determining Subsequent Additional
Degree of Mixing (Determination of TWA Concentrations)
See Section 3, p. 3-33.
3-33
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5. Index 2 Values (ug/L)
Disposal Sludge Disposal
Conditions and Rate (mt DW/day)
Site Charac- Sludge
teristics Concentration 0 825 1650
Typical Typical 0.0 0.000078 0.00016
Worst 0.0 0.0011 0.0021
Worst Typical 0.0 0.00068 0.0014
Worst 0.0 0.0092 0.018
6. Value Interpretation - Value equals the effective
increase in BaP concentration expressed as a TWA concen-
tration in seawater around a disposal site experienced by
an organism over a 24-hour period.
7. Preliminary Conclusion - Only slight increases of
seawater BaP concentrations occur after a 24-hour dumping
cycle.
C. Index of Toxicity to Aquatic Life (Index 3)
1. Explanation - Compares the effective increased concentra-
tion of pollutant in seawater around the disposal site
resulting from the initial mixing of sludge (Index 1)
with the marine ambient water quality criterion of the
pollutant, or with another value judged protective of
marine aquatic life. For BaP, this value is the
criterion that will protect marine aquatic organisms from
both acute and chronic toxic effects.
Wherever a short-term "pulse" exposure may occur as it
would from initial mixing, it is usually evaluated using
the "maximum" criteria values of EPA's ambient water
quality criteria methodology. However, under this
scenario, because the pulse is repeated several times
daily on a long-term basis, potentially resulting in an
accumulation of injury, it seems more appropriate to use
values designed to be protective against chronic tox-
icity. Therefore, to evaluate the potential for adverse
effects on marine life resulting from initial mixing con-
centrations, as quantified by Index 1, the chronically
derived criteria values are used.
2. Assumptions/Limitations - In addition to the assumptions
stated for Indices 1 and 2, assumes that all of the
released pollutant is available in the water column to
move through predicted pathways (i.e., sludge to seawater
to aquatic organism to man). The possibility of effects
arising from accumulation in the sediments is neglected
since the U.S. EPA presently lacks a satisfactory method
for deriving sediment criteria.
3-34
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4.
Data Used and Rationale
a. Concentration of pollutant in seawater around a
disposal site (Index 1)
See Section 3, p. 3-33.
b. Ambient water quality criterion (AHQC) = 300 Ug/L
Water quality criteria for the toxic pollutants
listed under Section 307(a)(l) of the Clean Water
Act of 1977 were developed by the U.S. EPA under
Section 304(a)(l) of the Act. These criteria were
derived by utilization of data reflecting the
resultant environmental impacts and human health
effects of these pollutants if present in any body
of water. The criteria values presented in this
assessment are excerpted from the ambient water
quality criteria document for polynuclear aromatic
hydrocarbons (PAHs).
No BaP-specific criteria values are immediately
available. The 300 Ug/L value chosen as the
criterion to protect saltwater organisms is an acute
toxicity value based on tests of polychaete worms
exposed to crude oil fractions. No data are pres-
ently available regarding the chronic effects of
PAHs on more sensitive marine aquatic life (U.S.
EPA, 1980).
Index 3 Values
Disposal
Conditions and
Site Charac- Sludge
teristics Concentration
Sludge Disposal
Rate (mt DW/day)
825
1650
Typical
Typical
Worst
0.0
0.0
0.00000095
0.000013
0.00000095
0.000013
Worst
Typical
Worst
0.0
0.0
0.0000081
0.00011
0.0000081
0.00011
Value Interpretation - Value equals the factor by which
the expected seawater concentration increase in BaP
exceeds the protective value. A value > 1 indicates that
acute or chronic toxic conditions may exist for organisms
at the site.
Preliminary Conclusion - Only slight increases in the
incremental hazard to aquatic life are evident for worst-
concentration sludges dumped at the typical and worst
sites. No increase is apparent for typical sludges
dumped at typical sites.
3-35
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D. Index of Human Cancer Risk. Resulting from Seafood Consumption
(Index 4)
1. Explanation - Estimates the expected increase in human
pollutant intake associated with the consumption of
seafood, a fraction.of which originates from the disposal
site vicinity, and compares the total expected pollutant
intake with the cancer risk-specific intake (RSI) of the
pollutant.
2. Assumptions/Limitations - In addition to the assumptions
listed for Indices 1 and 2, assumes that the seafood
tissue concentration increase can be estimated from the
increased water concentration by a bioconcentration
factor. It also assumes that, over the long term, the
seafood catch from the disposal site vicinity will be
diluted to some extent by the catch from uncontaminated
areas.
3. Data Used and Rationale
a. Concentration of pollutant in seawater around a
disposal site (Index 2)
See Section 3, p. 3-34.
Since bioconcentration is a dynamic and reversible
process, it is expected that uptake of sludge
pollutants by marine organisms at the disposal site
will reflect TWA concentrations, as quantified by
Index 2, rather than pulse concentrations.
b. Dietary consumption of seafood (QP)
Typical ' 14.3 g WW/day
Worst 41.7 g WW/day
Typical and worst-case values are the mean and the
95th percentile, respectively, for all seafood
consumption in the United States (Stanford Research
Institute (SRI) International, 1980).
c. Fraction of consumed seafood originating from the
disposal site (FS)
For a typical harvesting scenario, it was assumed
that the total catch over a wide region is mixed by
harvesting, marketing and consumption practices, and
that exposure is thereby diluted. Coastal areas
have been divided by the National Marine Fishery
Service (NMFS) into reporting areas for reporting on
data on seafood landings. Therefore it was conven-
ient to express the total area affected by sludge
disposal as a fraction of an NMFS reporting area.
3-36
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The area used to represent the disposal impact area
should be an approximation of the total ocean area
over which the average concentration defined by
Index 2 is roughly applicable. The average rate of
plume spreading of 1 cm/sec referred to earlier
amounts to approximately 0.9 km/day. Therefore, the
combined plume of all sludge dumped during one
working day will gradually spread, both parallel to
and perpendicular to current direction, as it pro-
ceeds down-current. Since the concentration has
been averaged over the direction of current flow,
spreading in this dimension will not further reduce
average concentration; only spreading in the perpen-
dicular dimension will reduce the average. If sta-
ble conditions are assumed over a period of days, at
least 9 days would be required to reduce the average
concentration by one-half. At that time, the origi-
nal plume length of approximately 8 km (8000 m) will
have doubled to approximately 16 km due to
spreading.
It is probably unnecessary to follow the plume
further since storms, which would result in much
more rapid dispersion of pollutants to background
concentrations are expected on at least a 10-day
frequency (NOAA, 1983). Therefore, the area
impacted by sludge disposal (AI, in km2) at each
disposal site will be considered to be defined by
the tanker path length (L) times the distance of
current movement (V) during 10 days, and is computed
as follows:
AI = 10 x L x V x 10~6 km2/m2 (1)
To be consistent with a conservative approach, plume
dilution due to spreading in the perpendicular
direction to current flow is disregarded. More
likely, organisms exposed to the plume in the area
defined by equation 1 would experience a TWA concen-
tration lower than the concentration expressed by
Index 2.
Next, the value of AI must be expressed as a
fraction of an NMFS reporting area. In the New York
Bight, which includes NMFS areas 612-616 and 621-
623, deep-water area 623 has an area of approxi-
mately 7200 km2 and constitutes approximately
0.02 percent of the total seafood landings for the
Bight (CDM, 1984b). Near-shore area 612 has an area
of approximately 4300 km2 and constitutes approxi-
mately 24 percent of the total seafood landings
(CDM, 1984c). Therefore the fraction of all seafood
landings (FSt) from the Bight which could originate
from the area of impact of either the typical (deep-
3-37
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water) or worst (near-shore) site can be calculated
for this typical harvesting scenario as follows:
For the typical (deep water) site:
uc - AI x 0.02Z = (2)
t!>t ~ 7200 km^
[10 x 8000 m x 9500 m x 10~6 ka^/m2] x 0.0002 _ 5
M " ^ i X 1U
7200 km2
For the worst (near shore) site:
FSt, ALJ
4300 km2
[10 x 4000 m x 4320 m x 10~6 km2/m2] x Q.24 3
r+ ~ ./ * o x i u
4300 km2
To construct a worst-case harvesting scenario, it
was assumed that the total seafood consumption for
an individual could originate from an area more
limited than the entire New York. Bight. For
example, a particular fisherman providing the entire
seafood diet for himself or others could fish habit-
ually within a single NMFS reporting area. Or, an
individual could have a preference for a particular
species which is taken only over a more limited
area, here assumed arbitrarily to equal an NMFS
reporting area. The fraction of consumed seafood
(FSW) that could originate from the area of impact
under this worst-case scenario is calculated as
follows:
For the typical (deep water) sice:
FSW = 'AI , = 0.11 (4)
7200 km2
For the worst (near shore) site:
FSW = Q-^r = 0.040 (5)
4300 km2
d. Bioconcentration factor of pollutant (BCP) =
11,100 L/kg
The value chosen is the weighted average BCF of BaP
for the edible portion of all freshwater and
estuarine aquatic organisms consumed by U.S. citi-
zens (U.S. EPA, 1980). The weighted average BCF is
derived as part of the water quality criteria devel-
oped by the U.S. EPA to protect human health from
the potential carcinogenic effects of BaP induced by
3-38
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4.
ingestion of contaminated water and aquatic
organisms. Although no measured steady-state BCF
for BaP is available, a BCF value for aquatic organ-
isms containing about 7.6% lipids can be estimated
from the octanol-water partition coefficient. The
weighted average BCF is derived by applying an
adjustment factor to the BCF estimate to correct for
the 32 lipid content of consumed fish and shellfish.
It should be noted, however, that the resulting
estimated weighted average BCF of 11,100 L/kg is a
possible overestimation. Although data concerning
the environmental impacts of PAHs are incomplete,
the results of numerous studies show that PAHs
demonstrate little tendency for bioaccumulation due
to their rapid metabolism (U.S. EPA, 1980). It
should be noted that lipids of marine species differ
in both structure and quantity from those of fresh-
water species. Although a BCF value calculated
entirely from marine data would be more appropriate
for this assessment, no such data are presently
available.
e. Average daily human dietary intake of pollutant (DI)
= 0.88 Ug/day
See Section 3, p. 3-10.
f. Cancer potency = 11.5 (mg/k.g/day)~^
See Section 3, p. 3-11.
g. Cancer risk-specific intake (RSI) = 0.00607 ug/day
See Section 3, p. 3-11.
Index 4 Values
Disposal
Conditions and
Site Charac- Sludge Seafood
teristics Concentration3 Intake3'"
Sludge Disposal
Rate (mt DW/day)
0
825 1650
Typical
Typical
Worst
Typical
Worst
140
140
140
150
140
160
Worst
Typical
Worst
Typical
Worst
140
140
140
170
140
200
a All possible combinations of these values are not
presented. Additional combinations may be calculated
using the formulae in the Appendix.
b Refers to both the dietary consumption of seafood (QF)
and the fraction of consumed seafood originating from
3-39
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the disposal site (FS). "Typical" indicates the use of
the typical-case values for both of these parameters;
"worst" indicates the use of the worst-case values for
both.
Value Interpretation - Value equals factor by which the
expected intake exceeds the RSI. A value >1 indicates a
possible human health threat. Comparison with the null
index value at 0 mt/day indicates the degree to which any
hazard is due to sludge disposal, as opposed to pre-
existing dietary sources.
Preliminary Conclusion - Increases in human health risk.
are apparent from consuming seafood taken from typical or
.worst sites after dumping of sludges containing worst
concentrations of BaP.
3-40
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SECTION 4
PRELIMINARY DATA PROFILE FOR BENZO(A)PYRENE
IN MUNICIPAL SEWAGE SLUDGE
I. OCCURRENCE
A. Sludge
1. Frequency of Detection
BaP was detected in 21 of 437 samples U.S. EPA, 1982
(5Z) and 3 of 42 samples (72) from 50 (pp. 42 and 50)
POTWs.
2. Concentration
Dry-weight sludge concentrations of BaP Statistically
found in a survey of POTWs: derived from
Median 0.143 ug/g DW data presented
95th percentile 1.937 Ug/g DW in U.S. EPA,
Mean 0.561 ug/g DW 1982
Minimum Not detected
Maximum 2.918 ug/g DW
Wet-weight sludge concentrations: U.S. EPA, 1982
1 to 490 Ug/L from 437 samples (p. 42)
from the 40-city study.
B. Soil - Unpolluted
1. Frequency of Detection
Data not immediately available.
2. Concent rat i on
The concentration in the upper layers of Suess, 1976
of the earth is in the range of 0.100 to (p. 244)
1.000 Ug/g of carcinogenic PAHs and
results from the activity of soil
bacteria and from decayed plants.
C. Mater - Unpolluted
1. Frequency of Detection
0 of 87 systems tested serving popula- Pendygraft
tions of >75,000 were positive for BaP. et al., 1979
(pp. 177 and
181)
4-1
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2. Concentration
a. Freshwater
Groundwater will have a carcinogenic Suess, 1976
PAH concentration of 0.001 to (p. 244)
0.010 Ug/L. Freshwater lakes will
have a PAH concentration of 0.010 to
0.025 ug/L.
b. Seawater
Data not immediately available.
c. Drinking Water
Water = 0.0011 Ug/day U.S. EPA, 1980
(p. 112)
D. Air
1. Frequency of Detection
Data not immediately available.
2. Concentration
a. Urban
Philadelphia average BaP concentra- Suess, 1976
tions for 1967-1969 for the four (p. 244)
quarters of the year were 6.3, 1.7,
1.4, and 6.7 ng/m^.
Pittsburgh average BaP concentrations Suess, 1976
for 1967-1969 for the four quarters (p. 246)
of the year were 21.3, 18.3, 6.0, and
9.4 ng/m3.
BaP in air of U.S. cities (ng/nr*): U.S. EPA, 1980
(p. C-32)
1966 1970 1976
3.2 2.1 0.5
4-2
-------
b. Rural
0.1 to 0.2 ng/m^ Suess, 1976
(p. 244)
BaP in air of U.S. rural areas U.S. EPA, 1980
ng/m3: (p. C-32)
1966 1970 1976
0.4 0.2 0,1
E. Food
1. Total Average Intake
Data not immediately available.
2. Concentration
Average Daily Intake of BaP: U.S. EPA, 1980
Water = 0.0011 Ug/day (p. C-112)
Food = 0.160 to 1.6 Ug/day
Estimated average adult intake for
food =0.88 Ug/day (based on mean
of the range values)
Estimated average toddler intake =
0.29 Ug/day (based on assumption
that toddler intake is 1/3 of adult
intake)
A test of 39 beers showed no BaP above Joe et al., 1981
a level of 0.5 ng/g. (p. 644)
BaP concentrations in vegetable oils and U.S. EPA, 1980
margarine showed BaP values of 0.2 to (p. C-13)
8.0 ng/g.
BaP concentrations in smoked fish ranged U.S. EPA, 1980
from trace amounts to 0.6 ng/g. (p. C-14)
BaP concentrations in smoked meat ranged U.S. EPA, 1980
from trace amounts to 10.5 ng/g. (p. C-21)
BaP concentrations in fruits from U.S. EPA, 1980
unpolluted environments ranged from (p. C-24)
trace amounts to 29.7 ng/g (data for
Europe and Japan).
BaP concentrations in cereals showed U.S. EPA, 1980
values of 0.1 to 60 ng/g (data for (p. C-25)
Europe and Japan).
4-3
-------
BaP concentrations in vegetables from U.S. EPA, 1980
unpolluted environments showed values of (p. C-26)
0.01 to 24.3 ng/g (data for Europe and
Japan).
II. HUMAN EFFECTS
A. Ingestion
1. Carcinogenicity
a. Qualitative Assessment
Numerous polycyclic aromatic com- U.S. EPA, 1980
pounds (such as BaP) are distinctive (p. C-72)
in their ability to produce tumors in
skin and most epithelial tissues of
almost all species tested. Latency
periods can be short, and tumors pro-
duced may resemble human carcinomas.
Carcinogenicity of BaP has not been U.S. EPA, 1980
studied as thoroughly by oral intake (pp. C-86, C-88,
as by other routes of administration; C-89)
however, tumors of various sites
result when BaP is administered orally
to rodents. Tumors include stomach
tumors, leukemias, lung adenomas,
esophagal tumors, and intestinal
tumors. With oral, intratracheal, and
intravenous routes of administration,
BaP is less effective than other PAHs
(e.g., 7,12-dimethylenz[a]anthracene,
3-methylcholanthrene, and dibenz(a,h)-
anthracene) in producing carcinomas,
but has remarkable potency for induc-
tion of skin tumors in mice.
b. Potency
Cancer potency = 11.5 (mg/kg/day)"1 U.S. EPA, 1980
(p. C-180)
The cancer potency was derived from
data reported by Neal and Rigdon
(1967), as cited in U.S. EPA (1980).
In this study, BaP was fed to CFW
mice at dietary concentrations rang-
ing from 1 to 250 ppm for approxi-
mately 110 days. Stomach tumors
(primarily squamous cell papillomas,
but some carcinomas) appeared with an
incidence statistically higher than
controls at several doses.
4-4
-------
Tumor incidences:
Dose Incidence
(mg/kg/dav) (No. Responding/No. Tested)
0.0 0/289
0.13 0/25
1.3 0/24
2.6 1/23
3.9 0/37
5.2 1/40
5.85 4/40
6.5 24/34
13.0 19/23
13.5 66/73
2. Chronic Toxicity
a. ADI
Not derived since cancer potency
was used to assess hazard.
b. Effects
See Section 4, p. 4-4.
3. Absorption Factor
Intestinal transport occurs readily, U.S. EPA, 1980
primarily by passive diffusion. (p. C-37)
Rats given BaP by gavage in starch solu- U.S. EPA, 1984b
tion (100 mg) or in the diet (250 mg) (p. 5)
absorbed approximately 50 percent of the
administered compound.
4. Existing Regulations
For maximum protection from carcinogenic U.S. EPA, 1980
effects, ambient water concentration for (p. vi)
PAHs should be zero, assuming no thresh-
old. Criteria for levels which may
result in incremental increase in risk of
cancer over the lifetime of 10~^f 10"^,
and 10~7 are 28.0 ng/L, 2.8 ng/L, and
0.28 ng/L, respectively.
1970 World Health Organization European U.S. EPA, 1980
Standards for Drinking Water recommends (p. C-108)
PAH concentration not to exceed 0.2 Ug/L.
4-5
-------
B. Inhalation
1. Carcinogenicity
a. Qualitative Assessment
BaP was the first carcinogenic hydro-
carbon identified in soot.
Intratracheal instillation of BaP in U.S. EPA, 1980
Syrian golden hamsters showed a dose (pp. C-89 and
response relationship for development C-91)
of respiratory tumors. Also, co-
administration of carrier particles
such as Fe203 can markedly increase
tumor incidence depending on the
conditions of the experiment and
physical characteristics of the
particle.
b. Potency
Cancer potency = 4.3 (mg/kg/day)'1 U.S. EPA, 1984b
(p. 32)
Cancer potency was derived by U.S.
-EPA (1984b) based on a study by
Thyssen et al. (1981) in which
Syrian golden hamsters were exposed
to BaP by inhalation at levels of
0, 2.2, 9.5, or 46.5 mg/m3 for 59.5
to 96.4 weeks. Incidence of tumors
were:
Dose Incidence
(mg/m3) (No; Responding/No. Tested)
0 0/27
2.2 0/27
9.5 9/26
46.5 13/25
2. Chronic Toxicity
a. Inhalation Threshold or MPIH
Data not assessed since the evalua-
tion was based on carcinogenicity.
b. Effects
See Section 4, p. 4-6.
4-6
-------
3. Absorption Factor
There is ample evidence that BaP is U.S. EPA, 1980
easily absorbed through the lungs. (p. C-37)
4. Existing Regulations
Substance Exposure Limit Agency
Coke Oven 150 ug/m3, 8-hr U.S. Occupational U.S. EPA, 1980
Emissions time-weighted Safety and Health (p. C-108)
average (TWA) Administration
Coal Tar 0.1 mg/m3, U.S. National
Products 10-hr TWA Institute for
Occupational
Safety and Health
Coal Tar Pitch 0.2 mg/ra3 American
of Volatiles (benzene Conference of
soluble fraction Governmental and
8-hr TWA) Industrial
Hygienists
III. PLANT EFFECTS
A. Phytotoxicity
Data not immediately available.
B. Uptake
See Table 4-1.
IV. DOMESTIC ANIMAL AND WILDLIFE EFFECTS
A. Toxicity
See Table 4-2.
B. Uptake
From available information on excretion of U.S. EPA, 1980
PAH in animals, extensive bioaccumulation is (p. C-49)
not likely to occur.
V. AQUATIC LIFE EFFECTS
A. Toxicity
1. Freshwater
Data not immediately available.
4-7
-------
2. Saltwater
Acute toxicity value of 300 ug/L is U.S. EPA, 1980
based on tests of polychaete worms (pp. B-l and
exposed to crude oil fractions. No B-2)
chronic data are presently available.
B. Uptake
The estimated weighted average BCF of BaP U.S. EPA, 1980
for the edible portion of all freshwater (p. C-19)
and estuarine aquatic organisms consumed
by U.S. citizens is 11,100.
VI. SOIL BIOTA EFFECTS
Data not immediately available.
VII. PHYSICOCHEMICAL DATA FOR ESTIMATING PATE AND TRANSPORT
Molecular weight: 252.32 NAS, 1977
BaP is very persistent in water and is (p. 691)
soluble at 0.004 mg/L at 27°C
Degradation rate: 0.01 day~"l Herbes and
Schwall, 1978
Koc (organic carbon partition coefficient) = Lyman, 1982
630,000 mL/g
4-8
-------
TABLE 4-1. UPTAKE OF BENZO(A)PYRENE BY PLANTS
*-
Plant/Tissue
Carrots/roots
Carrots/roots
Carrota/fol iage
Carrots/to! iage
Radi aheal roots
Radishes/foliage
Spinach/leaf
Soil
Type
sand
compost
sand
compost
NR
NR
NR
Chemical Form
Applied
BaP
BaP
BaP
BaP
BaP
BaP
BaP
Soil Concentration
(Mg/g W)
NRb
NH
NR
NH
NR
NR
NR
Tissue
Concentration
(Mg/g DW)
NR
NR
NR
NR
NR
NR
NR
0.75-1.
0.08 (0
0.08 (0
0.08 (0
0.08-0.
0.08 (0
0.16-0.
Uptake
Pactora
8(0.09-0.22)
.01)
.01)
.01)
16(0.01-0.02)
.01)a
42(0.02-0.05)
Reference*
Connor,
Connor,
Connor,
Connor,
Connor,
Connor,
Connor,
1984
1984
1984
1984
1984
1984
1984
(P-
(P-
-------
TABLE 4-2. TOX1C1TY OK BENZO(A)PYRENB TO DOMESTIC ANIMALS AND WILDLIFE
Feed Water
Chemical Form Concentration Concentration Daily Intake Duration
Species (H)a Fed (»g/g DW) (mg/L) (rag/kg) of Study Effects
Rat (40) BaP NKb '* NK 2.5 NR Papillomas in stomach of
3 of 40 animals
Mouse BaP 50-250 NK NR 110-197 days >70I incidence of stomach
tumors
Mouse BaP 30 NK NR 110 days No tumors
Mouse BaP 250 NK NR 1 day No tumors
Mouse BaP 250 NK NK 2-4 days 10Z tumor incidence
1 Mouse BaP 250 NH NK 5-7 days 30-40Z tumor incidence
O
Mouse BaP 250 NK NR 30 days 100Z tumor incidence
Mouse BaP 40-45 NH . NR 110 days Carcinogenic effects
References
U.S. EPA,
(p. C-88)
U.S. EPA,
(p. C-B8)
U.S. EPA,
(p. C-88)
U.S. EPA,
(p. C-88)
U.S. EPA,
(p. C-88)
U.S. EPA,
(p. C-88)
U.S. EPA,
(p. C-88)
NAS, 1977
(p. 692)
1980
1980
1980
1980
1980
1980
1980
N - Number of experimental animals when reported.
NK = Not reported.
-------
SECTION 5
REFERENCES
Abramowitz, M., and I. A. Stegun. 1972. Handbook of Mathematical
Functions. Dover Publications, New York, NY.
Bertrand, J. E., M. C. Lutrick, G. T. Edds, and R. L. West. 1981.
Metal Residues in Tissues, Animal Performance and Carcass Quality
with Beef Steers Grazing Pensacola Bahiagrass Pastures Treated with
Liquid Digested Sludge. J. Ani. Sci. 53:1.
Boswell, F. C. 1975. Municipal Sewage Sludge and Selected Element
Applications to Soil: Effect on Soil and Fescue. J. Environ.
Qual. 4(2):267-273.
Camp Dresser and McKee, Inc. 1984a. Development of Methodologies for
Evaluating Permissible Contaminant Levels in Municipal Wastewater
Sludges. Draft. Office of Water Regulations and Standards, U.S.
Environmental Protection Agency, Washington, D.C.
Camp Dresser and McKee, Inc. 1984b. Technical Review of the 106-Mile
Ocean Disposal Site. Prepared for U.S. EPA under Contract No.
68-01-6403. Annandale, VA. January.
Camp Dresser and McKee, Inc. 1984c. Technical Review of the 12-Mile
Sewage Sludge Disposal Site. Prepared for U.S. EPA under Contract
No. 68-01-6403. Annandale, VA. May.
Chaney, R. L., and C. A. Lloyd. 1979. Adherence of Spray-Applied
Liquid Digested Sewage Sludge to Tall Fescue. J. Environ. Qual.
8(3) -.407-411.
City of New York Department of Environmental Protection. 1983. A
Special Permit Application for the Disposal of Sewage Sludge from
Twelve New York City Water Pollution Control Plants at the 12-Mile
Site. New York, NY. December.
Connor, M. S. 1984. Monitoring Sludge-Amended Agricultural Soils.
BioCycle. January/February:47-51.
Donigian, A. S., 1985. Personal Communication. Anderson-Nichols & Co.,
Inc., Palo Alto, CA. May.
Farrell, J. B. 1984. Personal Communication. Water Engineering
Research Laboratory, U.S. Environmental Protection Agency,
Cincinnati, OH. December.
Freeze, R. A., and J. A. Cherry. 1979. Groundwater. Prentice-Hall,
Inc., Englewood Cliffs, NJ.
5-1
-------
Gelhar, L. W., and G. J. Axness. 1981. Stochastic Analysis of
Macrodispersion in 3-Dimensionally Heterogenous Aquifers. Report
No. H-8. Hydrologic Research Program, New Mexico Institute of
Mining and Technology, Soccorro, MM.
Gerritse, R. G., R. Vriesema, J. W. Dalenberg, and H. P. DeRoos. 1982.
Effect of Sewage Sludge on Trace Element Mobility in Soils. J.
Environ. Qual. 2:359-363.
Griffin, R. A. 1984. Personal Communication to U.S. Environmental
Protection Agency, ECAO - Cincinnati, OH. Illinois State
Geological Survey.
Herbes, S. E., and L. R. Schwall. 1978. Microbial Transformations of
Polycyclic Aromatic Hydrocarbons in Pristine and Petroleum-
Contaminated Sediments. Applied Environ. Microbiol. 35:306.
Joe, F. L., E. L. Roseboro, and T. Fazio. 1981. High Pressure Liquid
Chromatographic Method for Determination of Polynuclear Aromatic
Hydrocarbons in Beer. J. Assoc. Off. Anal. Chem. 64(3):641-646.
Lyman, W. J. 1982. Adsorption Coefficients for Soils and Sediments.
Chapter 4. In; Handbook of Chemical Property Estimation Methods.
McGraw-Hill Book Co., New York, NY.
National Academy of Sciences. 1977.. Drinking Water and Health. NAS,
National Research Council Safe Drinking Water Committee.
Washington, D.C.
National Oceanic and Atmospheric Administration. 1983. Northeast
Monitoring Program 106-Mile Site Characterization Update. NOAA
Technical Memorandum NMFS-F/NEC-26. U.S. Department of Commerce
National Oceanic and Atmospheric Administration. August.
Neal, J., and R. H. Rigdon. 1967. Gastric Tumors in Mice Fed
Benzo(a)pyrene: A Quantitative Study. Tex. Rep. Biol. Med.
25:553. (As cited in U.S. EPA, 1980.)
Overcash, M. 1984. Estimated Distribution of BaP with Sludge
Application to Land. Contract Report. Metro Seattle, WA.
Pendygraft, G. W., R. E. Schlegel, and M. J. Huston. 1979. Organics in
Drinking Water: Maximum Contaminant Levels as an Alternative to
the GAC Treatment Requirement. J. AWWA. 174-183. April.
Pennington, J. A. T. 1983. Revision of the Total Diet Study Food Lists
and Diets. J. Am. Diet. Assoc. 82:166-173.
Pettyjohn, W. A., D. C. Kent, T. A. Prickett, H. E. LeGrand, and F. E.
Witz. 1982. Methods for the Prediction of Leachate Plume
Migration and Mixing. U.S. EPA Municipal Environmental Research
Laboratory, Cincinnati, OH.
5-2
-------
Ryan, J. A., H. R. Pahren, and J. B. Lucas. 1982. Controlling Cadmium
in the Human Food Chain: A Review and Rationale Based on Health
Effects. Environ. Res. 28:251-302.
Sikora, L. J., W. D. Burge, and J. E. Jones. 1982. Monitoring of a
Municipal Sludge Entrenchment Site. J. Environ. Qual. 2(2): 321-
325.
Stanford Research Institute International. 1980. Seafood Consumption
Data Analysis. Final Report, Task II. Prepared for U.S. EPA under
Contract No. 68-01-3887. Menlo Park, CA. September.
Suess, M. J. 1976. The Environmental Load and Cycle of Polycyclic
Aromatic Hydrocarbons. Sci. Total Environ. 6:239-250.
Thornton, I., and P. Abrams. 1983. Soil Ingestion - A Major Pathway of
Heavy Metals into Livestock Grazing Contaminated Land. Sci. Total
Environ. 28:287-294.
Thyssen, J., J. Althoff, G. Kimmerle, and U. Mohr. 1981. Inhalation
Studies with Benzo(a)pyrene in Syrian Golden Hamsters. J. Natl.
Cancer Inst. 66(3):575-577. (As cited in U.S. EPA, 1984b.)
U.S. Department of Agriculture. 1975. Composition of Foods.
Agricultural Handbook No. 8.
U.S. Environmental Protection Agency. 1977. Environmental Assessment
of Subsurface Disposal of Municipal Wastewater Sludge: Interim
Report. EPA/530/SW-547. Municipal Environmental Research
Laboratory, Cincinnati, OH.
U.S. Environmental Protection Agency. 1979. Industrial Source Complex
(ISC) Dispersion Model User Guide. EPA 450/4-79-30. Vol. 1.
Office of Air Quality Planning and Standards, Research Triangle
Park, NC. December.
U.S. Environmental Protection Agency. 1980. Ambient Water Quality
Criteria for Polynuclear Aromatic Hydrocarbons. EPA/440/5-80-069.
Washington, D.C.
U.S. Environmental Protection Agency. 1982. Fate of Priority
Pollutants in Publicly-Owned Treatment Works. Final Report.
Vol. I. EPA 440/1-82/303. Effluent Guidelines Division,
Washington, D.C.
U.S. Environmental Protection Agency. 1983a. Assessment of Human
Exposure to Arsenic: Tacoma, Washington. Internal Document.
OHEA-E-075-U. Office of Health and Environmental Assessment,
Washington, D.C. July 19.
U.S. Environmental Protection Agency. 1983b. Rapid Assessment of
Potential Groundwater Contamination Under Emergency Response
Conditions. EPA 600/8-83-030.
5-3
-------
U.S. Environmental Protection Agency. 1984a. Air Quality Criteria for
Lead. External Review Draft. EPA 600/8-83-028B. Environmental
Criteria and Assessment Office, Research Triangle Park, NC.
September.
U.S. Environmental Protection Agency. 1984b. Health Effects Assessment
for Polycyclic Aromatic Hydrocarbons (PAHs). Final Draft. ECAO-
CIN-H036. Environmental Criteria and Assessment Office,
Cincinnati, OH. November.
5-4
-------
APPENDIX
PRELIMINARY HAZARD INDEX CALCULATIONS FOR BENZO(A)PYRENE
IN MUNICIPAL SEWAGE SLUDGE
I. LANDSPREADING AND DISTRIBUTION-AND-MARKETING
A. Effect on Soil Concentration of Benzo(a)pyrene
1. Index of Soil Concentration (Index 1)
a. Formula
cs = (SC x AR) + (BS x MS)
3 AR + MS
CSr = CSS [1 + O
where:
CSS = Soil concentration of pollutant after a
single year's application of sludge (ug/g
DW)
CSr = Soil concentration of pollutant after the
yearly application of sludge has been
repeated for n + 1 years (ug/g DW)
SC = Sludge concentration of pollutant (ug/g DW)
AR = Sludge application rate (mt/ha)
MS = 2000 mt ha/DW = assumed mass of soil in
upper 15 cm
BS = Background concentration of pollutant in
soil (ug/g DW)
t-j. = Soil half-life of pollutant (years)
b. Sample calculation
CSS is calculated for AR = 0, 5-, 50 mt/ha and 500
mt/ha*.
n inn - (0*1*3 UR/g DW x 5 mt/ha) + (0.1 ug/g DW x 2000 mt/ha)
~ (5 mt/ha DW + 2000 mt/ha DW)
CSr is calculated for AR = 5 mt/ha applied for 100
years
0.103 yg/g DW = 0.100 ug/g DW [1 + 0.5 (1/0.18986) + 0.52/0.18986)
* ... + 0.5 (99/0.18986)]
A-l
-------
B. Effect on Soil Biota and Predators of Soil Biota
1. Index of Soil Biota Toxicity (Index 2)
a. Formula
Index 2 = |j
where:
Ii = Index 1 = Concentration of pollutant in
sludge-amended soil (ug/g DW)
TB = Soil concentration toxic to soil biota
(Ug/g DW)
b. Sample calculation - Values were not calculated due to
lack of data.
2. Index of Soil Biota Predator Toxicity (Index 3)
a. Formula
IT x UB
3 = -
where:
Index -
ll = Index 1 = Concentration of pollutant in
sludge-amended soil (ug/g DW)
UB = Uptake factor of pollutant in soil biota
(Ug/g tissue DW [Ug/g soil DW]"1)
TR = Food concentration toxic to predator (ug/g
DW)
b. Sample calculation - Values were not calculated due to
lack of data.
C. Effect on Plants and Plant Tissue Concentration
1. Index of Phytotoxic Soil Concentration (Index 4)
a. Formula
Index 4 = ^
where:
Ij_ = Index 1 * Concentration of pollutant in
sludge-amended soil (yg/g DW)
TP = Soil concentration toxic to plants (ug/g DW)
A-2
-------
b. Sample calculation - Values were not calculated due to
lack of data.
2. Index of Plant Concentration Increment Caused by Uptake
(Index 5)
a. Formula
Index 5 = Ix x UP
where:
Ij = Index 1 = Concentration of pollutant in
sludge-amended soil (ug/g DW)
UP = Uptake factor of pollutant in plant tissue
(Ug/g tissue DW (ug/g soil DW]"1)
b. Sample Calculation
0.042 Ug/g DW = 0.100 ug/g DW x 0.42 Ug/g tissue DW (ug/g soil DW)-1
3. Index of Phytotoxic Plant Tissue Concentration (Index 6)
a. Formula
Index 6 = PP
where:
PP = Maximum plant tissue concentration associ-
ated with phytotoxicity Ug/g DW)
b. Sample calculation - Values were not calculated due to
lack of data.
D. Effect on Herbivorous Animals
1. Index of Animal Toxicity Resulting from Plant Consumption
(Index 7)
a. Formula
Index 7 ^
where:
15 = Index 5 = Concentration of pollutant in
plant grown in sludge-amended soil
(Ug/g DW)
TA = Feed concentration toxic to herbivorous
animal (ug/g DW)
A-3
-------
b. Sample calculation
0 0011 - 0.042 Ug/g DW
°'0011 40 Ug/g DW
2. Index of Animal Toxicity Resulting from Sludge Ingestion
(Index 8)
a. Formula
If AR = 0; Index 8=0
SC x GS
If AR * 0; Index 8 = TA
where:
AR = Sludge application rate (mt DW/ha)
SC = Sludge concentration of pollutant (ug/g DW)
GS = Fraction of animal diet assumed to be soil
TA = Feed concentration toxic to herbivorous
animal (ug/g DW)
b. Sample calculation
If AR = 0; Index 8=0
H A. , 0, 0.0001. - °
E. Effect on Humans
1. Index of Human Cancer Risk Resulting from Plant Consumption
(Index 9)
a. Formula
o - (Is x DT) * PI
Index 9 ^
where:
15 = Index 5 = Concentration of pollutant in
plant grown in sludge-amended soil
(Ug/g DW)
DT = Daily human dietary intake of affected
plant tissue (g/day DW)
DI = Average daily human dietary intake of
pollutant (ug/day)
RSI = Cancer risk-specific intake (ug/day)
b. Sample calculation (toddler)
(0.18 Ug/g DW x 74.5 g/day) + 0.29 ug/day
2259*4 ~ 0.00607 ug/day
A-4
-------
2. Index of Human Cancer Risk Resulting from Consumption of
Animal Products Derived from Animals Feeding on Plants
(Index 10)
a. Formula
(Ic x UA x DA) + DI
Index 10 = - -
where:
15 = Index 5 = Concentration of pollutant in
plant grown in sludge-amended soil (ug/g DW)
UA = Uptake factor of pollutant in animal tissue
(Ug/g tissue DW [yg/g feed DW]"1)
DA = Daily human dietary intake of affected
animal tissue (g/day DW) (milk products and
meat, poultry, eggs, fish)
DI = Average daily human dietary intake of
pollutant (Ug/day)
RSI = Cancer risk-specific intake (ug/day)
b. Sample calculation - Values were not calculated due to
lack of data.
3. Index of Human Cancer Risk Resulting from Consumption of
Animal Products Derived from Animals Ingesting Soil (Index
11)
a. Formula
(BS x GS x UA x DA) * DI
If AR = 0; Index 11 = - ^ -
j. n T j 11 (SC x GS x UA x DA) + DI
If AR $ 0; Index 11 =
where:
AR = Sludge application rate (mt DW/ha)
BS = Background concentration of pollutant in
soil (ug/g DW)
SC = Sludge concentration of pollutant (ug/g DW)
GS = Fraction of animal diet assumed to be soil
UA = Uptake factor of pollutant in animal tissue
(Ug/g tissue DW [yg/g feed DW]"1)
DA = Daily human dietary intake of affected
animal tissue (g/day DW) (milk products and
meat only)
DI = Average daily human dietary intake of
pollutant (ug/day)
RSI = Cancer risk-specific intake (ug/day)
Sample calculation (toddler) - Values were not
calculated due to lack of data.
A-5
-------
4. Index of Human Cancer Risk Resulting from Soil Ingestion
(Index 12)
a. Formula
(Ii x DS) + DI
Index 12 =
where:
ll = Index 1 = Concentration of pollutant in
sludge-amended soil (ug/g DW)
DS = Assumed amount of soil in human diet (g/day)
DI = Average daily human dietary intake of
pollutant (ug/day)
RSI » Cancer risk-specific intake (ug/day)
b. Sample calculation
(0.100 ug/g DW x 5 g/dav) * 0.29 ug/day
130 = 0.00607 ug/day
5. Index of Aggregate Human Cancer Risk (Index 13)
a. Formula
r 3DI
Index 13 = Ig + IIQ + 111 * I12 ~ ( RSI
where:
In = Index 9 = Index of human cancer risk
resulting from plant consumption (unitless)
1 10 = Index 10 = Index of human cancer risk
resulting from consumption of animal
products derived " from animals feeding on
plants (unitless)
111 = Index 11 = Index of human cancer risk
resulting from consumption of animal
products derived from animals ingesting soil
(unitless)
I12 = Index 12 = Index of human cancer risk
resulting from soil ingestion (unitless)
DI = Average daily human dietary intake of
pollutant (ug/day)
RSI = Cancer risk-specific level (ug/day)
Sample calculation (toddler) - Values were not
calculated due to lack of data.
A-6
-------
II. LANDFILLIHG
A. Procedure
Using Equation 1, several values of C/CO for the unsaturated
zone are calculated corresponding to increasing values of t
until equilibrium is reached. Assuming a 5-year pulse input
from the landfill, Equation 3 is employed to estimate the con-
centration vs. time data at the water table. The concentration
vs. time curve is then transformed into a square pulse having a
constant concentration equal to the peak concentration, Cu,
from the unsaturated zone, and a duration, to, chosen so that
the total areas under the curve and the pulse are equal, as
illustrated in Equation 3. This square pulse is then used as
the input to the linkage assessment, Equation 2, which esti-
mafes initial dilution in the aquifer to give the initial con-
centration, C0, for the saturated zone assessment. (Conditions
for B, minimum thickness of unsaturated zone, have been set
such that dilution is actually negligible.) The saturated zone
assessment procedure is nearly identical to that for the unsat-
urated zone except for the definition of certain parameters and
choice of parameter values. The maximum concentration at the
well, Cgjax, is used to calculate the index values given in
Equations 4 and 5.
B. Equation 1: Transport Assessment
C(y.t) = | [exp(Ai) erfc(A2) + exp(Bi) erfc(B2)] = P
-------
CF = 250 kg sludge solids/m^ leachate =
PS x 103
1 - PS
PS = Percent solids (by weight) of landfilled sludge
202
t = Time (years)
X = h = Depth to groundwater (m)
D* = a x V* (m2/year)
a = Dispersivity coefficient (m)
y* s 2 (m/year)
0 x R
Q = Leachate generation rate (m/year)
0 = Volumetric water content (unitless)
R = 1 + dry x Kd = Retardation factor (unitless)
0
pdry = Dry Dulk density (g/mL)
Kd = foc x Koc (mL/g)
foc = Fraction of organic carbon (unitless)
Koc = Organic carbon partition coefficient (mL/g)
c_U. (years)-l
i \
U = Degradation rate (day ^ )
and where for the saturated zone:
C0 = Initial concentration of pollutant in aquifer as
determined by Equation 2 (ug/L)
t - time (years)
X = AJ, = Distance from well to landfill (m)
D* = a x V* (m2/year)
a = Dispersivity coefficient (m)
v* - K x -? (m/year)
<4 x R
K = Hydraulic conductivity of the aquifer (m/day)
i = Average hydraulic gradient between landfill and well
(unitless)
since Kd = foc x Koc and foc is assumed to be zero
for the saturated zone
C. Equation 2. Linkage Assessment
0 x W _
co ~ cu x 365 [(K x i) * 0] x B
A-8
-------
where:
Co = Initial concentration of pollutant in the saturated
zone as determined by Equation 1 (Ug/D
Cu = Maximum pulse concentration from the unsaturated
zone (yg/L)
Q = Leachate generation rate (m/year)
W = Width oŁ landfill (m)
K = Hydraulic conductivity of the aquifer (ra/day)
i = Average hydraulic gradient between landfill and well
(unitless)
0 = Aquifer porosity (unitless)
B = Thickness of saturated zone (m) where:
B > <>.'W«' - and B > 2
K«x i x 365
Equation 3. Pulse Assessment
C(yit} = P(X,C) for 0 Ł t < t0
Co
QLŁl = P(X,t) - P(X,t - t0) for t > t0
co
where:
t0 (for unsaturated zone) = LT = Landfill leaching time
(years)
to (for saturated zone) = Pulse duration at the water
table (x ~ h) as determined by the following equation:
t0 = [ o/°> C dt] t Cu
C( Y t )
P(X,t) = -p.* . as determined by Equation 1
co
Equation 4. Index of Groundwater Concentration Resulting
from Landfilled Sludge (Index 1)
1. Formula
Index 1 = Cmax
where :
Cmax * Maximum concentration of pollutant at well =
maximum of C(Afi,,t) calculated in Equation 1
(Ug/L)
2. Sample Calculation
1.34 x 10~4 yg/L = 1.34 x 1(T4
A-9
-------
P. Equation 5. Index of Human Cancer Risk Resulting
from Groundwater Contamination (Index 2)
1. Formula
(I x AC) + DI
Index 2 =
where:
T! = Index 1 = Index of groundwater concentration
resulting from landfilled sludge (yg/L)
AC = Average human consumption of drinking water
(L/day)
DI = Average daily human dietary intake of pollutant
(Ug/day)
RSI = Cancer risk-specific intake (ug/day)
2. Sample Calculation
(1.34 x 1Q~4 Ug/L x 2 L/day) + 0.88 Ug/day
145 = 0.00607 Ug/day
III. INCINERATION
A. Index of Air Concentration Increment Resulting from
Incinerator Emissions (Index 1)
1. Formula
(C x PS x SC x FM x DP) + BA
Index 1 = gŁ
where:
C = Coefficient to correct for mass and time units
(hr/sec x g/mg)
DS = Sludge feed rate (kg/hr DW)
SC = Sludge concentration of pollutant (mg/kg DW)
FM = Fraction of pollutant emitted through stack (unitless)
DP = Dispersion parameter for estimating maximum
annual ground level concentration (ug/m3)
BA = Background concentration of pollutant in urban
air (ug/m3)
2. Sample Calculation
1.036 = [(2.78 x 10'7 hr/sec x g/mg x 2660 kg/hr DW x 0.143 mg/kg DW x 0.05
x 3.4 ug/m3) + 0.0005 ug/m3] * 0.0005 ug/m3
A-10
-------
B. Index of Human Cancer Risk Resulting from Inhalation of
Incinerator Emissions (Index 2)
1. Formula
[(Ii - 1) x BA] + BA
Index 2 =
EC
where:
1^ = Index 1 = Index of air concentration Increment
resulting from incinerator emissions
(unitless)
BA = Background concentration of pollutant in
urban air (yg/m3)
EC = Exposure criterion (yg/m3)
Sample Calculation
0 639 = [(1.036 - 1) x 0.0005 ug/m3] + 0.0005
0.00081 Ug/m3
IV. OCEAN DISPOSAL
Index of Seawater Concentration Resulting from Initial Mixing
of Sludge (Index 1)
1. Formula
SC x ST x PS
Index 1 =
W x D x L
where:
SC = Sludge concentration of pollutant (mg/kg DW)
ST = Sludge mass dumped by a single tanker (kg WW)
PS = Percent solids in sludge (kg DW/kg WW)
W = Width of initial plume dilution (m)
D = Depth to pycnocline or effective depth of
mixing for shallow water site (m)
L = Length of tanker path (m)
2. Sample Calculation
0.143 mg/kg DW x 1600000 kg WW x 0.04 kg DW/kg WW x 103
Wg " 200 m x 20 m x 8000 m x 103 L/m3
A-ll
-------
B. Index of Seawater Concentration Representing a 24-Hour Dumping Cycle
(Index 2)
1. Formula
SS x SC
Index 2 =
V x D x L
where:
SS = Daily sludge disposal rate (kg DW/day)
SC = Sludge concentration of pollutant (mg/kg DW)
V = Average current velocity at site (m/day)
D = Depth to pycnocline or effective depth of
mixing for shallow water site (m)
L = Length of tanker path (m)
2. Sample Calculation
, 82500Q kg DW/day x 0.143 me/kg DW x 103 Ug/mg
0.000078 Ug/L = - 9500 m/day x 20 m x 8000 m x Ifl3 L/n/
C. Index of Toxicity to Aquatic Life (Index 3)
1. Formula
Index 3 = AWQC
where:
ll = Index 1 = Index of seawater concentration
resulting from initial mixing after sludge
disposal (Ug/L)
AWQC = Criterion or other value expressed as an average
concentration to protect marine organisms from
acute and chronic toxic effects (yg/L)
2. Sample Calculation
0.00000095 - "
D. Index of Human Cancer Risk Resulting from Seafood Consumption
(Index 4)
1. Formula
(I2 x BCF x 10~3 kg/g x FS x QF) + PI
Index 4 = -
A-12
-------
where:
12 = Index 2 = Index of seawater concentration
representing a 24-hour dumping cycle (yg/L)
QF = Dietary consumption of seafood (g WW/day)
FS = Fraction of consumed seafood originating from the
disposal site (unitless)
BCF = Bioconcentration factor of pollutant (L/kg)
DI = Average daily human dietary intake of pollutant
(yg/day)
RSI = Cancer risk-specific intake (ug/day)
2. Sample Calculation
144.9 =
(0.000078 Ug/L x 111QO L/kg x 10~3 kg/g x 0.000021 x 14.3 g WW/day) + 0.88 ug/day
0.00607 lag/day
A-13
-------
TABLE A-l. INCUT DATA VARYING IN I.ANUKILL ANALYSIS AND RESULT FOR EACH CONDITION
Condition of Analysis
Input Data
Sludge concentration of pollutant, SC (pg/g DW)
Unsaturated zone
Soil type and characteristics
Dry bulk density, fjry (g/mL)
Volumetric water content, 6 (unitless)
Fraction of organic carbon, foc (unitless)
Site parameters
Leachate generation rale, Q, (m/year)
Depth to groundwater, h (m)
Dispersivity coefficient, a (m)
hp. Saturated zone
Ł Soil type and characteristics
Aquifer porosity, 0 (unitless)
Hydraulic conductivity of the aquifer,
K (m/day)
Site parameters
Hydraulic gradient, i (unilless)
Distance from well to landfill, AH, (m)
Dispersivily coefficient, a (m)
1
0.143
1.53
0.195
0.005
0.8 '
5
0.5
0.44
0.86
0.001
100
10
2
1.937
1.53
0.195
0.005
0.8
5
0.5
0.44
0.86
0.001
100
10
3
0.143
1.925
0.133
0.0001
0.8
5
0.5
0.44
0.86
0.001
100
10
4 5
0.143 0.143
NAb 1.53
NA 0.195
NA 0.005
1.6 0.8
0 5
NA 0.5
0.44 0.389
0.86 4.04
0.001 0.001
100 100
10 10
6
0.143
1.53
0.195
0.005
0.8
5
0.5
0.44
0.86
0.02
50
5
7 8
1.937 Na
NA N
NA N
NA N
1.6 N
0 N
NA N
0.389 N
4.04 N
0.02 N
50 N
5 N
-------
TABLE A-l. (continued)
Condition of Analysis
Results
Unsaturated zone assessment (Equations 1 and 3)
Initial leachate concentration, C0 (ug/L)
Peak concentration, Cu (pg/L)
Pulse duration, to (years)
Linkage assessment (Equation 2)
Aquifer thickness, B (m)
Initial concentration in saturated zone, Co
Saturated zone assessment (Equations 1 and 3)
H* Maximum well concentration, Cmax (ug/L)
Index of grounduater concentration resulting
from landfilled sludge, Index I ((ig/L)
(Equation 4)
Index of human toxici t y/cancer risk resulting
from groundwater contamination, Index 2
(unitless) (Equation 5)
135.8| 1484] Hi.8) 135.6]
14.64x10-4] |6.2BxlO-3] (3.87x10-2) (35.8]
(13700] (13700) (392) (5.00)
135.8) (35.8) [484] N
14.64x10-4) (4.64x10-4] [484] N
(13700) (13700) (5.00) N
1126) (126] (126) (253) (23.8) (6.32) (2.38) N
(4.64x10:4) (6.28x10-3] |3.87xlO-2| (35.8) (4.64x10-4) (4.64x10-4] |484] N
(1.34x10-4) (1.82x10-3) (3.30x10-4) )3.89xlO-3) (4.30x10-4) (4.64x10-4) (11.2) N
(1.34x10-4) |1.82xlO-3| (3.30x10-4) (3.89x10-3) (4.30x10-4) (4.64x10-4) 111.2] 0
(145)
|146|
(145]
(146)
(145]
(145) (3840) (145]
aN - Null condition, where no landfill exists; no value is used.
"NA = Not applicable tor this condition.
-------
BENZO(A)PYRENE
p. 3-2 should read;
Index 1 Values
Group^
Sludge Concentration
Sludge Application Rate (mt/ha)
0 5 50 500
Typical
Worst
0.01
0.01
0.01
0.014
0.013
0.057
0.01
0.015
p. 3-5 should read:
Index 5 Values (ug/g DW)
Sludge Application Rate (mt/ha)
Diet
Animal
Human
Sludge Concentration
Typical
Worst
Typical
Worst
0
0.0042
0.0042
0.018
0.018
5 -
0.0043
0.0062
0.019
0.026
50
0.0056
0.024
0.023
0.1
500
0.0043
0.0063
0.019
0.027
p. 3-7 should read;
Index 7 Values
Group
Sludge Concentration
Sludge Application Rate (mt/ha)
0 5 50 500
Typical
Worst
0.00011 0.00011 0.00014 0.00011
0.00011 0.00016 0.0006 0.00016
p. 3-11 should read!
Index 9 Values
Sludge Application Rate (mt/ha)
Group
Toddler
Adult
Sludge Concentration
Typical
Worst
Typical
Worst
0
48
48
140
140
5
55
150
170
440
50
120
1100
340
3000
500
55
160
170
440
-------
p. 3-16 should read:
Index 12 values
Sludge Application Rate (mt/ha)
Group Sludge Concentration 0 5 50 500
Toddler ~ Typical 60 56 59 56
Worst 60 56 95 60
Adult Typical 150 150 150 150
Worst 150 150 150 150
p. 3-2 Index 1 Values
Preliminary Conclusion - should read:
Landspreading of sludge may slightly increase the soil
concentration of BaP when sludge containing a typical concentration
of BaP is applied at the 50 mt/ha rate and when sludge containing
a high concentration of BaP is applied at the 5, 50, and 500
mt/ha rates.
p. 3-5 Index 5 Values
Preliminary Conclusion - should read:
Landspreading of sludge containing a worst concentration of
BaP is expected to increase the tissue concentration of BaP in
plants in the animal and human diet slightly at the 5 and 500
mt/ha application rates and significantly at the 50 mt/ha
application rate.
p. 3-11 Index 9 Values
Preliminary Conclusion - should read:
Landspreading of sludge containing BaP is expected to increase
the risk of cancer for adults or toddlers who consume plants
grown on the sludge-amended soil when applied at any application
rate (5 to 50Q mt/ha) at either typical or worst concentrations.
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