United Slates
Environmental Protection
Agency
Office of Water
Regulations and Standards
Wasnington. DC 20460
SEPA
Water
June. 1985
Environmental Profi!
and Hazard indices
for Constituents
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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, landfilling,
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 OP CONTENTS
Page
PREFACE x
1. INTRODUCTION 1-1
2. PRELIMINARY CONCLUSIONS FOR MERCURY IN MUNICIPAL SEWAGE
SLUDGE 2-1
Landspreading and Distribution-and-Marketing 2-1
Landf i 11 ing 2-2
Incineration 2-2
Ocean Disposal 2-2
3. PRELIMINARY HAZARD INDICES FOR MERCURY IN MUNICIPAL SEWAGE
SLUDGE 3"1
Landspreading and Distribution-and-Marketing 3-1
Effect on soil concentration of mercury (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) 3-9
Effect on humans (Indices 9-13) 3-12
Landfilling 3-21
Index of groundwater concentration increment resulting
from landfilled sludge (Index 1) 3-21
Index of human toxicity resulting from
groundwater contamination (Index 2) 3-27
Incineration 3-29
Index of air concentration increment resulting
from incinerator emissions (Index 1) 3-29
Index of human toxicity resulting from
inhalation of incinerator emissions (Index 2) 3-31
Ocean Disposal 3-33
Index of seawater concentration resulting from
initial mixing of sludge (Index 1) 3-33
Index of seawater concentration representing a
24-hour dumping cycle (Index 2) 3-37
11
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TABLE OF CONTENTS
(Continued)
Page
Index of toxicity to aquatic life (Index 3) .............. 3-38
Index of human toxicity resulting from
seafood consumption (Index 4) .......................... 3-39
4. PRELIMINARY DATA PROFILE FOR MERCURY IN MUNICIPAL SEWAGE
SLUDGE [[[ 4-1
Occurrence
Sludge [[[ 4-1
Soil - Unpolluted ........................................ 4-1
Water - Unpolluted ....................................... 4-2
Air [[[ 4-3
Food [[[ 4-4
Human Effects ................................................. 4-5
Ingestion ................................................ 4-5
Inhalation ............................................... 4-5
Plant Effects ................................................. 4-6
Phytotoxicity ............................................ 4-6
Uptake [[[ 4-6
Domestic Animal and Wildlife Effects .......................... 4-7
Toxicity ................................................. 4-7
Uptake [[[ 4-7
Aquatic Life Effects .......................................... 4-7
Toxicity ................................................. 4-7
Uptake [[[ 4-7
Soil Biota Effects ............................................ 4-8
Toxicity ................................................. 4-8
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SECTION 1
INTRODUCTION
This preliminary data profile is one of a series of profiles
dealing with chemical pollutants potentially of concern in municipal
sewage sludges. Mercury (Hg) 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 determin-
ing whether Hg 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_,t_,_ sludge * soil * plant uptake » animal uptake -* human toxicity).
The values and assumptions employed in these calculations tend to repre-
sent 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 MERCURY IN MUNICIPAL SEWAGE SLUDGE
The following preliminary conclusions have been derived from Che
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-AMD-MARKETING
A. Effect on Soil Concentration of Mercury
Landspreading of sludge may result in increased concentrations
of Ug in the soil except possibly when typical sludge is
applied at a low rate (5 mt/ha) (see Index 1).
B. Effect on Soil Biota and Predators of Soil Biota
Conclusions for effects on soil biota and predators of soil
biota were not drawn because index values were not calculated
due to lack of data (see Indices 2 and 3).
C. Effect on Plants and Plant Tissue Concentration
Landspreading of sludge is not expected to result in concen-
trations of Hg in soil that are phytotoxic (see Index 4).
Land application of sludge may result in increased plant
tissue concentration above background levels except possibly
when typical sludge is applied ac a low rate (5 mt/ha) and
when high-Hg sludge is applied at a low rate (5 mt/ha) for
crops consumed by humans (see Index 5). The concentrations of
Hg in plant tissues resulting from uptake of Hg from sludge-
amended soils are not expected to be limited by phytotoxic
levels (see Index 6).
D. Effect on Herbivorous Animals
Landspreading of sludge is not expected to result in plant
tissue concentrations of Hg that pose a dietary toxic threat
to herbivorous animals (see Index 7). The inadvertent inges-
tion of sludge-amended soil by grazing animals is not expected
to result in dietary concentrations of Hg that are toxic to
animals (see Index 8).
E. Effect on Humans
The consumption of crops grown on sludge-amended soil is not
expected to pose a toxic threat to humans due to Hg except
possibly for toddlers when high-Hg sludge is applied at a high
rate (500 mt/ha) (see Index 9). The consumption of animal
products derived from animals fed crops grown on sludge-
2-1
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amended soil may result in a toxic threat to toddlers due to
Hg when sludge is applied at a high rate (500 mt/ha) and when
high-Hg sludge is applied at a moderate rate (SO mt/ha).
Also, a toxic threat due to Hg for adults may result when
high-Hg sludge is applied at a high rate (500 mt/ha) (see
Index 10). The consumption of animal products derived from
grazing animals that have inadvertently ingested sludge-
amended soil may pose a toxic threat to humans (see Index 11).
The inadvertent ingestion of sludge-amended soil or pure
sludge is not expected to result in a toxic threat to humans
due to Hg except possibly for toddlers when high-Hg sludge is
landspread at a high rate (500 mt/ha) or when toddlers ingest
pure sludge (see Index 12). Landspreading of sludge may
result in an aggregate amount of Hg in che human diet that
poses a toxic threat (see Index 13).
II. LANDPILLING
Landfilling of sludge may result in increased concentrations of Hg
in the groundwater at the well (see Index 1). Landfilling of
sludge is not expected to pose a toxic threat to humans due to Hg
in groundwater at the well except possibly at landfills where all
worst-case parameters exist (see Index 2).
III. INCINERATION
Incineration of sludge may result in increased concentrations of Hg
in air above background levels (see Index 1). Incineration of
sludge is not expected to result in concentrations of Hg in air
that pose a toxic threat to humans except possibly when high-Hg
sludge is incinerated at a high feed rate (10,000 kg/hr DW) (see
Index 2).
IV. OCEAN DISPOSAL
Significant increases in the seawater concentration of Hg is
apparent for all the scenarios evaluated (see Inctex 1). The incre-
mental increase of Hg concentrations during a 24-hour dumping cycle
is significant, especially for sludge containing "worst" concentra-
tions dumped at the worst site (see Index 2). Increases in incre-
mental hazard are evident for worst concentration sludges dumped at
the worst and typical sites. Increase is also evident at the
worst-site with typical concentrations (see Index 3). No increase
in risk to human health is apparent from typical seafood intake
from organisms residing at the typical and worst sites after dump-
ing of sludges with typical concentrations of Hg. Slight
increases, however, are seen when site characteristics, sludge con-
centrations, and seafood intake are all worst case (see Index 4).
2-2
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SECTION 3
PRELIMINARY HAZARD INDICES FOR MERCURY
IN MUNICIPAL SEWAGE SLUDGE
I. LANDSPREADING AND DISTRIBUTION-AND-MARKETING
A. Effect on Soil Concentration of Mercury
1. Index of Soil Concentration Increment (Index 1)
a. Explanation - Shows degree of elevation of pollutant
concentration in soil to which sludge is applied.
Calculated for sludges with typical (median if
available) and worst (95th percentile if available)
pollutant concentrations, respectively, for each of
four sludge loadings. Applications (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 application as may be used on
public lands, reclaimed areas or home
gardens.
500 mt/ha Cumulative loading after years of
application.
b. Assumptions/Limitations - Assumes pollutant is dis-
tributed and retained within the upper 15 cm of soil
(i.e., the plow layer), which has an approximate
mass (dry matter) of 2 x 103 mt/ha.
c. Data Used and Rationale
i. Sludge concentration of pollutant (SC)
Typical 1.49 Ug/g DW
Worst 5.84 yg/g DW
The typical and worst sludge concentrations are
the median and 95th percentile values statis-
tically derived from sludge concentration data
from a survey of 40 publicly-owned treatment
3-1
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works (POTWs) (U.S. EPA, 1982). In this docu-
ment, it is assumed that inorganic Hg is the
prevalent form for incineration and alkyl mer-
cury is the form for Landspreading, landfill-
ing, and ocean disposal. However, the
possibility of conversion of alkyl mercury to
inorganic Hg does exist. (See Section 4,
p. 4-1.)
ii. Background concentration of pollutant in soil
(BS) = 0.10 pg/g DW
Cappon (1984), Erdman et al. (1976), and
Fleischer (1970) report Hg concentrations of
specific soils. U.S. Geological Survey (1970)
and Ratsch (1974) report that Hg content of
U.S. soils average 100 ng/g. (See Section 4,
p. 4-2.)
d. Index 1 Values
Sludge Application Rate (mt/ha)
Sludge
Concentration 0 5 50 500
Typical
Worst
1.0
1.0
1.0
1.1
1.3
2.4
3.8
12
e. Value Interpretation - Value equals factor by which
expected soil concentration exceeds background when
sludge is applied. (A value of 2 indicates concen-
tration is doubled; a value of 0.5 indicates
reduction by one-half.)
f. Preliminary Conclusion - Landspreading of sludge may
result in increased concentrations of Hg in the soil
except possibly when typical sludge is applied at a
low rate (5 mt/ha).
B. 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 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.
3-2
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c. Data Used and Rationale
i. Index of soil concentration increment (Index 1)
See Section 3, p. 3-2.
ii. Background concentration of pollutant in soil
(BS) = 0.10 Ug/g DW
See Section 3, p. 3-2.
iii. 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 tox-
icity 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. Index of soil concentration increment (Index 1)
See Section 3, p. 3-2.
ii. Background concentration of pollutant in soil
(BS) = 0.10 Ug/g DW
See Section 3, p'. 3-2.
iii. Uptake slope of pollutant in soil biota (UB) =
0.34 yg/g tissue DW (ug/g soil DW)'1
Bull et al. (1977) reported the Hg concentra-
tion in earthworms and in soil. The Hg was
3-3
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atmospherically deposited from an industrial
emission source. This is the only source of
data in the profile for soil biota. (See
Section 4, p. 4-13.)
iv. Background concentration in soil biota (BB) =
0.041 ug/g DW
Bull et al. (1977) reported the background con-
centration of Hg in earthworms. (See Sec-
tion 4, p. 4-13.)
v. 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 - Value 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.
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 Phytotoxicity (Index 4)
a. Explanation - Compares pollutant concentrations in
sludge-amended soil with the Lowest soil
concentration shown to be toxic for some plant.
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. Index of soil concentration increment (Index 1)
See Section 3, p. 3-2.
ii. Background concentration of pollutant in soil
(BS) =0.10 Ug/g DW
See Section 3, p. 3-2.
3-4
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iii. Soil concentration toxic to plants (TP) =
8.0 Ug/g DW
Reduced plant growth was observed for Bermuda
grass/leaf grown on Weswood soil amended with
8.0 mg/kg Hg (Weaver et al., 1984). 8.0 mg/kg
is the lowest concentration of Hg-amended soil
which resulted in a toxic effect. Lower con-
centrations of Hg produced toxic effects in
tests with plants growing in nutrient solu-
tions. The uptake rates of contaminants by
plants in nutrient solutions are not considered
to be analogous to the uptake rates of plants
in sludge-amended soils. Therefore, the phyto-
toxic concentrations in plants grown in nutri-
ent solutions are also not comparable to phyto-
toxic concentrations in Hg-amended soils. (See
Section 4, p. 4-9.)
d. Index 4 Values
Sludge Application Rate (mt/ha)
Sludge
Concentration 0 5 50 500
Typical
Worst
0.012
0.012
0.013
0.014
0.017
0.030
0.047
0.16
e. Value Interpretation - Value equals factor by which
soil concentration exceeds phytotoxic concentration.
Value > 1 indicates a phytotoxic hazard may exist.
f. Preliminary Conclusion - Landspreading of sludge is
not expected to result in concentrations of Hg in
soil that are phytotoxic.
2. Index of Plant Concentration Increment Caused by Uptake
(Index 5)
a. Explanation - Calculates expected tissue concentra-
tion increment 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 a linear uptake
slope. Neglects the effect of time; i.e., cumula-
tive loading over several years is treated equiva-
lently to single application of the same amount.
The uptake factor chosen for the animal diet is
assumed to be representative of all crops in the
3-5
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animal diet. See also Index 6 for consideration of
phytotoxicity.
Data Used and Rationale
i. Index of soil concentration increment (Index 1)
See Section 3, p. 3-2.
ii. Background concentration of pollutant in soil
(BS) = 0.10 yg/g DU
See Section 3, p. 3-2.
iii. Conversion factor between soil concentration
and application rate (CO) = 2 kg/ha (ug/g)"1
Assumes pollutant is distributed and retained
within upper 15 cm of soil (i.e. plow Layer)
which has an approximate mass (dry matter) of
2 x 103.
iv. Uptake slope of pollutant in plant tissue (UP)
Animal diet:
Bermuda grass/leaf
0.064 ug/g tissue DW (kg/haT1
Human diet:
Radish
0.017 yg/g tissue DW (kg/ha)"1
Bull et al. (1978), Elfving et al. (1978), Hogg
et al. (1978), John (1972), Lindberg et al.
(1979), MacLean (1974), and Weaver et al.
(1984) examined the effects of Hg compounds on
plants. All studied except that by Haney and
Lipsey (1973) were conducted on plants grown in
soil. The plants studied by Haney and Lipsey
were grown in nutrient solutions. The Hg val-
ues resulting from this study were not used
because .contaminant uptake by plants grown in
solution is not analogous to pollutant uptake
by plants grown in sludge-amended soils.
In the studies by Bull et al. (1977) and
Lindberg et al. (1979), plants were contami-
nated with Hg compounds from industrial emis-
sions. The deposition of these emissions on
the plants being studied resulted in. abnormally
high Hg concentration values in the plant tis-
sues. These concentrations are not representa-
tive of the uptake rates exhibited by plants
grown in sludge-amended soil. As such, these
values were not used for this study.
3-6
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John (1972) and Weaver et al. (1984) studied
plants grown in soils contaminated with HgC^.
The resultant values were used for index calcu-
lations because the effects of HgCl2 in soils
are the most analogous to the effects of Hg in
sludge-amended soils. Bermuda grass and
radishes were chosen because the uptake values
were the highest and were therefore considered
the worst case. (See Section 4, p. 4-10.)
v. Background concentration in plant tissue (BP)
Animal diet:
Bermuda grass/leaf 0.01 Ug/g DW
Human diet:
Radish 0.013 Ug/g DU
The highest background concentrations for ber-
muda grass and radish are found in John (1972)
and Weaver et al. (1984). The highest value is
chosen as a worst-case value from the stand-
point of effects on humans. (See Section 4,
p. 4-10.)
d. Index 5 Values
Sludge Application
Rate (mt/ha)
Sludge
Diet Concentration 0 5 50 500
Animal
Typical
Worst
1.0
1.0
1.0
1.2
1.4
2.8
4.6
16
Human Typical 1.0 1.0 1.1 1.7
Worst 1.0 1.0 1.4 4.0
e. Value Interpretation - Value equals factor by which
plant tissue concentration is expected to increase
above background when grown in sludge-amended soil.
f. Preliminary Conclusion - Land application of sludge
may result in increased plant tissue concentration
above background levels except possibly when typical
sludge is applied a low rate (5 mt/ha) and when
high-Hg sludge is applied at a low rate (5 mt/ha)
for crops consumed by humans.
3. Index of Plant Concentration Increment Permitted by
Phytotoxicity (Index 6)
a. Explanation - Compares maximum plant tissue concen-
tration associated with phytotoxicity with back-
3-7
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ground concentration in same plant tissue. The
purpose is to determine whether the plant concentra-
tion increments calculated in Index 5 for high
applications are truly realistic, or whether such
increases would be precluded by phytotoxicity.
b. Assumptions/Limitations - Assumes that tissue con-
centration will be a consistent indicator of
phytotoxicity.
c. Data Used and Rationale
i. Maximum plant tissue concentration associated
with phytotoxicity (PP)
Animal diet:
Bermuda grass/leaf 0.2 ug/g DW
Human diet:
Tomato seedling 1.5 Ug/g DW
Specific data on plant tissue concentration
associated with phytotoxicity are not available
for radish plants. The Hg content in plant
tissues associated with phytotoxicity of tomato
seedlings, used as a proxy for radishes, and
Bermuda grass are worst-case values. The Hg
concentration in the tomato seedling is assumed
to be equal to the concentration in the tomato
fruit. Tomato seedling stem elongation and
biomass increase were significantly inhibited
by Hg concentrations (in nutrient solution)
equal to, or greater than 0.01 ppm methyl Hg
hydroxide. This is equivalent to 1.5 ppm Hg in
the terminals (Haney and Lipsey, 1973). (See
Section 4, p. 4-9.)
ii. Background concentration in plant tissue (BP)
Animal diet:
Bermuda grass/leaf 0.01 ug/g DW
Human diet:
Tomato seedling 0.1 Ug/g DW
The highest Hg concentration for the tomato
seedling was reported by Haney and Lipsey
(1973) to be 0.1 ug/g DW. The highest value is
chosen as a worst-case value. (See Section 4,
p. 4-9.)
3-8
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d. Index 6 Values
Plant Index Value
Bermuda grass/leaf 20
Tomato seedling 15
e. Value Interpretation - Value gives the maximum
factor of tissue concentration increment (above
background) which is permitted by phytotoxicity.
Value is compared with values for the same or simi-
lar plant tissues given by Index 5. The lowest of
the two indices indicates the maximal increase which
can occur at any given application rate.
f. Preliminary Conclusion - The concentrations of Hg in
plant tissues resulting from uptake of Hg from
sludge-amended soils (see Index 5) are not expected
to be limited by phytotoxic levels.
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 food 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. Index of plant concentration increment caused
by uptake (Index S)
Index 5 values used are those for an animal
diet (see Section 3, p. 3-7).
ii. Background concentration in plant tissue (BP) =
0.01 Ug/g DW
The background concentration value used is for
the plant chosen for the animal diet (see
Section 3, p. 3-7).
3-9
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iii. Feed concentration toxic to herbivorous animal
(TA) = 2 ug/g DW
The National Academy of Science's (NAS) maximum
tolerable dietary level for domestic animals is
2 ppm Hg for both organic and inorganic forms
(NAS, 1980). (See Section 4, p. 4-7.) Com-
pounds of Hg do not always reflect toxicity
analogous to animal toxicity resulting from
consumption of plants grown on sludge-amended
soils. Other elements (of these compounds) may
contribute to the toxicity or may be toxic only
in combination with Hg. Also, the concentra-
tion of the compounds used in these studies
(see Section 4, p. 4-11) is much higher than
the concentrations normally found in sludge.
The studies either used higher Hg concentra-
tions than NAS maximum tolerable dietary level
or no adverse effects were observed. The
lethal concentration in feed for mink was lower
than the NAS value (Auerlich et al., 1974).
Mink is a carnivore and its diet is very dif-
ferent from a herbivore's. The data from the
mink study are not considered to be compatible
with this index.
d. Index 7 Values
Sludge Application Rate (mt/ha)
Sludge
Concentration 0 5 50 500
Typical 0.0050 0.0052 0.0072 0.023
Worst 0.0050 0.0059 0.014 0.078
e. Value Interpretation - Value equals factor by which
expected plant tissue concentration exceeds that
which is toxic to animals. Value > 1 indicates a
toxic hazard may exist for herbivorous animals.
f. Preliminary Conclusion - Landspreading of sludge is
not expected to result in plant tissue concentra-
tions of Hg that pose a dietary toxic threat 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.
3-10
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b. Assumptions/Limitations - Assumes that sludge is
applied over and adheres to growing forage, or chat
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 1.49 ug/g DW
Worst 5.84 ug/g DW
See Section 3, p. 3-1.
ii. Background concentration of pollutant in soil
(BS) = 0.10 ug/g DW
See Section 3, p. 3-2.
iii. Fraction of animal diet assumed to be soil (GS)
= 5%
Studies of sludge adhesion to growing forage
following applications of liquid or filter-cake
sludge show chat 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
forage was only 2.14 and 4.75 percent, respec-
tively (Bertrand et al., 1981). It seems rea-
sonable to assume that animals may receive
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
3-11
-------
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.
iv. Peed concentration toxic to herbivorous animal
(TA) = 2 Ug/g DW
See Section 3, p. 3-10.
d. Index 8 Values
Sludge Application Rate (mt/ha)
Sludge
Concentration 0 5 50 -SQO-
Typical
Worst
0.0025
0.0025
0.037
0.15
0.037
0.15
0.037
0.15
e. 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.
f. Preliminary Conclusion - The inadvertent ingestion
of sludge-amended soil by grazing animals is not
expected to result in dietary concentrations of Hg
that are toxic to animals.
E. Effect on Humans
1. Index of Human Toxicity 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 accept-
able daily intake (ADI) of the pollutant.
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 as the most responsive plant(s) (as chosen
in Index 5). Divides possible variations in dietary
intake into two categories: toddlers (18 months to
3 years) and individuals over 3 years old.
3-12
-------
Data Used and Rationale
i. Index of plant concentration increment caused
by uptake (Index 5)
Index S values used are those for a human diet
(see Section 3, p. 3-7).
ii. Background concentration in plant tissue (BP) =
0.013 ug/g DW
The background concentration value used is for
the plant chosen for the human diet (see
Section 3, p. 3-7).
iii. 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 (1984e). 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 estimated dry-weight
consumption of all non-fruit crops.
iv. Average daily human dietary intake of pollutant
(DI)
Toddler 0.9 Ug/day
Adult 5.0 Ug/day
The average U.S. total daily Hg intake for tod-
dlers and adults is an average of daily
intakes. Toddler = average of Fiscal Year (FY)
75, FY 76, and FY 77 total daily Hg intake of
0.9, 0.8, and 1.1 yg/day, respectively.
Adults = average of FY 75, FY 76, FY 77, and
FY 78 total Hg daily intake of 3.7, 6.5, 6.3,
and 3.4 yg/day, respectively. The toddler val-
ues do not fluctuate much from year to year.
The adult values appear to double and halve
from year to year; therefore, an average value
will better represent the total daily dietary
intake. Also, meat, fish, and poultry contri-
buted 73.1 percent of the daily Hg intake (FDA,
1980b). (See Section 4, p. 4-4.)
3-13
-------
v. Acceptable daily intake of pollutant (ADI)
Toddler 3 Ug/day
Adult 20 Ug/day
The World Health Organization (WHO, 1976) con-
cluded that a long-term daily intake of methyl
Hg of 3 to 7 ug/kg is the level at which the
earliest effects of Hg intoxication appear in
the most sensitive adults; U.S. EPA (1980,
1984b) concurred with that evaluation. An ADI
of 20 Ug/day was derived assuming a 70 kg adult
body weight and applying an uncertainty factor
of 10 (3 ug/kg/day x 70 kg * 10 «r 20 ug/day)
(U.S. EPA, 1980). Prenatal life is the most
sensitive life stage to methyl Hg exposure
(U.S. EPA, 1984b). Assuming that young chil-
dren may also be particularly sensitive, it
seems prudent to derive an intake level based
on the toddler body weight as well, so that
exposure is continually maintained below the
above stated effect level (3 to 7 Ug/kg/day) by
a factor of 10. Therefore, for the purposes of
this document, an ADI of 3 ug/day (3 ug/kg/day
x 10 kg t 10 = 3 Ug/day) will be used to eval-
uate oral exposure of toddlers to methyl Hg.
(See Section 4, p. 4-5.)
Index 9 Values
Sludge Application
Rate (mt/ha)
Sludge
Group Concentration 0 5 50 500
Toddler
Typical
Worst
0.30
0.30
0.30
0.31
0.33
0.42
0.53
1.3
Adult Typical 0.25 0.25 0.26 0.35
Worst 0.25 0.25 0.30 0.65
Value Interpretation - Value equals factor by which
expected intake exceeds ADI. Value >1 indicates a
possible human health threat. 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 - The consumption of crops
grown on sludge-amended soil is not expected to pose
a toxic threat to humans due to Hg, except possibly
for toddlers when high-Hg sludge is applied at a
high rate (500 mt/ha).
3-14
-------
2. Index of Human Toxicity Resulting from Consumption of
Animal Products Derived from Animals Feeding on Plants
(Index 10)
a. Explanation - Calculates human dietary intake
expected to result from consumption of animal
products derived from domestic animals given feed
grown on sludge-amended soil (crop or pasture land)
but not directly contaminated by adhering sludge.
Compares expected intake with ADI.
b. Assumptions/Limitations - Assumes that all animal
products are from animals receiving all their feed
from sludge-amended soil. The uptake slope of pol-
lutant in animal tissue (UA) used is assumed to be
representative of all animal tissue comprised by the
daily human dietary intake (DA) used. Divides pos-
sible variations in dietary intake into two categor-
ies: toddlers (18 months to 3 years) and
individuals over 3 years old.
c. Data Used and Rationale
i. Index of plant concentration increment caused
by uptake (Index 5)
Index 5 values used are those for an animal
diet (see Section 3, p. 3-7).
ii. Background concentration in plant tissue (BP) =
0.01 pg/g DW
The background concentration value used is for
the plant chosen for the animal diet (see
Section 3, p. 3-7).
iii. Uptake slope of pollutant in animal tissue (UA)
Duck liver
12.1 yg/g tissue DW (pg/g feed DW)"1
Duck muscle
2.33 ug/g tissue DW (ug/g feed DW)-1
Uptake values for duck liver and muscle are the
most analogous to uptake values for beef liver
and muscle (Finley and Stendell, 1978). The
uptake of contaminants by carnivores (mink in a
study by Auerlich et al., 1974) is not compat-
ible to this index. Kidneys are not a major
constituent of the U.S. diet and therefore kid-
ney data were not used. Highest values were
used in this index, assuming a worst case.
(See Section 4, p. 4-12.) Values presented in
3-15
-------
e.
f.
Section 4, p. 4-12 in wet weight terms have
been converted to dry weight concentrations for
this calculation.
iv. Daily human dietary intake of affected animal
tissue (DA)
Liver
Toddler
Adult
0.97 g/day
5.76 g/day
Muscle
Toddler
Adult
51.1 g/day
133 g/day
The FDA Revised Total Diet (Pennington, 1983)
lists average daily intake of beef liver, fresh
weight, for various age-sex classes. The 95th
percentile of liver consumption (chosen in
order to be conservative) is assumed to be
approximately 3 times the mean values. Conver-
sion to dry weight is based on data from U.S.
Department of Agriculture (1975).
v. Average daily human dietary intake of pollutant
(DI)
Toddler 0.9 Ug/day
Adult 5.0 Ug/day
See Section 3, p. 3-13.
vi. Acceptable daily intake of pollutant (ADI)
Toddler 3 ug/day
Adult 20 Ug/day
See Section 3, p. 3-14.
Index 10 Values
Group
Sludge
Concentration
Sludge Application
Rate (mt/ha)
5 50 500
Toddler
Typical
Worst
0.30
0.30
0.32
0.38
0.49
1.1
1.9
6.7
Adult
Typical
Worst
0.25
0.25
0.26
0.28
0.33
0.59
0.93
3.0
Value Interpretation - Same as for Index 9.
Preliminary Conclusion - The consumption of animal
products derived from animals fed crops grown on
sludge-amended soil may result in a toxic threat to
toddlers due to Hg when sludge is applied at a high
3-16
-------
race (500 mt/ha) and when high-Hg sludge is applied
at a moderate rate (50 mt/ha). Also, a toxic threat
due to Hg for adults may result when high-Hg sludge
is applied at a high rate (500 mt/ha).
3. Index of Human Toxicity 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 ADI.
b. Assumptions/Limitations - Assumes that all animal
products are from animals grazing sludge-amended
soil, and that aLLanimal 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 three
years old.
c. Data Used and Rationale
i. Animal tissue = Duck liver and muscle
See Section 3, p. 3-15.
ii. Background concentration of pollutant in soil
(BS) = 0.10 ug/g DW
See Section 3, p. 3-2.
iii. Sludge concentration of pollutant (SC)
-Typical 1.49 Ug/g DW
Worst 5.84 ug/g DW
See Section 3, p. 3-1.
iv. Fraction of animal diet assumed to be soil (GS)
= 5%
See Section 3, p. '3-11.
3-17
-------
v. Uptake slope of pollutant in animal tissue (DA)
Duck liver
12.1 Ug/g tissue DW (ug/g feed DW)'1
Duck muscle
2.33 Ug/g tissue DW (ug/g feed DW)'1
See Section 3, p. 3-15.
vi. Daily human dietary intake of affected animal
tissue (DA)
Liver Muscle
Toddler 0.97 g/day Toddler 51.1 g/day
Adult 5.76 g/day Adult 133 g/day
See Section 3, p. 3-16.
vii. Average daily human dietary intake of pollutant
(DI)
Toddler 0.9 Ug/day
Adult 5.0 Ug/day
See Section 3, p. 3-16.
viii. Acceptable daily intake of pollutant (ADI)
Toddler 3 Ug/day
Adult 20 Ug/day
See Section 3, p. 3-14.
d. Index 11 Values
Sludge Application
Rate (mt/ha)
Group
Toddler
Adult
Sludge
Concentration
Typical
Worst
Typical
Worst
0
0.52
0.52
0.34
0.3*
5
3.5
13
1.7
5.8
50
3.5
13
1.7
5.8
500
3.5
13
1.7
5.8
e. Value Interpretation - Same as for Index 9.
f. Preliminary Conclusion - The consumption of animal
products derived from grazing animals that have
inadvertently ingested sludge-amended soil may pose
a toxic threat to humans.
3-18
-------
4. Index of Human Toxicity 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 ADI.
b. Assumptions/Limitations - Assumes that the pica
child consumes an average of 5 g/day of sludge-
amended soil. If an ADI specific for a child is not
available, this index assumes that the ADI for a
10 kg child is the same as that for a 70 kg adult.
It is thus assumed that uncertainty factors used in
deriving the ADI provide protection for the child,
taking into account the smaller body size and any
other differences in sensitivity.
c. Data Used and Rationale
i. Index of soil concentration increment (Index 1)
See Section 3, p. 3-2.
ii. Sludge concentration of pollutant (SC)
Typical 1.49 Mg/g DW
Worst 5.84 yg/g DW
See Section 3, p. 3-1.
iii. Background concentration of pollutant in soil
(BS) = 0.10 yg/g DW
See Section 3, p. 3-2.
iv. 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 (1984e).
v. Average daily human dietary intake of pollutant
(DI)
Toddler 0.9 Mg/day
Adult 5.0 yg/day
See Section 3, p. 3-13.
3-19
-------
vi. Acceptable daily intake of pollutant (ADI)
d.
Toddler 3 ug/day
Adult 20 Ug/day
See Section 3, p. 3-14.
Index 12 Values
Sludge Application
Rate (mt/ha)
Group
Toddler
Adult
Sludge
Concentration
Typical
Worst
Typical
Worst
0
0.47
0.47
0.25
0.25
5
0.47
0.49
0.25
0.25
50
0.52
0.70
0.25
0.25
500
0.93
2.4
0.25
0.25
Pure
Sludg
2.8
10
0.25
0.26
e. Value Interpretation - Same as for Index 9.
f. Preliminary Conclusion - The inadvertent ingestion
of sludge-amended soil or pure sludge is not
expected to result in a toxic threat to humans due
to Hg except possibly for toddlers when high-Hg
sludge is landspread at a high rate (500 mc/ha) or
when toddlers ingest pure sludge.
5. Index of Aggregate Human Toxicity (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 AOI.
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
Sludge Application
Rate (mt/ha)
Group
Toddler
Adult
Sludge
Concentration
Typical
Worst
Typical
Worst
0
0.68
0.68
0.35
0.35
5
3.7
13
1.7
5.8
50
4.0
14
1.8
6.2
500
6.0
22
2.4
9.0
3-20
-------
e. Value Interpretation - Same as for Index 9.
£. Preliminary Conclusion - Landspreading of sludge may
result in an aggregate amount of Hg in the human
diet that poses a toxic threat.
II. LAMDPILLIMC
A. Index of Groundwater Concentration Increment 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 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
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; the pollutant source is a
pulse input; no dilution of the plume occurs by recharge
3-21
-------
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
Worst Sandy loam
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
-------
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
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 of 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
3-23
-------
of thumb, dispersivity may be set equal to
10 percent of the distance measurement of the
analysis (Gelhar and Axness, 1981). Thus,
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 1.49 mg/kg DW
Worst 5.84 mg/kg DW
See Section 3, p. 3-1.
(b) Degradation rate (jl) = 0 day'1
The degradation rate in the unsaturated zone is
assumed to be zero for all inorganic chemicals
(c) Soil sorption coefficient (Kj)
Typical 580 mL/g
Worst 322 mL/g
K
-------
Porosity is Chat 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).
ii. Site parameters
(a) Average hydraulic gradient between landfill and
well (i)
Typical 0.001 (unitless)
Worst 0.02 (unit-less)
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 grad-
ient values were provided by Donigian (1985).
(b) Distance from well to landfill (A£)
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
3-25
-------
These values are 10 percent of the distance
from well to landfill (AH), 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 pre-
existing 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^.
iii. Chemical-specific parameters
(a) Degradation rate (il) = 0 day'1
Degradation is assumed not to occur in the
saturated zone.
(b) Background concentration of pollutant in
groundvater (BC) =0.1 Ug/L
With few exceptions, che Hg content of ground-
water samples was below detection (0.1 Ug/L)
(U.S. EPA, 1980). Also, Cassidy and Furr
(1978) state that inland groundwater has a con-
centration of 0.1 ppb (0.1 Ug/L). (See
Section 4, p. 4-3.)
(c) Soil sorption coefficient (Kj) = 0 mL/g
Adsorption is assumed to be zero in the
saturated zone.
Index Values - See Table 3-1.
Value Interpretation - Value equals factor by which
expected groundwater concentration of pollutant at well
exceeds the background concentration (a value of 2.0
indicates the concentration is doubled, a value of 1.0
indicates no change).
3-26
-------
6. Preliminary Conclusion - Landfill ing of sludge may result
in increased concentrations of Hg in the groundwater at
the well.
B. Index of Human Toxicity Resulting from Groundwater
Contamination (Index 2)
1. Explanation - Calculates human exposure which could
result from groundwater contamination. Compares exposure
with acceptable daily intake (ADI) 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 increment result-
ing from landfilled sludge (Index 1)
See Section 3, p. 3-2.
b. Background concentration of pollutant in groundwater
(BC) = 0.1 yg/L
See Section 3, p. 3-26.
c. 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.
d. Average daily human dietary intake of pollutant (DI)
=5.0 ug/day
See Section 3, p. 3-16.
e. Acceptable daily intake of pollutant (ADI) =
20 Mg/day (Adult)
4. Index 2 Values - See Table 3-1.
5. Value Interpretation - Value equals factor by which pol-
lutant intake exceeds ADI. Value >1 indicates a possible
human health threat. Comparison with the null index
value indicates the degree to which any hazard is due to
landfill disposal, as opposed to pre-existing dietary
sources.
6. Preliminary Conclusion - Landfilling of sludge is not
expected to pose a toxic threat to humans due to Hg in
groundwater at the well, except possibly at landfills
where all worst-case parameters exist.
3-27
-------
TABLE 3-1. INDEX OF CROUNDWATER CONCENTRATION INCREMENT RESULTING FROM LANDFILLED SLUDGE (INDEX 1) AND
INDEX OF HUMAN TOXICITY RESULTING FROM GROUNDWATER CONTAMINATION (INDEX 2)
Site Characteristics
Condition of
34
Sludge concentration
Unsaturated Zone
ro
oo
W
N
Soil type and charac- T
teristicsd
Site parameters6 T
Saturated Zone
Soil type and charac- T
teristics^
Site parameters^ T
Index 1 Value 1.4
Index 2 Value 0.25
T W NA T T NA M
T T U T T W N
T T T W T W N
T T T T W W N
2.6 1.4 1.4 2.9 4.0 340 0
0.27 0.25 0.25 0.27 0.28 3.6 0.25
aT = Typical values used; U = worst-case values used; N = null condition, where no landfill exists, used as
basis for comparison; NA = not applicable for this condition.
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.
dDry bulk density (Pjry) and volumetric water content (6).
eLeachate generation rate (Q), depth to groundwater (h), and dispersivity coefficient (a).
^Aquifer porosity (0) and hydraulic conductivity of the aquifer (K).
Ellydraulic gradient (i), distance from well to landfill (AS.), and dispersivity coefficient (a).
-------
III. INCINERATION
A. Index of Air Concentration Increment Resulting from
Incinerator Emissions (Index 1)
1. Explanation - Shows the degree of elevation of the
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 (CDM, 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. Dilution
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. Data Used and Rationale
a. Coefficient to correct for mass and time units (O =
2.78 x 10~7 hr/sec x g/mg
b. Sludge feed rate (DS)
i. Typical = 2660 kg/hr (dry solids input)
A feedy 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
3-29
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ii. Worst = 10,000 kg/hr (dry solids input)
A feed rate of 10,000 kg/hr OW 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 - 26.6%
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 1.49 mg/kg DW
Worst 5.84 mg/kg DW
See Section 3, p. 3-1.
d. Fraction of pollutant emitted through stack (FM)
Typical 1 (unitless)
Worst 1 (unitless)
Emission estimates may vary considerably between
sources; therefore, the values used are based on a
U.S. EPA 10-city incineration study (Farrell and
Wall, 1981). Where data were not available from the
EPA study, a more recent report which thoroughly
researched heavy metal emissions was utilized (COM,
1983).
e. Dispersion parameter for estimating maximum annual
ground level concentration (DP)
Typical 3.4 pg/'m3
Worst 16.0 Ug/m3
The dispersion parameter is derived from the U.S.
EPA-ISCLT short-stack model.
f. Background concentration of pollutant in urban air
(BA) = 0.0010 ug/m3
Cassidy and Furr (1978) report a worldwide average
Hg concentration of 0.02 ug/m3. Fleischer (1970)
and U.S. EPA (1984b) report background levels of
0.001 to 0.002 ug/m3 Hg in air. U.S. EPA (1984c)
reports an average value of 0.010 pg/m3 occurs in
urban areas. (See Section 4, p. 4-3.)
3-30
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4. Index 1 Values
Sludge Feed
Fraction of Rate (kg/hr DW)a
Pollutant Emitted
Through Stack
Typical
Worst
Sludge
Concentration
Typical
Worst
Typical
Worst
0
1.0
1.0
1.0
1.0
2660
1.4
2.5
1.4
2.5
10,000
7.6
27
7.6
27
aThe typical (3.4 ug/m) and worst (16.0 Mg/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 equals factor by which
expected air concentration exceeds background levels due
to incinerator emissions.
6. Preliminary Conclusion - Incineration of sludge may
result in increased concentrations of Hg in air above
background levels.
B. Index of Human Toxicity Resulting from Inhalation of
Incinerator Emissions (Index 2)
1. Explanation - Shows the increase in human intake expected
to result from the incineration of sludge. For noncarci-
nogens, Levels typically were derived from the American
Conference of Governmental and Industrial Hygienists
(ACGIH) threshold Limit values (TLVs) for the workplace.
2. Assumptions/Limitations - The exposed population is
assumed to reside within the impacted area for 24 hours/
day. A respiratory volume of 20 m-Vday is assumed over a
70-year Lifetime.
3. Data Used and Rationale
a. Index of air concentration increment resulting from
incinerator emissions (Index 1)
See Section 3, p. 3-31.
b. Background concentration of pollutant in urban air
(BA) = 0.0010 Ug/m3
See Section 3, p. 3-30.
3-31
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c. Maximum permissible intake of pollutant by
inhalation (MPIH) =3.6 Ug/day
The MPIH for inorganic Hg is 3.6 Ug/day based on an
adjustment of the workplace Threshold Limit Value
(TLV) (U.S. EPA, 1984a) of 0.05 mg/m3 as a time-
weighted average (TWA) (ACGIU, 1983). See
Section 4, p. 4-6.)
d. Exposure criterion (EC) =0.18 Mg/m3
The exposure criterion is the level at which the
inhalation of the pollutant is expected to exceed
the maximum permissible intake for inhalation
(MPIH). The exposure criterion is calculated using
the following formula:
EC = MPIH
20 m3/day
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
0.56
0.56
0.076
0.14
0.42
1.5
Worst Typical 0.56 0.076 0.42
Worst 0.56 0.14 1.5
aThe 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.
5. Value Interpretation - Value equals factor by which
expected intake exceeds MPIH. Value >1 indicates a poss-
ible human health threat. 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 not
expected to result in concentrations of Hg in air that
pose a toxic threat to humans, except possibly when high-
Hg sludge is incinerated at a high feed rate
(10,000 kg/hr DW).
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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.
A. Index of Seawater Concentration Resulting from Initial Mixing
of Sludge (Index 1)
1. Explanation - Calculates relative concentrations
(compared to the background concentration of the pol-
lutant) (unitless) of pollutant in seawater around an
ocean disposal site assuming initial mixing.
2. Assumptions/Limitations - Assumes that the background
seawater concentration of pollutant is finite and known.
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 per-
pendicular 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 sea-
sonal 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) Sinele Tanker (ST) Path (L)
Typical 825 mt DW/day 1600 mt WW 8000 m
Worst 1650 mt DW/day 3400 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
3-33
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conversion Co dry weight assumes 4 percent solids by
weight. The worst-case value is an arbitrary doubl-
ing 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 S3 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,
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 DU/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 1.49 mg/kg DW
Worst 5.84 mg/kg DW
See Section 3, p. 3-1.
3-34
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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 orlong-term impact. The current
velocity of 11 cm/sec (9500 m/day) chosen is based
on the average current velocity in this area (CDM,
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 m 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
(CDM, 1984c).
d. Ambient water concentration of pollutant (CA) =
0.005 ug/L
The ambient water concentration of Hg ranges from
0.003 to 2.0 Mg/L (Cassidy and Furr, 1978; U.S. EPA,
1984b). The conservative value chosen is represen-
tative of unpolluted or open ocean values and ampli-
fies the relative impact of sludge disposal. (See
Section 4, p. 4-2.)
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.
3-35
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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 National Oceanic and
Atmospheric Administration (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 spread-
ing 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.
5. Index 1 Values
Disposal Sludge Disposal
Conditions and Rate (mt DW/day)
Site Charac- Sludge
teristics Concentration 0 825 1650
Typical
Typical
Worst
1.0
1.0
1.6
3.3
1.6
3.3
Worst Typical 1.0 6.1 6.1
Worst 1.0 21 21
6. Value Interpretation - Value equals the relative pollu-
tant concentration increase in seawater around a disposal
site as a result of sludge disposal after initial mixing
compared to the background concentration of the pollu-
tant. The null index value at 0 mt DW/day equals 1.
7. Preliminary Conclusion - Significant increases in the
seawater concentration of Hg is apparent for all the
scenarios evaluated.
3-36
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B. Index of Seawater Concentration Representing a 24-Hour Dumping
Cycle (Index 2)
1. Explanation - Calculates relative effective concentra-
tions (compared to the background concentration of the
pollutant) (unitless) 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 pycno-
cline 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. 3-33 to 3-35.
4. Factors Considered in Determining Subsequent Additional
Degree of Mixing (Determination of TWA Concentrations)
See Section 3, p. 3-37.
5. Index 2 Values
Disposal Sludge Disposal
Conditions and Rate (mt DW/day)
Site Charac- Sludge
teristics Concentration 0 825 1650
Typical
Typical
Worst
1.0
1.0
1.2
1.6
1.3
2.3
Worst Typical 1.0 2.4 3.8
Worst 1.0 6.6 12
6. Value Interpretation - Value equals the relative
effective pollutant concentration expressed as a TWA con-
centration in seawater around a disposal site experienced
by an organism over a 24-hour period compared to the
background concentration of the pollutant. The null
index value at 0 mt DW/day equals 1.
3-37
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7. Preliminary Conclusion - The incremental increase of Hg
concentrations during a 24-hour dumping cycle is signifi-
cant, especially for sludge containing "worst"
concentrations dumped at the worst site.
C. Index of Tozicity to Aquatic Life (Index 3)
1. Explanation - Compares the relative effective concentra-
tion (compared to the background concentration of Che
pollutant) of pollutant in seawater around the disposal
site (Index 2) expressed as a 24-hour TWA concentration
with the marine ambient water quality criterion of the
pollutant, or with another value judged protective of
marine aquatic life. For Hg, this value is the criterion
that will protect the marketability of edible marine
aquatic organisms against a Hg residue in edible tissue
hazard.
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. Data Used and Rationale
a. Concentration of pollutant in seawater around a
disposal site (Index 2)
See Section 3, p. 3-37.
b. Ambient water quality criterion (AWQC) = 0.025 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 resul-
tant 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 Hg.
The 0.10 Ug/L value chosen as the criterion to pro-
tect saltwater organisms is expressed as an average
concentration (U.S. EPA, 1980 as revised by U.S.
EPA, 1981). This concentration, the saltwater final
residue value, was derived by using the FDA action
level for marketability for human consumption of Hg
3-38
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in edible fish and shellfish (1 mk/kg), and a bio-
concentration factor (BCF) value of 10,000 for an
aquatic species tested.
c. Ambient water concentration of pollutant (CA) =
0.005 Ug/L
See Section 3, p. 3-35.
Index 3 Values
Disposal Sludge Disposal
Conditions and Rate (mt DW/day)
Site Charac- Sludge
teristics Concentration 0 825 1650
Typical
Typical
Worst
0.20
0.20
0.23
0.33
0.26
0.45
Worst Typical 0.20 0.48 0.77
Worst 0.20 1.3 2.4
5. Value Interpretation - Value equals the factor by which
the relative effective seawater concentration of Hg
exceeds the marine water quality criterion. A value >1
indicates that a tissue residue hazard may exist for
aquatic life. Even for values approaching 1, a Hg resi-
due in tissue hazard may exist, thus jeopardizing the
marketability of edible saltwater organisms. The criter-
ion value of 0.10 Ug/L is probably coo high because on
the average, the Hg residue in 50 percent of the aquatic
species similar to chose used Co derive the AWQC will
exceed the FDA action level for Hg (U.S. EPA, 1980,
p. 8-14).
6. Preliminary Conclusion - Increases in incremental hazard
are evident for worst concentration sludges dumped at the
worst and typical sites. Increase is also evident at the
worst-site with typical concentrations.
D. Index of Human Toxicity Resulting from Seafood Consumption
(Index 4)
1. Explanation - Estimates the expected increase in human
pollutant intake associated wich the consumpcion of se'a-
food, a fraction of which originates from the disposal
site vicinity, and compares the total expected pollutant
intake with the acceptable daily intake (ADI) of the
pollutant.
2. Assumptions/Limitations - In addition to the assumptions
listed for Indices 1 and 2, assumes that the seafood
tissue concentration will increase proportionally to the
water concentration increase. It also assumes chat, over
3-39
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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. 3-37.
Since bioconcentration is a dynamic and reversible
process, it is expected that uptake of sludge pollu-
tants by marine organisms at the disposal site will
reflect TWA concentrations, as quantified by Index
2, rather than pulse concentrations.
t>. Background concentration of pollutant in seafood
(CP) = 0.147 ug/g WW
The background concentration of Hg is the average
concentration in 50 varieties of seafood, weighted
according to mean consumption (Meaburn et al.,
1981).
c. Dietary consumption of seafood (QF)
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 con-
sumption in the United States (Stanford Research
Institute (SRI) International, 1980).
d. 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.
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
3-40
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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 km') 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-
water) or worst (near-shore) site can be calculated
for this typical harvesting scenario as follows:
3-41
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For Che typical (deep water) site:
_c AI x 0.02Z = (2)
FSt = 7200 km*
FID x 8000 m x 9500 m x IP"6 km2/m21 x 0.0002 . .__5
*> A 1 X 1U
7200 km2
For the worst (near shore) site:
FSt = AI x 24Z = (3)
4300 km2
TIP x 4000 m x 4320 m x 10"6 km2/m21 x 0.24 = g>6 ^ 1(J_3
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
habitually 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) site:
FSW = ^5- = 0.11 (4)
72QO km2
For the worst (near shore) site:
FSU = = = 0.040 (3)
4300 km2
e. Average daily human dietary intake of pollutant (DI)
= 5.0 ug/day
See Section 3, p. 3-16.
f. Acceptable daily intake of pollutant (ADI) =
20 yg/day
See Section 3, p. 3-14.
3-42
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4. Index 4 Values
Disposal
Conditions and
Site Charac-
teristics
Typical
Worst
Sludge Seafood
Concentration3 Intake3 »D
Typical Typical
Worst Worst
Typical Typical
Worst Worst
Sludge Disposal
Rate (mt DW/day)
0
0.25
0.25
0.25
0.25
825
0.25
0.27
0.25
0.32
1650
0.25
0.29
0.25
0.39
3 All possible combinations of these values are not
presented. Additional combinations may be calculated
using the formulae in the Appendix.
D Refers to both the dietary consumption of seafood (QF)
and the fraction of consumed seafood originating from
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.
5. Value Interpretation - Value equals factor by which the
expected pollutant intake exceeds the ADI. 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 preexisting dietary sources.
6. Preliminary Conclusion - No increase in risk to human
health is apparent from typical seafood intake from
organisms residing at the typical and worst sites after
dumping of sludges with typical concentrations of Hg.
Slight increases, however, are seen when site character-
istics, sludge concentrations, and seafood intake are all
worst case.
3-43
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SECTION 4
PRELIMINARY DATA PROFILE FOR MERCURY IN MUNICIPAL SEWAGE SLUDGE
I. OCCURRENCE
A. Sludge
1. Frequency of Detection
Detected in 267 of 435 samples (61%)
from 40 POTWs
Detected in 78 of 81 samples (96%)
from 10 POTWs
2. Concentration
1.49 and 5.84 mg/kg DW (median and
95th percentile, respectively) in
sludges from 39 POTWs. Statistically
derived from sludge concentrations
from a survey of 50 POTWs
110 to 690,000 ng/L from 39 POTWs
600 to 860,000 ng/L in sludges from
10 POTWs
1.9 Ug/g (DW) median
0.037 to 78 Ug/g (DW) range from
13 municipal sludges
3.4 to 18.0 Ug/g (DW) in sludges from
16 U.S. cities
B. Soil - Unpolluted
1. Frequency of Detection
Hg in earth's crust ranges from 0.01 to
20 Ug/g with less than 20% of rocks
sampled having more than l.-O Ug/g
Hg averages 0.05 Ug/g in earth's
crust
"Mercury is a rare element in the earth's
crust comprising less than 30 of each
billion of its parts. There are only 15
elements present in smaller amounts in
the earth than mercury."
U.S. EPA, 1982
(p. 41)
U.S. EPA, 1982
(p. 49)
U.S. EPA, 1982
(p. 41)
U.S. EPA, 1982
(p. 41)
U.S. EPA, 1982
(p. 49)
Naylor and
Loehr, 1982
(p. 20)
Furr et al.,
1976 (p. 684)
U.S. Geological
Survey, 1970
(p. 1)
Jenkins, 1980
(p. 30)
Cassidy and
Furr, 1978
(p. 317)
4-1
-------
c.
2. Concentration
0.156 ug/g (DW) garden soil
0.045 Co 0.160 Ug/g (DW) Geometric means
uncultivated soil
Unmineralized soils in California
0.02 to 0.06 Ug/g
Mineralized soils in British Columbia
0.05 to 25 Ug/g
Hg content of soils averages 0.1 Ug/g
Range 0.01 to 0.5 Ug/g, average 0.1 Ug/g
Sludge-amended soil
1st yr 0.230 Ug/g (DW)
2nd yr 0.360 Ug/g (DW)
Water - Unpolluted
1. Frequency of Detection
Assumed 100% due to ubiquitous nature
of Hg
2. Concentration
a. Freshwater
0.2 Ug/L in rainwater
0.1 Ug/L inland groundwater
0.6 Ug/L northeast U.S. inland water
Most natural water contains >2 ug/L
b. Seawater
0.03 to 2.0 Ug/L
3 ng/L open ocean
5 to 10 ng/L coastal waters
Cappon, 1984
(p. 100)
Erdman et al.,
1976 (p. C15)
Fleischer,
1970 (p. 57)
Fleischer,
1970 (p. 57)
U.S. Geological
Survey, 1970
(p. 1)
Ratsch, 1974
(p. 7)
Cappon, 1984
(p. 100)
Cassidy and
Furr, 1978
(p. 308)
Fleischer,
1970 (p. 6)
Cassidy and
Furr, 1978
(p. 308)
U.S. EPA,
1984b
(p. 3-13)
4-2
-------
c. Drinking Hater
In 698 samples of 273 water
supplies throughout the U.S., only
11 samples exceeded 1 Ug/L in
a range from 1.0 to 4.9 Ug/L
2.5Z of 512 Hg analyses of
finished water exceeded the pro-
posed 1975 standard of 2 Ug/L
10 to 50 ng/L
.d. Groundwater
With few exceptions below detection
(0.1 Ug/L)
Inland groundwater 0.1 ppb
D. Air
1. Frequency of Detection
Data not immediately available.
2. Concentration
World average: 20 ng/m3
In non-mineralized areas: 3 to 9 ng/m-*
Urban areas: 10 ng/m3
Rural areas: 3 to 4 ng/m3
Background levels of >1 to a few
nanograms per cubic meter
1 to 2 ng/m3 background levels
NAS, 1978
(p. 69)
NAS, 1978
(p. 69)
U.S. EPA, 1984b
(p. 3-13)
U.S. EPA, 1980
(p. A-l)
Cassidy and
Furr, 1978
(p. 308)
Cassidy and
Furr, 1978
(p. 307)
U.S. EPA, 1984c
(p. I-D
Fleischer, 1970
(p. 6)
U.S. EPA, 1984b
(p. 3-12)
4-3
-------
E. Pood
1. Total Average Intake
Daily intake of Hg - Adult
Total Daily Intake (ug/day)
FY75 FY76 FY77 FY78
3.7 6.5 6.3 3.4
Daily intake of Hg - Toddler
Total Daily Intake (ue/day)
FDA, 1980b
FDA, 1980a
FY75
FY76
FY77
0.9
0.8
1.1
2. Concentration
1 to 123 ng/g range in vegetable samples
from Texas; 4 to 282 ng/g range in fresh
fruit samples from Texas
>20 ng/g WW most food stuffs
(non-fish food)
Fiscal Year 1978 Daily Intake of Hg
Gerdes et al.,
1974 (pp. 16
and 17)
U.S. EPA, 1984b
(p. 3-15)
FDA, no date
(Attachment I)
Food Group
Dairy
Meat, fish, poultry
Grains and cereals
Potatoes
Leafy vegetables
Legume root vegetables
Root vegetable
Garden fruits
Fruits
Oils and fats
Sugars and adjuncts
Beverages
Total
Group
Daily
Intake
(Ug/day)
0.08
2.34
0.59
0.10
0.03
0.08
0.03
0.01
0.05
0.10
0.01
0.0
3.42
Intake
as % of
Daily
Intake
2.3
68.4
17.3
2.9
0.9
2.3
0.9
0.3
1.5
2.9
0.3
0.0
100.0
1 to 27 ng/g of Hg range in total diet
studies, 1978
FDA, No date
(Attachment F)
4-4
-------
II. HUMAN EFFECTS
A. Ingestion
1. Carcinogenicity
Adequate data regarding carcinogenic
effects of Hg could not be located in
available literature.
2. Chronic Toxicity
a. ADI
Alkyl Hg: Adult 20 Ug/day
Inorganic Hg: Adult 3 Ug/day
b. Effects
Micromercurialism and other central
nervous disorders.
No effects observed at drinking water
levels of 15.8 ug/kg/day
3. Absorption Factor
7% inorganic Hg (mercuric nitrate)
4. Existing Regulations
Ambient Water Quality Criteria =
144 ng/L
U.S. EPA 2 Ug/L drinking water
WHO 1 Ug/L drinking water
Ingestion through contaminated aquatic
(freshwater and marine fish and shellfish)
organisms alone ambient water =
146 ng/L
B. Inhalation
1. Carcinogenicity
No evidence of being carcinogenic
to humans when inhaled.
U.S. EPA, 1984c
(p. VIII-12)
WHO, 1976 as
cited in U.S.
EPA, 1980
U.S. EPA, 1984a
U.S. EPA, 1984c
(p. 1-3)
U.S. EPA, 1984c
(p. III-l)
U.S. EPA, 1984c
(p. 1-3)'
U.S. EPA, 1980
(p. C-92)
4-5
-------
2. Chronic Toxicity
a. Inhalation Threshold or MPIH
The MPIH for inorganic Ug is
3.6 tig/day, based on an adjustment
of the workplace TLV (see below,
"Existing Regulations").
b. Effects
Micromercurialism and other central
nervous disorders
3. Absorption Factor
vT80% through the lungs
4. Existing Regulations
Threshold Limit Value (TLV) for
inorganic Hg is 0.05 mg/m-* as a time-
weighted average (TWA).
III. PLANT EFFECTS
A. Phytotoxicity
See Table 4-1.
Increased clay content reduces Hg toxicity
Stem elongation and biomass increase were
significantly inhibited by concentrations
equal to or greater than 0.01 ppm
(tomato seedlings).
Hg concentration in leaf at treatment
0.006 ppm methyl Hg hydroxide is
1.5 ppm Hg wet weight (WW)
B. Uptake
See Table 4-2.
12.2 Mg/g Hg found in tomato fruit grown
on high Hg sludge
U.S. EPA, 1984a
U.S. EPA, 1984c
(p. 1-3)
U.S. EPA, 1984b
(p. 3)
ACGIH, 1983
Weaver et al.,
1984 (p. 137)
Haney and
Lipsey, 1973
(p.308)
CAST, 1976
(p. 29)
4-6
-------
IV. DOMESTIC ANIMAL AND WILDLIFE EFFECTS
A. Toxicity
See Table 4-3.
Suggested maximum tolerable dietary level NAS, 1980
for domestic animals is 2 ppm for both the (p. 313)
organic and inorganic forms.
B. Uptake
See Table 4-4.
V. AQUATIC LIFE EFFECTS
A. Toxicity
1. Freshwater
a. Acute
One-hour average concentration does U.S. EPA, 1985
not exceed 2.4 Ug/L more than once (p. 23)
every three years on average.
b. Chronic
Four-day average concentration does U.S. EPA, 1985
not exceed 0.012 ug/L more than (p. 23)
once every three years on average.
2. Saltwater
a« Acute
One-hour concentration does not U.S. EPA, 1985
exceed 2.1 Ug/L more than once (p. 24)
every three years on average.
b. Chronic
Four-day average concentration does U.S. EPA, 1985
not exceed 0.025 Ug/L more than (p. 24)
once in every three years on average.
B. Uptake
Methylmercuric chloride with an oyster U.S. EPA, 1980
BCF = 40,000. Based on FDA action level
1 mg/kg and BCF = 23,000. The Freshwater
Final Residue Value = 0.043
4-7
-------
Slow race of demethylation is responsible U.S. EPA, 1980
for biological half-life of J*2 to 3 years.
VI. SOIL BIOTA EFFECTS
A. Toxicity
Data not immediately available.
B. Uptake
See Table 4-5.
VII. PHYSICOCHEMICAL DATA FOR ESTIMATING FATE AND TRANSPORT
Molecular weight: 200.59
Density: 13.59
Slightly volatile at room temperature
Insoluble in water
44 to 56% of total Hg added to turf grass was Gilmour and
lost in 57 days which was attributed to volatili- Miller, 1973
zation of metallic Hg formed in the turf grass- (p. 145)
soil system.
4-8
-------
TABLE 4-1. PIIYTOTOXIC1TY OF MERCURY
Plant/tissue
Bermuda grass/
leaf
Bermuda grass/
leaf
Tomato/seedling
Tomato/seedling
Tomato/seedling
Tomato/ seedling
Corn/seedling
Corn/seedling
Corn/seedling
Bean/ seedling
Bean/seedling
Chemical
Form
Applied
HgCl2 (Pot)c
HgCl2 (Pot)
MMIIa (Pot)
MMH (Pot)
MMH (Pot)
MMH (Pot)
MMH (Pot)
MMH (Pot)
MMH (Pot)
MMH (Pot)
HMH (Pot)
Control
Tissue
Soil Concentration
pH (M8/8 DW)
4.7
7.7
Nutrient
Solution
Nutrient
Sol ut ion
Nutrient
Solut ion
Nutrient
Sol ut ion
Nutrient
Sol ut l on
Nutrient
Solution
Nutrient
Solution
Nutrient
Solution
Nutrient
Solution
<1.0
-------
TABLE 4-2. UPTAKE OP MERCURY BY PLANTS
Plant/tissue
Festuca/plant
Bean/edible
Cabbage/edible
Carrot/edible
Millet/edible
Onion/edible
Potato/edible
Tomato/edible
Bromegrass/stem
Bromegrass/root
Lettuce/edible
Spinach/edible
Broccoli/edible
Caul if lower/edible
Peas/edible
Oats/grain
Radishes/edible
Carrot/edible
Alfalfa/root
Lettuce/edible
Lettuce/edible
Bermuda grass/
leaf
Bermuda grass/
leaf
Tomato/seedling
a Uptake slope: * =
Chemical Form
Applied
Atmospheric
deposited llg (field)d
Hg fungicide (field)
llg fungicide (field)
Hg fungicide (field)
Hg fungicide (field)
Hg fungicide (field)
llg fungicide (field)
Hg fungicide (field)
Soil
pll
NRD
NR
NH
NR
NR
NK
NH
NR
PMAe (Pot)h (sewage/et fluent) NR
NMCf (Pot) (etfluent/sewage)
HgCl2 (Pot)
HgCI2 (Pot)
UgCl2 (Pot)
HgCl2 (Pot)
HgCl2 (Pot)
HgCl2 (Pot)
HgCl2 (Pot)
HgCl2 (Pot)
Atmospheric
deposited Ug (field)
llg fungicide (Pol)
Hg fungicide (Pot)
HgCl2 (Pot)
HgCl2 (Pot)
MMUC (Pot)
R/R tissue DU. e PHA
kg/ha DW f MMC
NR
5.
5.
5.
5.
5.
5.
5.
5.
5.1-5.3
5.9
7.1
7.6
4.7
Nutrient
Solution
= Hhcnyl
= Methyl
Range of
Application Rates
(kg/ha)
0.04-25.2
0.2- .0
0.2- .0
0.2- .0
0.2- .0
0.2- .0
0.2- .0
0.2- .0
0-20
0-20
0-40
0-40
0-40
0-40
0-40
0-40
0-40
0-40
2.3-184
0.012-14.26
NOB- 3. 28
0-99.9
0-99.9
0.002-0.118
mecuric acetate.
mercuric chloride.
Control Tissue
Concentration
(Mg/g DW)
0.07
0.1
0.1
0.1
0.1
0.2
0.1
0.1
0.095
0.11
0.031
0.094
0.063
0.079
0.001
0.009
0.013
0.044
0.56
0.033
0.023
0.01
0.01
0.1
Uptake*
Slope References
0.53 Bull et al., 1977 (p. 138)
Elfving et al., 1978 (p. 96)
--
0.039 Hogg et al., 1978 (p. 449)
2.12
0.001 John, 1972 (p. 79)
0.014
0.001
0.001
0.017
0.057 Lindberg ec al., 1979 (p. 575)
0.005 HacLean, 1974 (p. 289)
0.047
0.025 Weaver et al., 1984 (pp. 135 to
138)
0.064
24.7 Haney and Lipsey, 1973 (p. 305)
b NR = Not reported.
c MMII = Methylmercury hydroxide
d Field = Field test.
8 NO = Nul delected.
n Pot = Pot test.
-------
TABLE 4-3. TOXICITY OP MERCURY TO DOMESTIC ANIMALS AND WILDLIFE
Speciea (N)a
Rat
Rat (54)
Rat (54)
Rac (54)
CaK
Calf
Cattle (10)
1 Sheep (12)
t-i
""* Pigs (5)
Pigs (7)
Mink
Mink
Mink
Mallard
(13 pairs)
Chemical
Form Fed
Hg2*
CII3Hg
CH3Hg
HgCl
Methylmercury
Nethylmercury
Nethylmercury
dicyandiamide
Phenylmercuric
chloride
Phenylmercuric
CH3llgCl
CH3HgCl
HgCl
Methyl llg
Methyl /mercury
dicyandiamide
Feed Con- Water Con- Daily
centration centracion Intake Duration
(pg/g) (mg/L) (mg/kg BU) of Study
8000 ~ NRb
1 Life-term
5 Life-term
,5 Life-term
0.1 90 days
0.2-0.4 75 days
0.225 40-60 days
0.19 90 days
0.38-0.76
2.28-4.56 90 days
0.1 ~ ~ 93 days
l.B ~ 93 days
10 ~ 150 days
5 1 month
3 ~ 28 weeks
Effects References
Lethal Cough et al., 1979 (p. 36)
Increased body weight Schroeder and Mitchner,
1975 (p. 452)
Decreased body weight,
highly toxic
No effect
"Tolerated" HAS, 1980 (p. 309)
Methylmercury toxicosis
Incoordination and
unsteady gait
No effect
accumulation
Kidney and colon
nercosis
No effect HAS, I960 (p. 310)
Lethal
No effect Auerlich et al., 1974
(p. 43)
Lethal
Reduced chick size, Finley and Stendell,
halchability, duckling 1978 (p. 51)
survival
N = Number of animals per treatment group.
b NR = Nat reported.
-------
TABLE 4-4. UPTAKE OF MERCURY BY DOMESTIC ANIMALS AND WILDLIFE
Species (N)a
Duck
Duck
Duck
Duck
4S Mink (24)
ro Mink (24)
Mink (22)
Mink (10)
Mink (10)
Hink (8)
Chemical
Form Fed
HB
Hg
»8
Hg
Methyl Mercury
Methyl Mercury
Methyl Mercury
Methyl Mercury
Methyl Mercury
Methyl Mercury
Range (N)a
of Feed
Concentrations
(Mg/B DW)
<0. 05-3(2)
<0. 05-3(2)
<0. 05-3(2)
<0. 05-3(2)
0-5(2)
0-5(2)
0-5(2)
0-1(2)
0-1(2)
0-1(2)
Tissue
Analyzed
Egg
Liver
Kidney
Muscle
Liver
Kidney
Muscle
Liver
Kidney
Muscle
Control Tissue
Concentration
(pg/g UU)
0.07
0.13
0.06
<0.05
0.28
0.68
0.05
0.28
0.68
0.05
Uptakeb«c
Slope References
2.06 Finley and Stendell, 1978 (pp. 56 and 60)
12.1
7.04
2.33
11.1 Auerlich et al.. 1974 (p. 48)
7.4
5.0
0.29
3.21
0.01
a N = Number of experimental animals or feed concentrations when reported.
b Uptake slope: y = animal tissue concentration; x = teed concentration.
c Uhen tissue values were reported as wet weight, unless otherwise indicated a moisture content of 77Z was assumed for kidney, 70Z for liver and 72Z
for muscle.
-------
TABLE 4-5. UPTAKE OF MERCURY BY SOIL BIOTA
u>
Species
Earthworm
Range (N)b
of Soil
Concentrations Tissue
Chemical Form (MB/6 W> Analyzed
Atmospherically 0.106-3.81(2) Whole
deposited llg
_^
Control Tissue
Concentration Uptake8
(ug/g DU) Slope References
0.0^1 0.34 Bull et al., 1977 (p. 137)
==================================^==
8 Uptake slope = y/x: y = tissue concentrations; x = soil concentrations.
b M = Number of feed concentrations used.
-------
SECTION 5
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5-1
-------
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MacLean, A. J. 1974. Mercury in Plants and Retention of Mercury by
Soils in Relation to Properties and Added Sulfur. Am. J. Soil Sci.
54:287.
Meanburn, G. M., K. B. Bolton, H. L. Seagran, T. S. Siewicki, S. M.
Bingham, and P. J. Eldridge. 1981. Application of a Computer
Simulation Model to Estimate Dietary Intake of Cadmium from Seafood
by U.S. Consomers. NOAA Tech. Memorandum NMFS SEFC-74. April.
5-3
-------
National Academy of Sciences. 1978. An Assessment of Mercury in the
Environment. Panel on Mercury of the Coordinating Committee for
Scientific and Technical Assessments for Environmental Pollutants.
Washington, D.C.
National Academy of Sciences. 1980. Mineral Tolerances of Domestic
Animals. Subcommittee on Mineral Toxicity in Animals. 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.
Naylor, L. M., and R. C. Loehr. 1982. Priority Pollutants in Municipal
Sewage Sludge. BioCycle. July/August:18.
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 che Prediction of Leachate Plume
Migration and Mixing. U.S. EPA Municipal Environmental Research
Laboratory, Cincinnati, OH.
Ratsch, H. C. 1974. Heavy Metal Accumulation in Soil and Vegetation
from Smelter Emissions. EPA 660/3-74-012. U.S. Environmental Pro-
tection Agency Office of Research and Development, Corvallis, OR.
23 pp.
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.
Schroeder, H. A., and M. Mitchner. 1975. Life-Term Effects of Mercury,
Methyl-Mercury, and Nine Other Trace Mecals on Mice. J. Nutr.
105:452.
Sikora, L. J., W. D. Surge, 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 11. Prepared for U.S. EPA under
Contract No. 68-01-3887. Menlo Park, CA. September.
Steel, E. W., and T. J. McGhee. 1979. In: Water Supply and Sewerage,
5th Ed. McGraw-Hill Book Co., New York, NY.
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.
5-4
-------
U.S. Department of Agriculture. 1975. Composition of Foods. Agricul-
tural 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 Mercury. EPA 440/5-80-058. U.S. Environmental
Protection Agency, 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.
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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.
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for Mercury. Program Office Draft. ECAO-CIN-H042. Environmental
Criteria and Assessment Office, Cincinnati, OH.
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Update. EPA 600/8-84-019F. U.S. Environmental Protection Agency,
Washington, D.C.
U.S. Environmental Protection Agency. 1984c. Drinking Water Criteria
Document for Mercury. ECAO-CIN-025. U.S. Environmental Protection
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Document for Public Comments: Methods for Prediction of Leachate
Plume Migration and Mixing. Draft. Municipal Environmental
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Criteria for Lead. External Review Draft. EPA 600/8-83-028B.
Environmental Criteria and Assessment Office, Research Triangle
Park, NC. September.
5-5
-------
U.S. Environmental Protection Agency. 1985. Ambient Water Quality
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U.S. Geological Survey. 1970. Mercury in the Environment. Geological
Survey Professional Paper 713. U.S. Geological Survey, Washington,
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Weaver, R. W., J. R. Melton, W. DeShin, and R. L. Duble. 1984. Uptake
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World Health Organization. 1976. Environmental Health Criteria,
Mercury. Geneva. (As cited in U.S. EPA, 1980.)
5-6
-------
APPENDIX
PRELIMINARY HAZARD INDEX CALCULATIONS FOR MERCURY
IN MUNICIPAL SEWAGE SLUDGE
I. LANDSPREADING AND DISTRIBUTION-AND-MARKETING
A. Effect on Soil Concentration of Mercury
1. Index of Soil Concentration Increment (Index 1)
a. Formula
T . . (SC x AR) + (BS x MS)
Index 1 = BS (AR * MS)
where:
SC = Sludge concentration of pollutant
(Ug/g DW)
AR = Sludge application rate (mt DW/ha)
BS = Background concentration of pollutant in
soil (ug/g DW)
MS = 2000 mt DW/ha = Assumed mass of soil in
upper 15 cm
b. Sample calculation
(1.49 Ug/g DW x 5 mt/ha) + (0.10 Ug/g DW x 2000 mt/ha)
= 0.10 ug'/g DW (5 mt/ha + 2000 mt/ha)
B. Effect on Soil Biota and Predators of Soil Biota
1. Index of Soil Biota Toxicity (Index 2)
a. Formula
Ii x BS
Index 2 =
where:
II = Index 1 = Index of soil concentration
increment (unitless)
BS = Background concentration of pollutant in
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.
A-l
-------
2. Index of Soil Biota Predator Toxicity (Index 3)
a. Formula
Q! - 1)(BS x UB) + BB
Index 3 = - ^ -
where:
II = Index 1 = Index of soil concentration
increment (unitless)
BS = Background concentration of pollutant in
soil (yg/g DW)
UB = Uptake slope of pollutant in soil biota
(Ug/g tissue DW [ug/g soil DW]'1)
BB = Background concentration in soil biota
(Ug/g DW)
TR = Feed 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 Phytotoxicity (Index 4)
a. Formula
x BS
Index 4 =
where :
II = Index 1 = Index of soil concentration
increment (unitless)
BS = Background concentration of pollutant in
soil (Ug/g DW)
TP = Soil concentration toxic to plants (ug/g
DW)
b. Sample calculation
1.03 x 0.10 Ug/g DW
8.0 ug/g DW
A-2
-------
2. Index of Plant Concentration Increment Caused by Uptake
(Index 5)
a. Formula
(Ii - 1) x BS
Index 5 = = - x CO x UP + 1
BP
where :
II = Index 1 = Index of soil concentration
increment (unitless)
BS = Background concentration of pollutant in
soil (ug/g DW)
CO = 2 kg/ha (ug/g)~^ = Conversion factor
between soil concentration and application
rate
UP = Uptake slope of pollutant in plant tissue
(Ug/g tissue DW [kg/ha]'1)
BP = Background concentration in plant tissue
(Ug/g DW)
b. Sample calculation
(1.03 - 1) x 0.10 ug/g DW 2 kg/ha
i>UQ ~ 0.01 ug/g DW *Ug/g soil
0.064 ug/g tissue .
X kg/ha l
3. Index of Plant Concentration Increment Permitted by
Phytotoxicity (Index 6)
a. Formula
PP
Index 6 =
where:
PP = Maximum plant tissue concentration
associated with phytotoxicity (ug/g DW)
BP = Background concentration in plant tissue
(Ug/g DW)
b. Sample calculation
0 _ 0.2 Ug/g DW
0.01 Ug/g DW
A-3
-------
C. Effect on Herbivorous Animals
1. Index of Animal Toxicity Resulting from Plant Consumption
(Index 7)
a. Formula
I5 x BP
Index 7 » -=-=^
where:
15 = Index 5 = Index of plant concentration
increment caused by uptake (unitless)
BP = Background concentration in plant tissue
(Ug/g DW)
TA = Feed concentration coxic to herbivorous
animal (Mg/g DW)
b. Sample calculation
2. Index of Animal Toxicity Resulting from Sludge Ingestion
(Index 8)
a. Formula
if ii.o. 1-ssa
if AR 4 a, i8 » SCT* cs
where:
AR = Sludge application rate (mt DU/ha)
SC = Sludge concentration of pollutant
(Ug/g DW)
BS = Background concentration of pollutant in
soil (yg/g DW)
CS = Fraction of animal diet assumed to be soil
(unitless)
TA = Feed concentration toxic to herbivorous
animal (pg/g DW)
b. Sample calculation
« AR . 0, 0.0025 - "-'
««,.. ...37 - ^
A-4
-------
E. Effect on Humans
1. Index of Human Toxicity Resulting from Plant Consumption
(Index 9)
a. Formula
[(I5 - 1) BP x DT] + DI
Index 9 =
ADI
where:
15 = Index 5 = Index of plant concentration
increment caused by uptake (unicless)
BP = Background concentration in plant tissue
(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)
ADI = Acceptable daily intake of pollutant
(Ug/day)
b. Sample calculation (toddler)
n f(1.009 - 1) x 0.013 ue/g DW x 74.5 g/dayl * 0.9 Ug/day
0>3° = 3 ug/day
2. Index of Human Toxicity Resulting from Consumption of
Animal Products Derived from Animals Feeding on Plants
(Index 10)
a. Formula
[(I5 - 1) BP x UADA] + DI
Index 10 =
where:
UADA = (UAL x DAL) + (UAm x DA,,,)
UAL = UA for liver
DAL = DA for liver
UA,,, = UA for muscle
DAm = DA for muscle
15 = Index 5 = Index of plant concentration
increment caused by uptake (unitless)
BP = Background concentration in plant tissue
(Ug/g DW)
UA = Uptake slope of pollutant in animal tissue
(Ug/g tissue DW fug/g feed DW]'1)
DA = Daily human dietary intake of affected
animal tissue (g/day DW)
A-5
-------
DI = Average daily human dietary intake of
pollutant (ug/day)
ADI = Acceptable daily intake of pollutant
(Ug/day)
b. Sample calculation (toddler)
0.32 =
[(1.04 - 1) x 0.01 ug/g DW x 130.8 ug/g tissuefug/g feed]"1 (g/day)1 + 0.9 ue/dav
3 Ug/day
3. Index of Human Toxicity Resulting from Consumption of
Animal Products Derived from Animals Ingesting Soil
(Index 11)
a. Formula
_, AD _ _ . .. (BS x GS x UADA) + DI
If AR = 0, Index 11 = r:r=
T, AD , _ T . ., (SC x GS x UADA) + DI
If AR f 0, Index 11 =
where:
UADA = (UAL x DAL) + (UAm x
UAL = UA for liver
DAL = DA f°r liver
UAm = UA for muscle
DAm = DA for muscle
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
(unitless)
UA = Uptake slope of pollutant in animal tissue
(Ug/g tissue DW fug/g feed DW'1]
DA = Average daily human dietary intake of
affected animal tissue (g/day DW)
DI = Average daily human dietary intake of
pollutant (ug/day)
ADI - Acceptable daily intake of pollutant
(Ug/day)
b. Sample calculation (toddler)
3.5 =
(1.49 Ug/g DW x 0.05 x 130.8 Ug/g tissue [ug/g feed]"1 (g/day DW) + 0.9 Ug/day
3 Ug/day
A-6
-------
4. Index of Human Toxicity Resulting from Soil Ingestion
(Index 12)
a. Formula
(I x BS x DS) + DI
ADI
(SC x DS) + DI
Index 12
Pure sludge ingestion: Index 12 =
where:
II = Index 1 = Index of soil concentration
increment (unitless)
SC = Sludge concentration of pollutant
(Ug/g DW)
BS = Background concentration of pollutant in
soil (ug/g DW)
DS = Assumed amount of soil in human diet
(g/day)
DI = Average daily dietary intake of pollutant
(Ug/day)
ADI = Acceptable daily intake of pollutant
(Ug/day)
b. Sample calculation (toddler)
0 47 (1.03 x 0.10 ug/g DW x 5 g soil/day) * 0.9 Ug/day
3 Ug/day
Pure sludge:
28 = (1.49 Ug/g DW x 5 g soil/day) + 0.9 Ug/day
3 ug/day
5. Index of Aggregate Human Toxicity (Index 13)
a. Formula
Index 13 - I9 * I10 * In * 112
where:
Ig = Index 9 = Index of human toxicity
resulting from plant consumption
(unicless)
IIQ = Index 10 = Index of human toxicity
resulting from consumption of animal-
products derived from animals feeding on
plants (unicless)
111 = Index 11 = Index of human toxicity
resulting from consumption of animal
A-7
-------
products derived from animals ingesting
soil (unitless)
= Index 12 = Index of human toxicity
resulting from soil ingestion (unitless)
DI = Average daily dietary intake of
pollutant dig/day)
ADI = Acceptable daily intake of pollutant
(Vlg/day)
b. Sample calculation (toddler)
3 *
3.7 = (0.30 * 0.32 * 3.5 + 0.47) - (
II. LANDFILLING
A. Procedure
Using Equation 1, several values of C/C0 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 estimates initial dilution in the aquifer to
give the initial concentration, C0, for the saturated zone
assessment. (Conditions for B, 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 unsaturated zone except for the definition of
certain parameters and choice of parameter values. The maxi-
mum concentration at the well, Cmax, is used to calculate the
index values given in Equations 4 and 5.
* !
B. Equation 1: Transport Assessment
C(y.t) -i [exp(A!) erfc(A2) + exp^) erfc(B2)] = P(x»t>
Co
Requires evaluations of four dimensionless input values and
subsequent evaluation of the result. Exp(A^) denotes the
exponential of Aj, e *, where erfc(A2) denotes the
complimentary error function of A2. Erfc(A2) produces values
between 0.0 and 2.0 (Abramowitz and Stegun, 1972).
where:
A. - *_ [V* - (V*2 + AD* x u
Al 2D*
A-8
-------
V - t (V*2 * 4D* x
A2 = (4D* x t)*
Bl _ *__ [V* + (V*2 + 4D* x
1 2D*
y + t (V*2 + 4D* x
and where for the unsaturated zone:
C0 = SC x CF = Initial leachate concentration (yg/L)
SC = Sludge concentration of pollutant (mg/kg DW)
CP = 250 kg sludge solids/m3 leachate =
PS x 103
1 - PS
PS = Percent solids (by weight) of landfilled sludge -
20%
t = Time (/ears)
X = h = Depth to groundwater (m)
D* = a x V* (m2/year)
Ct = Dispersivity coefficient (m)
V* = 2 (m/year)
0 x R
Q = Leachate generation rate (m/year)
0 = Volumetric water content (unitless)
R = 1 + drv x KJ = Retardation factor (unitless)
0
^dry = Dry bulk density (g/mL)
K
-------
C. Equation 2. Linkage Assessment
_ Q x W
«o "u - 365 [(K x i) t fl] x B
where:
C0 = Initial concentration of pollutant in the saturated
zone as determined by Equation 1 (ug/L)
Cu = Maximum pulse concentration from the unsaturated
zone (ug/D
Q = Leachate generation rate (m/year)
W = Width of landfill (m)
K = Hydraulic conductivity of the aquifer (m/day)
i = Average hydraulic gradient between landfill and well
(unitless)
0 = Aquifer porosity (unitless)
B = Thickness of saturated zone (m) where:
B > Q x W x fl and B > 2
K x i x 365
D. Equation 3. Pulse Assessment
C(x't) = P(X,C) for 0 < t < t0
co
P(x,t) - P(X,t - t0) for t > t
where:
t0 (for unsaturated zone) = LT = Landfill leaching time
(years)
t0 (for saturated zone) = Pulse duration at the water
table (x = h) as determined by Che following equation:
t0 = [ Q/ °° C dt] t Cu
C( Y t )
P(X,t) = Jr as determined by Equation 1
co
E. Equation 4. Index of Ground water Concentration Increment
Resulting from Landfilled Sludge (Index 1)
1. Formula
T , , Cmax * BC
Index 1 =
where:
Cmax = Maximum concentration of pollutant at well =
Maximum of C(A£,t) calculated in Equation 1
(Ug/L)
A-10
-------
BC = Background concentration of pollutant in
groundwater (yg/L)
2. Sample Calculation
i ,n 0.0401 Ug/L + 0.1 Ug/L
l'40 o"l Ug/L
P. Equation 5. Index of Human Toxicity Resulting from
Groundwater Contamination (Index 2)
1. Formula
[(I I - 1) BC x AC] + PI
Index 2 =
where:
II = Index 1 = Index of groundwater concentration
increment resulting from landfilled sludge
BC = Background concentration of pollutant in
groundwater (ug/L)
AC = Average human consumption of drinking water
(L/day)
DI = Average daily human dietary intake of pollutant
(jig/day)
ADI = Acceptable daily intake of pollutant (yg/day)
2. Sample Calculation
... f(1.40 - 1) x 0.1 ue/L x 2 L/davl + 5.0 ug/day
°'254 = 20
III. INCINERATION
A. Index of Air Concentration Increment Resulting from Incinerator
Emissions (Index 1)
1. Formula
T _, . (C x PS x SC x FM x DP) * BA
Index 1 = :-g7
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
A-ll
-------
BA = Background concentration of pollutant in urban
air (ug/m3)
2. Sample Calculation
1.37 = [(2.78 x 10~7 hr/sec x g/mg x 2660 kg/hr DW x
1.49 mg/kg DW x 1 x 3.4 ug/m3) + 0.0010 ug/m3] t
0.0010 ug/m3
B. Index of Human Toxicity Resulting from Inhalation of
Incinerator Emissions (Index 2)
1. Formula
[(II - 1) x BA] + BA
Index 2 =
EC
where:
II = Index 1 = Index of air concentration increment
resulting from incinerator emissions
(unitless)
BA = Background concentration of pollutant in
urban air (ug/m3)
EC = Exposure criterion (ug/m3)
2. Sample Calculation
.) x 0.
0.18 ug/m3
0 Q76 = [(1.3-7 - 1) x 0.010 ug/m3] + 0.0010 ug/m3
IV. OCEAN DISPOSAL
A. Index of Seawater Concentration Resulting from Initial Mixing
of Sludge (Index 1)
1. Formula
r j i SC x ST x PS .
Index 1. = £ : rr + 1
W x D x L x CA
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)
CA = Ambient water concentration of pollutant (ug/L)
A-12
-------
2. Sample Calculation
= 1.49 mg/kg DW x 1600000 kg WW x 0.04 kg DW/kg WW x 103 ue/me + l
200 m x 20 m x 8000 m x 0.005 Ug/L x 103 L/m3
B. Index of Seawater Concentration Representing a 24-Hour Dumping
Cycle (Index 2)
1 . Formula
SS x SC .
T j >
Index 2 =
V x D x L x CA
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)
CA - Ambient water concentration of pollutant (lig/L)
2. Sample Calculation
x 16 825000 kg DW/day x 1.49 mg/kg DW x 1Q3 ug/mg ^
9500 m/day x 20 m x 8000 m x 0.005 ug/L x 103 L/m3
C. Index of Toxicity to Aquatic Life (Index 3)
1. Formula
1 2 x CA
IndSX 3 = AWQC
where:
12 - Index 2 = Index of seawater concentration
representing a 24-hour dumping cycle
AWQC = Criterion expressed as an average concentration
to protect the marketability of edible marine
organisms (ug/L)
CA = Ambient water concentration of pollutant (ug/L)
2. Sample Calculation
n _ 1.16 Ug/L x 0.005 Ug/L
°'2J " 0.025 Ug/L
A-13
-------
D. Index of Human Toxicity Resulting from Seafood Consumption
(Index 4)
1.
Formula
Index 4
[(I 2-D x CF x FS x QF] + DI
ADI
where:
\2 ~ Index 2 = Index of seawater concentration
representing a 24-hour dumping cycle
QF = Dietary consumption of seafood (g WW/day)
FS = Fraction of consumed seafood originating from
the disposal site (unitless)
CF = Background concentration of pollutant in
seafood (ug/g)
DI = Average daily human dietary intake of
pollutant (ug/day)
ADI = Acceptable daily intake of pollutant (ug/day)
2. Sample Calculation
Kl.16 -1) x 0.147 ug/g x 0.000021 x 14.3 g WW/day) * 5.0 Ug/dav
""" " 20 Ug/day
A-14
-------
TABLE A-l. INPUT DATA VARYING IN LANDFILL ANALYSIS AND RESULT FOR EACH CONDITION
Condition of Analysis
Input Data
Sludge concentration of pollutant, SC (|ig/g DU)
Unsaturated zone
Soil type and characteristics
Dry bulk density, Pjry (g/mL)
Volumetric water content, B (unitless)
Soil sorption coefficient, Kj (mL/g)
Site parameters
i Leachate generation rate, Q (in/year)
*"" Depth to groundwator, h (m)
Dispersivity coefficient, a (m)
Saturated zone
Soil type and characteristics
Aquifer porosity, 0 (unitless)
Hydraulic conductivity of the aquifer,
K (m/day)
Site parameters
Hydraulic gradient, i (unitless)
Distance from well to landfill, At (m)
Dispersivity coefficient, a (m)
1
1.49
1.925
0.133
580
0.8
5
0.5
0.44
0.86
0.001
100
10
2
5.84
1.925
0.133
580
0.8
5
0.5
0.44
0.86
0.001
100
10
3
1.49
1.53
0.195
322
0.8
5
0.5
0.44
0.86
0.001
100
10
4
1.49
NAD
NA
NA
1.6
0
NA
0.44
OJ. 86
0.001
100
10
5
1.49
1.925
0.133
580
0.8
5
0.5
0.389
4.04
0.001
100
10
6
1.49
1.925
0.133
322
0.8
5
0.5
0.44
0.86
0.02
50
5
7 8
5.84 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)
Condi l ion of Analysis
Results
Unsaturated zone assessment (Equations 1 and 3)
Initial leachate concentration, Co (pg/1.)
Peak concentration, Cu (|ig/L)
Pulse duration, t0 (years)
Linkage assessment (Equation 2)
Aquifer thickness, B (m)
Initial concentration in saturated zone, C0
(MB/U
Saturated zone assessment (Equations 1 and 3)
Maximum well concentration, Cma> (tig/D
Index of grounduater concentration increment
resulting from landfilled sludge,
Index I (unitless) (Equation 4)
Index of human toxicity resulting from
grounduater contamination, Index 2
(unitless) (Equation S)
1 2 3
373 1460 373
0.297 1.16 0.673
6270 6270 2770
126 126 126
0.297 1.16 0.673
0.0401 0.157 0.0405
1.40 2.57 1.41
0.254 0.266 0.254
4 S 6 7
373 373 373 1460
373 0.297 0.297 1460
5.00 6270 6270 5.00
253 23.8 6.32 2. 38
373 0.297 0.297 1460
0.0405 0.18S 0.297 33.8
1.41 2.85 3.97 339
0.254 0.269 0.280 3.63
8
N
M
N
N
N
N
0
0.250
BH s Null condition, where no landfill exists; no value is used.
bHA = Not applicable for this condition.
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