United States
Environmental Protection
Agency
Office of Water
Regulations and Standards
Washington, DC 20460
Water
June, 1985
Environmental Profiles
and Hazard Indices
for Constituents
of Municipal Sludge:
Methylene Chloride
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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 OF CONTENTS
Page
PREFACE i
1. INTRODUCTION 1-1
2. PRELIMINARY CONCLUSIONS FOR METHYLENE CHLORIDE IN
MUNICIPAL SEWAGE SLUDGE 2-1
Landspreading and Distribution-and-Marketing 2-1
Landfilling 2-1
Incineration 2-2
Ocean Disposal 2-2
3. PRELIMINARY HAZARD INDICES FOR METHYLENE CHLORIDE IN
MUNICIPAL SEWAGE SLUDGE 3-1
Landspreading and Distribution-and-Marketing 3-1
Effect on soil concentration of methylene
chloride (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) 3-6
Effect on humans (Indices 9-13) 3-8
Landf illing 3-13
Index of groundwater concentration resulting
from landfilled sludge (Index 1) 3-13
Index of human cancer risk resulting from
groundwater contamination (Index 2) 3-20
Incineration 3-21
Index of air concentration increment resulting
from incinerator emissions (Index 1) 3-21
Index of human cancer risk resulting from
inhalation of incinerator emissions (Index 2) 3-23
Ocean Disposal 3-25
4. PRELIMINARY DATA PROFILE FOR METHYLENE CHLORIDE IN
MUNICIPAL SEWAGE SLUDGE 4-1
11
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TABLE OP CONTENTS
(Continued)
Page
Occurrence 4-1
Sludge 4-1
Soil - Unpolluted 4-1
Water * Unpolluted 4-1
Air 4-2
Food 4-3
Human Effects 4-3
Ingestion 4-3
Inhalation 4-4
Plant Effects 4-5
Domestic Animal and Wildlife Effects 4-5
Tozicity 4-5
Uptake 4-5
Aquatic Life Effects 4-5
Soil Biota Effects 4-5
Physicochemical Data for Estimating Fate and Transport 4-6
5. REFERENCES 5-1
APPENDIX. PRELIMINARY HAZARD INDEX CALCULATIONS FOR
METHYLENE CHLORIDE IN MUNICIPAL SEWAGE SLUDGE A-l
ill
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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. Methylene chloride was initially identified as being of
potential concern when sludge is landspread (including distribution and
marketing), placed in a landfill, or incinerated.* This profile is a
compilation of information that may be useful in determining whether
methylene chloride poses an actual hazard to human health or the
environment when sludge is disposed of by these methods.
The focus of this document is tLe calculation of "preliminary
hazard indices" for selected potential exposure pathways, as shown in
Section 3. Each index illustrates the hazard that could result from
movement of a pollutant by a given pathway to cause a given effect
(e.g., sludge •*• soil •*• plant uptake •* animal uptake •* human toxicity).
The values and assumptions employed in these calculations tend to rep-
resent 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", Sec-
tion 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, Landfill ing,
and incineration 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 METHYLENE CHLORIDE
IN MUNICIPAL SEWAGE SLUDGE
The following preliminary conclusions have been derived from the
calculation of "preliminary hazard indices", which represent conserva-
tive or "worst case" analyses of hazard. The indices and their basis
and interpretation are explained in Section 3. Their calculation
formulae are shown in the Appendix.
I. LANDSPREADING AND DISTRIBUTION-AND-MARKETING
A. Effect on Soil Concentration of Methylene Chloride
Landspreading of sludge is expected to increase the
concentration of methylene chloride in soil (see Index 1).
B. Effect on Soil Biota and Predators of Soil Biota
Conclusions were not drawn because index values could not be
calculated due to lack of data.
C. Effect on Plants and Plant Tissue Concentration
Conclusions were not drawn because index values could not be
calculated due to lack of data.
D. Effect on Herbivorous Animals
Conclusions were not drawn because index values could not be
calculated due to lack of data.
E. Effect on Humans
Conclusions were not drawn because index values could not be
calculated due to lack of data.
II. LANDPILLING
Landfilled sludge is expected to increase groundwater concentra-
tions of methylene chloride; this increase may be large at disposal
sites with all worst-case parameters (see Index 1).
The effect on human cancer risk due to methylene chloride resulting
from groundwater contamination could not be calculated due to lack
of data (see Index 2).
2-1
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III. INCINERATION
Sludge incineration is not expected to increase he concentration
of methyLena chloride in urban air (see Index 1).
The human cancer risk due to methylene chloride by inhalation is
not expected to increase as a result of sludge incineration (see
Index 2).
IV. OCEAN DISPOSAL
Based on the recommendations of the experts at the OWRS meetings
(April-May, 1984), an assessment of this reuse/disposal option is
not being conducted at this time. The U.S. EPA reserves the right
to conduct such an assessment for this option in the future.
2-2
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SECTION 3
PRELIMINARY HAZARD INDICES FOR METHYLENE CHLORIDE
IN MUNICIPAL SEWAGE SLUDGE
I. LANDSPREADING AND DISTRIBUTION-AMD-MARKETING
A. Effect on Soil Concentration of Methylene Chloride
1. Index of Soil Concentration (Index 1)
a. Explanation -Calculates concentrations in Ug/g DW
of pollutant in sludge-amended soil. Calculated for
sludges with typical (median, if available) and
worst (95 percentile, if available) pollutant
concentrations, respectively, for each of four
applications. Loadings (as dry matter) are chosen
and explained as follows:
0 mt/ha No sludge applied. Shown for all indices
for purposes of comparison, to distin-
guish hazard posed by sludge from pre-
existing hazard posed by background
levels or other sources of the pollutant.
5 mt/ha Sustainable yearly agronomic application;
i.e., loading typical of agricultural
practice, supplying *s*50 kg available
nitrogen per hectare.
SO mt/ha Higher single application as may be used
on public lands, reclaimed areas or home
gardens.
500 mt/ha Cumulative loading after 100 years of
application at 5 mt/ha/year.
b. Assumptions/Limitations - Assumes pollutant is
incorporated into the upper 15 cm of soil (i.e., the
plow layer), which has an approximate mass (dry
matter) of 2 x 10^ mt/ha and is then dissipated
through first order processes which can be expressed
as a soil half-life.
c. Data Used and Rationale
i. Sludge concentration of pollutant (SC)
Typical 1.6 Ug/g DW
Worst 19 Ug/g DW
The typical and worst sludge concentrations are
the 50th and 95th percentile, respectively,
3-1
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statistically derived from sludge concentration
data from a U.S. EPA study of 40 publicly-own*.d
treatment works (POTWs) (U.S. EPA, 1982). 'See
Section 4, p. 4-1.)
ii. Background concentration of pollutant in soil
(BS) = 0 Ug/g DW
A value of zero was assumed due to lack of
available data.
iii. Soil half-life of pollutant (tj) - Data not
immediately available.
For purposes of calculating the index, it was
assumed that methylene chloride does not
degrade in soil (the worst-case condition).
d. Index 1 Values (pg/g DW)
Sludge Application Rate (mt/ha)
Sludge
Concentration
Typical
Worst
0
0
0
5
0.004
0.047
50
0.04
0.46
500
0.32
3.8
e. Value Interpretation - Value equals the expected
concentration in sludge-amended soil.
f. Preliminary Conclusion - Landspreading of sludge is
expected to increase the concentration of methylene
chloride in soil. Rote, however, that in lieu of an
available soil half-life, it was assumed that methy-
lene chloride does not degrade in soil. Thus, the
concentrations predicted for 100 years of cumulative
loading are probably higher than would normally be
expected.
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 soil organism.
b. Assumptions/Limitations - Assumes pollutant form in
sludge-amended soil is equally bioavailable and
toxic as form used in study where toxic effects were
demonstrated.
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c. Data Used and Rationale
i. Concentration of pollutant in sludge-amended
soil (Index 1)
See Section 3, p. 3-2.
ii. Soil concentration toxic to soil biota (TB) -
Data not immediately available.
d. Index 2 Values - Values were not calculated due to
lack of data.
e. Value Interpretation - Value equals factor by which
expected soil concentration exceeds toxic concentra-
tion. Value > 1 indicates a toxic hazard may exist
for soil biota.
f. Preliminary Conclusion - Conclusion was not drawn
because index values could not be calculated.
2. Index of Soil Biota Predator Toxicity (Index 3)
a. Explanation - Compares pollutant concentrations
expected in tissues of organisms inhabiting sludge-
amended soil with food concentration shown to be.
toxic to a predator on soil organisms.
b. Assumptions/Limitations - Assumes pollutant form
bioconcentrated by soil biota is equivalent in
toxicity to form used to demonstrate toxic effects
in predator. Effect level in predator may be
estimated from that in a different species.
c. Data Used and Rationale
i. Concentration of pollutant in sludge-amended
soil (Index 1)
See Section 3, p. 3-2.
ii. Uptake factor of pollutant in soil biota (UB) -
Data not immediately available.
iii. Peed concentration toxic to predator
(TR) - Data not immediately available.
d. Index 3 Values - Values were not calculated due to
lack of data.
e. Value Interpretation - Values equals factor by which
expected concentration in soil biota exceeds that
which is toxic to predator. Value > 1 indicates a
toxic hazard may exist for predators of soil biota.
3-3
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f. Preliminary Conclusion - Conclusion was not drawn
because index values could not be calculated.
C. Effect on Plants and Plant Tissue Concentration
1. Index of Phytotoxic Soil Concentration (Index 4)
a. Explanation - Compares pollutant concentrations in
sludge-amended soil with the lowest soil
concentration shown to be toxic for some plants.
b. Assumptions/Limitations - Assumes pollutant form in
sludge-amended soil is equally bioavailable and
toxic as form used in study where toxic effects were
demonstrated.
c. Data Used and Rationale
i. Concentration of pollutant in sludge-amended
soil (Index 1)
See Section 3, p. 3-2.
ii. Soil concentration toxic to plants (TP) - Data
not immediately available.
d. Index 4 Values - Values were not calculated due to
lack of data.
e. Value Interpretation - Value equals factor by which
soil concentration exceeds phytotoxic concentration.
Value > 1 indicates a phytotoxic hazard may exist.
f. Preliminary Conclusion - Conclusion was not drawn
because index values could not be calculated.
2. Index of Plant Concentration Caused by Uptake (Index 5)
a* Explanation - Calculates expected tissue
concentrations, in Ug/g DW, in plants grown in
sludge-amended soil, using uptake data for the most
responsive plant species in the following
categories: (1) plants included in the U.S. human
diet; and (2) plants serving as animal feed. Plants
used vary according to availability of data.
b. Assumptions/Limitations - Assumes an uptake factor
that is constant over all soil concentrations. The
uptake factor chosen for the human diet is assumed
to be representative of all crops (except fruits) in
the human diet. The uptake factor chosen for the
animal diet is assumed to be representative of all
crops in the animal diet. See also Index 6 for
consideration of phytotoxicity.
3-4
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c. Data Used and Rationale
i. Concent -ation of pollutant in sludge-amended
soil (IiK >T 1)
See Section 3, p. 3-2.
ii. Uptake factor of pollutant in plant tissue
(UP) - Data not immediately available.
d. Index 5 Values - Values were not calculated due to
lack of data.
e. Value Interpretation - Value equals the expected
concentration in tissues of plants grown in sludge-
amended soil. However, any value exceeding the val-
ue of Index 6 for the same or a similar plant
species may be unrealistically high because it would
be precluded by phytotoxicity.
f. Preliminary Conclusion - Conclusion was not drawn
because index values could not be calculated.
3. Index of Plant Concentration Permitted by Phytotoxicity
(Index 6)
a. Explanation - The index value is the maximum tissue
concentration, in yg/g DW, associated with
phytotoxicity in the same or similar plant species
used in Index 5. The purpose is to determine
whether the plant tissue concentrations determined
in Index S for high applications are realistic, or
whether such concentrations would be precluded by
phytotoxicity. The maximum concentration should be
the highest at which some plant growth still occurs
(and thus consumption of tissue by animals is
possible) but above which consumption by animals is
unlikely.
b. As sumptions/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) - Data not immediately
available.
d. Index 6 Values (yg/g DH) - Values were not
calculated due to lack of data.
e. Value Interpretation - Value equals the maximum
plant tissue concentration which is permitted by
3-5
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phytotoxicity. Value is compared with values for
the same or similar plant species given by Index 5.
The lowest of the two indices indicates the maximal
increase that can occur at any given application
rate.
f. Preliminary Conclusion - Conclusion was not drawn
because index values could not be calculated.
D. Effect on Herbivorous Animals
1. Index of Animal Toxicity Resulting from Plant Consumption
(Index 7)
a. Explanation - Compares pollutant concentrations
expected in plant tissues grown in sludge-amended
soil with feed concentration shown to be toxic to
wild or domestic herbivorous animals. Does not con-
sider direct contamination of forage by adhering
sludge.
b. Assumptions/Limitations - Assumes pollutant form
taken up by plants is equivalent in toxicity to form
used to demonstrate toxic effects in animal. Uptake
or toxicity in specific plants or animals may be
estimated from other species.
Co Data Used and Rationale
i. Concentration of pollutant in plant grown in
sludge-amended soil (Index 5) - Values were not
calculated due to lack of data.
ii. Peed concentration toxic to herbivorous animal
(TA) - Data not immediately available.
d. Index 7 Values - Values were not calculated due to
lack of data.
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 - Conclusion was not drawn
because index values could not be calculated.
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
adhesion to forage or from incidental ingestion of
sludge-amended soil and compares this with the
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dietary toxic threshold concentration for a grazing
animal.
b. Assumptions/Limitations •* Assumes that sludge is
applied over and adheres to growing forage, or that
sludge constitutes 5 percent of dry matter in the
grazing animal's diet, and that pollutant form in
sludge is equally bioavailable and toxic as form
used to demonstrate toxic effects. Where no sludge
is applied (i.e., 0 mt/ha), assumes diet is 5 per-
cent soil as a basis for comparison.
c. Data Used and Rationale
i. Sludge concentration of pollutant (SC)
Typical 1.6 yg/g DW
Worst 19 Ug/g DW
See Section 3, p. 3-1.
ii. Fraction of animal diet assumed to be soil (GS)
= 5Z
Studies of sludge adhesion to growing forage
following applications of liquid or filter-cake
sludge show that when 3 to 6 mt/ha of sludge
solids is applied, clipped forage initially
consists of up to 30 percent sludge on a dry-
weight basis (Chaney and Lloyd, 1979; Boswell,
1975). However, this contamination diminishes
gradually .with time and growth, and generally
is not detected in the following year's growth.
For example, where pastures amended at 16 and
32 mt/ha were grazed throughout a growing sea-
son (168 days), average sludge content of for-
age was only 2.14 and 4.75 percent,
respectively (Bertrand et al., 1981). It seems
reasonable 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
months when forage is reduced (Thornton and
Abrams, 1983). If the soil were sludge-
3-7
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amended, it is conceivable that up to 5 percent
sludge may be ingested in this manner as well.
Therefore, this value accounts for either of
these scenarios, whether forage is harvested or
grazed in the field.
iii. Peed concentration toxic to herbivorous animal
(TA) - Data not immediately available.
d. Index 8 Values - Values were not calculated due to
lack of data.
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 - Conclusion was not drawn
because index values could not be calculated.
E. Effect on Humans
Index of Human Cancer Risk Resulting from Plant
Consumption (Index 9)
a. Explanation - Calculates dietary intake expected to
result from consumption of crops grown on sludge-
amended soil. Compares dietary intake with the
cancer risk-specific intake (RSI) of the pollutant.
b. Assumptions/Limitations - Assumes that all crops are
grown on sludge-amended soil and that all those con-
sidered to be affected take up the pollutant at the
same rate. Divides possible variations in dietary
intake into two categories: toddlers (18 months to
3 years) and individuals over 3 years old.
c. Data Used and Rationale
i. Concentration of pollutant in plant grown in
sludge-amended soil (Index 5) - Values were not
calculated due to lack of data.
ii. Daily human dietary intake of affected plant
tissue (DT)
Toddler 74.5 g/day
Adult 205 g/day
The intake value for adults is based on daily
intake of crop foods (excluding fruit) by
vegetarians (Ryan et al., 1982); vegetarians
were chosen to represent the worst case. The
value for toddlers is based on the FDA Revised
3-8
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Total Diet (Pennington, 1983) and food
groupings listed by the U.S. EPA (1984a). Dry
weights for individual foot groups were
estimated from composition data given by the
U.S. Department of Agriculture (USDA) (1975).
These values were composited to estimate dry-
weight consumption of all non-fruit crops.
iii. Average daily human dietary intake of pollutant
(DI) - Data not immediately available.
iv. Cancer potency - Data not immediately
available.
Has not been derived by U.S. EPA for the
ingestion route of exposure. (See Section 4,
p. 4-4.)
v. Cancer risk-specific intake (RSI) - Data not
immediately available.
The RSI is the pollutant intake value which
results in an increase in cancer risk of 10"^
(1 per 1,000,000). The RSI is calculated from
the cancer potency using the following formula:
R = 1Q"6 x 70 kg x 103 Ug/mg
Cancer potency
d. Index 9 Values - Values were not calculated due to
lack of data.
e. Value Interpretation - Value > 1 indicates a poten-
tial increase in cancer risk of > 10"^ (1 per
1,000,000). Comparison with the null index value at
0 mt/ha indicates the degree to which any hazard is
due to sludge application, as opposed to pre-
existing dietary sources.
f. Preliminary Conclusion - Conclusion was not drawn
because index values could not be calculated.
2. Index of Human Cancer Risk Resulting from Consumption of
Animal Products Derived from Animals Feeding on Plants
(Index 10)
a. Explanation - Calculates human dietary intake
expected to result from pollutant uptake by domestic
animals given feed grown on sludge-amended soil
(crop or pasture land) but not directly contaminated
by adhering sludge. Compares expected intake with
RSI.
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b. Assumptions/Limitations - Assumes that all animal
products are from animals receiving all their feed
from sludge-amended soil. Assumes that all animal
products consumed take up the pollutant at the
highest rate observed for muscle of any commonly
consumed species or at the rate observed for beef
liver or dairy products (whichever is higher).
Divides possible variations in dietary intake into
two categories: toddlers (18 months to 3 years) and
individuals over 3 years old.
c. Data Used and Rationale
i. Concentration of pollutant in plant grown in
sludge-amended soil (Index 5) - Values were not
calculated due to lack of data.
ii. Uptake factor of pollutant in animal tissue
(UA) - Data not immediately available.
iii. Daily human dietary intake of affected animal
tissue (DA)
Toddler 43.7 g/day
Adult 88.5 g/day
The fat intake values presented, which comprise
meat, fish, poultry, eggs and milk products,
are derived from the FDA Revised Total Diet
(Pennington, 1983), food groupings listed* by
the U.S. EPA (1984a) and food composition data
given by USDA (1975). Adult intake of meats is
based on males 25 to 30 years of age and that
for milk products on males 14 to 16 years of
age, the age-sex groups with the highest daily
intake. Toddler intake of milk products is
actually based on infants, since infant milk
consumption is the highest among that age group
(Pennington, 1983).
iv. Average daily human dietary intake of pollutant
(DI) - Data not immediately available.
v. Cancer risk-specific intake (RSI) - Data not
immediately available.
d. Index 10 Values - Values were not calculated due to
lack of data.
e. Value Interpretation - Same as for Index 9.
f. Preliminary Conclusion - Conclusion was not drawn
because index values could not be calculated.
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3. Index of Human Cancer Risk Resulting from Consumption of
Animal Products Derived from Animals Ingesting Soil
(Index 11)
a. Explanation - Calculates human dietary intake
expected to result from consumption of animal
products derived from grazing animals incidentally
ingesting sludge-amended soil. Compares expected
intake with RSI.
b. Assumptions/Limitations - Assumes that all animal
products are from animals grazing sludge-amended
soil, and that all animal products consumed tt'-.e 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
(IS months to 3 years) and individuals over 3 years
old.
c. Data Used and Rationale
i. Animal tissue - Data not immediately available.
ii. Sludge concentration of pollutant (SC)
Typical 1.6 Mg/g DW
Worst 19 Ug/g DW
See Section 3, p. 3-1.
iii. Background concentration of pollutant in soil
(BS) = 0 Ug/g DW
See Section 3, p. 3-2.
iv. Fraction of animal diet assumed to be soil (GS)
= 52
See Section 3, p. 3-7.
v. Uptake factor of pollutant in animal tissue
(UA) - Data not immediately available.
vi. Daily human dietary intake of affected animal
tissue (DA)
Toddler 39.4 g/day
Adult 82.4 g/day
The affected tissue intake value is assumed to
be from the fat component of meat only (beef,
pork, lamb, veal) and milk products
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(Pennington, 1983). This is a slightly more
limited choice than for Index 10. Adult intake
of meats is based on males 25 to 30 years of
age and the intake for milk products on males
14 to 16 years of age, the age-sex groups with
the highest daily intake. Toddler intake of
milk products is actually based on infants,
since infant milk consumption is the highest
among that age group (Pennington, 1983).
vii. Average daily human dietary intake of pollutant
(DI) - Data not immediately available.
vi'ii. Cancer risk-specific intake (RSI) - Data not
immediately available.
d. Index 11 Values - Values were not calculated due to
lack of data.
e. Value Interpretation - Same as for Index 9.
f. Preliminary Conclusion - Conclusion was not drawn
because index values could not be calculated.
4. Index of Human Cancer Risk from Soil Ingestion (Index 12)
a. Explanation - Calculates the amount of pollutant in
the diet of a child who ingests soil (pica child)
amended with sludge. Compares this amount with RSI.
*•
b. Assumptions/Limitations - Assumes that the pica
child consumes an average of 5 g/day of sludge-
amended soil. If the RSI specific for a child is
not available, this index assumes the RSI for a
10 kg child is the same as that for a 70 kg adult.
It is thus assumed that uncertainty factors used in
deriving the RSI provide protection for the child,
taking into account the smaller body size and any
other differences in sensitivity.
c. Data Used and Rationale
i. Concentration of pollutant in sludge-amended
soil (Index 1)
See Section 3, p. 3-2.
ii. Assumed amount of soil in human diet (OS)
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
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Exposure Assessment Group (U.S. EPA, 1983a).
The value of 0.02 g/day for an adult is an
estimate from U.S. EPA, 1984a.
iii. Average daily human dietary intake of pollutant
(DI) - Data not immediately available.
iv. Cancer risk-specific intake (RSI) - Data not
immediately available.
d. Index 12 Values - Values were not calculated due to
lack of data.
e. Value Interpretation - Same as for Index 9.
f. Preliminary Conclusion - Conclusion was not drawn
because index values could not be calculated.
5. Index of Aggregate Human Cancer Risk (Index 13)
a. Explanation - Calculates the aggregate amount of
pollutant in the human diet resulting from pathways
described in Indices 9 to 12. Compares this amount
with RSI.
b. Assumptions/Limitations - As described for Indices 9
to 12.
c. Data Used and Rationale - As described for Indices 9
to 12.
d. Index 13 Values - Values were not calculated due to
lack of data.
e. Value Interpretation - Same as for Index 9.
f. Preliminary Conclusion - Conclusion was not drawn
because index values could not be calculated.
II. LANDFILLING
A. Index of Groundwater Concentration Resulting from Landfilled
Sludge (Index 1)
1. Explanation - Calculates groundwater contamination which
could occur in a potable aquifer in the landfill vicin-
ity. Uses U.S. EPA1s 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,
3-13
-------
and boundary or source conditions are evaluated. Trans-
port parameters i&rlude the interstitial pore water
velocity and dispersion coefficient. Pollutant fate
parameters include * he degradation/decay coefficient and
retardation factor. Retardation is primarily a function
of the adsorption process, which is characterized by a
linear, equilibrium partition coefficient representing
the ratio of adsorbed and solution pollutant concentra-
tions. This partition coefficient, along with soil bulk
density and volumetric water content, are used to calcu-
late the retardation factor. A computer program (in
FORTRAN) was developed to facilitate computation of the
analytical solution. The program predicts pollutant con-
centration as a function of time and location in both the
unsaturated and saturated zone. Separate computations
and parameter estimates are required for each zone. The
prediction requires evaluations of four dimensionless
input values and subsequent evaluation of the result,
through use of the computer program.
2. Assumptions/Limitations - Conservatively assumes that the
pollutant is 100 percent mobilized in the leachate and
that all leachate leaks out of the landfill in a finite
period and undiluted by precipitation. Assumes that all
soil and aquifer properties are homogeneous and isotropic
throughout each zone; steady, uniform flow occurs only in
the vertical direction throughout the unsaturated zone,
and only in the horizontal (longitudinal) plane in the
saturated zone; pollutant movement is considered only in
direction of groundwater flow for the saturated zone; all
pollutants exist in concentrations that do not signifi-
cantly affect water movement; for organic chemicals, the
background concentration in the soil profile or aquifer
prior to release from the source is assumed to be zero;
the pollutant source is a pulse input; no dilution of the
plume occurs by recharge from outside the source area;
the leachate is undiluted by aquifer flow within the
saturated zone; concentration in the saturated zone is
attenuated only by dispersion.
3. Data Used and Rationale
a. Unsaturated zone
i. Soil type and characteristics
(a) Soil type
Typical Sandy loam
Worst Sandy
These two soil types were used by Gerritse et
al. (1982) to measure partitioning of elements
between soil and a sewage sludge solution
3-14
-------
phase. They are used here since these parti-
tioning measurements (i.e., K«j values) are con-
sidered the best available for analysis of
metal transport from landfilled sludge. The
same soil types are also used for nonmetals for
convenience and consistency of analysis.
(b) Dry bulk density (Pdry)
Typical 1.53 g/mL
Worst 1.925 g/mL
Bulk density is the dry mass per unit volume of
the medium (soil), i.e., neglecting the mass of
the water (Camp Dresser and McKee, Inc. (COM),
1984).
(c) Volumetric water content (9)
Typical 0.195 (unitless)
Worst 0.133 (unitless)
The volumetric water content is the volume of
water in a given volume of media, usually
expressed as a fraction or percent. It depends
on properties of the media and the water flux
estimated by infiltration or net recharge. The
volumetric water content is used in calculating
the water movement through the unsaturated zone
(pore water velocity) and the retardation
coefficient. Values obtained from CDM, 1984.
(d) Fraction of organic carbon (£Oc)
Typical 0.005 (unitless)
Worst 0.0001 (unitless)
Organic content of soils is described in terms
of percent organic carbon, which is required in
the estimation of partition coefficient, Kj.
Values, obtained from R. Griffin (1984) are
representative values for subsurface soils.
ii. Site parameters
(a) Landfill leaching time (LT) = 5 years
Sikora et al. (1982) monitored several sludge
entrenchment sites throughout the United States
and estimated time of landfill leaching to be 4
or 5 years. Other types of landfills may leach
for longer periods of time; however, the use of
a value for entrenchment sites is conservative
because it results in a higher leachate
. generation rate.
3-15
-------
(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 i-e worst case. Thus, the
initial depth of liquid is 4 and 8 m, and
average yearly leachate generation is 0.8 and
1.6 m, respectively.
(c) Depth to groundwater (h)
Typical 5 m
Worst 0 m
Eight landfills were monitored throughout the
United States and depths to groundwater below
them were listed. A typical depth to ground-
water of 5 m was observed (U.S. EPA, 1977).
For the worst case, a value of 0 m is used to
represent the situation where the bottom of the
landfill is occasionally or regularly below the
water table. The depth to groundwater must be
estimated in order to evaluate the likelihood
that pollutants moving through the unsaturated
soil will reach the groundwater.
(d) Dispersivity coefficient (a)
Typical 0.5 m
Worst Not applicable
The dispersion process is exceedingly complex
and difficult to quantify, especially for the
unsaturated zone. It is sometimes ignored in
the unsaturated zone, with the reasoning that
pore water velocities are usually large enough
so that pollutant transport by convection,
i.e., water movement, is paramount. As a rule
of thumb, dispersivity may be set equal to
10 percent of the distance measurement of the
analysis (Gelhar and Axness, 1981). Thus,
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.
'3-16
-------
iii. Chemical-specific parameters
(a) Sludge concentration of pollutant (SC)
Typical 1.6 mg/kg DW
Worst 19 mg/kg DW
See Section 3, p. 3-1.
(b) Soil half-life of pollutant (tp - Data not
immediately available.
(c) Degradation rate (y) = 0 day'1
Due to the lack of data on the soil half-life
of the pollutant, a conservative value of
0 day'1 was chosen for the degradation rate.
(d) Organic carbon partition coefficient (Koc) =
10 mL/g
The organic carbon partition coefficient is
multiplied by the percent organic carbon
content of soil (foc) to derive a partition
coefficient (K
-------
Porosity is that portion of the total volume of
soil that is made up of voids (*>xr) and water.
Values corresponding to the abo.? 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 estima s flow velocity
based on Darcy's Equation. It is a measure of
the volume of liquid that can flow through a
unit area or media with time; values can range
over nine orders of magnitude depending on the
nature of the media. Heterogenous conditions
produce large spatial variation in hydraulic
conductivity, making estimation of a single
effective value extremely difficult. Values
used are from Freeze and Cherry (1979) as
presented in U.S. EPA (1983b).
(d) Fraction of organic carbon (foc) =
0.0 (unitless)
Organic carbon content, and therefore adsorp-
tion, is assumed to be 0 in the saturated zone.
ii. Site parameters
(a) Average hydraulic gradient between landfill and
well (i)
Typical 0.001 (unitless)
Worst 0.02 (unitless)
The hydraulic gradient is the slope of the
water table in an unconfined aquifer, or the
piezometric surface for a confined aquifer.
The hydraulic gradient must be known to
determine the magnitude and direction of
groundwater flow. As gradient increases, dis-
persion is reduced. Estimates of typical and
high gradient values were provided by Donigian
(1985).
(b) Distance from well to landfill (AA)
Typical 100 m
Worst 50 m
3-18
-------
This distance is the distance between a
landfill and any functioning public or private
water supply or livestock water supply.
(c) Dispersivity coefficient (a)
Typical 10 m
Worst 5 m
These values are 10 percent of the distance
from well to landfill (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
preexisting flow is very limited and therefore
dilution of the plume entering the saturated
zone is negligible.
(e) Width of landfill (W) = 112.8 m
The landfill is arbitrarily assumed to be
circular with an area of 10,000 m2.
iii. Chemical-specific parameters
(a) Degradation rate (y) = 0 day"1
Degradation is assumed not to occur in the
saturated zone.
(b) Background concentration of pollutant in
groundwater (BC) = 0 yg/L
It is assumed that no pollutant exists in the
soil profile or aquifer prior to release from
the source.
4. Index Values - See Table 3-1.
S. Value Interpretation - Value equals the maximum expected
groundwater concentration of pollutant, in Ug/L, at the
well.
3-19
-------
6. Preliminary Conclusion - Landfilled sludge is expected to
increase groundwater concentrations of methylene chlor-
ide; this increase may be large at disposal sites wi h
all worst-case parameters.
B. Index of Human Cancer Risk Resulting from Groundwater
Contamination (Index 2)
1. Explanation - Calculates human exposure which could
result from groundwater contamination. Compares exposure
with cancer risk-specific intake (RSI) of pollutant.
2. As sumptions/Limitations - Assumes long-term exposurr to
maximum concentration at well at a rate of 2 L/day.
3. Data Used and Rationale
a. Index of groundwater concentration resulting from
landfilled sludge (Index 1)
See Section 3, p. 3-26.
b. Average human consumption of drinking water (AC) =
2 L/day
The value of 2 L/day is a standard value used by
U.S. EPA in most risk assessment studies.
c. Average daily human dietary intake of pollutant (DI)
- Data not immediately available.
d. Cancer potency - Data not immediately available.
Has not been derived by U.S. EPA for the ingestion
route of exposure. (See Section 4, p. 4-4.)
e. Cancer risk-specific intake (RSI) - Data not
immediately available.
4. Index 2 Values - Values were not calculated due to lack
of data.
S. Value Interpretation - Value >1 indicates a potential
increase in cancer risk of 10"^ (1 in 1,000,000) due only
to groundwater contaminated by landfill. The value does
not account for the possible increase in risk resulting
from daily dietary intake of pollutant since DI data were
not immediately available.
6. Preliminary Conclusion - Conclusion was not drawn because
index values could not be calculated.
3-20
-------
III. INCINERATION
A. Index of Alt Concentration Increment Resulting from
Incinerator Envisions (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, 1984). 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 (C) -
2.78 x 10~7 hr/sec x
b. Sludge feed rate (DS)
i. Typical = 2660 kg/hr (dry solids input)
A feed rate of 2660 kg/hr DW represents an
average dewatered sludge feed rate into the
furnace. This feed rate would serve a commun-
ity of approximately 400,000 people. This rate
was incorporated into the U.S. EPA-ISCLT model
based on the following input data:
EP = 360 Ib H20/mm BTU
Combustion zone temperature - 1400°F
Solids content - 282
Stack height - 20 m
Exit gas velocity - 20 m/s
Exit gas temperature - 356.9°K (183°F)
Stack diameter - 0.60 m
3-21
-------
ii. Worst = 10,000 kg/hr (dry solids input)
A feed rate of 10,000 kg/hr DW represents a
higher feed rate and would serve a major U.S.
city. This rate was incorporated into the U.S.
EPA-ISCLT model based on the following input
data:
EP = 392 Ib H20/mm BTU
Combustion zone temperature - 1400°F
Solids content - 26.62
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 1.6 mg/kg DW
Worst 19 mg/kg DW
See Section 3, p. 3-1.
d. Fraction of pollutant emitted through stack (FM)
Typical O.OS (unitless)
Worst * 0.20 (unitless)
These values were chosen as best approximations of
the fraction of pollutant emitted through stacks
(Farrell, 1984). No data was available to validate
these values; however, U.S. EPA is currently testing
incinerators for organic emissions.
e. Dispersion parameter for estimating maximum annual
ground level concentration (DP)
Typical 3.4
Worst 16.0
The dispersion parameter is derived from the U.S.
EPA-ISCLT short-stack model.
f. Background concentration of pollutant in urban air
(BA) =7.8
This value is a geometric mean calculated from con-
centrations of methylene chloride in urban air for
seven cities as reported by U.S. EPA (1983c). How-
ever, this level is not necessarily representative
of the United States as a whole because the cities
reported are predominantly non-industrial in charac-
ter. According to U.S. EPA (1983c), "The dispersive
uses of methylene chloride ... are distributed
3-22
-------
geographically approximately with the industrialized
population in th
-------
b. Background concentration of pollutant in urban air
(BA) =7.8 Ug/m3
See Section 3, p. 3-22.
c. Cancer potency = 0.00063 (mg/kg/day)"1
This potency value was derived from the results of
studies in which rats exposed to methylene chloride
developed salivary sarcoma. Uncertainty factors
have not been associated with this value (U.S. EPA,
1983c). (See Section 4, p. 4-4.)
d. Exposure criterion (EC) = 5.6 Ug/m^
A lifetime exposure level which would result in a
10~6 cancer risk was selected as ground level con-
centration against which incinerator emissions are
compared. The risk estimates developed by CAG are
defined as the lifetime incremental cancer risk in a
hypothetical population exposed continuously
throughout their lifetime to the stated concentra-
tion of the carcinogenic agent. The exposure
criterion is calculated using the following formula:
_ 10"6 x 103 ug/mg x 70 kg
— -
Cancer potency x 20 mj/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
1.4
1.4
1.4
1.4
1.4
1.4
Worst Typical 1.4 1.4 1.4
Worst 1.4 1.4 1.4
a The typical (3.4 yg/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 > 1 indicates a potential
increase in cancer risk of > 10~6 (1 per 1,000,000).
Comparison with the null index value at 0 kg/hr DW indi-
cates the degree to which any hazard is due to sludge
incineration, as opposed to background urban air
concentration.
3-24
-------
6. Preliminary Conclusion - The human cancer risk due to
methylene chloride by inhalation is not expected to
increase as a result of sludge in fneration.
IV. OCEAN DISPOSAL
Based on the recommendations of the experts at the OWRS meetings
(April-May, 1984), an assessment of this reuse/disposal option is
not being conducted at this time. The U.S. EPA reserves the right
to conduct such an assessment for this option in the future.
3-25
-------
TABLE 3-1 INDEX OF GROUNDWATER CONCENTRATION RESULTING FROM LANDFILLED SLUDGE (INDEX 1) AND
INDEX OF HUMAN CANCER RISK RESULTING FROM CROUNDWATER CONTAMINATION (INDEX 2)
Site Characteristics
Condition of Analysis8****0
3456
V
Sludge concentration
Unsaturated Zone
W
N
Soil type and charac-
teristics"
Site parameters6
Saturated Zone
Soil type and charac-
teristics^
Site parameters**
Index 1 Value (pg/L)
Index 2 Value
T
T
T
T
0.043
NCh
T
T
T
T
0.52
NC
W
T
T
T
0.043
NC
NA
W
T
T
0.043
NC
T
T
W
T
0.23
NC
T
T
T
W
1.7
NC
NA
W
W
W
110
NC
N
N
N
N
0
NC
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.
"Index values for combinations other than those shown may be calculated using the formulae in the Appendix.
cSee Table A-l in Appendix for parameter values used.
^Dry bulk density (Pjry)* volumetric water content (6), and fraction of organic carbon (foc).
eLeachate generation rate (Q), depth to groundwater (h), and dispersivity coefficient (a).
'Aquifer porosity (0) and hydraulic conductivity of the aquifer (K).
^Hydraulic gradient (i), distance from well to landfill (Ad), and dispersivity coefficient (a).
h Not calculated due to lack of data.
-------
SECTION 4
PRELIMINARY DATA PROFILE FOR METHYLEME CHLORIDL
IM MUNICIPAL SEWAGE SLUDGE
I. OCCURRENCE
Methylene chloride is a high volume chemical
widely used to remove paint, clean metal, and
propel aerosol sprays.
A. Sludge
1. Frequency of Detection
Observed in 318 of 436 samples (73Z)
from 40 POTWs
Observed in 17 of 41 samples (41Z) from
10 POTWs
2. Concentration
Median (50th percentile) concentration
= 1.6 ug/g DW and 95th percentile
concentration = 19 Ug/g DW from a survey
of 40 POTWs
1 to 10,500 ug/L range for 40 POTWs
1 to 567 ug/L range for 10 POTWs
Median 89 Ug/L (WW), range 5 to
1,055 Ug/L; median 25 Ug/L (DW),
range 0.06 to 30.0 Ug/g
B. Soil - Unpolluted
Data not immediately available.
C. Water - Unpolluted
1. Frequency of Detection
"Methylene chloride has been detected in
ambient air and in surface and drinking
water samples throughout the
United States."
Methylene chloride observed in 5 of 5
cities evaluated
U.S. EPA, 1982
(p. 41)
U.S. EPA, 1982
(p. 49)
Statistically
derived from
data in
U.S. EPA, 1982
U.S. EPA, 1982
(p. 41)
U.S. EPA, 1982
(p. 49)
Naylor and
Loehr, 1982
(p. 20)
U.S. EPA, 1983c
(p. 3-11)
U.S. EPA, 1983c
(p. 3-20)
4-1
-------
Methylene chloride detected in water
supplies in 9 of 10 cities studied
i. jtected in 32 of 204 surface water
sites near industries
U.S. EPA, 1983c
(p. 3-22)
Methylene chloride is formed during National
chlorination in water treatment. The Academy of
Region V survey showed methylene chloride Science (NAS),
in 1Z of raw water supplies and 8% of 1977 (p. 743)
finished water.
Concentration
a. Surface water
Methylene chloride in Mississippi
River water:
mean 2.581 Ug/L
maximum 15.8 Ug/L
b. Seawater
Data not immediately available.
c. Drinking water
1.6 Ug/L in Lawrence, MA water
supply highest level detected.
Mean of <1 Ug/L for water supplies
evaluated by Region V.
0.13 Ug/L mean, 1.1 Ug/L
max. in Jefferson Parrish, LA
drinking water
D. Air
1. Frequency of Detection
"Methylene chloride has been detected in
ambient air and in surface and drinking
water samples throughout the United
States."
"The dispersive uses of methylene chlor-
ide are varied and widespread and are
distributed geographically approximately
with the industrialized population in
the United States."
U.S. EPA, 1983c
(p. 3-22)
U.S. EPA, 1983c
(p. 3-22)
U.S. EPA, 1983c
(p. 3-22)
U.S. EPA, 1983c
(p. 3-11)
U.S. EPA, 1983c
(p. 3-6)
4-2
-------
2. Concentration
Background levels are approximately
0.174 Ug/rn^ with many urban levels
2 or 3 orders of magnitude higher.
a. Urban
Methylene chloride in urban air
(Wg/m3)
City
Mean
Range
Phoenix
San Jose
Los Angeles
Baton Rouge
St. Louis
Edison (NJ)
Houston
3.10
1.39
13.02
0.87
1.35
90.28
1.98
0.29-17.90
0.21-6.67
2.09-41.77
0.16-1.91
0.56-2.15
0-239.5
0-4.51
b. Rural
Methylene chloride in rural air
(Ug/m3)
Location
Mean
Range
E. Pood
Data not immediately available.
II. HUMAN EFFECTS
A. Ingest ion
1. Carcinogenicity
a. Qualitative Assessment
Testing of methylene chloride for
Carcinogenicity by the oral route in
rats and mice is being conducted by
the NCI; results are not yet
available.
U.S. EPA, 1983c
(p. 3-11)
U.S. EPA, 1983c
(p. 3-12)
U.S. EPA, 1983c
(p. 3-12)
Point Arena (CA)
Jet mar (KS)
Reese River (NV)
Pullman (WA)
0.156
0.188
0.180
0.121
0.045-0.354
0.115-0.365
0.052-0.343
U.S. EPA, 1984b
(p. 25)
4-3
-------
Potency
Insufficient information exists on
which to b.'se a potency estimate for
ingested methylene chloride.
Effects
None demonstrated for oral route.
2. Chronic Toxicity
Data not assessed because evaluation
based on carcinogenicity.
3. Absorption Factor
Data not immediately available.
4. Existing Regulations
U.S. EPA's Office of Drinking Water has
developed health advisories for one-day,
ten-day, and long-term exposure. One-
day, ten-day, and long-term health
advisories are 13, 1.5, and 0.15 mg/L,
respectively.
B. Inhalation
1. Carcinogenicity
a. Qualitative Assessment
Based on limited animal evidence and
lack of human evidence, U.S. EPA has
given methylene chloride an IARC
rating of 3, or "cannot be classi-
fied as to its carcinogenic poten-
tial for humans."
b. Potency
Cancer potency = 6.3 x 10~^
(mg/kg/day)~l. Value was derived
from unit risk for inhalation study
data.
c. Effects
Salivary carcinoma development in
rats given 500, 1500, and 3500 ppm
doses.
U.S. EPA, 1984b
(p. 25)
U.S. EPA, 1983c
(p. 5-106)
U.S. EPA, 1985
U.S. EPA, 1983c
(p. 1-4)
U.S. EPA, 1983c
(pp. 5-103 to
5-106)
U.S. EPA, 1983c
(p. 5-104)
4-4
-------
2. Chronic Toxicity
Data not assessed because evaluation
based on carcinogenicity.
3. Absorption Factor
Data not immediately available.
4. Existing Regulations
OSHA health standard requires that a
worker's exposure to methylene chloride
should not exceed 500 ppm in any 8-hour
work day.
III. PLANT EFFECTS
Few studies on the effects of methylene chloride
on vascular plants are available.
IV. DOMESTIC ANIMAL AND WILDLIFE EFFECTS
A. Toxicity
1.6 to 2.3 mL/kg LD5Q for mice
2.25 g/18 L drinking water for 91 days,
no effect on rats
1,987 mg/kg LD5Q for mice
2,388 to A,368 mg/kg LD$Q for rats
B. Uptake
An approximate bioconcentration factor for
methylene chloride of 5.2 has been calculated.
V. AQUATIC LIFE EFFECTS
Data not immediately available.
VI. SOIL BIOTA EFFECTS
Methylene chloride is readily degraded by
bacteria in concentration up to 400 Ug/g.
Bacterial growth from sewage effluent was sus-
tained with methylene chloride and mineral salts.
U.S. EPA, 1983c
(p. 3-26)
U.S. EPA, 1983c
(p. 3-25)
NAS, 1977
(p. 744)
U.S. EPA, 1983c
(p. 5-8)
U.S. EPA, 1983c
(p. 3-25)
U.S. EPA, 1983c
U.S. EPA, 1983c
(p. 3-8)
4-5
-------
VII. PHYSICOCHEMICAL DATA FOR ESTIMATING PATE AND TRANSPORT
Chemical formula: CH2Cl2 U.S. EPA, 1983c
Molecular weight: 84.94 (p. 3-3)
Boiling point (760 mm Hg) = 40°C
Melting point: -95 to -97°C
Vapor density: 2.93
Density: 1.326 g/mL (20°C)
Solubility: 2.0 g/100 mL water at 20°C
Vapor pressure: 230 mm Hg at 10°C
349 mm Hg at 20°C
436 mm Hg at 25°C
511 mm Hg at 30°C
600 mm Hg at 36°C
Organic carbon partition coefficient: 10 mL/g Lyman, 1982
4-6
-------
SECTION 5
REFERENCES
Abramowitz, M., and I. A. Stegun. 1972. Handbook of Mathematical
Functions. Dover Publications, New York, NY.
Bertrand, J. E., M. C. Lutrick, G. T. Edds, and R. L. West. 1981.
Metal Residues in Tissues, Animal Performance' and Carcass Quality
with Beef Steers Grazing Pensacola Bahiagrass Pastures Treated with
Liquid Digested Sludge. J. Anim. Sci. 53:1.
Boswell, F. t 1975. Municipal Sewage Sludge and Selected Element
Applications to Soil: Effect on Soil and Fescue. J. Environ.
Qual. 4(2):267-273.
Camp Dresser and Mckee, Inc. 1984. Development of Methodologies for
Evaluating Permissible Contaminant Levels in Municipal Wastewater
Sludges. Draft. Office of Water Regulations and Standards,
U.S. Environmental Protection Agency, Washington, D.C.
Chaney, R. L., and C. A. Lloyd. 1979. Adherence of Spray-Applied
Liquid Digested Sewage Sludge to Tall Fescue. J. Environ. Qual.
8(3):407-411.
Donigian, A. S. 1985. Personal Communication. Anderson-Nichols & Co.,
Inc., Palo Alto, CA. May.
Farrell, J. B. 1984. Personal Communication. Water Engineering
Research Laboratory, U.S. 'Environmental Protection Agency,
Cincinnati, OH. December.
Freeze, R. A., and J. A. Cherry. 1979. Groundwater. Prentice-Hall,
Inc., Englewood Cliffs, NJ.
Gelhar, L. W., and G. J. Axness. 1981. Stochastic Analysis of
Macrodispersion in 3-Dimensionally Heterogeneous Aquifers. Report
No. H-8. Hydrologic Research Program, New Mexico Institute of
Mining and Technology, Soccorro, NM.
Gerritse, R. G., R. Vriesema, J. W. Dalenberg, and H. P. DeRoos. 1982.
Effect of Sewage Sludge on Trace Element Mobility in Soils. J.
Environ. Qual. 2:359-363.
Griffin, R. A. 1984. Personal Communication to U.S. Environmental
Protection Agency, ECAO - Cincinnati, OH. Illinois State
Geological Survey.
Lyman, W. J. 1982. Adsorption Coefficients for Soils and Sediments.
Chapter 4. In; Handbook of Chemical Property Estimation Methods.
McGraw-Hill Book Co., New York, NY.
5-1
-------
National Academy of Science. 1977. Drinking Water and Health.
National Research Council Safe Drinking Water Committee.
Washington, D.C.
Naylor, L. M., and R. C. Loehr. 1982. Priority Pollutants in Municipal
Sewage Sludge. Bio Cycle. July/August 18-22.
Pennington, J. A. T. 1983. Revision of the Total Diet Study Food Lists
and Diets. J. Am. Diet. Assoc. 82:166-173.
Pettyjohn, W. A., D. C. Kent, T. A. Prickett, H. E. LeGrand, and F. E.
Witz. 1982. Methods for the Prediction of Leachate Plume
Migration and Mixing. U.S. EPA Municipal Environmental Research
Laboratory, Cincinnati, OH.
Ryan, J. A., H. R. Pahren, and J. B. Lucas. 1982. Controlling Cadmium
in the Human Food Chain: A Review and Rationale Based on Health
Effects. Environ. Res. 28:251-302.
Sikora, L. J., W. D. Burge, and J. E. Jones. 1982. Monitoring of a
Municipal Sludge Entrenchment Site. J. Environ. Qual. 2(2):321-
325.
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.
U.S. Department of Agriculture. 1975. Composition of Foods.
Agricultural Handbook No. 8.
U.S. Environmental Protection Agency. 1977. Environmental Assessment
of Subsurface Disposal of Municipal 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. 1982. Fate of Priority
Pollutants in Publicly-Owned Treatment Works. EPA 440/1-82/303.
U.S. Environmental Protection Agency, Washington, D.C.
U.S. Environmental Protection Agency. 1983a. Assessment of Human
Exposure to Arsenic: Tacoma, Washington. Internal Document.
OHEA-E-075-U. Office of Health and Environmental Assessment,
Washington, D.C. July 19.
U.S. Environmental Protection Agency. 1983b. Rapid Assessment of
Potential Groundwater Contamination Under Emergency Response
Conditions. EPA 600/8-83-030.
5-2
-------
U.S. Environmental Protection Agency. 1983c. Health Assessment
Document for Dichloromethane (Methylene Chloride). Review Draft
Copy. EPA 600/8-82-0(X.3. U.S. Environmental Protection Agency,
Washington, D.C.
U.S. Environmental Protection Agency. 1984a. Air Quality Criteria for
Lead. External Review Draft. EPA 600/8-83-0288. Environmental
Criteria and Assessment Office, Research Triangle Park, NC.
September.
U.S. Environmental Protection Agency. 1984b. Health Effects Assessment
for Methylene Chloride. Final Draft. ECAO-CIN-H028. Cincinnati,
OH.
U.S. Environmental Protection Agency. 1985. Memorandum to E. Lomnitz,
Office of Water Regulations and Standards. April 22.
5-3
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APPENDIX
PRELIMINARY HAZARD INDEX CALCULATIONS FOR METHYLENE CHLORIDE
IN MUNICIPAL SEWAGE SLUDGE
I. LANDSPREADING AND DISTRIBUTION-AND-MARKETING
A. Effect on Soil Concentration of Nethylene Chloride
1. Index of Soil Concentration (Index 1)
a. Formula
_ (SC x AR) + (BS x MS)
C5s " AR + MS
CSr = CSS [1 + O.S^/t*) + 0.5^/ti') + ... + Q.5(
where:
CSg = Soil concentration of pollutant after a
single year's application of sludge
(Ug/g DW)
CSr = Soil concentration of pollutant after the
yearly application of sludge has been
repeated for n + 1 years (ug/g DW)
SC = Sludge concentration of pollutant (ug/g DW)
AR = Sludge application rate (mt/ha)
MS = 2000 mt ha/DW = assumed mass of soil in
upper 15 cm
BS = Background concentration of pollutant in
soil (yg/g DW)
t^ = Soil half-life of pollutant (years)
n =99 years
b. Sample calculation
CSS is calculated for AR = 0, 5, and 50 mt/ha only
n ™/ „ / nu (1.6 ue/g DW x 5 mt/ha) * (0 ug/g DW x 2000 mt/ha)
0,004 W8/g DW (5 mt/ha DW + 2000 mt/ha DW)
CSr is calculated for AR = 500 mt/ha applied for 1 year
„ , nu _ (1.6 ue/g DW x 500 mt/ha) + (0 ug/g DW x 2000 mt/ha)
U8/g UW ~ (500 mt/ha DW + 2000 mt/ha DW)
A-l
-------
B. Effect on Soil Biota and Predators of Soil Biota
1. Index of Soil Biota Toxicit,, (Index 2)
a. Formula
Index 2 = —
where :
Ij = Index 1 = Concentration of pollutant in
sludge-amended soil (ug/g DW)
TB = Soil concentration toxic to soil biota
(Ug/g
b. Sample calculation - Values were not calculated due to
lack of data.
2. Index of Soil Biota Predator Toxicity (Index 3)
a. Formula
T , , *1 x UB
Index 3 = — —
where :
II = Index 1 = Concentration of pollutant in
sludge-amended soil (ug/g DW)
UB = Uptake factor of pollutant in soil biota
(UgVg tissue DW [ug/g soil DW]"1)
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 Phytotoxic Soil Concentration (Index 4)
a. Formula
Index 4 = —
where:
1} = Index 1 = Concentration of pollutant in
sludge-amended soil (ug/g DW)
TP = Soil concentration toxic to plants (ug/g DW)
A-2
-------
b* Sample calculation - Values were not calculated due to
lack of data.
2. Index of Plant Concentration Caused by Uptake (Index 5)
a. Formula
Index 5 = Ij. x UP
where:
1} = Index 1 = Concentration of pollutant in
sludge - amended soil (ug/g DW)
UP = Uptake factor of pollutant in plant tissue
(Ug/g tissue DW [yg/g soil DW]"1)
b. Sample Calculation - Values were not calculated due to
lack of data.
3. Index of Plant Concentration Permitted by Phytotoxicity
(Index 6)
a. Formula
Index 6 = PP
where:
PP = Maximum plant tissue concentration associ-
ated with phytptoxicity (yg/g DW)
b. Sample calculation - Values were not calculated due to
lack of data.
D. Effect on Herbivorous Animals
1. Index of Animal Toxicity Resulting from Plant Consumption
(Index 7)
a. Formula
Index 7 - g
where:
15 = Index 5 = Concentration of pollutant in
plant grown in sludge-amended soil (ug/g DW)
TA = Feed concentration toxic to herbivorous
animal (ug/g DW)
b. Sample calculation - Values were not calculated due to
lack of data.
A-3
-------
2. Index of Animal Toxicity Resulting from Sludge Ingestion
(Index 8)
a. Formula
If AR = 0; Index 8=0
If AR t 0; Index 8 = SC
where :
AR = Sludge application rate i it DW/ha)
SC = Sludge concentration of pollutant (pg/g DW)
GS = Fraction of animal diet assumed to be soil
TA = Feed concentration toxic to herbivorous
animal (Ug/g DW)
b. Sample calculation - Values were not calculated due to
lack of data.
E. Effect on Humans
1. Index of Human Cancer Risk Resulting from Plant Consumption
(Index 9)
a. Formula
(I5 x DT) + DI
Index 9 = -2
where :
15 = Index 5 = Concentration of pollutant in
plant grown in sludge-amended soil (ug/g DW)
DT = Daily human dietary intake of affected plant
tissue (g/day DW)
DI = Average daily human dietary intake of
pollutant (ug/day)
RSI = Cancer risk-specific intake (yg/day)
b. Sample calculation (toddler) - Values were not
calculated due to lack of data.
2. Index of Human Cancer Risk Resulting from Consumption of
Animal Products Derived from Animals Feeding on Plants
(Index 10)
a. Formula
(1 5 x UA x DA) + DI
Index 10
RSI
A-4
-------
where:
15 = Index 5 = Concentration of pollutant in
plant grown in sludge-amended soil (yg/g DW)
UA = Uptake factor of pollutant in animal tissue
(yg/g tissue DW [yg/g feed DW]'1)
DA = Daily human dietary intake of affected
animal tissue (g/day DW) (milk products and
meat, poultry, eggs, fish)
DI = Average daily human dietary intake of
pollutant (yg/day)
RSI = Cancer risk-specific intake (yg/day)
b. Sample calculation (toddler) - Values were not
calculated due to lack of data.
3. Index of Human Cancer Risk Resulting from Consumption of
Animal Products Derived from Animals Ingesting Soil (Index
11)
a. Formula
rr *n n T j 11 (BS X GS X UA X DA) + DI
If AR = 0; Index 11 = jjrrr
Tr AO J. n. T j 11 (SC x GS x UA x DA) + DI
If AR F 0; Index 11 = T^T
Kol
where:
AR = Sludge application rate (mt DW/ha)
BS - Background concentration of pollutant in
soil (yg/g DW)
SC = Sludge concentration of pollutant (yg/g DW)
GS = Fraction of animal diet assumed to be soil
UA = Uptake factor of pollutant in animal tissue
(Ug/g tissue DW [ug/g feed DW]~1)
DA = Daily human dietary intake of affected
animal tissue (g/day DW) (milk products and
meat only)
DI = Average daily human dietary intake of
pollutant (yg/day)
RSI = Cancer risk-specific intake (yg/day)
b. Sample calculation (toddler) - Values were not
calculated due to lack of data.
4. Index of Human Cancer Risk Resulting from Soil Ingestion
(Index 12)
a. Formula
x DS) + DI
Index 12 =
RSI
A-5
-------
where:
II = Index 1 = Concentration of pollutai. in
sludge-amended soil (yg/g DW)
DS = Assumed amount of soil in human diet (g/day)
DI = Average daily human dietary intake of
pollutant (yg/day)
RSI = Cancer risk-specific intake (yg/day)
b. Sample calculation (toddler) - Values were not
calculated due to lack of data.
5. Index of Aggregate Human Cancer Risk (Index 13)
a. Formula
3DI
Index 13
% RSI
where:
Ig = Index 9 = Index of human cancer risk
resulting from plant consumption (unitless)
Index 10 = Index of human cancer risk
resulting from consumption of animal
products derived from animals feeding on
plants (unitless)
Index 11 = Index of human cancer risk
resulting from consumption of animal
products derived from animals ingesting soil
(unitless)
112 = Index 12 = Index of human cancer risk
resulting from soil ingestion (unitless)
DI = Average daily human dietary intake of
pollutant (yg/day)
RSI = Cancer risk-specific intake (yg/day)
b. Sample calculation (toddler) - Values were not
calculated due to lack of data.
II. LANDFILLING
A. Procedure
Using Equation 1, several values of C/CO for the unsaturated
zone are calculated corresponding to increasing values of t
until equilibrium is reached. Assuming a S-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
A-6
-------
the input to the linkage assessment, Equation 2, which esti-
mates initial dilution in the aquifer to give the initial con-
centration, Co, for the saturated zone assessment. (Conditions
for B, minimum thickness of unsaturated zone, have been set
such that dilution is actually negligible.) The saturated zone
assessment procedure is nearly identical to that for the unsat-
urated zone except for the definition of certain parameters and
choice of parameter values. The maximum concentration at the
well, Cmax, is used to calculate the index values given in
Equations 4 and 5.
B. Equation 1: Transport Assessment
C(y.t) = i [exp(Ai> erfc(A2) + exp(Bi) erfc(B2)] = P(X»t)
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 ^2- Erfc(A2) produces values
between 0.0 and 2.0 (Abramowitz and Stegun, 1972).
where:
Al = X_ [V* - (V*2 + AD* x
1 2D*
(V*2 •»
2 ~ (AD* x t)
B. = X— [V* + (V*2 •«• 4D* x
°1 2D*
Y •«• t (V*2 * 4D* x
82 = (4D* x t)±
and where for the unsaturated zone:
Co = SC x CF = Initial leachate concentration (jag/L)
SC = Sludge concentration of pollutant (mg/kg DW)
CF = 250 kg sludge solids/m^ leachate =
PS x 103
1 - PS
PS = Percent solids (by weight) of landfilled sludge
20Z
t = Time (years)
X = h = Depth to groundwater (m)
D* » a x V* (m2/year)
a = Dispersivity coefficient (m)
V* = —2— (m/year)
0 x R
A-7
-------
Q = Leachate generation rate (m/year)
0 = Volumetric water content (unitless)
R = 1 + _^EZ x Kd = Retardation factor (unitless)
6
pdry = Drv bulk density (g/mL)
Kd = foc x Koc (mL/g)
foc = Fraction of organic carbon (unitless)
Koc - Organic carbon partition coefficient (mL/g)
u* = 36LSJ1 ( )-l
i
U = Degradation rate (day"1)
and where for the saturated zone:
Co = Initial concentration of pollutant in aquifer as
determined by Equation 2 (pg/L)
t = Time (years)
X = Afi, = Distance from well to landfill (m)
D* = a x V* (m2/year)
a = Dispersivity coefficient (m)
V* = K x * (m/year)
6 x R
K = Hydraulic conductivity of the aquifer (m/day)
i = Average hydraulic gradient between landfill and well
(unitless)
0 = Aquifer porosity (unitless)
R = 1 + -dr/ x K«j = Retardation factor = 1 (unitless)
q.*"** and B > 2
— K x i x 365 —
A-8
-------
D. Equation 3. Pulse Assessment
C(Xtt) = P(X,O for 0 < t < t0
C(Xtt) = P(x,t) - P(X,t - t0) for t > t0
Co
where :
t0 (for unsaturated zone) = LT = Landfill leaching time
(years)
to (for saturated zone) = Pulse duration at the water
table (x = h) as determined by the following equation:
t0 = [ o/°° C dt] * Cu
C( Y C )
P(X»t) = *T as determined by Equation 1
co
E. Equation 4. Index of Groundwater Concentration Resulting
from Landfilled Sludge (Index 1)
1 . Formula
Index 1 =
where:
Cmax = Maximum concentration of pollutant at well =
maximum of C(A£,t) calculated in Equation 1
(Ug/L)
2. Sample Calculation
0.043 Ug/L = 0.043 ug/L
P. Equation 5. Index of Human Cancer Risk Resulting from
Groundwater Contamination (Index 2)
1 . Formula
(Ii x AC) + DI
Index2= - RSI -
where :
II - Index 1 = Index of groundwater concentration
resulting from Landfilled sludge (yg/L)
AC = Average human consumption of drinking water
(L/day)
A-9
-------
DI = Average daily human dietary intake of pollutant
(yg/day)
RSI = Cancer risk-specific intake dig/day)
2. Sample Calculation - Values were not calculated due to
lack of data.
III. INCINERATION
A. Index of Air Concentration Increment Resulting from
Incinerator Emissions (Index 1)
1. Formula
_ , . (C x PS x SC x FM x DP) + BA
Index 1 = —
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 (yg/m3)
BA = Background concentration of pollutant in urban
air (yg/m3)
2. Sample Calculation
1.000 = [(2.78 x 10~7 hr/sec x g/mg x 2660 kg/hr DW x 1.6 mg/kg DW x
0.05 x 3.4 yg/m3) + 7.8 yg/m3] * 7.8 yg/m3
B. Index of Human Cancer Risk Resulting from Inhalation of
Incinerator Emissions (Index 2)
1. Formula
[(II - 1) x BA] + BA
Index 2 =
EC
where:
II = Index 1 = Index of air concentration increment
resulting from incinerator emissions
(unitless)
BA = Background concentration of pollutant in
urban air (yg/m3)
EC = Exposure criterion (yg/m3)
A-10
-------
2. Sample Calculation
_ fd.OQO - 1) x 7.8 ug/m--] + 7.8 ue/m3
~ —
5.6
IV. OCEAN DISPOSAL
Based on the recommendations of the experts at the OWRS meetings
(April-May, 1984), an assessment of this reuse/disposal option is
not being conducted at this time. The U.S. EPA reserves the right
to conduct such an assessment for this option in the future.
A-ll
-------
TABLE A-l. INPUT DATA VARYING IN LANDFILL ANALYSIS AND RESULT FOR EACH CONDITION
Condition of Analysis
Input Data
Sludge concentration of pollutant, SC (pg/g DU)
Unsaturated cone
Soil type and characteristics
Dry bulk density, Pjry (K/°>L)
Volumetric water content, 8 (unitless)
Fraction of organic carbon, foc (unitless)
Site parameters
Leachate generation rate, Q (m/year)
Depth to groundwater, h (m)
Dispersivity coefficient, a (m)
Saturated cone
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, Afc (m)
Dispersivity coefficient, a (m)
1
1.6
1.53
0.195
0.005
0.8
S
O.S
0.44
0.86
0.001
100
10
2
19
1.33
0.19S
O.OOS
0.8
S
0.5
•
0.44
0.86
0.001
100
10
3
1.6
1.925
0.133
0.0001
0.8
5
0.5
0.44
0.86
0.001
100
10
4 S
1.6 1.6
NAb 1.53
NA 0.195
NA 0.005
1.6 0.8
0 5
NA 0.5
0.44 0.389
0.86 4.04
0.001 0.001
100 100
10 10
6
1.6
1.53
0.195
0.005
0.8
5
0.5
0.44
0.86
0.02
50
5
7 8
19 H«
NA N
NA N
NA N
1.6 N
0 N
NA N
0.389 N
4.04 N
0.02 N
SO N
5 N
-------
TABLE A-l. (continued)
T
M
10
Condition of Analysis
Results
Unsaturated zone assessment (Equations 1 and 3)
Initial leachate concentration, C0 (pg/L)
Peak concentration, Cu (pg/L)
Pulse duration, to (years)
Linkage assessment (Equation 2)
Aquifer thickness, B (m)
Initial concentration in saturated zone, Co
(M8/D
1
400.0
399
5.01
126
399
2
4750
4740
S.01
126
4740
3
400.0
400.0
5.00
126
400.0
4
400.0
400.0
5.00
253
400.0
5
400.0
399
5.01
23.8
399
6
400.0
399
5.01
6.32
399
7
4750
4750
5.00
2.38
4750
8
N
N
M
N
N
Saturated zone assessment (Equations 1 and 3)
Maximum well concentration, Cmax (pg/L)
Index of groundwater concentration resulting
from landfilled sludge, Index 1 (yg/L)
(Equation 4)
Index of human cancer risk resulting from
groundwater contamination, Index 2
(unitless) (Equation 5)
0.0435
0.0435
0.516
0.516
0.0435
0.0435
NCC
MC
NC
0.0435 0.231
0.0435 0.231
NC NC
1.74 110.0 N
1.74 110.0
NC
NC
NC
aN = Null condition, where no landfill exists; no value is used.
bNA = Not applicable for this condition.
CNC = Not calculated due to lack of data.
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