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:
Chlorinated Dibenzofurans
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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 i
1. INTRODUCTION 1-1
2. PRELIMINARY CONCLUSIONS FOR TETRACHLORODIBENZOFURANS IN
MUNICIPAL SEWAGE SLUDGE 2-1
Landspreading and Distribution-and-Marketing 2-1
Landfilling 2-1
Incineration 2-1
Ocean Disposal 2-1
3. PRELIMINARY HAZARD INDICES FOR TETRACHLORODIBENZOFURANS IN
MUNICIPAL SEWAGE SLUDGE 3-1
Landspreading and Distribution-and-Marketing 3-1
Landfilling 3-1
Incineration 3-1
Index of air concentration increment resulting
from incinerator emissions (Index 1) 3-1
Index of human cancer risk resulting from
inhalation of incinerator emissions (Index 2) 3-3
Ocean Disposal 3-5
Index of seawater concentration resulting from
initial mixing of sludge (Index 1) 3-5
Index of seawater concentration representing a
24-hour dumping cycle (Index 2) 3-8
Index of toxicity to aquatic life (Index 3) 3-9
Index of human cancer risk resulting from seafood
consumption (Index 4) 3-10
4. PRELIMINARY DATA PROFILE FOR TETRACHLORODIBENZOFURANS IN
MUNICIPAL SEWAGE SLUDGE 4-1
Occurrence 4-1
Sludge 4-1
Soil - Unpolluted 4-1
Water - Unpolluted 4-1
Air 4-1
Food 4-2
11
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TABLE OP CONTENTS
(Continued)
Page
Human Effects 4-2
Ingestion 4-2
Inhalation 4-3
Plant Effects 4-3
Domestic Animal and Wildlife Effects 4-3
Toxicity 4-3
Uptake 4-3
Aquatic Life Effects 4-4
Toxicity 4-4
Uptake 4-4
Soil Biota Effects 4-4
Toxicity 4-4
Uptake 4-4
Physicochemical Data for Estimating Fate and Transport 4-4
5. REFERENCES 5-1
APPENDIX. PRELIMINARY HAZARD INDEX CALCULATIONS FOR
TETRACHLORODIBENZOFURANS IN MUNICIPAL SEWAGE SLUDGE A-l
111
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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. Tetrachlorodibenzofurans (TCDFs) were initially identi-
fied as being of potential concern when sludge is incinerated or ocean
disposed.* This profile is a compilation of information that may be use-
ful in determining whether TCDFs pose an actual hazard to human health
or the environment when sludge is disposed of by these methods.
The focus of this document is the calculation of "preliminary
hazard indices" for selected potential exposure pathways, as shown in
Section 3. Each index illustrates the hazard that could result from
movement of a pollutant by a given pathway to cause a given effect
(e.g., sludge •* air -»• human toxicity; sludge •* seawater •* marine organ-
isms •* human toxicity). The values and assumptions employed in these
calculations tend to represent a reasonable "worst case"; analysis of
error or uncertainty has been conducted to a limited degree. The
resulting value in most cases is indexed to unity; i.e., values >1 may
indicate a potential hazard, depending upon the assumptions of the
calculation.
The data used for index calculation have been selected or estimated
based on information presented in the "preliminary data profile",
Section 4. Information in the profile is based on a compilation of the
recent literature. An attempt has been made to fill out the profile
outline to the greatest extent possible. However, since this is a pre-
liminary analysis, the literature has not been exhaustively perused.
The "preliminary conclusions" drawn from each index in Section 3
are summarized in Section 2. The preliminary hazard indices will be
used as a screening tool to determine which pollutants and pathways may
pose a hazard. Where a potential hazard is indicated by interpretation
of these indices, further analysis wilL include a more detailed exami-
nation of potential risks as well as an examination of site-specific
factors. These more rigorous evaluations may change the preliminary
conclusions presented in Section 2, which are based on a reasonable
"worst case" analysis.
The preliminary hazard indices for selected exposure routes
pertinent to 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 TETRACHLORODIBENZOFURANS
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
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.
II. LANDPILLING
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.
III. INCINERATION
Conclusions were not drawn because index values could not be
calculated due to lack of data.
IV. OCEAN DISPOSAL
Conclusions were not drawn because index values could not be
calculated due to lack of data.
2-1
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SECTION 3
PRELIMINARY HAZARD INDICES FOR TETRACHLORODIBENZOFURANS
IN MUNICIPAL SEWAGE SLUDGE
I. LANDSPREADING AND DISTRIBUTION-AMD-MARKETING
Based on Che 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.
II. LANDFILLING
Based on the recommendations of the experts at the OURS 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.
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 (Camp Dresser and McKee, Inc. (CDM),
1984a). This model uses the thermodynamic and mass bal-
ance relationships appropriate for multiple hearth incin-
erators 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 concen-
trations 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 g/mg
3-1
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b. Sludge feed rate (DS)
i. Typical = 2660 kg/hr (dry solids input)
A feed rate of 2660 kg/hr DW represents an
average dewatered sludge feed rate into the
furnace. This feed rate would serve a commun-
ity of approximately 400,000 people. This rate
was incorporated into the U.S. EPA-ISCLT model
based on the following input data:
EP - 360 Ib H20/mm BTU
Combustion zone temperature - 1400°F
Solids content - 28%
Stack height - 20 m
Exit gas velocity - 20 m/s
Exit gas temperature - 356.9°K (183°F)
Stack diameter - 0.60 m
ii. Worst = 10,000 kg/hr (dry solids input)
A feed rate of 10,000 kg/hr DW represents a
higher feed rate and would serve a major U.S.
city. This rate was incorporated into the U.S.
EPA-ISCLT model based on the following input
data:
EP = 392 Ib H20/mm BTU
Combustion zone temperature - 1400°F
Solids content - 26.6%
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) - Data not
immediately available.
Concentrations of TCDFs in municipal sewage sludge
were not analyzed in the U.S. EPA (1982a) study of
50 publicly-owned treatment works (POTWs) and were
not available for sludge -data for POTWs located
throughout the United States (COM, 1984b).
d. Fraction of pollutant emitted through stack (PM)
Typical 0.05 (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.
3-2
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e. Dispersion parameter for estimating maximum annual
ground level concentration (DP)
Typical 3.4
Worst 16.0
The dispersion parameter is derived from the U.S.
EPA-ISCLT short-stack model.
f. Background concentration of pollutant in urban air
(BA) = 0.0000001 Ug/m3
Assuming that polychlorinated biphenyl (PCB) is con-
taminated with «/*1.25 ppm TCDFs, and that ambient air
concentration of PCB is 100 ng/m3, an ambient air
concentration for TCDFs of 0.0000001 Ug/m3 can be
estimated (U.S. EPA, 1983). (See Section 4,
p. 4-1.)
4. Index 1 Values - Values were not calculated due to lack
of data.
5. Value Interpretation - Value equals factor by which
expected air concentration exceeds background levels due
to incinerator emissions.
6. Preliminary Conclusion - Conclusion was not drawn because
index values could not be calculated.
B. Index of Human Cancer Risk Resulting from Inhalation of
Incinerator Emissions (Index 2)
1. Explanation - Shows the increase in human intake expected
to result from the incineration of sludge. Ground level
concentrations for carcinogens typically were developed
based upon assessments published by the U.S. EPA Carcino-
gen Assessment Group (CAG). These ambient concentrations
reflect a dose level which, for a lifetime exposure,
increases the risk of cancer by 10~6.
2. Assumptions/Limitations - The exposed population is
assumed to reside within the ' impacted area for 24
hours/day. A respiratory volume of 20 m3/day is assumed
over a 70-year lifetime.
3. Data Used and Rationale
a. Index of air concentration increment resulting from
incinerator emissions (Index 1) - Values were not
calculated due to lack of data.
See Section 3, p. 3-3.
3-3
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b. Background concentration of pollutant in urban air
(BA) = 0.0000001 Ug/m3
See Section 3, p. 3-3.
c. Cancer potency - Data not immediately available.
d. Exposure criterion (EC) - Data not immediately
available.
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:
Ec _ 10"6 x 103 Ug/mg x 70 kg
Cancer potency x 20 m-Vday
4. Index 2 Values - Values were not calculated due to lack
of data.
5. Value Interpretation - Value > 1 indicates a potential
increase in cancer risk of > 10"^ (1 per 1,000,000).
Comparison with the null index value at 0 kg/hr DW indi-
cates the degree to which any hazard is due to sludge
incineration, as opposed to background urban air
concentration.
6. Preliminary Conclusion - Conclusion was not drawn because
index values could not be calculated.
3-4
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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 increased concentrations in ug/L
of pollutant in seawater around an ocean disposal site
assuming initial mixing.
2. Assumptions/Limitations - Assumes that the background
seawater concentration of pollutant is unknown or zero.
The index also assumes that disposal is by tanker and
that the daily amount of sludge disposed is uniformly
distributed along a path transversing the site and
perpendicular to the current vector. The initial
dilution volume is assumed to be determined by path
length, depth to the pycnocline (a layer separating
surface and deeper water masses), and an initial plume
width defined as the width of the plume four hours after
dumping. The seasonal disappearance of the pycnocline is
not considered.
3. Data Used and Rationale
a. Disposal conditions
Sludge Sludge Mass Length
Disposal Dumped by a of Tanker
Rate (SS) Single Tanker (ST) Path (L)
Typical 825 mt DW/day 1600 mt WW 8000 m
Worst 1650 mt DW/day 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 conversion to
3-5
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dry weight assumes 4 percent solids by weight. The
worst-case value is an arbitrary doubling of the
typical value to allow for potential future increase.
The assumed disposal practice to be followed at the
model site representative of the typical case is a
modification of that proposed for sludge disposal at
the formally designated 12-mile site in the New York
Bight Apex (City of New York, 1983). Sludge barges
with capacities of 3400 mt WW would be required to
discharge a load in no less than 53 minutes travel-
ing at a minimum speed of 5 nautical miles (9260 m)
per hour. Under these conditions, the barge would
enter the site, discharge the sludge over 8180 m and
exit the site. Sludge barges with capacities of
1600 mt WW would be required to discharge a load in
no less than 32 minutes traveling at a minimum speed
of 8 nautical miles (14,816 m) per hour. Under
these conditions, the barge would enter the site,
discharge the sludge over 7902 m and exit the site.
The mean path length for the large and small tankers
is 8041 m or approximately 8000 m. Path length is
assumed to lie perpendicular to the direction of
prevailing current flow. For the typical disposal
rate (SS) of 825 mt DW/day, it is assumed that this
would be accomplished by a mixture of four 3400 mt
WW and four 1600 mt WW capacity barges. The overall
daily disposal operation would last from 8 to 12
hours. For the worst-case disposal rate (SS) of
1650 mt DW/day, eight 3400 mt WW and eight 1600 mt
WW capacity barges would be utilized. The overall
daily disposal operation would last from 8 to 12
hours. For both disposal rate scenarios, there
would be a 12 to 16 hour period at night in which no
sludge would be dumped. It is assumed that under
the above described disposal operation, sludge
dumping would occur every day of the year.
The assumed disposal practice at the model site
representative of the worst case is as stated for
the typical site, except that barges would dump half
their load along a track,' then turn around and
dispose of the balance along the same track in order
to prevent a barge from dumping outside of the site.
This practice would effectively halve the path
length compared to the typical site.
b. Sludge concentration of pollutant (SC) - Data not
immediately available.
See Section 3, p. 3-2.
3-6
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c. Disposal sice characteristics
Average
current
Depth to velocity
pycnocline (D) at site (V)
Typical 20 m 9500 in/day
Worst 5 m 4320 m/day
Typical site values are representative of a large,
deep-water site with an area of about 1500 km*
located beyond the continental shelf in the New York
Bight. The pycnocline value of 20 m chosen is the
average of the 10 to 30 m pycnocline depth range
occurring in the summer and fall; the winter and
spring disappearance of the pycnocline is not consi-
dered and so represents a conservative approach in
evaluating annual or long-term impact. The current
velocity of 11 cm/sec (9500 m/day) chosen is based
on the average current velocity in this area (CDM,
198Ac).
Worst-case values are representative of a near-shore
New York Bight site with an area of about 20 km2.
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, 1984d).
4. Factors Considered in Initial Nixing
When a load of sludge is dumped from a moving tanker, an
immediate mixing occurs in the turbulent wake of the
vessel, followed by more gradual spreading of the plume.
The entire plume, which initially constitutes a narrow
band the length of the tanker path, moves more-or-less as
a unit with the prevailing surface current and, under
calm conditions, is not further dispersed by the current
itself. However, the current acts to separate successive
tanker loads, moving each out of the immediate disposal
path before the next load is dumped.
Immediate mixing volume after barge disposal is
approximately equal to the length of the dumping track
with a cross-sectional area about four times that defined
by the draft and width of the discharging vessel
(Csanady, 1981, as cited in NOAA, 1983). The resulting
plume is initially 10 m deep by 40 m wide (O'Connor and
Park, 1982, as cited in NOAA, 1983). Subsequent
spreading of plume band width occurs at an average rate
3-7
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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 ()ig/L) - Values cannot be calculated due
to lack of data on detection limits for TCDFs in sludge.
If this information were available, all null values would
be 0, and all other values would be expressed in the form
of "less than".
6. Value Interpretation - Value equals the expected increase
in TCDF concentration in seawater around a disposal site
as a result of sludge disposal after initial mixing.
7. Preliminary Conclusion - Conclusion was not drawn because
index values could not be calculated.
B. Index of Seawater Concentration Representing a 24-Hour Dumping
Cycle (Index 2)
1. Explanation - Calculates increased effective concentra-
tions in Ug/L of pollutant in seawater around an ocean
disposal site utilizing a time weighted average (TWA)
concentration. The TWA concentration is that which would
be experienced by an organism remaining stationary (with
respect to the ocean floor) or moving randomly within the
disposal vicinity. The dilution volume is determined by
the tanker path length and depth to pycnocline or, for
the shallow water site, the 10 m effective mixing depth,
as before, but the effective width is now determined by
current movement perpendicular to the tanker path over 24
hours.
2. Assumptions/Limitations - Incorporates all of the assump-
tions used to calculate Index 1. In addition, it is
assumed that organisms would experience high-pulsed
sludge concentrations for 8 to 12 hours per day and then
experience recovery (no exposure to sludge) for 12 to 16
hours per day. This situation can be expressed by the
use of a TWA concentration of sludge constituent.
3-8
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3. Data Used and Rationale
See Section 3, pp. 3-5 to 3-7.
4. Factors Considered in Determining Subsequent Additional
Degree of Mixing (Determination of TWA Concentrations)
See Section 3, p. 3-8.
5. Index 2 Values (yg/L) - Values cannot be calculated due
to lack of data on detection limits for TCDFs in sludge.
If this information were available, all null values would
be 0, and all other values would be expressed in the form
of "less than".
6. Value Interpretation - Value equals the effective
increase in TCDF concentration expressed as a TWA concen-
tration in seawater around a disposal site experienced by
an organism over a 24-hour period.
7. Preliminary Conclusion - Conclusion was not drawn because
index values could not be calculated.
C. Index of Toxicity to Aquatic Life (Index 3)
1. Explanation - Compares the effective increased concentra-
tion of pollutant in seawater around the disposal site
resulting from the initial mixing of sludge (Index 1)
with the marine ambient water quality criterion of the
pollutant, or with another value judged protective of
marine aquatic life. For TCDFs, this value is the
criterion that will protect marine aquatic organisms from
both acute and chronic toxic effects.
Wherever a short-term, "pulse" exposure may occur as it
would from initial mixing, it is usually evaluated using
the "maximum" criteria values of EPA's ambient water
quality criteria methodology. However, under this
scenario, because the pulse is repeated several times
daily on a long-term basis, potentially resulting in an
accumulation of injury, it seems more appropriate to use
values designed to be protective against chronic
toxicity. Therefore, to evaluate the potential for
adverse effects on marine life resulting from initial
mixing concentrations, as quantified by Index 1, the
chronically derived criteria values are used.
2. Assumptions/Limitations - In addition to the assumptions
stated for Indices 1 and 2, assumes that all of the
released pollutant is available in the water column to
move through predicted pathways (i.e., sludge to seawater
to aquatic organism to man). The possibility of effects
arising from accumulation in the sediments is neglected
since the U.S. EPA presently lacks a satisfactory method
for deriving sediment criteria.
3-9
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3. Data Used and Rationale
a. Concentration of pollutant in seawater around a
disposal site (Index 1) - Values could noc be
calculated due .to lack of data.
See Section 3, p. 3-8.
b. Ambient water quality criterion (AWQC) = 1,800 Ug/L
The criterion is based on acute toxicity results for
one species of saltwater fish. Data necessary to
derive chronic toxicity criterion are not presently
available (U.S. EPA, 1982b).
4. Index 3 Values - Values could not be calculated due to
lack of Index 1 values.
5. Value Interpretation - Value would equal the factor by
which the expected seawater concentration increase in
TCDFs exceeds the marine water quality criterion. A
value >1 would indicate that a toxic hazard might exist
for aquatic life.
6. Preliminary Conclusion - Conclusion was not drawn because
index values could not be calculated.
D. Index of Human Cancer Risk Resulting from Seafood Consumption
(Index 4)
1. Explanation - Estimates the expected increase in human
pollutant intake associated with the consumption of
seafood, a fraction of which originates from the disposal
site vicinity, and compares the total expected pollutant
intake with the cancer risk-specific intake (RSI) of the
pollutant.
2. Assumptions/Limitations - In addition to the assumptions
listed for Indices 1 and 2, assumes that the seafood
tissue concentration increase can be estimated from the
increased water concentration (Index 2) by a bioconcen-
tration factor. It also assumes that, over the long
term, the seafood catch from the disposal site vicinity
will be diluted to some extent by the catch from
uncontaminated areas.
3. Data Used and Rationale
a. Concentration of pollutant in seawater around a
disposal site (Index 2) - Values could not be
calculated due to lack of data.
See Section 3, p. 3-9.
3-10
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Since biconcentration is a dynamic and reversible
process, it is expected that uptake of sludge
pollutants by marine organisms at the disposal site
will reflect TWA concentrations, as quantified by
Index 2, rather than pulse concentrations.
b. Dietary consumption of seafood (QP)
Typical 14.3 g WW/day
Worst 41.7 g WW/day
Typical and worst-case values are the mean and the
95th percentile, respectively, for all seafood
consumption in the United States (Stanford Research
Institute (SRI) International, 1980).
c. Fraction of consumed seafood originating from the
disposal site (PS)
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
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
3-11
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impacted by sludge disposal (AI, in km2) at each
disposal site will be considered to be defined by
the tanker path length (L) times the distance of
current- movement (V) during 10 days, and is computed
as follows:
AI = 10 x L x V x 10~6 -km2/m2 (1)
To be consistent with a conservative approach, plume
dilution due to spreading in the perpendicular
direction to current flow is disregarded. More
likely, organisms exposed to the plume in the area
defined by equation 1 would experience a TWA concen-
tration lower than the concentration expressed by
Index 2.
Next, the value of AI must be expressed as a
fraction of an NMFS reporting area. In the New York
Bight, which includes NMFS areas 612-616 and 621-
623, deep-water area 623 has an area of
approximately 7200 km2 and constitutes approximately
0.02 percent of the total seafood landings for the
Bight (CDM, 1984c). Near-shore area 612 has an area
of approximately 4300 km2 and constitutes
approximately 24 percent of the total seafood
landings (CDM, 1984d). 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:
For the typical (deep water) site:
__ AI x 0.02% = (2)
tbt ~ 7200 km-'
[10 x 8000 m x 9500 m x IP"6 km2/m2] x 0.0002 a 2 1 x 10~5
7200 km2
For the worst (near shore) site:
x 242
FSt =
4300 km2
[10 x 4000 m x 4320 m x 10~6 km2 7m2] x 0.24 _ , ,._•>
2- = 9.o x 10 J
,^w« ™
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
3-12
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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 = AI . = 0.11 (4)
7200 km2
For the worst (near shore) site:
FSW = ^—r- = 0.040 (5)
w 4300 km2
d. Bioconcentration factor of pollutant (BCP) - Data
not immediately available.
e. Average daily human dietary intake of pollutant
(Dl) - Data not immediately available.
f. Cancer potency - Data not immediately available.
g. 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:
RSI = 10"6 x 70 kg 1Q3 ug/mg
Cancer potency
4. Index 4 Values - Values could not be calculated due to
lack of data.
5. Value Interpretation - Value >1 -would indicate a poten-
tially toxic hazard for humans. Comparison with the null
index value at 0 mt/day would indicate the degree to
which any hazard is due to sludge disposal, as opposed to
preexisting dietary sources.
6. Preliminary Conclusion - Conclusion was not drawn because
index values could not be calculated.
3-13
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SECTION 4
PRELIMINARY DATA PROFILE FOR TETRACHLORODIBENZOFURANS
IN MUNICIPAL SEWAGE SLUDGE
I. OCCURRENCE
The halogenated dibenzofurans (DBFs) entered
the environment as unintentional impurities
in polychlorinated biphenyls (PCBs) and prod-
ucts derived from chLorophenols and chloro-
benzenes, as well as being pyrolysis and
photochemical products of PCBs and probably
polychlorinated diphenylethers (PCDPEs). The
alky! DBFs and unsubstituted DBFs are pyroly-
sis products of coal conversion. Both alkyl
and halogenated DBFs have been implicated as
resulting from trace residues of fire, most
notably incineration of anthropogenic wastes.
A. Sludge
Data not immediately available.
B. Soil - Unpolluted
Data not immediately available.
C. Hater - Unpolluted
2.4 x 10~6 pg/L interim ambient water
criterion for protection of human health
from the toxic properties of halogenated
DBFs ingested through water or contaminated
aquatic organisms.
D. Air
U.S. EPA, 1982b
(p. vi)
U.S. EPA, 1982b
(p. 1-2)
No data available on ambient concentrations
of DBFs.
A sample of polychlorinated biphenyl (PCB)
was shown to contain si.25 ppm TCDF.
If the ratio of TCDF to PCB is assumed
to be the same in air as in the measured
PCB, and the ambient air concentration of
PCP is «/*100 ng/m3, then an ambient air
concentration of 0.0000001 yg/m3 TCDF can
be estimated.
Fly ash contains traces (100 ng/g or less)
of DBFs.
U.S. EPA, 1983
(p. 3-3)
U.S. EPA, 1982b
(p. 13-2)
4-1
-------
0.3 and 0.1 Ug/g PCDFs in 2 fly ash Buser et al.,
samples from a municipal incinerator 1978 (p. 426)
Flue gas has been shown to contain PCDFs. Buser et al.,
1978 (p. 428)
B. Food
TCDFs have been detected in fish U.S. EPA, 1983
collected from the Ohio and Hudson Rivers. (p. 3-1)
An estimate of dietary consumption of
2,3,7,8-TCDF resulting from fish consump-
tion equals 0.2 yg/day.
II. HUMAN EFFECTS
A. Ingestion
1. Carcinogenic!ty
a. Qualitative Assessment
There is no experimental evidence U.S. EPA, 1983
to suggest that any of the halo- (p. 5-1)
genated dibenzofurans are carcino-
genic. However, the similarities
in structure, and biological
effects between TCDDs, which are
regarded as being carcinogenic,
and TCDFs raise the suspicion that
TCDFs may be carcinogenic.
b. Potency
Data not immediately available.
c. Effects
Data not immediately available.
2. Chronic Tozicity
a. ADI
Data not immediately available.
b. Effects
Approximately 1,200 Japanese people U.S. EPA, 1983
ingested rice oil which was acci- (p. 5-5)
dentally contaminated with PCBs
(1000 ppm) and consequently PCDFs
(5 ppm). Individuals exhibited a
variety of symptoms including fever,
4-2
-------
headaches, spasms of hands and feet,
skin eruptions and discoloration
of skin and mucosa.
3. Absorption
Rats receiving a single intraperitoneal
injection of a PCDF mixture, exhibited
complete hepatic retention of the
dosed 2,3,7,8-TCDF component 5 days
after the initial administration.
4. Existing Regulations
Data not immediately available.
B. Inhalation
Data not immediately available.
III. PLANT EFFECTS
"No data could be found concerning effects of
chlorinated dibenzofurans on plants."
IV. DOMESTIC ANIMAL AND WILDLIFE EFFECTS
A. Toxicity
PCDFs have not been studied in model
ecosystems and there are very few data
available on wildlife.
"While specific causative agents cannot be
assigned to effects observed in poisoning
incidents, the available data do indicate
that adverse effects may be expected to
result from exposure of domestic animals to
DBFs."
<3Z of the PCDFs given in the diet over
one year accumulated in tissues of mallards.
See Table 4-1.
B. Uptake
Data not immediately available.
U.S. EPA, 1983
(p. 4-2)
U.S. EPA, 1982b
(p. 8-1)
U.S. EPA, 1982b
(p. 5-3)
U.S. EPA, 1982b
(p. 9-1)
Norstrom et al.,
1976 (p. 7-1)
4-3
-------
V. AQUATIC LIFE EFFECTS
A. Toxicity
1. Freshwater
a. Acute
Toxicicy value for one inverte-
brate species = 1700 Ug/L.
b. Chronic
Data not immediately available.
2. Saltwater
a. Acute
Toxicity value for one species
of marine fish = 1800 Ug/L.
b. Chronic
Data not immediately available.
B. Uptake
Data not immediately available.
VI. SOIL BIOTA EFFECTS
A. Toxicity
"No data could be found concerning the
stability of chlorinated dibenzofurans to
microbes, or if chlorinated dibenzofurans
exerted toxic effects."
Chlorinated dibenzofurans substituted at the
8-position appear to be bactericidal.
U.S. EPA, 1982b
(p. 11-8)
U.S. EPA, 1982b
(p. 11-8)
U.S. EPA, 1982b
(p. 7-1)
U.S. EPA, 1982b
(p. 7-1)
B. Uptake
Data not immediately available.
VII. PHYSICOCHEMICAL DATA FOR ESTIMATING FATE AND TRANSPORT
DBF water solubility: 3 mg/L at 2S°C
DBFs quite soluble in organic solvents
TCDFs melting point: 169 to 228°C
DBF octanol-water partitioning coefficient: 1,527
DBF boiling point: 287°C at 760 mm Hg
U.S. EPA, 1982b
(Chapter 2)
4-4
-------
TCDFs vapor pressure: (1.8 to 2.5) x 10~6 torr
at 25°C (estimated)
DBF specific gravity: 1.0886
Higher DBFs are degraded by light
At present, virtually nothing is known about U.S. EPA, 1982b
the dynamics of PCDFs in the environment. (p. 5-1)
4-5
-------
TABLE 4-1. TOXICITY OP DIBENZOFURAN TO DOMESTIC ANIMALS AND WILDLIFE
Species (N)*
Guinea Pig
Mouse/Rat
Rhesus Monkey
Monkey
Chicks
Chicks
Mouse (10)
Mouse (10)
Mouse (10)
Mouse (10)
====^==:^=^====
Feed
Chemical Concentration
Form Fed 6
1
0.001
0.005
30.0
44-67
100-150
225
Duration
of Study
6 mos.
21 days
21 days
30 days
30 days
30 days
30 days
Effects
LD50
LD50
LD50
2 of 3 monkeys died
16 percent mortality
100 percent mortality
OZ mortality
10Z mortality
30Z mortality
45Z mortality
~
References
U.S. EPA, 1982b
U.S. EPA, 1982b
U.S. EPA, 1982b
U.S. EPA, 1982b
McKinney et al.
(p. 12-23)
McKinney et al.
(p. 12-23)
Nishisumi, 1978
(p. 68)
(p. 12-1)
(p. 12-1)
(p. 12-1)
(p. 12-1)
, 1976
, 1976
a N • number of experimental animals when reported.
D TCDF = Tetrachlorodibenzofuran.
c PCDPs = Polychlorinated dibenzofurans.
-------
SECTION 5
REFERENCES
Buser, H. R., H. Bosshardt, C. Rapp, and R. Lindahl. 1978. Identifica-
tion of Polychlorinated Dibenzofuran Isomers in Fly Ash and PCB
Pyrolyses. Chemosphere 5:419-29.
Camp Dresser and McKee, Inc. 1984a. Development of Methodologies for
Evaluating Permissible Contaminant Levels in Municipal Wastewater
Sludges. Draft. Office of Water Regulations and Standards, U.S.
Environmental Protection Agency, Washington, D.C.
Camp Dresser and McKee, Inc. 1984b. A Comparison of Studies of Toxic
Substances in POTW Sludges. Prepared for U.S. EPA under Contract
No. 68-01-6403. Annandale, VA. August.
Camp Dresser and McKee, Inc. 1984c. Technical Review of the 106-Mile
Ocean Disposal Site. Prepared for U.S. EPA under Contract No.
68-01-6403. Annandale, VA. January.
Camp Dresser and McKee, Inc. 1984d. Technical Review of the 12-Mile
Sewage Sludge Disposal Site. Prepared for U.S. EPA under Contract
No. 68-01-6403. Annandale, VA. May.
City of New York Department of Environmental Protection. 1983. A
Special Permit Application for the Disposal of Sewage Sludge from
Twelve New York City Water Pollution Control Plants at the 12-Mile
Site. New York, NY. December.
Farrell, J. B. 1984. Personal Communication. Water Engineering
Research Laboratory, U.S. Environmental Protection Agency,
Cincinnati, OH. December.
McKinney, J. D., K. Chae, N. Gupta et al. 1976. Toxicological Assess-
ment of Hexachlorobiphenyl Isomers and 2,3,7,8-Tetrachlorodibenzo-
furan in Chicks. Toxicol. & Appl. Pharmacol. 36:65-80.
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.
Nishisumi, M. 1978. Acute Toxicity of Polychlorinated Dibenzofurans in
CF-1 Mice. Toxicol. & Appl. Pharmacol. 45:209-212.
Norstrom, R. J., R. W. Risebrough, and D. J. Cartwright. 1976.
Elimination of Chlorinated Dibenzofurans Associated with
Polychlorinated Biphenyls Fed to Mallards (Anas platyrynchos).
Toxicol. & Appl. Pharmacol. 37:217-228.
Stanford Research Institute International. 1980. Seafood Consumption
Data Analysis. Final Report, Task II. Prepared for U.S. EPA under
Contract No. 68-01-3887. Menlo Park, CA. September.
5-1
-------
U.S. Environmental Protection Agency. 1979. Industrial Source Complex
(ISC) Dispersion Model User Guide. EPA 650/4-79-30. Vol. 1.
Office of Air Quality Planning and Standards, Research Triangle
Park, NC. December.
U.S. Environmental Protection Agency. 1982a. Fate of Priority
Pollutants in Publicly-Owned Treatment Works. EPA 440/1-82/303.
U.S. Environmental Protection Agency, Washington, DC.
U.S. Environmental Protection Agency. 1982b. Multimedia Water Quality
Criteria Document for: Dibenzofuran. Preliminary Draft Document.
ECAO-CIN-D007. U.S. Environmental Protection Agency, Cincinnati,
OH.
U.S. Environmental Protection Agency. 1983. Health and Environmental
Effects Profile for: Tetra-, Penta-, and Hexachlorodibenzofurans.
Program Office Draft. ECAO-CIN-P003. U.S. Environmental
Protection Agency, Cincinnati, OH.
5-2
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APPENDIX
PRELIMINARY HAZARD INDEX CALCULATIONS FOR TETRACHLORODIBENZOFURANS
IN MUNICIPAL SEWAGE SLUDGE
I. LANDSPREADING AND DISTRIBUTION- AMD-MARKETING
Based on Che recommendations of Che 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
Co conduct such an assessment for this option in the future.
II. LANDPILLING
Based on the recommendations of the experts at the OURS 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.
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 l = - — -
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 (ing /kg DW)
FM = Fraction of pollutant emitted through stack (unitless)
DP = Dispersion parameter for estimating maximum
annual ground level concentration (ug/m^)
BA = Background concentration of pollutant in urban
air (yg/m3)
2. Sample Calculation - Values were not calculated due to
lack of data.
B. Index of Human Cancer Risk Resulting from Inhalation of
Incinerator Emissions (Index 2)
1. Formula
[(Ii - 1) x BA] + BA
Index 2
A-l
-------
where:
II = Index 1 = Index of air concentration increment
resulting from incinerator emissions
(unitless)
BA = Background concentration of pollutant in
urban air (yg/m^)
EC = Exposure criterion (yg/m^)
2. Sample Calculation - Values were not calculated due to lack
of data.
IV. OCEAN DISPOSAL
A. Index of Seawater Concentration Resulting from Initial Mixing
of Sludge (Index 1)
1. Formula
T j i SC x ST x PS
Index 1 = — » ;
W x D x L
where:
SC = Sludge concentration of pollutant (mg/kg DW)
ST = Sludge mass dumped by a single tanker (kg WW)
PS = Percent solids in sludge (kg DU/kg WW)
W = Width of initial plume dilution (m)
D = Depth to pycnocline or effective depth of mixing
for shallow water site (m)
L = Length of tanker path (m)
2. Sample Calculation - Values were not calculated due to lack
of data.
B. Index of Seawater Concentration Representing a 24-Hour Dumping
Cycle (Index 2)
1. Formula
SS x SC
Index 2 =
V x D x L
where:
SS = Daily sludge disposal rate (kg DW/day)
SC = Sludge concentration of pollutant (mg/kg DW)
V = Average current velocity at site (m/day)
D = Depth to pycnocline or effective depth of
mixing for shallow water site (m)
L = Length of tanker path (m)
A-2
-------
2. Sample Calculation - Values were not calculated due to
lack.
C. Index of Tozicity to Aquatic Life (Index 3)
1. Formula
Index 3 = AWQC-
where:
1} = Index 1 = Index of seawater concentration
resulting from initial mixing after sludge
disposal (yg/L)
AWQC = Criterion or other value expressed as an average
concentration to protect marine organisms from
acute and chronic toxic effects (ug/L)
2. Sample Calculation - Values were not calculated due to
lack of data.
D. Index of Human Cancer Risk Resulting from Seafood Consumption
(Index 4)
1. Formula
(12 x BCF x 10~3 kg/g x FS x QF) + DI
Index 4 = —
where:
12 = Index 2 = Index of seawater concentration
representing a 24-hour dumping cycle (yg/L)
QF = Dietary consumption of seafood (g WW/day)
FS = Fraction of consumed seafood originating from the
disposal site (unitless)
BCF = Bioconcentration factor of pollutant (L/kg)
DI = Average daily human dietary intake of pollutant
(lig/day)
RSI = Cancer risk-specific intake" (yg/day)
2. Sample Calculation - Values were not calculated due to
lack of data.
A-3
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