ENVIRONMENTAL FATE OF CONTAMINANTS
FROM SLUDGE DISPOSAL ALTERNATIVES
TO OCEAN DUMPING
Incineration Report
AQUA TERRA CONSULTANTS
' ElNViRONMEINTAl
WATER RESOURCES w
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8601
August 1986
ENVIRONMENTAL FATE OF CONTAMINANTS
FROM SLUDGE DISPOSAL ALTERNATIVES
TO OCEAN DUMPING
Incineration Report
B.R. Bicknell
A.S. Donigian, Jr.
AQUA TERRA Consultants
Mountain View, CA 94043-1011
prepared for
Environmental Research Center
University of Nevada
Las Vegas, NV 89154
and
Michael Conti
EPA Project Officer
Integrated Environmental Management Division
U.S. Environmental Protection Agency
Washington, D.C. 20460
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ABSTRACT
The EPA Office of Policy, Planning, and Evaluation is conducting
a cross-media analysis of proposed revisions to the ocean dumping
regulations to evaluate the environmental impacts of land-based
alternatives to ocean disposal of sewage sludge. A model has
been developed for comparing the environmental risks and costs of
major disposal options including land application, landfilling,
incineration, distribution and marketing, and ocean disposal.
This model requires the input of unit concentrations of contami-
nants in ground water, surface water, and air for all exposure
pathways identified for each disposal alternative. These unit
values are the environmental concentrations produced by a unit
(e.g., 1000 kg/ha/yr) rate of sludge disposal; concentrations for
other disposal rates increase linearly as a function of the
disposal rate. These environmental concentrations provide the
basis for performing the comparative risk and cost-effectiveness
assessment in the model.
This report describes and demonstrates the methodology developed
for estimating the unit air concentrations of chemicals resulting
from incineration of municipal sludge. The methodology utilizes
a point source atmospheric dispersion model to calculate contami-
nant concentrations under regional meteorologic site conditions,
and typical sludge incineration design and operating procedures.
The report includes a model description, discussion of the
methodology assumptions and procedures for modeling sludge
incineration, and results of case study applications in New York
and Florida.
11
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CONTENTS
Page
Abstract . . . . ii
Figures iv
Tables iv
Acknowledgments v
1.0 Introduction 1
1.1 Objective and Scope 2
2.0 Incineration Methodology 4
2.1 Incineration Methodology Overview 4
2.2 Incineration Scenario.... 6
2. 3 Adjustment of Unit Concentrations 13
3.0 Case Study Applications - New York and Florida 14
4.0 ISCLT Atmospheric Dispersion Model 19
4.1 Model Description 19
4. 2 Model Input Data and Parameters 20
5. 0 References 24
iii
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FIGURES
' Page
2.1 Flow chart for incineration methodology 5
2.2 Distributions of incineration facilities - capacity,
stack height, stack diameter, and stack gas
exit velocity 11
3.1 Polar coordinate receptor diagram and maximum
concentration directions for New York and
Florida case study applications 15
3.2 ISCLT unit concentrations 17
TABLES
1.1 Contaminants of Concern 3
2.1 Concentrations of Selected Pollutants in Sludge:
EPA Survey and Other Surveys 7
2.2 Contaminant Concentration and Fraction Emitted
Through Stack - OWRS Incineration Methodolgy 9
3.1 ISCLT Unit Concentrations 16
4.1 ISCLT Source Input Data for Stacks 21
IV
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ACKNOWLEDGMENTS
This work is the integrated result of efforts and support by a
number of individuals and organizations. The study was funded by
the Office of Policy, Planning, and Evaluation of the U.S.
Environmental Protection Agency. Mr. Michael Conti was the EPA
Project Officer during the course of this work. His administra-
tive guidance and support contributed to the successful
completion of this study and is gratefully acknowledged.
Mr. John Haigh and his associates at Temple, Barker, and Sloane,
Inc. provided valuable technical input and direction to insure
that our efforts produced the technical results needed for their
overall cost-effectiveness and risk analysis.
For AQUA TERRA Consultants, Mr. Brian Bicknell was the Project
Manager and key technical staff person. He developed the
modeling methodology, estimated required parameters, executed the
ISCLT model runs, analyzed the results, and wrote the project
report. Mr. Anthony Donigian was the Project Director providing
overall technical direction, review, and administrative support.
Report word processing was performed by Ms. Dorothy Inahara, and
figures were prepared by Ms. Marythomas Hutchins. The contribu-
tions and support from all these individuals is sincerely
appreciated.
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SECTION 1.0
INTRODUCTION
The ocean dumping regulations are being revised to include
provisions for the use of cross media analysis (CMA) in evalu-
ating ocean dumping permit applications. CMA will be.used to
establish relative risk to human health and the environment and
the relative costs of the use of ocean and land-based disposal
alternatives. Ocean disposal will be allowed if an applicant can
demonstrate that no safer land-based alternative exists at a
reasonable incremental cost.
In 1981, U.S. District Court Judge Abraham Sofaer ruled that the
EPA could not prohibit the ocean dumping of sewage sludge that
violated marine water quality criteria without considering
whether available land-based disposal options are environmentally
less preferable. To comply with this decision, EPA's proposed
revisions to the ocean dumping regulations would allow a
permittee to dump wastes in the ocean if no practicable disposal
alternative with less total impact on the environment is
available.
The EPA Office of Policy Analysis' . Integrated Environmental
Management Division (IEMD) has developed a model for comparing
the risks and costs of disposing sewage sludge among major
disposal options. The IEMD Sludge Analysis Model provides for a
national analysis which identifies high risk areas either in
terms of contaminants or disposal practices and develops a
profile of the disposal options in terms of the cost-effective-
ness of reducing risk. The model requires the input of unit
concentrations of contaminants in ground water, surface water,
and air for all exposure pathways identified for each disposal
alternative. For incineration, these unit values are the
environmental concentrations produced by a unit (e.g., 1 g/s)
rate of chemical emission from the incinerator stack; concentra-
tions for other disposal rates increase linearly as a function of
the disposal rate. These environmental concentrations provide
the basis for performing the comparative risk and cost-effective-
ness assessment in the model.
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1.1 OBJECTIVE MID SCOPE
The objective of this study is to determine the environmental
unit concentrations required for the IEMD Sludge Analysis Model
by performing an environmental fate assessment of selected sludge
contaminants and disposal practices. The scope of this effort
includes the disposal practices and associated exposure media and
pathways listed below:
Environmental
Disposal Alternative Exposure Media
Landfill Ground Water
Land Application Surface Water,
Ground Water
Incineration Air
For each disposal alternative, the contaminants of concern have
been identified by U.S. EPA (1985a) and are listed in Table 1.1;
these include both organic and inorganic compounds. Thus, for
each disposal alternative and exposure media, unit concentrations
are needed for each contaminant included in Table 1.1 resulting
from a unit disposal rate.
The analysis is designed to be performed on,a-regional-basis by
defining "representative" environmental, Ce^laphic, and hydrogeo-
logic conditions for coastal areas where applications for ocean
dumping permits may be likely. Approximately, six coastal
regions, including three on the East Coast, two on the West
Coast, and one on the Gulf Coast may be needed to provide
adequate coverage of the coastal U.S. For each representative
coastal region, mathematical models will be used to assess
contaminant fate and estimate unit environmental concentrations.
Meteorologic input and model parameters will be derived to
represent likely conditions - climate, soils, topography,
hydrogeology - in each region.
The assembled methodology will also be available to be applied by
an applicant for a specific site if required.
This report describes our approach to the assessment of the air
exposure pathway for sludge incineration, including an overview
of the methodology, a summary of the application and results,
and a brief description of the model and required input
parameters. Section 2.0 provides the methodology overview,
while Section 3.0 describes the methodology application and
results. The model is described briefly in Section 4.0, along
with the model input data and parameters.
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TABLE 1.1 CONTAMINANTS OF CONCERN (By Disposal Option)
Dedicated
Land Application/
Landfilling
Arsenic
Benzene
Benzo(a)pyrene
Chlordane
Copper
Cyanide
DDT
DEHP
Dimethylnitrosamine
Lead
Lindane
Mercury
Nickel
PCBs
Trichloroethylene
Toxaphene
Incineration
Aldrin
Arsenic
Benzo(a)pyrene
Beryllium
Cadmium
Chlordane
Chromium
DEHP
Lead
Nickel
PCBs
Toxaphene
Vinyl Chloride
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SECTION 2.0
INCINERATION METHODOLOGY
2.1 INCINERATION METHODOLOGY OVERVIEW
The incineration methodology utilizes the point-source,
atmospheric dispersion model ISCLT to estimate average annual
ground-level concentrations ofcontaminants at various distances
from the incinerator. The (ISCLT model was chosen because it is
an EPA approved model, and because of its use in other EPA sludge
incineration studies (EPA, 1985b; MacArthur et al., 1986^The
model uses a steady-state Gaussian plume equation for a
continuous source in Jrlat terrain. Meteorologic input data for
ISCLT consist of annual statistical summaries of wind speed, wind
direction, and Pasquill-Gifford stability categories for each of
sixteen compass point directions. Receptors are given on polar
or cartesian coordinate systems, and are generally located
between 100 m and 50 km of the source.
A diagram showing the methodology is shown in Figure 2.1. The
methodology is similar to that utilized by EPA Office of Water
Regulations and Standards (OWRS) to assess human health and
environmental impacts resulting from incineration of municipal
sewage sludge (EPA, 1985a,b). In this methodology, the emission
rate of a specific contaminant from the incinerator is determined
by the sludge input rate (MT/day), the contaminant concentration
in sludge (mg/kg), and the fraction of contaminant loading
emitted from the stack. The actual ground-level concentrations
at various points downwind of the facility are determined by
multiplying these contaminant-specific emission rates by the
concentrations predicted by ISCLT using a unit (1.0 g/s) emission
rate. Contaminant-specific processes such as degradation
depositign__are J^sg^^ct.ed: and since multiple sources (stacks^
not corTsTdered, the predicted ground-level concentrations are
linear wTEFfFespect to emission rates.
In addition to the emission rate, other source-related parameters
are the stack height and diameter, stack gas^exit___tejmp,er.at.ur.e.,-
and exit velocity. In the OWRS methodology, six actual plants
located in various parts of the country were selected. Data from
these facilities provided input to a series of standard heat and
mass balance calculations (for incinerators) which yielded the
exit temperatures and velocities. In the current methodology, a
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CHEMICAL INPUT
8LUOQE FEED RATE
CHEMICAL
CONCENTRATION
FRACTION
'EMITTED
INCINERATION
PROCESS
^
MODEL. PLANT
STACK HEIGHT.
DIAMETER.
EXIT VELOCITY.
^
ISCLT
ATMOSPHERIC
DISPERSION
ENVIRONMENTAL
CONCENTRATIONS
ui
Figure 2.1 Flow chart for incineration methodology.
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series of model plants were modeled at each site, and representa-
tive values of the source parameters listed above were selected
from an EPA (1985c) database of sludge incinerators.
ISCLT model executions were performed using the EPA Office of
Toxic Substances GEMS computer facility. A polar coordinate
receptor network consisting of sixteen compass direction sectors
and ring distances of 0.1, 0.2, 0.3, 0.4, 0.5, 0.75, 1, 2, 3, 4,
5, 10, 15, 20, 25, and 50 km was selected. Meteorologic input to
the model, in the form of STAR data summaries, are accessible on-
line for a large number of locations in the U.S., and are
selected to be representative of the appropriate regions.
2.2 INCINERATION SCENARIO
2.2.1 Chemical Concentrations in Sludge
Since contaminant concentrations in sludge are highly variable,
this methodology uses a unit contaminant concentration which
allows the flexiblity to adjust the resulting environmental
concentrations by any desired sludge contaminant concentration.
Table 2.1 shows the results of a recent comprehensive EPA (1985b)
survey of POTW sludge quality as well as compilations from
several other studies (Fricke and Clarkson, 1984). Table 2.2
lists typical and worst-case values adopted by EPA (1985b) in the
OWRS study.
2.2.2 Fraction of Chemical Emitted From the Stack
Atmospheric emissions of contaminants from incinerators result
from 1) the mass of contaminant in the sludge, 2) the fraction
contained in the flue gas (gaseous and particulate), and 3) the
fraction removed by the air pollution controls. The latter two
factors are determined largely by combustion temperature and
scrubber efficiency. In this methodology, the effects of these
two factors are included in an overall "fraction of contaminant
emitted from the stack," and a unit value is used to allow
flexibility to adjust the environmental concentrations by any
desired emission fraction. Typical and worst-case values adopted
by EPA (1985b) in the OWRS study are also shown in Table 2.2.
The data for metals are based on measurements and estimates by
Farrell and Wall (1981) and Farrell (1985) for ten sewage sludge
incinerators operating at conventional temperatures. Additional
values for higher temperature incinerators have been compiled
from the literature by Gerstle and Albrinck (1982). In the
absence of significant data for organic chemicals, the OWRS
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TABLE 2.1 CONCENTRATIONS OF SELECTED POLLUTANTS IN SLUDGE:
SURVEY AND OTHER SURVEYS
EPA
POLLUTANT
EPA POTW SURVEY OTHER STUDIES AND SURVEYS
(Concentrations in mg/kg dry wt.) (mg/kg dry wt.)
MEAN MEDIAN MINIMUM MAXIMUM WT.MEAN MINIMUM MAXIMUM
METALS AND CYANIDE
Arsenic
Beryllium
Cadmium
Chromium
Cobalt
Copper
Lead
Mercury
Molybdenum
Nickel
Selenium
Zinc
Cyanide
VOLATILE COMPOUNDS
(PURGEABLE)
Benzene
Carbon tetrachlcride 4.48
Chlorobenzene
Chloroform
1,2-Dichloroethane
Methylene chloride
Tetrachloroethylene
Toluene
Trichloroethylene
Vinyl chloride
ACID COMPOUNDS
(ACID EXTRACTABLE)
Pentachlorophenol 10.4
Phenol 19.3
2,4,6-Trichlorophenol 2. 3
5.9
1.2
32.2
427.9
562.4
378.0
2.8
133.9
2.6
1409.2
748.5
4.7
0.47
8.3
252.9
380.9
246.0
2.0
70.4
1.4
769.4
423.1
0.33
0.16
0.38
22.6
36.1
32.8
0.01
3.1
0.14
169.9
0.29
27.5
10.0
612.8
1904.8
2970.6
1627.2
11.3
803.3
28.2
8467.7
5018.7
10.6
0.6
43.7
785.1
14.6
909.7
519.9
4.6
8.3
216.9
2.0
2194.0
84.4
0.3
0.2
<1
6
3.9
22
10
0.6
4.5
4
0.21
29.7
6.8
50
3.4
1200
35900
27.9
7700
28200
130
11.6
13000
25
34300
150
1.46
,e 4.48
1.16
0.85
25.03
8.65
3.47
1718^8
9.10
35.4
0.34
2.42
0.29
0.23
0.29
1.62
0.68
16.2
1.84
11.9
0.03
0.17
0.02
0.02
0.06
0.02
0.02
0.77
0.05
2.9
17.0
12.9
12.9
10.1
201.5
195.3
42.1
68643.9
193.9
110.2
NA
SA
55.4
NA
NA
1.22
<0.01
17.77
NA
NA
0.002
0.155
0.0065
0.004
0.022
0.075
9.62E-06
0.214
0.001
0.045
0. 170
0.155
846
0.150
0.022
2.666
2.8
2400
0.466
0.045
3.9
7.5
2.3
0.17
0.16
0.04
91.1
113.4
4.6
81.1
9.1
42.3
0.17
0.0166
0.195
8490
288
1330
NA = Not available
Notes: Means, medians, and ranges are for concentrations where detected only.
Weighted means include Michigan, New York City, Indiana, Galveston,
Albuquerque, and Phoenix surveys only.
9.62E-06 = 0.00000962
SOURCE: EPA, 1985b
(continued)
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TABLE 2.1 Continued
EPA POTW SURVEY OTHER STUDIES AND SURVEYS
(Concentrations in mg/kg dry wt.) (mg/kg dry wt.)
POLLUTANT
MEAN
MEDIAN MINIMUM
MAXIMUM
HP. MEAN
MINIMUM MAXIMUM
BASE/NEUTRAL COMPOUNDS
(BASE/NEUTRAL
EXTRAC TABLE )
Benzidine
Benzo( a) anthracene
Benzo ( a ) pyr ene
Benzo( b) f luoranthene
bis(2-Ethylhexyl)
phthalate
Chrysene
3,3'-Dichloro-
benzidine
Hexachlorobenzene
Hexachlorobutadiene
n-Nitrosodi
methylamine
Phenanthrene
Pyr ene
PESTICIDES AND PCB'S
Aldrin
Gamma-BHC (Lindane)
Chlordane
2,4-D
4, 4 'DDT
4, 4 'DDE
4, 4 '-ODD
Dieldrin
Endrin
Heptachlor
Malathion
PCB's
Toxaphene
OTHERS
Flouride
Tricresyl phosphate
9.1
256.6
1.76
157.6
8.3
1.64
1.25
4.5
0.04
5.9
6.8
ND
0.02
ND
ND
0.06
ND
0.02
ND
0.02
ND
ND
0.81
0.61
1.02
101.3
1.01
1.64
0.92
4.5
0.04
4.0
2.1
ND
0.02
ND
ND
0.06
ND
0.02
ND
0.02
ND
ND
0.03
0.09
0.02
4.1
0.03
0.98
0.37
0.92
0.04
0.04
0.08
ND
0.02
ND
ND
0.06
ND
0.02
ND
0.02
ND
ND
177.4
1279.1
6.0
764.0
177.4
2.29
2.31
8.0
0.04
30.1
164.1
ND
0.03
ND
ND
0.06
ND
0.02
ND
0.02
ND
ND
12.7
1.53
1.34
3.28
1169.5
2.20
3.13
468.0
0.22
NA
0.18
NA
0.15
0.04
3.01
4.64
0.28
0.25
0.21
0.08
NA
0.10
0.63
29.06
7.88
3091
39.9
2.575
0.67
0.40
1.34
0. 14
0.87
2.76
<0.13
9.24E-05
NA
0.10
0.141
0.01
0.02666
0.0170
2.12
0.06
0.00058
0.081
0.0006
0.11
0.09
0.63
0.0015
4.69
106.8
0.0690
12.7
9.850
9.00
5.04
58300
4.74
3.5
26200
3.74
NA
43.5
0.338
0.64
0.22
12
7.16
0.93
0.47
0.50
0.81
0.17
0.10
0.63
620
10.79
. 7500
1650
BHC = Benzene hexachloride DDT = Dichlorodiphenyltrichlorethane
DDE = Dichlorodiphenyldichloroethylene ODD = Dichlorodiphenyldichloroethane
NA = Not available ND = Not detected
Notes: Means, medians/ and ranges are for concentrations where detected only.
Weighted means include Michigan, New York City, Indiana, Galveston,
Albuquerque, and Phoenix surveys only.
SOURCE: EPA, 1985b
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TABLE 2.2 CONTAMINANT CONCENTRATION AND FRACTION EMITTED
THROUGH STACK - OWRS INCINERATION METHODOLOGY
Concentration (yg/g)
Fraction Emitted
Contaminant
Aldrin
Benzo(a)pyrene
Chlordane
DEHP
PCBs
Toxaphene
Vinyl Chloride
Arsenic
Beryllium
Cadmium
Chromium
Lead
Nickel
Typical
0.22
0.143
3.2
94.28
4.
7.88
0.43
4.6
0.313
8.15
230.1
248.2
44.7
Worst
0.81
1.937
12.0
459.25
23.
10.79
311.94
20.77
1.168
88.13
1499.7
1070.8
662.7
Typical
0.05
0.05
0.05
0.05
0.05
0.05
0.05
0.30
0.01
0.30
0.003
0.04
0.002
Worst
0.20
0.20
0.20
0.20
0.20
0.20
0.20
0.40
0.03
0.40
0.006
0.10
0.006
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methodology adopted "best approximations" of the emission
fractions. These values are included in Table 2.2.
2.2.3 Model Plant Selection
Model incinerators were developed to provide the input parameters
needed for performing the air dispersion modeling. These model
incinerators were developed from data representative of actual
incineration facilities. The EPA (1985c) Office of Air Quality
Planning and Standards compiled a data base of POTW incinerators
in the U.S. This database contains information on most design
and operational parameters of incinerators required for
defining them as point sources in air dispersion modeling. These
variables include incineration type, sludge capacity, stack
parameters (height, diameter, exit velocity), building dimen-
sions, type of pollution control equipment, location (for meteor-
ologic data input), and the terrain and population around the
site.
For purposes of this analysis and use of the ISCLT model, the
following variables are necessary:
Capacity
Stack height
Stack diameter
Exit velocity
Exit temperature
Location
Distributions of capacity, stack height and diameter, and exit
velocity are shown in Figure 2.2. Since this methodology uses a
unit value of sludge feed rate (i.e., the user adjusts the
results for any desired incinerator capacity), capacity is not a
required variable for the actual modeling; however, 3 model plant
capacities were selected as representative. The temperature
distribution is not shown since most values were identical
(3220K). Based on the distributions shown in Figure 2.2, the
following values were selected to represent each of the
variables:
Capacity 10 MT/day
40 MT/day
300 MT/day
Stack Height 10 m
20 m
45 m
Stack Diameter 1 m
Exit Velocity 3 m/s
16 m/s
10
-------
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30 -
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19 -
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fxl
a
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2O 4O 60 BO 10O 12O 14O 160 18O 2OO 400
CAPACITY - DRY METRIC TONS/DAY
B
§
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28 -
26 -
24 -
22 -
20
18 -
16 -
14 -
12 -
10 -
a -
6 -
4 -
2 -
O -
r/ir/1
I/I I/I
TlMM
-
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20 24 28 32 36 4O
STACK HEIGHT - M
13
80
70 -
60 -
| -
fe 40-j
O 30-
20 -
10-
O
/'/
O.9
1.0
1.9 2.0 2.3 3.0 3.9 4.0
STACK DIAMETER - M
6.0
8 10 12 14 16 18 20
STACK CAS EXIT VELOCITY (M/S)
Figure 2.2
Distributions of incinerator facilities - capacity, stack height
diameter, and stack gas exit velocity.
22 24 26
, stack
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Since there is little correlation between parameters, all
possible combinations were modeled, providing a series of model
plants which represent most existing POTW sludge incinerators.
2.2.4 Atmospheric Dispersion Modeling
Atmospheric dispersion modeling of incineration stack sources was
performed using the steady-state Gaussian plume model ISCLT.
This model has been summarized above (Section 2.1) and is
described in detail in Section 4. ISCLT assumes a continuous
source located in flat terrain. Several optional features in
ISCLT are not utilized in this methodology. In particular, the
effect of building aerodynamics on plume downwash is ignored in
this non-site specific analysis. Neglect of this effect should
be considered carefully since many sludge incinerators have short
stacks and little plume rise (MacArthur et al., 1986), and are
thus subject to building aerodynamics effects.
Other assumptions specific to this analysis are the use of a
single stack at each facility, and neglect of plume losses due to
deposition and chemical degradation; ignoring these chemical
attenuation processes will lead to conservative unit concentra-
tion estimates. The use of ISCLT also precludes the considera-
tion of receptor point elevations greater than the stack height;
however, the assumption of flat terrain is reasonable for the
coastal areas modeled in this analysis.
2.2.5 Methodology Summary and Assumptions
The incineration methodology and the key assumptions inherent in
this methodology are summarized as follows:
ISCLT atmospheric dispersion model used to compute long-
term (yearly average) ground-level concentrations based
on constant source rate incinerators.
Source parameters (stack dimensions, stack gas exit
velocity, etc.) defined by a series of model incineration
facilities based on a database of incinerators across
the U.S.
Unit concentrations (based on unit sludge feed rate,
sludge chemical concentration, and fraction of chemical
emitted) are adjusted by the user for a specific
situation.
No effect of buildings on plume.
12
-------
No plume losses caused by deposition or degradation.
Level terrain and all terrain is lower than the stack,
2.3 ADJUSTMENT OF UNIT CONCENTRATIONS
The unit concentrations computed by the model correspond to a
source, rate of 1 g/s; consequently, they must be adjusted for
specific facility size and chemical scenarios. Each unit ground-
level atmospheric concentration is a direct linear function of
three factors: 1) the sludge feed rate, 2) the sludge chemical
concentration, and 3) the fraction of chemical emitted from the
stack. Thus, the predicted environmental concentrations for a
particular scenario may be computed as follows:
AC = CF * SR *SC * FE * UA (2-1)
where AC = adjusted ground-level atmospheric concentration
(>jg/m3)
SR = sludge feed rate (dry metric tons/day)
SC = sludge chemical concentration (mg/kg)
FE = fraction of chemical emitted (-}
CF = 1.157E-5 = conversion factor to correct the time and
mass units; this normalizes the concentration for
SR = SC = FE = 1.0
UA = unit concentration corresponding to 1 g/s emission
rate (yg/n»3)
13
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SECTION 3.0
CASE STUDY APPLICATIONS - NEW YORK AND FLORIDA
ISCLT was executed for the New York and Florida coastal areas
using facility parameters described in Section 2.2, a source rate
equal to 1 g/s, and meteorologic data for the appropriate
regions. STAR data sets containing meteorologic data for ISCLT
were selected from those avilable on the EPA Office of Toxic
Substances GEMS computer system. The two ' data sets are
summarized as follows:
STATION NAME LATITUDE
New York - Laguardia, NY N 40 46
Orlando - Jetport, FL N 28 27
LONGITUDE
W 73 54
W 81 18
PERIOD OF
RECORD
1965-70
1941-74
Ground-level concentrations were computed by the model at a
network of receptor points out to a distance of 50 km. The
receptor points corresponding to distances from 0.1 to 1. km are
located at the midpoints of the arc segments shown in Figure 3.1.
For each scenario modeled, the concentrations along the compass
direction which exhibited the highest values were chosen to
represent the scenario. Figure 3.1 shows the direction or sector
having the highest concentrations for the New York and Florida
case study applications. Table 3.1 lists the resulting unit
concentrations out to 50 km for all facility scenarios. As
expected, scenarios with lower stack heights and exit velocities
result in higher environmental concentrations. In order to
illustrate the variations with distance, stack height, and stack
exit velocity, the concentrations from 0.1 to 5 km are shown in
Figure 3.2.
The unit concentrations shown in Table 3.1 must be adjusted for
the specific incinerator capacity and chemical scenarios. This
calculation is described in Section 2.3, and is illustrated in
the following example:
Scenario
300 MT/day incinerator located near the coast in New York
Stack height - 10 m
14
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Direction of maximum
concentration for
New York case.
W 270
Direction of maximum
concentration* for
Florida case.
Figure 3.1 Polar Coordinate Receptor Diagram and maximum
concentration directions for New York and Florida
case study applications.
15
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TABLE 3.1 ISCLT UNIT CONCENTRATIONS
NEW YORK
CONCENTRATION FROM ISCLT (1)
(ug/m3)
0V
STACK STACK
HEIGHT EXIT VEL.
(m) (m/B)
DISTANCE FROM STACK (km)
0.10 0.20 0.30 0.40 0.50 0.75 1.00 2.00 3.00 4.00 5.00 10.0 15.0 20.0 25.0
50.0
10
20
45
10
20
45
10
20
45
10
20
45
3
3
3
16
16
16
3
3
3
16
16
16
2.19
0.086
IE-OS
0.033
O.OOOS
1E-08
2.970
0.2370
3E-04
0.0385
0.0023
5E-07
6.25
0.87
0.018
0.61
0.094
0.0013
5.510
1.460
0.0922
0.595
0.1360
0.0050
5.49
1.70
0.078
1.29
0.34
0.018
4.530
1.910
0.2920
1.010
0.373
0.0421
4.20
1.86
0.14
1.51
0.57
0.047
3.590
1.810
0.393
1.100
0.526
0.1000
3.25
1.74
0.21
1.48
0.70
0.081
FLORIDA
3.050
1.610
0.421
1.080
0.593
0.1480
1.95
1.26
0.33
1.16
0.72
0.16
2.440
1.310
0.396
0.950
0.582
0.199
1.33
0.92
0.35
0.88
0.61
0.21
2.050
1.170
0.361
0.879
0.545
0.205
0.54
0.40
0.21
0.40
0.31
0.16
1.040
0.693
0.275
0.627
0.416
0.167
0.31
0.23
0.14
0.24
0.19
0.11
0.629
0.445
0.214
0.444
0.311
0.144
0.20
0.16
0.098
0.17
0.13
0.084
0.427
0.313
0.1690
0.330
0.239
0.1230
0.15 0.055 0.030 0.020 0.015
0.11 0.042 0.024 0.016 0.012
0.074 0.030 0.017 0.011 0.0084
0.13 0.049 0.028 0.019 0.014
0.098 0.039 0.022 0.015 0.011
0.065 0.027 0.016 0.011 0.0079
0.315 0.1180 0.0663 0.0439 0.0323
0.234 0.0910 0.0518 0.0345 0.0255
0.1350 0.0604 0.0360 0.0246 0.0184
0.255 0.1060 0.0615 0.0415 0.030B
0.1880 0.0812 0.0479 0.0325 0.0242
0.1040 0.0525 0.0327 0.0228 0.0173
0.0057
0.0045
0.0033
0.0055
0.0043
0.0032
0.0128
0.0101
0.0075
0.0124
0.0098
0.0072
(1) CONCENTRATION FOR SECTOR WHERE MAXIMUM CONCENTRATION OCCURS
SOURCE = 1 g/s
STACK EXIT TEMPERATURE - 322 K
STACK DIAMETER "1m
RURAL CONDITIONS
-------
NEW YORK
ui
o
o
o
Stack Exit
Legend Height Velocity
10 3
20 3
45 3
10 16
20 16
45 16
2 4
DISTANCE FROM INCINERATOR (km)
FLORIDA
10
E
o>
3
O
I
UI
O
o
o
fc
2 4
DISTANCE FROM INCINERATOR (km)
Figure 3.2 ISCLT unit concentrations,
17
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Stack gas exit velocity = 3 m/s
Chemical = cadmium
Chemical concentration in sludge = 88.13 mg/kg (worst case)
Fraction emitted from stack = 0.4 (worst case)
Receptor located 0.2 km from the incinerator (unit
concentration = 6.25)
AC = (1.157E-5) * (300) * (88.13) * (0.4) * (6.25)
AC = 0.76 yg/m3
18
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SECTION 4.0
ISCLT ATMOSPHERIC DISPERSION MODEL
4.1 MODEL DESCRIPTION
The ISCLT (Industrial Source Complex Long-Term) (Bowers et al.,
1979) dispersion model can be used to assess the air quality
impacts of emissions from the incineration of sludge. The model
is a sector-averaged model that extends and combines basic
features of the Air Quality Display Model (AQDM) and the Clima-
tological Dispersion Model (COM). The long-term model uses
statistical wind summaries to. calculate seasonal (quarterly)
and/or annual ground-level concentration or deposition values.
ISCLT uses either a polar or a Cartesian receptor grid.
The major features of ISCLT are:
Plume rise due to momentum and buoyancy as a function of
downwind distance for stack emissions
9 Procedures suggested by Huber and Snyder for evaluating
building wake effects
Procedures suggested by Briggs for evaluating stack-tip
down-wash
Separation of multiple point sources
Consideration of the effects of gravitational settling
and dry deposition on ambient particulate concentrations
Capability of simulating line, volume and area sources
Capability to calculate dry deposition
Variation with height of wind speed (wind-profile
exponent law)
Concentration estimates for 1-hour to annual average
Terrain-adjustment procedures for complex terrain
Consideration of time-dependent exponential decay of
pollutants
19
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4.2 MODEL INPUT DATA AND PARAMETERS
The input requirements for the ISC Model long-term computer
program (ISCLT) consist of four categories:
Meteorological data
f Source data
Receptor data
Program control parameters
Each of these data categories is discussed separately below.
4.2.1 Meteorological Data
Seasonal or annual "STAR" summaries (statistical tabulations of
the joint frequency of occurrence of wind-speed and wind-
direction categories, classified according to the PasquilL
stability categories) are the principal meteorological inputs to
ISCLT. The program accepts STAR summaries with six Pasquill
stability categories (A through F) or five stability categories
(A through E with the E and F categories combined). ISCLT is not
designed to use the Climatological Dispersion Model (COM) STAR
summaries which subdivide the neutral D stability category into
day and night D categories. Additional meteorological data
requirements include seasonal average maximum and minimum mixing
heights and ambient air temperatures. These data are contained
in STAR summary data sets for a large number of locations in the
U.S.; and are accessible online.
4.2.2 Source Data
The ISCLT program accepts three source types: stack, area, and
volume. For each source, input data requirements include the
source location with respect to a user-specified origin, the
source elevation (if terrain effects are to be included in the
model calculations), and the pollutant emission rate. For each
stack, additional source input requirements include the physical
stack height, the stack inner diameter, the stack exit
temperature, the stack exit velocity, and if the stack is
adjacent to a building and aerodynamic wake effects are to be
considered the length, width and height of the building.
Table 4.1 lists the ISCLT source input parameters for stacks.
20
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TABLE 4.1 ISCLT SOURCE INPUT DATA FOR STACKS
DATA TYPE UNITS
Pollutant Emission Rate g/s
Pollutant Decay Coefficient s-1
Elevation of Base of Stack m
Stack Height m
Stack Inner Diameter m
Stack Exit Temperature deg K
Stack Exit Velocity m/s
Gravitational Settling Data
Adjacent Building Dimensions -
COMMENT
Unit Rate (=1.)
Assumed = 0
Assumed = 0
See Section 2.2
See Section 2.2
See Section 2.2
See Section 2.2
Not used
Not used
21
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In the cases of area and volume sources, the horizontal
dimensions and effective emission height are required for each
source. If the calculations are to consider particulates with
appreciable gravitational settling velocities, source inputs for
each source also include the mass fraction of particulates in
each gravitational settling-velocity category as well as the
surface reflection coefficient and settling velocity of each
settling-velocity category. Because industrial pollutant
emission rates are often highly variable, emission rates for each
source may be held constant or varied.
4.2.3 Receptor Data
The ISCLT program uses either a polar (r, 6 ) or a Cartesian (X,
Y) coordinate system. The typical polar receptor array consists
of 36 radials (one for every 10 degrees of azimuth) and five to
ten downwind ring distances for a total of 180 to 360 receptors.
However, the user is not restricted to a 10-degree angular
separation of receptors. Receptor locations in the Cartesian
coordinate system may be given as Universal Transverse Mercator
(UTM) coordinates or as X (east-west) and Y (north-south)
coordinates with respect to a user-specified origin. Discrete
receptor points corresponding to the locations of air quality
monitors, elevated terrain, or other points of interest may also
be used with either coordinate system. If terrain effects are to
be included in the calculations, the elevation of each receptor
is also required.
In this methodology, a polar coordinate receptor network is used
which consists of sixteen compass direction sectors and ring
distances of 0.6, 1, 2, 3, 4, 5, 10, 15, 25, and 50. km.
4.2.4 Program Control Parameters and Options
A number of user controlled parameters and options are available
to allow the user to select specific types of analyses and
results. Some of the analysis options are:
f calculate average concentration or total deposition
selection of a cartesian or a polar receptor grid system
specification of an elevation for each receptor (level
terrain is assumed by the program otherwise)
make calculations for either urban or rural mode
22
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compute plume rise as either a function of downwind
distance or for all distances
vary emissions by season, wind speed, and/or Pasquill
stability category
evaluate stack-tip downwash for all sources using the
Briggs procedures
23
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SECTION 5.0
REFERENCES
Bowers, J.F., J.R. Bjorklund and C.S. Cheney. 1979. Industrial
Source Complex (ISC) Dispersion Model User Guide. EPA
450/4-79-30. Vol. 1. U.S. Environmental Protection Agency,
Office of Air Quality Planning and Standards, Research
Triangle Park, NC.
Farrell, J.B. 1985. Percentage Loss in Metals from MHF
Incinerators Equipped with Wet Scrubbers. Memo. U.S.
Environmental Protection Agency. Water Engineering Research
Laboratory, Cincinnati, OH.
Farrell, J.B. and H. Wall. 1981. Air Pollution Discharges from
Ten Sewage Sludge Incinerators. U.S. Environmental
Protection Agency. Municipal Environmental Research
Laboratory, Cincinnati, OH.
Fricke, C* and. C. Clarkson. 1984. A Comparison of Studies of
Toxic Substances in POTW Sludges. EPA Contract 68-01-6403.
Gerstle, R.W. and D.N. Albrinck. 1982. Atmospheric Emissions of
Metals from Sewage Sludge Incineration. J. Air Pollution
Assoc. Vol. 32, No. 11.
MacArthur, R.S., G.E. Anderson and M.A. Yocke. 1986. Sludge
Incinerator Air Quality Modeling. Draft Report prepared by
Systems Applications, Inc. for U.S. Environmental Protection
Agency, Office of Air Quality Planning and Standards,
Durham, NC.
U.S. EPA. 1985a. Environmental Profiles and Hazard Indices for
Constituents of Municipal Sludge. U.S. Environmental
Protection Agency. Office of Water Regulations and
Standards, Washington, DC.
U.S. EPA. 1985b. Methodology for Evaluating the Health and
Environmental Impact of Incineration of Sewage Sludge.
Draft Report prepared by U.S. Environmental Protection
Agency. Office of Water Regulations and Standards,
Washington, DC.
24
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U.S. EPA. 1985c. POTW Sludge Incineration Model Plant
Selection. Draft Report prepared by U.S. Environmental
Protection Agency. Office of Water Regulations and
Standards. U.S. Environmental Protection Agency,
Washington, DC.
U.S. EPA. 1982. Fate of Priority Pollutants on Publicly Owned
Treatment Works, 30-Day Study. Effluent Guidelines
Division, EPA 440/1-82-302.
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