S-/EPA
United States
Environmental Protection
Agency
Industrial Environmental Resean
Laboratory
Research Triangle Park NC 2771
Research and Development
EPA-600/S7-81 -003a Apr. 1981
Project Summary
Emissions Assessment of
Conventional Stationary
Combustion Systems:
Volume
External Combustion Sources
for Electricity Generation
C. C. Shih, R. A. Orsini, D. G. Ackerman, R. Moreno, E. L. Moon, L L Scinto,
and C. Yu
Multimedia emissions from external
combustion sources for electricity
generation are characterized in this
study. In the assessment process,
existing emissions data were first
examined to determine the adequacy
of the data base. This was followed by
the conduct of a measurement pro-
gram to fill the identified data gaps.
Emissions data obtained from the
sampling and analysis program were
combined with existing emissions
data to provide estimates of emission
levels, and to define the need for
additional data.
The results of this study indicate
that external combustion sources for
electricity generation contribute signi-
ficantly to the nationwide emissions
burden. Flue gas emissions of NO.,
SO2, and particulate matter from
these sources account for approxi-
mately 50 percent. 57 percent, and 25
percent, respectively, of the emissions
of these pollutants from all stationary
sources. Flue gas emissions of sulfates
and several trace elements from coal-
and oil-fired utility boilers also require
further attention. POM compounds in
flue gas emissions are mostly naphtha-
lene, phenanthrene, and pyrena. Al-
though, dibenz(a,h)anthraceneand
possibly benzo(a)pyrene, both active
carcinogens, were also detected at a
limited number of coal-fired sites.
A second major source of air emis-
sions is vapors and drifts from cooling
towers. Air emissions of chlorine,
magnesium, phosphorus, and sulfates
from mechanical draft cooling towers
were found to be comparable to flue
gas emissions of these pollutants from
oil-fired utility boilers.
The multiple use of water in steam
electric plants results in wastewater
streams from several operations. In
general, concentrations of iron, mag-
nesium, manganese, nickel, and phos-
phorus are at levels that may be of
environmental concern. Average
organic levels ranged from 0.01 mg/l
for ash pond effluents to 6.0 mg/l for
boiler blowdown. No POM com-
pounds were detected.
Data on coal fry ash and bottom ash
show that from eleven to sixteen trace
-------
'
elements are present at potentially
harmful levels. The only POM com-
pounds detected, however, were naph-
thalene, alkyl naphthalenes, and other
relatively nontoxic compounds.
This Project Summary was develop-
ed by EPA's Industrial Environmental
Research Laboratory, Research Tri-
angle Park. NC. to announce key find-
ings of the research project that is fully
documented in a separate report of the
same title (see Project Report ordering
information at back).
Introduction
Emissions from external combustion
sources for electricity generation are
characterized in this study. According to
the classification system in the current
study, all fossil-fuel-fired boilers owned
by public and private utilities to generate
electricity are included in this source
category.
For the purposes of this study, all
major process operations and onsite
facilities involved in the generation of
power by utilities are covered in this
source category. Support facilities and
operations addressed in this report
include: coal storage, cooling water'
systems, makeup water treatment,
chemical cleaning of boiler tubes, air
and water pollution control, and solid
waste disposal. Fugitive emissions from
ash handling and storage and fuel
handling are not considered here.
Assessment Methodology
The phased approach to environment-
al assessment is designed to provide
comprehensive emissions information
on all process waste streams in a cost
effective manner. To achieve this goal,
two distinct sampling and analysis
levels are being employed in this project.
Level I utilizes semiquantitative (± a
factor of 3) techniques of sample collec-
tion and laboratory and field analyses to:
provide preliminary emissions data for
waste streams and pollutants not ade-
quately characterized; identify potential
problem areas; and prioritize waste
streams and pollutants in those streams
for further, more quantitative testing.
Using the information from Level I,
available resources can be directed
toward Level II testing which involves
specific, quantitative analysis of compo-
nents of those streams which contain
significant pollutant loadings. The data
developed at Level II are used to identify
control technology needs and to further
define the environmental hazard asso-
ciated with each process stream.
The Existing Emissions Data
Base
Decisions as to the adequacy of the
existing data base were made using
critieria developed by considering both
the reliability and variability of the data.
Estimated environmental risks associ-
ated with the emission of each pollutant
were also considered in the determina-
tion of the need for, and extent of, the
sampling and analysis program. For
criteria pollutants, comparison of calcu-
lated maximum ground level concentra-
tions with national primary ambient air
quality standards was used as the basis
for estimation of environmental risks.
As a result of the data evaluation effort,
a number of data inadequacies have
been identified. For flue gas emissions,
the status of the existing data base can
be summarized as follows:
• The existing data base for criteria
pollutants is generally adequate.
• For sulfuric acid emissions, the
existing data base is adequate for
bituminous-coal-fired boilers, re-
sidual-oil-fired boilers, and gas-
fired boilers, but inadequate for
lignite-fired boilers. For emissions
of primary sulfates, the existing
data base is adequate for pulverized
bituminous dry bottom and wet
bottom boilers, residual oil-fired
boilers, gas-fired boilers, but in-
adequate for other combustion
source categories.
• For emissions of particulates by
size fraction and trace elements,
the existing data base is adequate
for gas-fired boilers but inadequate
for all other combustion source
categories.
• For emissions of specific organics
and poly cyclic organic matter (POM),
the existing data base is inadequate
for all combustion source categories.
Two other sources of air emissions of
environmental concern are cooling
tower emissions and emissions from
coal storage piles. The existing data
bases characterizing air emissions from
these two sources are considered to be
inadequate, because past studies were
primarily focused on the measurements
of a limited number of chemical constit-
uents and total particulates.
For wastewater effluents from exter-
nal combustion sources for electricity
generation, the existing data base is
considered to be adequate for wastewater
from water treatment processes, and in-
adequate for all other streams. This is be-
cause past studies were limited to the
characterization of gross parameters
such as pH and total suspended solids
(TSS) and a few inorganic constituents.
Organic characterization data are gen-
erally not available.
The evaluation of existing emissions
data for solid wastes indicated the inad-
equacy of the organic data base for coal
fly ash and bottom ash, and the inade-
quacy of the inorganic and organic data
bases for FGD sludges. On the other.
hand, the inorganic content for coal ash
is considered to be adequately charac-
terized.
Similarly, the data base for water
treatment wastes is considered to be ad-
equate, because the waste constituents
are inorganic and can be estimated from
the raw water constituents and the
treatment method used.
The Source Measurement
Program
Because of the deficiencies in the
existing emissions data base, 46 sites
were selected for sampling and analysis
of flue gas emissions, and 6 sites were
selected for sampling and analysis of air
emissions from cooling towers. At a se-
lected number of these sites, waste-
water streams and solid wastes were
also sampled and analyzed. Wastewater
streams sampled and analyzed included
cooling tower blowdown, once-through
cooling water, boiler blowdown, fly ash
pond overflow, bottom ash pond overflow,
and combined ash pond overflow. Inter-
mittent wastewater streams such as
chemical cleaning wastes and coal pile
runoff were not sampled. Solid waste
streams sampled and analyzed included
fly ash, bottom ash, and FGD scrubber
sludge.
Sampling and Analysis Meth-
odology
Level I Field Testing
The Source Assessment Sampling
System (SASS) train, developed by EPA,
was used to collect both vapor and
particulate emissions in quantities
sufficient for the wide range of analyses
needed to adequately characterize
emissions from external combustion
sources.
In addition to using the SASS train for
stack gas sampling, other equipment
-------
was employed to collect those compo-
nents that could not be analyzed from
the train samples. A gas chromatograph
(GC) with flame ionization detection
was used in the field to analyze hydro-
carbons in the boiling point range of
-160 to 90°C (reported as Ci-Ce) col-
lected in gas sampling bags. These
samples were also analyzed for CO,
CO2, 02, and SOz by GC using a thermal
conductivity detector.
Water samples were generally taken
by either tap sampling or dipper sam-
pling. Tap samples were obtained on
contained liquids in motion or static
liquids in tanks or drums. This sampling
method was generally applicable to
cooling tower blowdown or boiler blow-
down. The dipper sampling procedure,
applicable to sampling ponds or open
discharge streams, was used in the
acquisition of ash pond discharge sam-
ples. After sample recovery, water
analyses using the Hach kit were per-
formed in the field to determine pH,
conductivity, total suspended solids
(TSS), hardness, alkalinity or acidity,
ammonia nitrogen, cyanide, nitrate
nitrogen, phosphate, sulf ite and sulfate.
For solids sampling, the fractional
shovel grab samples procedure was
used unless the plant had an automatic
sampling system. The concept of frac-
tional shoveling involves the acquisition
of a time-integrated grab sample repre-
sentative of overall process input or
output during a given run time period.
When plants were equipped with auto-
matic samplers to remove representative
cross sections of a stream while auto-
matically forming a homogeneous com-
posite, these were used in preference to
the shovel technique.
In addition to the above sampling
methods, sampling for air emissions
from cooling towers was performed
using a modified EPA Method 5 train
without the filter assembly.
Modified Level I Laboratory
Analysis
The basic Level I schematic outlining
flow of samples and analysis plans for
paniculate and gaseous emissions is
depicted in Figure 1. The corresponding
schematic for solid, slurry, and liquid
samples is presented in Figure 2. Details
of the sample handling, transfer, and
analysis procedures can be found in the
IERL-RTP Procedures Manual: Level I
Environmental Assessment. EPA-600/
2-76-160a (NTIS PB 257 850), now
superceded.
Inorganic Analyses
Level I analysis was used for all
inorganic analyses. It was designed to
identify all elemental species in the
SASS train fractions and to provide
semiquantitative data on the elemental
distributions and total emission factors.
The primary tool for Level I inorganic
analysis is the Spark Source Mass
^articulate
^Matter
I
Opacity I *
(Stacks) I I
,
^^ 1 "• '-'A* ^
i3W j_
IT^U
J==T
H f//fer
— »•
— ^
rrooe ana
Cyclone
Rinses
Sass Train Gas
Conditioner
Condensate
Sass Train
Impingers
Extraction
• A . ^Physical Separation | i " 1
2nd
SrtT1
urganics
Extract
Inorganics
Inorganics
As, Sb, Hg
^ 1 Inorganics
Extraction j >| Organics
Into LC Fractions, 1 \I
IR/LRMS M 0r9anlcs
Elements (SSMS) and
Selected Anions
Elements and
Selected Anions
Elements (SSMS) and
Selected Anions
Physical Separation
into LC Fractions. IR/LRMS
\ Same as above
Elements
(SSMS) and
Selected Anions^
Physical Separation
into LC Fractions
IR/LRMS
Gas
* Weigh
Individual
Catches
t/f Inorganics
Are Greater Than
1O% Total Catch.
1/VOx Chemiluminescence
or Method 7
(Inorganic
(Grab)
1 Organic
Material >C6
Organic
Material Ci-C6
On-Site Gc
Chromato-
graphy
XAD-2 _
Absorber,
Module Rii
On-Site Gi
Chromatog
is
1
»l Extraction
is
raphy
'
Inorganics
Organics
Organics
>Cl6
Elements (SSMS) and
Aliquot for Gas
Chromatographic
Analysis
Physical Separation
into LC Fractions. IR/LRMS
Figure 1. Basic Level 1 sampling flow and analytical plan for particulates and gases.
-------
Organics
Solids
Slurries
1
t
Liquids
L*
^
^
Leacnaoie
Materials
Organics
Suspended
Solids
Selected
\A/s*tar
Tests
Organic
or Direct
Analysis
' »| Inorganics
Elements fSSMS) and
Selected Anions
into LC Fractions, IR/LRMS
Elements (SSMS) and
C / W A
^ Orqanics
>c™
^ Qrganir.s
300°C,
corresponding to the boiling points of
>Ci8 n-alkanes and reported as >Ci6) to <
supplement data for gaseous organics
(boiling point range of -160 to 90°C,
corresponding to the boiling points of
Ci-Ce n-alkanes and reported as Ci-C8)
measured in the field. Organics in the
XAD-2 module condensate trap and
XAD-2 resin were recovered by methyl-
ene chloride extraction. SASS train
components including the tubing were
carefully cleaned with methylene chlo-
ride or methylene chloride/methanol
solvent to recover all organics collected.
Because all samples were too dilute
to detect organic compounds by the
majority of instrumental techniques
employed, the first step in the analysis
was to concentrate the sample fractions
from as much as 1000 ml to 10 ml in a
Kuderna-Danish apparatus in which
rinse solvent is evaporated while the
organics of interest are retained*.
Kuderna-Danish concentrates were
then evaluated by gas chromatography
(GC), infrared spectrometry (IR), liquid
chromatography (LC), gravimetric anal-
ysis, low resolution mass spectroscopy
(LRMS), and sequential gas chromatog-
raphy/mass spectrometry (GC/MS)f.
The extent of the organic analysis was
determined by the stack gas concentra-
tions found for total organics (volatile
and non-volatile). If the total organics
indicated a stack gas concentration
below 500 ug/m3, a liquid concentration
below 0.1 mg/l, or a solid concentration
below 1 mg/kg, further analysis was
"Kuderna-Danish is a glass apparatus for evaporat-
ing bulk amount of solvents.
fThe major modification in the Level I sampling and
analysis procedure was the addition of GC/MS
analysis for POM.
-------
not conducted. If the concentrations
were above these levels, a class fraction-
ation by liquid chromatography was
conducted followed by GC and IR anal-
yses. If the concentrations in a LC
fraction were above these levels, LRMS
were conducted for that particular LC
fraction.
Conclusions
Characteristics of Flue Gas
Emissions
The results of the field measurements
for flue gas emissions .from utility
boilers, along with supplementary values
for certain pollutants obtained from the
existing data base, are presented in
Tables 1, 2, and 3.
Criteria Pollutants—
• Emissions of NO, from external
combustion sources for electricity
generation are a significant envir-
onmental problem. These emis-
sions account for approximately 50
percent of the total NO, emissions
from all stationary sources. Of the
N0« emissions from external com-
bustion sources for electricity gen-
eration, 77 percent are contributed
by burning of bituminous coal.
Source severity factors for NO,
emissions from utility boilers range
from 0.13 for bituminouscoal-fired
stokers to 6.4 for bituminous coal-
fired cyclone boilers.
Emissions of S02 from external
combustion sources for electricity
generation contribute significantly
to the national emissions burden.
These emissions account for ap-
proximately 57 percent of the total
SOz emissions from all stationary
sources. Approximately 88 percent
of the SOz emissions from external
combustion sources for electricity
generation are contributed by burn-
ing of bituminous coal. Source
severity factors for Uncontrolled
SOz emissions range from 0.0007
for natural gas, wall-fired boilers to
3.3 for bituminous coal-fired cy-
clone boilers.
Emissions of particulates from
external combustion sources for
electricity generation, despite the
widespread application of control
devices, are still a significant envi-
ronmental problem. These emis-
sions account for approximately 25
percent of the total particulate
emissions from all stationary sources.
Almost all (95 percent) particulate
emissions from external combustion
sources for electricity generation
are contributed by burning of bitu-
minous coal. Source severity factors
for particulate emissions range
from 0.001 for natural gas, wall-
fired boilers to 0.74 for lignite-fired
cyclone boilers.
Emissions of total hydrocarbons
from external combustion sources
for electricity generation contribute
approximately 4 percent of the total
emissions of these pollutants from
all stationary sources. Source se-
verity factors for emissions of total
hydrocarbons range from 0.005 to
0.12.
Emissions of CO from external
combustion sources for electricity
generation are not an environment-
al concern. Source severity factors
for CO emissions are all well below
0.05. Total CO emissions from
these sources account for approxi-
mately 0.6 percent of CO emissions
from all stationary sources.
Table 1. Summary of Assessment Results for Flue Gas Emissions from Bituminous Coal-Fired
Utility Boilers
Pulverized Dry Bottom Pulverized Wet Bottom Cyclone
Stokers
Pollutant
NO,
Total Hydrocarbons
CO
Particulates (Controlled/
SOi 1 Uncontrolled)
SO,
Particulate Sulfate (Controlled)
Trace Elements^
Aluminum
Beryllium
Calcium
Chlorine
Fluorine
Iron
Lead
Lithium
Nickel
Phosphorus
Silicon
POM
Dibenz(a,h)anthracene
Benzofalpyrene/Benzofelpyrene
Total POM
Emission
Factor
fng/J)
259\ 379f
4.5
17
251
1.407
13.9
0.72
8.5
O.0022
5.6
33.9
4.1
8.4
0.039
0.024
0.062
0.11
15.2
0.00022
BD
0.0039
Source
Severity
Factor
1.95". 2.S5f
0.027
0.0005
066
2.64
3.50
0.15
0.53
0.23
0.12
1.03
0.34
0.22
0.053
0.23
0.13
0.22
0.31
0.50
NA
NA
Emission
Factor
fng/J)
380
4.5
86
213
1.407
13.9
2.9
6.9
00018
4.6
33.9
4.1
6.8
0.031
0.020
0.050
0.086
12.4
BD
0.0035
0042
Source
Severity
Factor
1.70
0.016
0.0015
0.33
1.57
2.09
0.37
016
O.It
0.056
0.61
0.20
0.11
0.026
0.11
0.60
0.11
0.15
NA
21
NA
Emission
Factor
(ng/J)
678
9.5
82
57
1.407
14.1
10.8
1.4
0.00037
0.95
33.9
4.1
1.4
0.0066
0.0041
0.011
0.018
2.6
BD
BD
0.0059
Source
Severity
Factor
6.36
0.072
0.0030
0.19
3.29
4.45
2.84
0.071
0.048
0.025
1.28
0.42
0.047
0.011
0.048
0.027
0.046
0.066
NA
NA
NA
Emission
Factor
(ng/J)
241
11
157
603
1.407
13.9
10.5
2.6
0.0055
2.6
33.9
4.1
20.9
0.61
0.011
1.4
0.55
8.7
BD
BD
0.015
Source
Severity
Factor
O.13
0.0048
0.0003
0.12
0.19
0.26
0.16
0.008
0.041
0.004
0.075
0.024
0.040
0.061
0.008
0.211
0.083
0.013
NA
NA
NA
BD - Below detection limit. Detection limit for POM was 0,3 ug/m3 or approximately O.OO01 ng/J.
NA - Not applicable.
"For tangentially-fired pulverized bituminous dry bottom boilers.
jFor wall-fired pulverized bituminous dry bottom boilers.
jFor pulverized dry bottom, pulverized wet bottom, and cyclone boilers, the trace element emission factors presented are for units
equipped with electrostatic precipitators. For stokers, the trace element emission factors presented are for units equipped
with multiclones.
-------
Table 2. Summary of Assessment Results for Flue Gas Emissions from Lignite-Fired Utility Boilers
Pulverized Dry Bottom
Cyclone
Stokers
Pollutant
NO,
Total Hydrocarbons
CO
Particulates (Controlled)
S02 (Uncontrolled/
SOa
Paniculate Sulfate (Controlled)
Trace Elements"
Aluminum
Barium
Beryllium
Calcium
Copper
Fluorine
Magnesium
Nickel
Phosphorus
POM
Biphenyl
Trimethyl propenyl naphthalene
Emission
Factor
(ng/J)
260
9.0
33
62
628
NO
0.82
0.068
<0.025
<0.001
0.39
-------
Sulfates—
• Flue gas emissions of SOs (in the
form of sulfuric acid vapor and
aerosol) and particulate sulfate
from bituminous coal-fired, lignite-
fired, and residual oil-fired utility
boilers require further attention.
Source severity factors for known
SOs emissions range from 0.26 to
7.4. Source severity factors for
controlled emissions of particulate
sulfate range from 0.15 to 0.93.
Trace Elements—
• Of the trace elements present in
bituminous coal, flue gas emissions
of aluminum, beryllium, chlorine,
cobalt, chromium, iron, nickel,
phosphorus, lead, and silicon from
most coal-fired boilers are of envi-
ronmental significance.
• Of the trace elements present in
residual oil, flue gas emissions of
beryllium, chlorine, copper, mag-
nesium, nickel, phosphorus, lead,
selenium, and vanadium from resi-
dual oil-fired boilers, with mean
source severity factors greater
than 0.05, warrant special concern.
• Measurements of flue gas emis-
sions from gas-fired utility boilers
indicated that the average emis-
sions of chlorine, copper, mercury,
nickel, and phosphorus were asso-
ciated with source severity factors
greater than 0.05. This is a surpris-
ing result requiring further charac-
terization studies for confirmation.
Organics and POM—
• Analysis of organic emissions from
utility sites indicated that the princi-
pal organic constituents in flue gas
are glycols, ethers, ketones, and
saturated and aliphatic hydrocar-
bons. The most prevalent species
appear to be the glycols and ethers
which have MATE values in the
range of 10 to 1100 mg/m3. Mean
source severities calculated using
these MATE values indicated that
emissions of specific organics
(excluding POM) are probably not
of concern with respect to human
health.
• POM compounds emitted at the
highest concentrations in flue gas
streams from bituminous coal-
fired sources include naphthalene,
phenanthrene, and pyrene. Dibenz-
(a,h)anthracene and possibly benzo
(a)pyrene, both active carcinogens,
were detected at a limited number
of sites at levels of environmental
concern.
• The only POM compounds identified
in flue gas emissions from lignite-
fired sources were biphenyl and
trimethyl propenyl naphthalene.
Carcinogenic POM compounds
were not detected. The POM data
base for lignite-fired utility boilers
is considered to be adequate.
• For residual oil-fired sources, POM
compounds emitted at the highest
concentrations in flue gas streams
are naphthalene and biphenyl.
Carcinogenic POM compounds
were not detected. The POM data
base for residual oil-fired utility
boilers is adequate.
• No POM was detected in flue gas
streams from gas-fired utility boiler
sites.
Characteristics of Air Emissions
From Cooling Towers
• Air emissions of chlorine, magne-
sium, and phosphorus from mech-
anical draft cooling towers with
high drift rates are comparable to
flue gas emissions of these ele-
ments from residual oil-fired utility
boilers and of environmental signi-
ficance.
• Sulfate emissions from mechanical
draft cooling towers employing
sulfuric acid as an additive, and
with design drift losses in the 0.1 to
0.2 percent range, are of the same
magnitude as sulfate emissions
from coal-fired and oil-fired utility
boilers.
Characteristics of Wastewater
Discharges
• The results of sampling and analysis
for cooling tower blowdown, boiler
blowdown, and ash pond overflow,
combined with existing data, are
summarized in Table 4. Also listed
in this table are discharge severi-
ties, defined as the ratio of dis-
charge concentration to the health
based water Minimum Acute Toxi-
city Effluent (MATE) value.
• Characterization data for water
treatment wastewater, FGD wet
scrubber wastewater, coal pile
runoff, and chemical cleaning wastes,
based on previous studies are
summarized in Tables 5 and 6.
• The major sources of wastewater
discharges from external combus-
tion sources for electricity genera-
tion are: once-through cooling
water, blowdown from recirculating
cooling systems, wastes from water
treatment processes, chemical
cleaning wastes, and coal pile
runoff. Discharges from once-
through cooling systems amount to
7,780,000 I/sec and account for
approximately 99.8 percent of the
total wastewater from conventional
utility power plants. Of the remain-
ing sources, blowdown from recir-
cjjlating cooling systems is the
largest contributor to wastewater
discharge.
• From an environmental standpoint,
the pollutants of most concern in
wastewater effluents from conven-
tional utility power plants are iron,
magnesium, manganese, nickel,
and phosphorus.
• The average organic levels in the
ash pond effluents sampled were
less than 0.1 mg/l. Average organic
levels in the cooling tower blow-
down and boiler blowdown sampled
were 1.5 mg/l and 6.0 mg/l,
respectiveV- POM compounds were
not found above the detection limit
of 2 fjg/\.
• Based on discharge severities, the
once-through cooling water and
ash pond overflow streams appear
to be of lesser environmental signi-
ficance than the other wastewater
streams from conventional fossil-
fueled steam electric plants. Total
pollutant loading from wastewater
streams will, however, depend on
individual discharge flow rates.
Characteristics of Solid Wastes
• The results from analysis of fly ash
and bottom ash samples from bitu-
minous coal-fired and lignite-fired
utility boilers, supplemented by
data from previous studies, are
summarized in Table 7.
• Solid waste streams generated by
conventional utility power plants
consist primarily of coal ash and
sludge from FGD systems. In 1978,
total ash production was 63.6 Tg
and total FGD sludge production
was 2.1 Tg (on ash-free basis).
• Concentrations of 11 to 16 trace
elements in bituminous coal ash
and lignite ash exceed their health
based solid MATE values. The
pollutants of most concern are
aluminum, arsenic, calcium, chro-
mium, iron, manganese, nickel,
potassium, and silicon.
-------
Table 4. Summary of Assessment Results for Cooling Tower Slowdown, Boiler Slowdown, and Ash Pond
Overflow
Cooling Tower Slowdown Boiler Slowdown Fly Ash Pond Overflow Bottom Ash fond Overflow Combined Ash Pond Overflow
Constituent
Gross Parameters
pH
Conductivity,
(jmhos/cm
Hardness,
(as CaC03). mg/l
Alkalinity
(as CaCOa), mg/l
TSS, mg/l
BOD, mg/l
COD. mg/l
Trace Elements, mg/l
Arsenic
Calcium
Cadmium
Chromium
Iron
Magnesium
Manganese
Nickel
Phosphorus
Selenium
Silicon
Chloride, mg/l
Sulfate, mg/l
Phenols, mg/l
Organics, mg/l
Total volatile
(Cj-CieJ
Total nonvolatile
f>C,,J
Effluent
Concentration
7.3
3,050
1,220
56
26
18
94
0.28
1,700
0.094
0.48
1.8
650
0.30
—
9.9
0.081
—
—
1,300
—
0.021
1.41
Discharge
Severity
NA
NA
NA
NA
NA
NA
NA
1.1
0.89
1.9
1.9
1.2
1.4
1.2
—
6.6
1.6
—
—
1.0
—
NA
NA
Effluent
Concentration
10.5
150
340
97
87
3.0
53
—
—
—
—
—
—
—
—
8.0
—
—
—
—
0.026
1.3
4.7
Discharge
Severity
NA
NA
NA
NA
NA
NA
NA
—
—
—
—
—
—
—
—
5.3
—
—
—
—
5.2
NA
NA
Effluent
Concentration
5.8
10,000
220
30
49
ND
ND
8.7
—
—
—
1.2
—
0.25
0.40
—
—
—
—
—
—
0
0.056
Discharge
Severity
NA
NA
NA
NA
NA
NA
NA
35
—
—
—
0.80
—
1.0
1.8
—
—
—
—
—
—
NA
NA
Effluent
Concentration
7.4
6,000
205
62
41
ND
ND
2.2
—
—
—
2.5
410
0.19
—
—
—
—
—
—
—
0.007
0.090
Discharge
Severity
NA
NA
NA
NA
NA
NA
NA
8.9
—
—
—
1.7
0.85
0.76
—
—
— '
—
—
—
—
NA
NA
Effluent
Concentration
9.2
480
185
81
33
ND
ND
—
—
—
—
—
—
—
—
—
—
—
—
—
—
0
0.070
Discharge
Severity
NA
NA
NA
NA
NA
NA
NA
—
—
—
—
—
—
—
—
—
—
—
—
—
—
NA
NA
ND - No data because analysis for these parameters was not performed.
NA - Not applicable because there are no MATE values associated with these parameters to compute discharge severities.
Data for constituents with discharge severities less than 1.0 are indicated by "—".
• Organics in bituminous coal ash
and lignite ash are mostly present
as the C16 fraction. POM concen-
trations in fly ash and bottom ash
are not at levels of environmental
concern. The only POM compounds
detected were naphthalene, alkyl
naphthalenes, and other compounds
with high MATE values.
Recommendations
Because of inadequacies in the data
base that characterizes emissions from
external combustions for electricity
generation, it is recommended that
•additional studies be conducted to
provide the identified key data needs.
These key data needs are discussed as
follows.
Flue Gas Emissions—
• The combination of emissions data
from this measurement program
and the existing data base provides
adequate characterization of flue
gas emissions of criteria pollutants
from most external combustion
sources for electricity generation.
The notable exception is the lack of
emissions data for pulverized dry
bottom boilers firing Texas lignite.
This is a serious data deficiency be-
cause approximately 16,000 MW
of added generating capacity are
planned for this source category in
the 1978-1985 period.
• Size distribution data for flue gas,
emissions of particulates are inade-
quate for bituminous coal-fired.
lignite-fired , and residual oil-fire
utility boilers.
For bituminous coal-fired and resi
dual oil-fired utility boilers, th
data base for SO3 emissions i
adequate. However, 80s emission
data for lignite-fired sources ar
presently unavailable.
The data base for uncontrolle
paniculate sulfate emissions froi
residual oil-fired sources is adc
quate. The data base for controlle
paniculate sulfate emissions froi
bituminous coal-fired and ligniti
fired sources, however, is inadi
quate.
For bituminous coal-fired boilei
equipped with electrostatic precip
tators, the data base characterize
8
-------
Tabled.
Summary of Assessment Results for Water Treatment Wastawater, Wet Scrubber Wastewater,
and Coal Pile Runoff
Water Treatment Wastewater Wet Scrubber Coal Pile Runoff
Waatawater'
Constituent
Ion Exchange
Effluent Ditcharge
Concentration Severity
Clarification Effluent Discharge. Effluent Discharge
Effluent Discharge Concentration Severity Concentration Severity
Concentrataion Severity
Gross Parameters
pH
Hardness
(as CaC03), mg/l
Alkalinity
(as CaC03), mg/l
TSS, mg/l
BOD, mg/l
COD,mg/l
Trace Elements,mg/l
Aluminum
Beryllium
Chromium
Copper
Iron
Lead
Magnesium
Manganese
Mercury
Nickel
Phosphorus
Selenium
Sodium
Zinc
Chloride, mg/l
Sulfate, mg/l
Ammonia, mg/l
Hydrazine, mg/l
Phenols, mg/l
ND
1.000
560
32
36
48
—
—
0.27
—
4.2
—
—
—
—
—
—
—
3,200
—
1,800
—
—
—
—
NA
NA
NA
NA
NA
NA
—
—
1.0
—
2.8
—
—
—
—
—
—
—
4.0
—
1.5
—
—
—
—
ND
3,300
340
25,200
20
160
160
—
0.61
—
350
—
—
—
—
0.32
—
—
—
—
—
—
—
—
- —
NA
NA
NA
NA
NA
NA
1.1
—
2.4
—
233
—
—
—
—
1.5
—
—
—
—
—
—
—
—
— —
7.5
ND
108
ND
ND
185
—
0.04
—
—
—
—
500
0.95
0.044
0.50
—
0.59
MOO
—
2,500
4,700 *
—
—
—
NA
NA
NA
NA
NA
NA
—
1.3
—
—
—
—
1.2
3.4
4.4
2.3
—
12
1.4
—
2.1
3.6
—
—
—
2.7
ND
ND
330
ND
ND
150
0.03
—
—
660
—
—
33
—
1.5
—
—
—
—
—
—
—
—
—
NA
NA
NA
NA
NA
NA
1.0
1.0
—
—
440
—
—
131
—
6.6
—
—
—
—
—
—
—
—
—
*Sludge liquor from lime/limestone FGD scrubber
ND - No data.
NA - Not applicable because there are no MATE values associated with these parameters to compute discharge severities.
Data for constituents with discharge severities less than 1.0 are indicated by "—".
flue gas emissions is adequate for
most trace elements. Similar data
bases characterizing flue gas emis-
sions of trace elements from sources
equipped with wet scrubbers and
mechanical precipitators, however,
are inadequate.
Existing data for flue gas emissions
of trace elements from lignite-fired
utility boilers are generally not
available. Analysis of the data ac-
quired in this program indicated
the need for additional characteri-
zation studies. The most serious
data deficiency is the characteriza-
tion of flue gas emissions of trace
elements from pulverized dry bottom
boilers firing Texas lignite, a source
category with increasing importance
in power generation.
The data base characterizing flue
gas emissions of trace elements
from residual oil-fired utility boilers
appears to be adequate except for
beryllium, calcium, chlorine, copper,
fluorine, magnesium, lead, seleni-
um, and vanadium. The emissions
data base for these trace elements
can be improved.by analysis of
additional residual oil samples.
The Level I SSMS technique has
served its purpose in providing
valuable trace element survey and
screening data. To more accurately
determine the emission levels of
these potentially hazardous trace
elements, it is important that future
source tests and analyses be con-
ducted using Level II techniques on
a selected number of trace elements,
with the primary objective that
meaningful enrichment factors
can be calculated.
• Although current data indicated
that emissions of specific organics
(excluding POM) are probably not
of concern with respect to human
health, more detailed Level II organic
analysis would be required to con-
clusively determine the significance
of organic emissions.
• The data base characterizing flue
gas emissions of POM from bitumi-
nous coal-fired sources is adequate
except for dibenz(a,h)anthracene
and benzo(a)pyrene. Emissions of
these specific POM compounds
will require further characteriza-
tion.
-------
Table 6. Summary of Assessment Results for Chemical Cleaning Wastes
Chemical Cleaning Wanes
Constituent
Gross Parameters
PH
Hardness
(as CaC03), mg/l
Alkalinity
(as CaC03), mg/l
TSS, mg/l
BOD. mg/l
COD, mg/l
Trace Elements, mg/l
Aluminum
Beryllium
Chromium
Copper
Iron
Lead
Magnesium
Manganese
Mercury
Nickel
Phosphorus
Selenium
Sodium
Zinc
Chloride, mg/l
Suit 'ate, mg/l
Ammonia, mg/l
Hydrazine, mg/l
Phenols, mg/l
Acid Phase Composite
Cffluent
Concentration
1.1
ND
ND
45
ND
2.870
—
—
2.9
15
2,880
2.1
—
19
—
178
35
—
—
48
—
—
—
—
0.044
Alkaline Phase Composite
Neutralization Drain
Discharge Effluent Discharge Effluent Discharge
Severity Concentration Severity Concentration Severity
NA
NA
NA
NA
NA
NA
—
—
12
3.0
1.920
8.2
—
77
—
809
23
—
—
1.9
—
—
—
—
8.8
ND
ND
ND
67
ND
90
—
—
—
530
2.4
—
—
-
—
1.6
143
—
—
—
—
—
2,740
—
—
NA
NA
NA
NA
NA
NA
—
—
—
106
1.6
—
—
—
—
7.1
95
—
—
—
—
—
10
—
—
11.4
ND
ND
47
ND
70
—
—
—
5.1
7.3
—
—
—
—
—
755
—
0.060
—
—
—
—
0.013
—
NA
NA
NA
NA
NA
NA
—
—
—
1.0
4.8
—
—
—
—
—
503
—
;.c
—
—
—
—
5.;
—
ND - No data.
NA - Not applicable because there are no MA TE values associated with these parameters to compute discharge severities.
Data for constituents with discharge severities less than 1.0 are indicated by "—"
Wastewater Discharges—
• The data bases characterizing cool-
ing tower blowdown, ash pond
overflow, chemical cleaning wastes,
wet scrubber wastewater, and coal
pile runoff are inadequate. The
present study has been instrumen-
tal in applying Level I techniques to
identification of wastewater constit-
uents which pose potential environ-
mental problems. Since potential
problems were detected by Level I
techniques, further studies using
Level II techniques will be required
to adequately characterize waste-
water effluents from utility boilers.
Solid Wastes—
• Data on FGD scrubber sludge are
limited. Needed data will be provided
by extensive scrubber sludge char-
acterization studies currently in
10
progress under the direction of EPA
and the Electric Power Research
Institute (EPRI).
-------
Table 7. Summary of Assessment Results for Fly Ash and Bottom Ash from Bituminous Coal-Fired and Lignite-Fired Boilers
Bituminous Fly Ash Bituminous Bottom Ash Lignite Fry Ash Lignite Bottom Ash
Pollutant
Trace Elements
Aluminum
Arsenic
Barium
Boron
Calcium
Chromium
Cobalt
Iron
Lead
Lithium
Magnesium
Manganese
Mercury
Nickel
Phosphorus
Potassium
Selenium
Silicon
Organics
Total Volatile
Concentration
Ippm)
4.300-100.000
3-240
280-640
25-700
1.100-121,000
19-300
7-57
32,000-143,000
7-110
46-86
820-13.400
100-300
0.01-28
10-250
82-5,100
2,900-20,000
4-32
17.000-276.000
<14-87
Discharge
Severity
0.27-6.3
0.06-4.8
0.28-0.64
0.003-0.075
0.023-2.5
0.38-6.0
0.047-0.38
110-480
0. 14-2.2
0.66-1.2
0,046-0.74
2.0-6.0
0.0005-1.4
0.22-5.6
0.027-1.7
0.69-4.8
0.4-3.2
0.57-9.2
NA
Concentration
Ippm)
3.700-90.000
1-18
220-450
5.5-300
3. 100-93,000
15-220
4-31
47,000-213.000
6-120
3-60
1.300-12,400
37-860
0.1-0.5
0.3-100
120-3,800
1,000-15,800
<1-5.6
7.500-276.000
<14-S7
Discharge
Severity
0.23-5.6
0.02-0.36
0.22-0.45
0.0006-0.032
0.065-1.9
0.30-4.4
0.027-0.21
160-710
0.12-2.4
0.043-0.86
0.072-0.69
0.74-17
0.005-0.025
0.007-2.2
0.04-1.3
0.24-3.8
<0. 1-0.56
0.25-9.2
NA
Concentration
(ppml
3,500-35,000
73-830
1.200-15.000
320-13.0OO
27.000-130,000
8.1-64
7.1-1,200
1.000-11,000
9.3-160
1.3-62
17.000-32,000
200-1.300
0.086-2.0
21-1.600
120-4.600
1.200-30,000
<0.21-19
34,000-53,000
0.5-15
Discharge
Severity
0.22-2.2
1.6-17
1.2-15
0.034-1.4
0.56-2.7
0.16-1.3
0.047-8.0*
3.3-37
0.19-3.2
0.019-0.89
0.94-1.8
4.0-26
0.0043-0.1
0.47-36
0.04-1.5
0.29-7.1
<0.21-1.9
1.1-1.8
NA
Concentration
Ippm)
8. 100-27.000
22-400
2, 100-20.000
490-6.300
63,000- 130,000
5.1-22
6-11
27,000-71,000
4.3-150
3.8-79
4.600-35,000
310- 1.000
<0.017-0.094
44-140
110-5.200
660-15,000
1.3-5.5
31.000-50,000
0.9-11
Discharge
Severity
0.51-1.7
0.44-8.0
2.1-20
0.053-0.68
1.3-2.7
0.10-0.44
0.04-0.073
90-240
0.086-3.0
0.054-1.1
0.26-1.9
6.2-20
Cie organics were not computed because there is no representative
MATE value for either group.
C. C. Shih. R. A. Orsini, D. G. Acker man, R. Moreno, E. L Moon, L L Scinto, and
C. Yu are with TRW Environmental Engineering Division, Redondo Beach, CA
90278.
Michael C. Osborne is the EPA Project Officer (see below).
The complete report, entitled "Emissions Assessment of Conventional Station-
ary Combustion Systems: Volume III. External Combustion Sources for
Electricity Generation," (Order No. PB 81-145 195; Cost: $33.50, subject to
change) will be available only from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
Industrial Environmental Research Laboratory
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711
* U£ QOVERNMEHT PWNTINO OFFICE 1981 757-012/7072
-------
CO
8
o
3'
o
5'
3
at
O
I
4*
Ol
N>
CD
00
m > TJ m
?1 1 1
CO O O O
CO-< ^. 3
CO
CO-<
01
------- |