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

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 '
 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

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 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.

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                                                                          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.

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 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

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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

-------
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