x> EPA
United States
Environmental Protection
Agency
Off ice of Air Quality
Planning and Standards
Research Triangle Park NC 27711
EPA-450/1-89-003
January 1989
Air/Superfund
AIR/SUPERFUND
NATIONAL TECHNICAL
GUIDANCE STUDY SERIES
Volume III - Estimation
of Air Emissions from
Cleanup Activities at
Superfund Sites
Interim Final
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VOLUME III
ESTIMATION OF AIR EMISSIONS
FROM CLEAN-UP ACTIVITIES
AT SUPERFUND SITES
INTERIM FINAL
by
Radian Corporation
8501 Mo-Pac Boulevard
P. 0. Box 201088
Austin, Texas 78720-1088
Prepared for:
Mr. John Summerhays
U.S. ENVIRONMENTAL PROTECTION AGENCY
OFFICE OF AIR QUALITY PLANNING AND STANDARDS
RESEARCH TRIANGLE PARK, NORTH CAROLINA 27711
January 1989
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PREFACE
This Is one In a series of manuals dealing with air pathway analysis at
hazardous waste sites. This document was developed for the Office of Air
Quality Planning and Standards in cooperation with the Office of Emergency
and Remedial Response (Superfund). It has been reviewed by the National
Technical Guidance Study Technical Advisory Committee and an expanded review
group consisting of State agencies, various groups within the U.S. Environ-
mental Protection Agency, and the private sector. This document is an
interim final manual offering technical guidance for use by a diverse
audience including EPA Air and Superfund Regional and Headquarters staff,
State Air and Superfund program staff, Federal and State remedial and removal
contractors, and potentially responsible parties in analyzing air pathways at
hazardous waste sites. This manual is written to serve the needs of in-
dividuals having different levels of scientific training and experience in
designing, conducting, and reviewing air pathway analyses. Because assump-
tions and judgments are required in many parts of the analysis, the in-
dividuals conducting air pathway analyses need a strong technical background
in air emission measurements, modeling, and monitoring. Remedial Project
Managers, On Scene Coordinators, and the Regional Air program staff,
supported by the technical expertise of their contractors, will use this
guide when establishing data quality objectives and the appropriate
scientific approach to air pathway analysis. This manual provides for flexi-
bility in tailoring the air pathway analysis to the specific conditions of
each site, the relative risk posed by this and other pathways, and the pro-
gram resource constraints.
Air pathway analyses cannot be reduced to simple "cookbook" procedures.
Therefore, the manual is designed to be flexible, allowing use of profes-
sional judgment. The procedures set out in this manual are intended solely
for technical guidance. These procedures are not intended, nor can they be
relied upon, to create rights substantive or procedural, enforceable by any
party in litigation with the United States.
It is envisioned that this manual will be periodically updated to incor-
porate new data and information on air pathway analysis procedures. The
Agency reserves the right to act at variance with these procedures and to
change them as new information and technical tools become available on air
pathway analyses without formal public notice. The Agency will, however,
attempt to make any revised or updated manual available to those who
currently have a copy through the registration form included with the manual.
Copies of this report are available, as supplies permit, through the
Library Services Office (MD-35), U.S. Environmental Protection Agency,
Research Triangle Park, North Carolina 27711 or from the National Technical
Information Services, 5285 Port Royal Road, Springfield, Virginia 22161.
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DISCLAIMER
Mention of trade names or commercial products does not constitute
endorsement or recommendation for use by the Air Management Division, U.S.
Environmental Protection Agency.
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CONTENTS
Figures vii
Tables ix
Superfund Abbreviations/Acronyms xii
Key to Parameters Used In Equations xiv
Acknowledgement xvi
1.0 Introduction 1
1.1 Background 1
1.2 Objectives 3
1.3 Approach 3
1.4 Recommended Uses of This Manual 4
1.5 Document Organization 8
2.0 Discussion of Emissions during Site Cleanups 9
2.1 Thermal Destruction 9
2.1.1 Emission Sources 10
2.1.2 Key Parameters Affecting Emissions 18
2.1.3 Possible Control Technologies 27
2.2 Air Stripping of Ground Water 34
2.2.1 Emission Sources 34
2.2.2 Key Parameters Affecting Emissions 36
2.2.3 Possible Control Technologies 38
2.3 In-Situ Venting 40
2.3.1 Emission Sources 40
2.3.2 Key Parameters Affecting Emissions 46
2.3.3 Possible Control Technologies 49
2.4 Soils Handling 50
2.4.1 Emission Sources 50
2.4.2 Key Parameters Affecting Emissions 52
2.4.3 Possible Control Technologies 56
iii
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CONTENTS (Continued)
2.5 Stabilization/Solidification 63
2.4.1 Emission Sources 63
2.4.2 Key Parameters Affecting Emissions 65
2.4.3 Possible Control Technologies 65
3.0 Protocol for Estimating Emissions 69
3.1 Presentation of Protocol Steps 69
3.2 Preliminary Emissions Estimation Procedure 71
3.3 Estimation of Emissions for Thermal Destruction Devices 76
3.3.1 Organic Compounds 77
3.3.2 Particulate Matter 82
3.3.3 Metals ^ 83
3.3.4 Acid Gas 85
3.3.5 NOX 87
3.3.6 Fugitive Emissions 87
3.4 Air Stripping of Ground Water 88
3.5 In-s1tu Venting 89
3.6 Soils Handling 93
3.6.1 Presentation of Equations and Steps in the
Process 93
3.6.2 Data Assumptions and Limitations 119
3.7 Solidification/Stabilization 123
3.8 No Action/Post Clean-Up Emissions 125
IV
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CONTENTS (Continued)
4.0 Input Data Collection 126
4.1 Site Description 126
4.2 Preliminary Assessment of Emissions Potential 127
4.3 Emissions Estimate for Scenario One 127
4.3.1 VOC Emissions From Soils Handling 128
4.3.2 Particulate Emission Factors from Soils Handling 132
4.3.3 Particulate Emission Rates from Soils Handling. . 137
4.4 Emission Estimate for Scenario Two 145
4.4.1 Waste Handling Emissions 145
4.4.2 Stack Emissions 148
4.4.3 Organic Compounds 148
4.4.4 Particulate Matter (PM) 150
4.4.5 Metal Emissions 150
4.4.6 Acid Gas Emissions 151
4.4.7 Fugitive Emissions 151
4.5 Emissions Estimate for Scenario Three 153
4.5.1 Uncontrolled Emissions 153
4.5.2 Controlled Emissions 154
4.6 Emissions Estimate for Scenario Four 154
4.7 Summary and Data Analysis 155
5.0 INPUT DATA COLLECTION 159
5.1 Data Needs/Data Quality Objectives 159
5.2 Data Collection Approaches 163
5.2.1 Emission Source Assessments 163
5.2.2 Ambient Concentration Assessments 165
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CONTENTS (Continued)
6.0 REFERENCES 167
Appendix A - Annotated Bibliography A-l
Appendix B - Superfund Glossary of Terms B-l
Appendix C - Advantages and Disadvantages of Various
Incineration Technologies C-l
Appendix D - Estimation Procedures for Air Dispersion. ... D-l
vi
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FIGURES
Number Page
1 Superfund flow chart 6
2 Process flow diagram for a typical hazardous waste
Incineration system 15
3 Typical air stripper and blower 35
4 An example of a subsurface ventilation system (vacuum type). 41
5 Illustration of air-flow patterns active in subsurface
ventilation systems employing (a) vacuum, (b) impermeable
barriers, and (c) air intake wells 43
6 Pressure subsurface ventilation system designed to prevent
encroaching vapors from entering through the basement of a
dwelling 44
7 Passive subsurface ventilation system utilizing horizontal
perforated pipe 45
8 Cross-sectional view of the soil system. (The soil is a
three-phase system consisting of solids, liquids, and gases.
Only the gas space is available for movement of VOC vapors.) 48
9 Flowchart of air pathway analysis for remediation 70
10 Flowchart for incineration air emissions estimation 78
11 Vapor pressures of metals 84
12 Schematic of vapor recovery well and associated pressure
gradient 91
vi i
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FIGURES
13 Flowchart A: Soils handling emissions estimating methodology 94
14 Flowchart B: Estimating volatile organic emissions 103
15 Flowchart C: Estimating excavation emissions 107
16 Flowchart D: Estimating transport emissions 108
17 Flowchart E: Estimating dumping emissions 109
18 Flowchart F: Estimating storage emissions 110
19 Flowchart G: Estimating grading emissions Ill
20 Flowchart I: Determination of RCRA metal enrichment on
fugitive particulate emissions 112
21 Mean number of days with >0.254 mm (0.01 in.) of
precipitation per year 116
22 Flowchart H: Estimating solidification and stabilization
emissions 124
23 Flowchart for input data collection 161
vi ii
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TABLES
Number Page
1 Thermal Destruction Technologies 12
2 Applicability of Available Incineration Processes to the
Burning of Waste (By Waste Type) 17
3 Factors Affecting Incineration System Emissions 19
4 Typical Ranges of Uncontrolled Emissions for Incineration 21
5 Typical Temperatures and Residence Times for Hazardous
Waste Destruction 22
6 Emissions of D1ox1ns and Furans from Hazardous Waste
Incineration Facilities 24
7 Incineration System Air Pollution Control Devices 29
8 Spray Dryer Control of Dioxins and Furans 30
9 Effectiveness of Acid Gas Controls (% Removal) 32
10 Typical Ranges of Emissions 53
11 Important Parameters in Determining and Controlling Emissions
From Remedial Action 55
12 Control Technologies Available for Each Soils Handling
Emissions Category 57
13 Efficiencies of Various Control Technologies 58
14 Typical Ranges of Emissions 66
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TABLES (Continued)
15 Important Parameters in Determining and Controlling Emissions
from Remedial Action 67
16 Control Technologies Available for Each Soils Handling
Emissions Category 68
17 Control Technologies Available for Each Remedial Option 72
18 Summary of Typical Air Emission Values by Source Type 74
19 Emission Factor (EF) Equations for Incineration Systems 79
20 Ranges of Particulate Metals Emissions for Five Hazardous
Waste Incinerator Tests 86
21 Emission Factor (EF) Equations for SOils Handling (Total
Suspended Particulate) 97
22 Definitions of Parameters and Units for Soils Handling
Emissions Factors 98
23 Typical Particle Size Multipliers (K, Dimensionless) 99
24 Emission Factor Equations for Inhalable or Smaller
Particulates: Excavation and Grading 100
25 Typical Particulate Size Distributions as Weight Percent of
Emissions 101
26 Baseline VOC Emissions Factors for Hazardous Wastes 104
27 Increase in Emissions Due to Soils Handling 1"06
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TABLES (Continued)
28 Typical Values of Physical Properties for Various Materials
with Ranges Parentheses 114
29 Ranges of Source Conditions for Transport and Excavation
Equations with Typical Values by Vehicle Type 115
30 Metal Concentration and Enrichment Data 118
31 Conversion of Emission Factors to Emission Per Unit Time 120
32 Typical Operating Rates for Soil Handling Activities 121
33 Erewhon Site Parameters (To Estimate Emissions From Soil
Handling) 129
34 Summary - Emissions From Soils Handling Total Suspended
Particulate (TSP, <30 urn) 143
35 Summary - Emissions From Soils Handling Inhalable
Particulate (<15 urn) 144
36 Site Parameters 149
37 Stack Emissions Due to Incineration 152
38 Summary of Emission Rate Estimates 156
39 Summary of Analytical Levels Appropriate to Data Uses 162
XI
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SUPERFUND ABBREVIATIONS/ACRONYMS
ACGIH American Conference of Government Industrial Hygienists
ACL Alternate Concentration Limit
AO Administrative Order on Consent
APA Air Pathway Analysis
APCD Air Pollution Control Device
ARAR Applicable or Relevant and Appropriate Requirement (Cleanup
Standard)
ATSDR Agency for Toxic Substances and Disease Registry
CAA Clean Air Act
CAS Carbon Adsorption System
CD Consent Decree
CERCLA Comprehensive Environmental Response. Compensation, and Liability
Act
CERCLIS Comprehensive Environmental Response. Compensation, and Liability
Information System
CERI Center for Environmental Research Information
CR Community Relations
CRF Combustion Research Facility--Pine Bluff. Arkansas
CFR Code of Federal Regulations
CWA Clean Water Act
DQO Data Quality Objective
DRE Destruction and Removal Efficiency
EDD Enforcement Decision Document
ERT Environmental Response Team
ESP Electrostatic Precipitator
FIFRA Federal Insecticide. Fungicide, and Rodenticide Act
FP Fine Particulate
FS Feasibility Study
HRS Hazard Ranking System
HSWA Hazardous Waste Engineering Amendments to RCRA. 1984
HWERL Hazardous Waste Engineering Research Laboratory
IDLH Immediately Dangerous to Life or Health
MCL Maximum Contaminant Level
MCLG Maximum Contaminant Level Goal
NBAR Nonbinding Preliminary Allocation of Responsibility
NCP National Contingency Plan
NEIC National Enforcement Investigations Center
NFPA National Fire Protection Association
NIOSH National Institute of Occupational Safety and Health
NPL National Priorities List
NRC National Response Center
NRT National Response Team
NTIS National Technical Information Service
OERR Office of Emergency and Remedial Response
O&M Operation and Maintenance
ORD Office of Research and Development
OSC On-Scene Coordinator
OSH Act Occupational Safety and Health Act
OSHA Occupational Safety and Health Administration
OSWER Office of Solid Waste and Emergency Response
OTA Office of Technology Assessment
PA Preliminary Assessment
xii
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PEL Permissible Exposure Limits
PIC Products of Incomplete Combustion
PM-20 Participate Matter with Physical Diameter <20 urn
PRP Potentially Responsible Party
QA/QC Quality Assurance/Quality Control
QAPP Quality Assurance Project Plan
RA Remedial Action
RCRA Resource Conversation and Recovery Act
RD Remedial Design
REL Recommended Exposure Limit
RI Remedial Investigation
RI/FS Remedial Investigation/Feasibility Study
ROD Record of Decision
RPM Remedial Project Manager
RRT Regional Response Team
RQ Reportable Quantity
SAB Science Advisory Board
SARA Superfund Amendments and Reauthorization Act
SCAP Superfund Comprehensive Accomplishments Plan
SI Site Inspection
SITE Superfund Innovative Technology Evaluation
SWDA Solid Waste Disposal Act (RCRA predecessor)
TLV Threshold Limit Value
TLV-C Threshold Limit Value - Ceiling
TLV-STEL Threshold Limit Value - Short-Term Exposure Limit
TLV-TWA Threshold Limit Value - Time-Weighted Average
TSDF Treatment Storage and Disposal Facility
TSCA Toxic Substances Control Act
TSP Total Suspended Particulate
Title III Emergency Planning and Community Right-to-Know Act (SARA)
T&E Testing and Evaluation
UST Underground Storage Tank
VO Volatile Organics
VOC Volatile Organic Compound
xiii
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KEY TO PARAMETERS USED IN EQUATIONS
Parameter
A
Ash
CE
C,
C1f In
C,, out
ORE
d
ER,
E,
g
h
i
1d
k
k.
L
1
LPr
M
%MF
"I
n«
n
P
PH20
Definition
Cross-sectional or surface area
Ash content of waste feed
Control efficiency
Concentration of species 1
C, of Influent stream
C, of effluent stream
Destruction and removal efficiency
Drop height
Densit of air
Emission factor for species 1
Emission rate of species 1
Emissions of species 1
Acceleration due to gravity
Vertical distance
Industrial augmentation factor
Inside diameter
Particle size multiplier
Air permeability in soil
Surface dust loading
Distance
Liquid product recovery rate
Moisture content
Metal emitted as % of metal fed
Mass flow rate of waste
Viscosity of air
Number of traffic lanes
Pressure
Pressure
Units
m2
g/kg
%
ug/L or g/kg or g/m3
m
g/m3
kg/hr or kg/unit operation
g/sec or g/m2"sec
kg
m/sec2
m
m
m/sec
kg/km
m
L/sec
Ut. %
%
kg/sec
Nsec/m2
N/m2
m of H20
xiv
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KEY TO PARAMETERS USED IN EQUATIONS (Continued)
Parameter
PMQuench
PMDrop
Q
Definition
Units
Solids produced by quenching kg/hr
Solids resulting from droplet carryover kg/hr
Flow rate m3/min
Number of days/year with precipitation days
RE
RT
S
s
sL
T
U
V
VKT
v
W
x
X.Y.Z
Removal efficiency %
Retention time sec
Mean vehicle speed km/hr
Silt content Ut. %
S1lt loading of road surface g/m2
Temperature *C
Number of days that remedial option
X Is performed days
Mean wind speed m/sec
Volume m3
Vehicle kilometer traveled km
Velocity m/sec
Mean vehicle weight Mg
Weight fraction of component i in
process stream kg/kg
Mean number of wheels
Generic remedial options
xv
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ACKNOWLEDGEMENTS
This manual was prepared for the U.S. Environmental Protection Agency by
Radian Corporation, Austin. Texas. Mr. Leigh Hayes (project manager) and Ms.
Susan Fernandes (contract manager) managed the project. Mr. Bart Eklund
served as project director and author of several sections. Other authors
Included Ms. Fritzl Scheffel and Mr. Kelly Wert. Radian reviewers Included
Messrs. Dave Balfour and Charles Schmidt.
Mr. Joe Padgett and his staff at the Office of Air Quality Planning and
Standards, U.S. Environmental Protection Agency, provided overall program
direction. Mr. John Summerhays of the U.S. EPA A1r Management Division.
Region V. directed efforts on this particular manual.
Other support was provided by the program's Technical Advisory Committee.
the members of which Include:
Mr. Joe Padgett. U.S. EPA OAQPS
Mr. Jim Durham. U.S. EPA OAQPS
Mr. Stan Sleva. U.S. EPA OAQPS
Mr. Joe Tlkvart, U.S. EPA OAQPS
Mr. Ed Ellis. U.S. EPA OAQPS
Mr. Jim Southerland. U.S. EPA OAQPS
Mr. David Dunbar. PEI Associates. Inc.
Mr. Jim Vickery. U.S. EPA HSCD
Mr. Abe Ferdas. U.S. EPA Region III
Mr. Tom Pritchett, Emergency Response Team. NOA
Mr. John Summerhays. U.S. EPA Region V
Ms. Margaret McDounough. U.S. EPA Region I
Mr. Mark Garrison. U.S. EPA Region III
Mr. Al dmorelli. U.S. EPA Region III
Mr. Ron Stoner. NUS Corporation
Mr. Bart Eklund, Radian Corporation
Mr. Chuck Schmidt. Radian Corporation
This program also received support from the Regional Air Superfund
Program and its participants.
Peer review of the manual was provided by the Technical Advisory
Committee memebers and by others including: Grace Musumeci (EPA. Region II).
Donna Abrams (EPA. Region III). Mark Hansen (EPA. Region VI). Henry Holman
(Region VI). and Thomas Shen (NY. DEC).
xvi
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SECTION 1
INTRODUCTION
1.1 BACKGROUND
The United States Environmental Protection Agency (EPA) is responsible
for the assessment and cleanup of National Priority List (NPL) sites, under
the Comprehensive Environmental Response. Compensation, and Liability Act
(CERCLA) and the Superfund Amendments and Reauthorization Act (SARA). CERCLA
created a tax on the chemical and petroleum industries. The money collected
from the tax goes to a Trust Fund (commonly referred to as the Superfund) to
clean up abandoned or uncontrolled hazardous waste sites.
The law authorizes the EPA to implement two types of response actions:
• Short-term removal actions to quickly address actual or threatened
releases requiring expedited response: and
• Longer term remedial actions that end or reduce the actual or
threatened releases of hazardous substances that are serious, but
not immediately life-threatening.
The response actions may include removal to a licensed hazardous waste
facility, permanent containment of the waste, on-site destruction or
treatment, or removal of the source of ground-water contamination while
halting further transport of the contaminants.
The primary motivations for clean-up of NPL sites are to protect the
general environment and to protect the health and safety of persons in
proximity to the site. Contamination at a given NPL site may pose a current
or future risk by exposure from a number of potential pathways. These include
direct contact with the in-situ pollutants, subsurface migration of the
contaminants via vapor plumes or ground-water plumes, contamination of surface
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waters, and atmospheric transport (and deposition) of gaseous, aerosolized, or
wind-blown contaminants. To successfully assess and clean up an NPL site, it
is necessary to characterize the initial state of the site and to analyze the
potential effects of pollutant transport via the applicable exposure pathways
for each step of the assessment and clean-up process. The EPA is developing a
four-volume set of guidance manuals to assist the RPN in assessing air impacts
throughout the Superfund process. This manual (Volume III) provides guidance
for estimating the impact of contaminant migration from one pathway, the air
pathway, during remediation, a key step of the overall process.
In addition to the federal program for the cleanup of hazardous waste
sites, most states have implemented similar programs and many private parties
are also initiating cleanups of hazardous waste sites. Although the
terminology in this manual tends to refelct the structure and approaches of
the federal program, the information in this manual should also be applicable
to the cleanup of any kind of site with hazardous wastes or hazardous
substances.
Emissions of organic and inorganic contaminants from hazardous waste
sites may pose a potential risk, even from undisturbed sites. Clean-up
activities have the potential to greatly increase undisturbed or baseline
emissions and may result in significant impacts to the local air quality for
both on-site workers and the surrounding community. However, the air quality
impacts of clean-up methods such as soil removal, incineration, air stripping
and soil vapor extraction have not been fully characterized. Therefore, the
air pathway has historically been difficult to assess for remedial actions.
This manual is a preliminary step in meeting the EPA's stated needs to:
• Establish the range of clean-up operations that can lead to
significant air emissions:
• Determine what emissions estimation techniques are available:
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• Establish emissions relationships based on ambient air monitoring
data; and
• Develop a uniform assessment technique for performing air pathway
analyses (APA).
1.2 OBJECTIVES
The overall goal of this program Is to develop guidelines for predicting
and/or measuring air emissions during remedial activities. For this
preliminary version of the manual, the objectives were to:
1) Present a protocol for estimating air emissions from remedial
activities at NPL sites:
2) Identify existing data gaps or limitations in the protocol; and
3) Provide guidance for collecting data to estimate or confirm air
emissions.
Field studies are scheduled to address one of the data gaps that has been
identified. A revised version of this manual will be published subsequent to
this research.
1.3 APPROACH
To meet the objectives of this program, three steps were undertaken to
compile and assess existing information: 1) Conduct a literature search.
2) Perform a survey of key researchers, and 3) Review and evaluate the
collected information. This work served as the basis for developing the
protocol for estimating air emission factors for remediation presented herein.
Each step of the approach is discussed below.
A computer-assisted search of 15 databases was performed to identify
published literature of potential interest. Keywords were formulated into a
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search strategy to identify abstracts related to both baseline and remedial
emissions. Approximately 1400 abstracts were reviewed, and over one hundred
publications were identified as pertinent and obtained by staff librarians.
The literature search was augmented by a telephone survey to locate and
access unpublished data or research in progress. A list of contacts was
developed that included regional EPA personnel, employees of EPA research
offices. EPA contractors, university researchers, and referrals from those
initially contacted. A set of questionnaires was used to put the responses
obtained during the phone survey in a standard format.
The collected data were reviewed and evaluated with respect to the
following:
• Which remedial operations have significant potential air
emissions;
• What parameters influence air emissions:
• What relationship exists between emissions and waste concentration
and composition:
• What types of monitoring data are available: and
• What data gaps still exist.
The information was then used to develop emission relationships for use in the
protocol development.
1.4 RECOMMENDED USES OF THIS MANUAL
This manual is. to the extent possible, a complete, stand-alone
document. It is. however, intended to complement existing guidance manuals
for the Superfund program. This manual (Volume III) was developed
concurrently with three related manuals that also address air issues arising
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from hazardous waste sites. The first manual (1) presents more generalized
guidance for addressing air Issues throughout the clean-up process depicted In
Figure 1. The second manual (2) presents guidelines for developing baseline
emission factors for NPL sites prior to remediation. The fourth manual (3)
presents guidance for air monitoring and modeling at NPL sites. Together.
these four manuals provide a complete treatment of air issues for Superfund
applications.
The steps in the NPL site clean-up process, from site discovery to
remediation and subsequent operation and maintenance, are shown in Figure
1. Volume III may be useful at several steps for assessing potential air
impacts from site remediation; these steps are labeled in the figure by "Air"
and an input arrow.
The primary intended use for this manual (Volume III) is for estimating
air impacts as part of the evaluation of alternative remedial options (e.g..
incineration versus ground-water stripping versus removal, etc.). Therefore.
the manual's guidance is input to the record of decision (ROD) step, as well
as the RI/FS and remedial design (RD) steps. A second use of the manual is
for estimating emissions once a specific remedial action (RA) or removal plan
has been selected. The manual can be used to estimate the air impact from
altering the rate of clean-up or changing some other key engineering parameter
for a given remedial technology. This manual also provides several secondary
functions, including guidance on control technologies and an Introduction to
collecting input (monitoring and modeling) data.
Furthermore, this manual provides the important function of
standardizing the air pathway analysis (APA) for remediation of NPL sites.
thereby ensuring that a uniform and systematic approach is followed for the
diverse universe of NPL sites. The manual provides a step-by-step protocol
for estimating air quality impacts resulting from site mitigation. For each
step, a three-tiered approach is presented. The approaches in order of
preference are:
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Site Discovery
Preliminary
Assessments
Site Inspections
Air
Air
National
Priorities List
(NPL)
Remedi al
Investigations/
Feasibility Studies
Records of Decision
Remedial Designs
Remedial Action
Operation and
Maintenance
.Air
• Air
Air
Figure 1. Superfund flow chart, noting elements where this manual may apply.
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1) Use of site-specific field data:
2) Use of predictive contaminant transport models using site-specific
inputs;
3) Use of tabulated default values when site-specific information is
unavailable.
Therefore, emissions can be estimated regardless of the state of knowledge
regarding a given site. Of course, the confidence of the emissions estimates
depends on the associated confidence of the inputs to the estimation
procedure.
Limitations of the emissions estimation procedures should be borne in
mind. The primary limitation is that the data quality of any emissions
estimate is dependent on the data quality of the inputs and on the quality of
the assumptions that are made. The use of site-specific data as input to the
estimation procedure is preferable to the use of predictive models, which in
turn are preferable to the use of tabulated generic emission factors. Data of
known quality (confidence) should be used whenever available. In many cases.
the conceptual site model will be developed from a limited database. The
resulting estimates of volume of contaminated material, the type of
contaminants present, the concentration of the contaminants, etc. will have
large associated uncertainties. Therefore, any emissions derived from such
data will have an even larger overall uncertainty.
In addition, the estimation procedure has its own inherent limitations.
The predictive equations and typical values given in the succeeding sections
for each remedial technology were designed to be applicable to as wide a range
of sites as possible. They are most applicable for the "typical" use of a
given technology at a "typical" site. Atypical site characteristics such as
permafrost, high ground-water table, naturally immobilized waste, impeded air
dispersion routes, etc. or atypical remedial technologies or other
applications may affect the validity of the emission estimation procedure.
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Similarly, the step of the overall protocol—estimate concentration at the
receptors—has inherent limitations. Dispersion models do not work well for
estimating dispersion over very short distances (i.e.. much closer than 100
meters). Finally, the action levels selected for the receptors of interest
are themselves extremely arbitrary. Exposure standards are still evolving and
even at their best only address the exposure for an average person. Persons
with respiratory or other problems may be adversely affected by concentrations
of pollutants well below any established standards.
1.5 DOCUMENT ORGANIZATION
There are five remaining sections to Volume III. Section 2 is a dis-
cussion of emission processes during remedial operations. Section 3 presents
detailed procedures for estimating air emissions during remediation. A
protocol for estimating emissions is first presented and discussed, then
specific inputs for each applicable remedial technology are given. A
hypothetical case study is given in Section 4 to demonstrate the use of the
manual. An introduction to monitoring, modeling, and data quality issues is
given in Section 5 for users of the manual requiring additional input data for
the protocol. Section 6 lists the references cited in the manual.
Ancillary information is given as appendices to this manual. Appendix A
is an annotated bibliography for the documents reviewed during the protocol
development. A glossary of terms is given as Appendix B. Appendix C presents
the relative advantages and disadvantages of various incineration
technologies. A brief discussion of the steps in the overall protocol for
estimating air quality impacts from emissions is given in Appendix D.
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SECTION 2
DISCUSSION OF EMISSIONS DURING SITE CLEANUPS
This section is intended to provide the user with sufficient background
information regarding remedial technologies to use the estimation procedures
presented in Section 3. The section addresses potential emission sources.
Potential air quality impacts and receptors of concern are discussed in Volume
IV (3). Users should consult the references cited in this section and those
listed in the bibliography (Appendix A) for further background material.
Potential emission sources include point sources such as incineration,
air stripping of ground water, and in-situ soil venting; and area sources such
as soils handling and fixation/stabilization. The discussion of each remedial
technology covers sources, key parameters affecting emissions, and possible
control technologies.
Remedial technology point sources are first addressed, followed by
remedial technologies categorized as area sources.
2.1 THERMAL DESTRUCTION
The following section describes emission processes from thermal
destruction. Thermal destruction includes a number of processes with
incineration being the most widely studied and used.
As applicable or relevant and appropriate requirements (ARARs), several
of the requirements under the Resource Conservation and Recovery Act (RCRA)
and the Toxic Substances Control Act (TSCA) will also be applied to the
thermal destruction of wastes from NPL sites. Most notably, RCRA requires
99.99% destruction and removal of regulated organic wastes. Similarly, TSCA
governs wastes containing PCBs and dioxins and requires 99.9999% destruction
and removal efficiency. Regulations under these Acts also generally require
-------
trial burns to demonstrate the achievement of these and other related
requirements. Assuming these requirements under RCRA or TSCA are also taken
as requirements for thermal destruction of an NPL site's wastes, this
obviously simplifies the estimation of the maximum emissions from that site.
The main value of this manual would thus be: 1) to estimate emissions for
pollutants (such as products of Incomplete combustion) not directly covered by
RCRA or TSCA regulations, 2) to evaluate whether Incinerator designs are
likely to achieve desired emissions controls, and 3) to estimate emissions for
cases when RCRA and TSCA requirements are judged to be neither applicable nor
appropriate. This section also provides discussion of types of thermal
destruction devices, types of pollutants emitted, tpyes of control devices,
and considerations In applying thermal destruction technologies.
2.1.1 Emission Sources
Thermal destruction of hazardous waste Is an engineered process In which
controlled combustion Is used to decompose the chemical structures of organic
compounds thereby substantially reducing the volume and toxicity of the
hazardous components of the waste. The physical forms of wastes which can be
destroyed by thermal destruction Include gases, liquids, solids, and sludges.
Thermal destruction is usually a cost-effective remedial option for highly
toxic organic wastes and for those organic wastes having a large inherent
heating value.
While thermal destruction has long been seen as a viable and effective
means of hazardous waste disposal, changes in the environmental issues,
economics, and regulatory climate surrounding waste management technologies
have caused thermal destruction to become recognized as one of the best
demonstrated and available methods of waste destruction. CERCLA favors
treatment over removal, and on-site waste treatment over off-site; existing
thermal destruction technologies can fulfill these goals for many types of
sites.
10
-------
A variety of effective thermal destruction technologies are available
and the selection of an appropriate system requires an understanding of the
chemical, physical, and thermodynamlc properties of the waste to be destroyed.
The major existing and emerging thermal destruction technologies are listed In
Table 1.
Liquid Injection incinerators are typically refractory lined cylinders
in which pumpable liquids as well as gases are burned. Rotary kiln units are
also refractory lined cylinders, but they are mounted at slight incline from
the horizontal plane. These units are suitable for destroying solids,
sludges, containerized wastes, and liquids. Rotation of the kiln moves the
waste through the kiln and simultaneously provides good mixing of the waste.
To achieve high waste destruction, a rotary kiln unit usually employs a
secondary combustion chamber or afterburner. The afterburner is essentially a
gas incinerator which burns the residual wastes contained in the rotary kiln
exhaust gas. Cement kilns are large-scale rotary kilns which are used for the
commercial production of cement. The cement kiln provides the high
temperatures and extended residence times required for waste destruction.
Industrial boilers are another example of a commercial process in which many
hazardous materials may be economically destroyed. In boilers, the waste
(usually a liquid) is typically injected with an auxiliary fuel through the
unit's burner nozzles.
In Infrared incineration, wastes are moved through the primary
combustion chamber on a steel belt and electrically powered, silicon carbide
rods mounted along the chamber walls provide the necessary heat. Off-gas from
the primary chamber enters the secondary chamber or afterburner, which
contains a gas-fired burner to ignite the combustible gases. Infrared heating
elements may also beused in the after-burner.
Hearth incinerators (also called controlled, starved air, or pyrolytic
incinerators) also employ a two stage combustion process. In these units,
waste is ram fed into the primary combustion chamber and burned under starved
air conditions (pyrolysis). The resulting combustion gases containing
11
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TABLE 1. THERMAL DESTRUCTION TECHNOLOGIES
Incineration Technologies:
Liquid Injection
Rotary Kiln
Cement Kiln
Boilers
Multiple Hearth
Infrared
Fluidlzed-bed
At-Sea
Emerging Thermal Destruction Technologies:
Molten Matrix
High-Temperature Fluid Wall
Plasma Arc
Super-Critical Water
Sources: References 4 and 5
12
-------
primarily volatilized hydrocarbons, carbon monoxide, and partially combusted
hydrocarbons pass Into the secondary combustion chamber where excess air and
sometimes fuel are added to ensure complete combustion.
The last major type of incineration system is the fluidized bed
incinerator. Fluidized bed units are used primarily for burning liquids,
sludges, and finely shredded (<1 in. x 1 in.) solid materials. They are
refractory lined vessels which contain particles of sand, alumina, calcium
carbonate, or other fluidizing material. Combustion air is introduced through
distributors in the floor of the unit at a velocity sufficient to cause the
bed to fluidize, providing enhanced turbulence and heat transfer; hence,
increased waste destruction.
At-sea incineration involves the use of a ship-mounted liquid
incinerator. The operations of incinerators at-sea versus on land are quite
similar. The same equations apply for estimating emissions and the same
control considerations would apply at-sea as on land. Historically, at-sea
incinerators have not been equipped with acid gas scrubbers and have relied on
the ocean's buffering capacity to neutralize acidic emissions.
Molten matrix systems employ molten salt or glass to achieve waste
destruction. The matrix is maintained in a molten state in an electric
furnace into which the waste Is fed. Temperatures in the vicinity of 1100°C
(2000'F) promote high destruction levels. The ash is trapped in the melt,
thus providing relatively low particulate emission levels for these systems.
In high-temperature fluid wall units, waste is passed through a vertical
heated porous carbon tube. Using electric heaters, the heat is applied to the
external surface of the tube, generating temperatures in the tube in excess of
220CPC (4000*F). Nitrogen is forced from the outside to the inside of the
porous tube, thereby preventing the waste particles from collecting on the
wall. The required residence time is on the order of seconds, but the waste
feed must be introduced in a consistent and finely divided condition.
13
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Plasma arc destruction Involves passage of waste through ultrahigh
temperature electric arc plasma. Temperatures in excess of 2200°C (4000'F)
promote high destruction efficiencies, and the gases produced by the unit can
be passed through a conventional treatment unit such as a scrubber.
Destruction of wastes on super-critical water is based on the fact that
many gases (including oxygen) and organic compounds are readily dissolved in
water existing at super-critical conditions (greater than 374'C and 3200 psi).
Waste is fed as an organic/water slurry containing 5 to 10 weight percent
organics. The slurry is pressurized and heated to super-critical conditions
using super-critical water. Oxygen or air is introduced with the feed and all
organics are oxidized and the heat of combustion is released into the water.
The relative advantages and disadvantages of each type of technology are
given in Table 1 of Appendix C. Because a vast majority of the thermal
destruction performed to date has involved incineration (thermal oxidation),
most of the emissions data available pertains to incinerators rather than the
emerging technologies such as molten salt or plasma arc destruction.
Therefore, unless otherwise noted, the discussion and data presented on
thermal destruction in this document apply primarily to incineration
technologies.
A typical thermal destruction system is composed of several subsystems.
These include the waste feed system, primary and secondary (in some cases)
combustion chambers, and exhaust gas conditioning systems. The flow diagram
for a typical waste incineration system is shown in Figure 2.
The first step in a hazardous waste incineration system is the waste
feed process. The configuration of the waste feed system is determined by the
physical characteristics of the waste. Solid wastes, normally packed in fiber
drums, are introduced to the combustion chamber by means of conveyer or
pneumatic rams. Other solid wastes may require shredding or preheating before
introduction to the incinerator. Liquids are injected into the incinerator by
means of an atomization nozzle which uses steam or compressed air as an
14
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COMBUSTION CHAMBERS
DOOOODDO
Roury Kin
FlMd HMftll
DEMISTER
AND
STACK
ASH AND SLUDGE
DISPOSAL
Omitting
Chwnlcal
Stabilization
Undlill
Figure 2. Process Flow Diagram for a Typical Hazardous Waste
Incineration System
15
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atomlzation fluid. Liquids with entrained solids may require screening to
prevent clogging of the atomizer nozzle. Gases are usually fed to the
incinerator through ductwork and a blower. If the waste stream contains
oxygen, dilution air 1s frequently added to the gas stream so that the
resulting mixture is below its lower explosive limit.
Because the bulk of the waste destruction usually takes place in the the
primary combustion chamber, it is an important part of an incineration system.
The incinerator system 1s usually named after the primary combustor. The most
commonly used types of combustion chambers Include: liquid injection, rotary
kiln, hearth (controlled air), and fluidized bed. Table 2 shows the types of
wastes which may be burned in each of these incinerators.
After the combustion gases leave the incinerator, they may be routed
through a variety of air pollution control devices including gas conditioning,
particulate removal, and acid gas removal units. Gas conditioning is
accomplished with equipment such as waste heat boilers or quench units.
Typical particulate removal devices include venturi scrubbers, wet or dry
electrostatic predpitators, ionizing wet scrubbers, and fabric filters. Acid
gas removal units include packed, spray, or tray tower absorbers; ionizing wet
scrubbers; and wet electrostatic precipitators.
The desired goal of incineration is to maximize the reduction of
hazardous waste into relatively harmless products such as carbon dioxide,
water vapor, and inert ash. In actuality, the extent of destruction is con-
strained by the physical and chemical equilibria present in the incinerator.
A properly designed and operated incineration system is capable of achieving
high levels of destruction of organic compounds. However, the large number of
complex chemical reactions taking place do not go to 100 percent completion,
and some fraction of the wastes may pass through the system uncombusted.
Further, some reactions may produce a number of simpler organic compounds
(known as PICs or Products of Incomplete Combustion) which may also exit in
the stack gases. PICs may include dioxin, formaldehyde, and benzo(a)pyrene
16
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TABLE 2. APPLICABILITY OF AVAILABLE INCINERATION PROCESSES TO THE
BURNING OF WASTE (BY WASTE TYPE)
Waste Type
Solids
Granular, homogeneous
Irregular, bulky
(pellets, etc.)
High melting point
(tars, etc.)
Organic compounds with
fusible ash constituents
Unprepared, large, bulky
material
Rotary
Kiln
X
X
X
X
X
Fixed Hearth
Liquid Fluidized (Controlled
Injection Bed3 Air)
X Xb
Xc Xc X
X
Gases
Organic vapor-laden
Liquids
Xd
Xd
High organic- strength
aqueous waste often toxic
Organic liquids
Solids/LiQuids
Waste contains halogenated
aromatic compounds
Aqueous organic sludge
Xe
Xe
X
Xs
X
X
Xf
X
X
X
Source: Reference 4
'Suitable for pyrolysis operation.
Handles large material on a limited basis.
clf material can be melted and pumped.
dlf properly fed into the incinerator.
elf equipped with auxiliary liquid injection nozzles.
flf atomizable liquid.
9Wastes which become sticky upon drying may cause feed problems.
17
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and other polynuclear aromatic hydrocarbons. PIC formation is not restricted
to the combustion chamber; the reactions which produce PICs may continue to
occur in the combustion gases as they travel through the incineration system
and out the exhaust stack.
Other pollutants which may be present in the incinerator exhaust gas
include trace metals, particulate matter, carbon monoxide (CO), nitrogen
oxides (NOX), sulfur oxides (SOX), and hydrogen chloride (HC1). In addition
to emissions associated with the stack gas, incineration facilities can
produce ash waste which may contain significant quantities of inorganic and
some organic pollutants. Similarly, the use of air pollution control devices
such as venturi scrubbers or fabric filters can produce solid and/or liquid
wastes containing significant amounts of contaminants. Finally, each
processing step and equipment component in the Incineration process is capable
of producing fugitive emissions. Fugitive emissions may occur from handling
and transfer operations or from leaking connections and seals in pumps,
valves, tanks, etc. When taken as a whole, they may actually represent the
largest fraction of total pollutant emissions from a particular facility.
2.1.2 Kev Parameters Affecting Emissions
Pollutant emissions from incineration facilities can be affected by a
number of factors. Table 3 lists the major parameters which may influence
emissions. While there is a large amount of data available which quantifies
emissions measured in various incinerator studies, there is almost no
Information which actually provides numerical correlations for estimating
emission rates by use of incinerator operating data. Therefore, while the
following paragraphs discuss the relationships between operating conditions
and emissions, and even the relative importance of the various operating
parameters, this information does not provide an actual means of calculating
emissions from operating data.
18
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TABLE 3. FACTORS AFFECTING INCINERATION SYSTEM EMISSIONS
Typical Importance to Emission Level
Parameter
Participates/
Metals
Volatile
Organics
Acid Gases
Waste Characteristics
Physical State
Moisture Content
Particle Size
Thermal Content
Chemical Composition
Operating Characteristics
Waste Feed Rate
Temperature
Residence Time
Excess Air Rate
Facility Size/Type
Atomization
Control Device Efficiency
High
Low
High
Low
High
High
Medium
Medium
Medium
Medium
Low
High
Medium
High
Low
High
High
High
High
High
Medium
Medium
High
Low
Low
Low
Low
Low
High
High
High
Medium
Medium
Medium
Low
High
19
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The following discussion of emissions and their controlling factors is
divided into incinerator emissions (stack gas, bottom ash, and APCD residuals)
and fugitive emissions (uncontrolled or undetected equipment leakage). For
the purposes of this discussion, all incinerator types can be considered to be
equivalent In emissions potential if properly operated. Exceptions are noted
in the text.
Incinerator emissions are composed of fugitive emissions and the
pollutants leaving in the combustion gas (organics, metals, particulate, acid
gases, etc.), solids exiting the system (metals, etc.) with the combustion
chamber bottom ash and APCD residuals, and liquids exiting the system
(scrubber liquors, blowdown, etc.) The means by which pollutants are
initially introduced to the incinerator include the waste streams (gas,
liquid, or solid phase) as well as the auxiliary fuel (e.g., fuel oil, coal,
or natural gas). Table 4 lists the typical range of uncontrolled stack
emissions from incineration.
Undestroyed Organics--
In general, incinerators treating wastes from NPL sties must achieve a
destruction and removal efficiency of either 99.99% for RCRA wastes or
99.9999% for PCB- or dioxin-contaminated wastes. In designing an incinerator
to achieve such destruction and removal efficiencies, the factor which seems
to most strongly affect the destruction and removal of any particular
hazardous organic in an incinerator is the concentration of the compound in
the waste feed stream. Assuming proper design and operation of an
incinerator, the higher the compound's concentration in the waste stream, the
greater the percentage of that compound destroyed in the incinerator (6).
This percentage destruction is known as the destruction and removal efficiency
(ORE). The heat of combustion, currently used to determine the relative
incinerability of various compounds in a waste stream, apparently does not
correlate well with the ORE. Furthermore, amongst the operational factors
which might affect the ORE (e.g., combustion chamber temperature, residence
time, and stack gas oxygen content), only combustion chamber temperature
appears to be most strongly related to ORE (6). Table 5 presents the
20
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TABLE 4. TYPICAL RANGES OF UNCONTROLLED EMISSIONS FOR INCINERATION
Contaminant
Volatile Organ Ics
Dioxlns/Furans
Part icul ate Matter/Metals
NOX
HF
HC1
S02
Stack Gas
Concentrations
0.1 - 1500 ug/m3
Undectablec
0.5-23 g/m3
10 - 4,000 ppm
20 - 200 ppm
50 - 5,000 ppm
10 - 12,000 ppm
Emissions3
0.065-980 mg/min
320 - 15,000 g/mln
17 - 6,900 g/mln
20 - 200 g/min
27 - 2,700 g/mln
10 - 12,000 g/mln
Fugitive
Emissions
(kg/hr)
__b
Undectable
Negligible
Negligible
Negligible
Negligible
Negligible
" Based on an exhaust gas rate of 650 m3/min.
b When compared to stack emissions, fugitive VO emissions typically occur at a
rate equal to 4 to 80 percent of the stack VO emission rate.
c Emissiona re generally undetectable, though emissions of up to 12 ug/min
have been measured.
21
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TABLE 5. TYPICAL TEMPERATURES AND RESIDENCE TIMES FOR
HAZARDOUS WASTE DESTRUCTION
Temperature Temperature Residence Time DRE
Waste Type (*C) (*F) (seconds) (%)
Lean gases containing 650-750 1200-1400 0.5 - 0.75 99
hydrocarbons of sulfur,
fume streams
Liquid streams containing 900-1000 1600-1800 1.0 - 2.0 99.99
hydrocarbons, vapor
streams containing CO
or ammonia
Halogenated hydrocarbons 1000-1100 1800-2000 1.5-2.0' 99.99
liquids and vapors, long
chain hydrocarbons, waste
liquids
Combustible solids 1100-1300 2000-2400 1.5 - 2.0 99.99
NOX or compounds with 1300-1400 2400-2600 1.0 - 2.0 99.99
bound nitrogen (reducing
atmosphere, i.e., excess
fuel)
PCBs, dioxins 1200-1300 2200-2400 1.0 - 2.0 99.9999
22
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temperatures and residence times at which various wastes may be destroyed to a
given ORE.
Products of Incomplete Combustlon--
PICs are compounds found in the stack gases, but not detected in the
waste feed stream. Several possible explanations for these compounds exist
(6): 1) The PICs are present in the feed stream in concentrations below
detection limits, and experience little or no destruction. As the volume of
surrounding waste is decreased, the presence of the PICs becomes easier to
detect. The trend of decreasing ORE with decreasing waste feed concentration
supports this and could explain the presence of many of the PICs detected.
2) Some PICs are introduced from non-waste feed sources. Chloroform, for
example, has been shown to be introduced to the system from the scrubber
makeup water. Fuel oil can also be a source for PICs. 3) Compounds which are
actually created in the combustion process. The presence of simple stable
compounds such as chlorinated methanes, ethanes, and benzene compounds in most
stacks supports this hypothesis.
Dioxins and furans are incinerator combustion by-products which have
been subjects of intense scrutiny by the scientific, regulatory, and public
sectors. Most dioxins and furans emission studies have been conducted on
municipal waste incinerators, and only limited data are available for
hazardous waste incinerators. EPA studies on 17 hazardous waste incinerators,
kilns, and Industrial boilers discovered only five which were emitting
detectable levels of dioxins and furans. Table 6 presents these data. As a
means of comparison, average dioxins and furans emissions compiled from an EPA
study of 22 municipal waste incinerators were nearly 1,000 times greater than
those from the hazardous waste Incineration facilities (7).
This large difference in dioxin and furan emissions is due to
differences in operating practices between hazardous waste and municipal
incinerators. Hazardous waste incinerators are typically well mixed, burn at
elevated temperatures, and have an excess oxygen content of at least 3%.
Municipal incinerators are relatively large, have pockets of poor mixing, and
may have cold spots where dioxins and furans can form.
23
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TABLE 6. STACK CONCENTRATIONS DIOXINS AND FURANS FROM HAZARDOUS WASTE
INCINERATION FACILITIES
Facility Type
Commercial Rotary Kiln/
Liquid Injection
Combustion Incinerator
Fixed Hearth Incinerator
Liquid Injection Incinerator
Horizontal Liquid Injection
Incinerator
Incinerator Ship
4 Lime/Cement Kilns
Fixed Hearth Incinerator
Rotary Ki In/Li quid Injection
Industrial Boiler
Industrial Boiler
Industrial Boiler
Industrial Boiler
Industrial Boiler
Dioxins
(ug/m3)
NDa
16
NO
ND
ND
ND
ND
ND-48
75-76
0.64-0.8
ND
ND
1.1
Furans
(ug/m3)
ND-1.7
56
ND
7.3
0.3-3
ND
ND
0.6-95
ND
ND
ND
ND
ND
ND - not detected.
Source: Reference 7
24
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Metal s-
The metals introduced to the Incinerator via the waste feed stream are
not destroyed. Depending on their boiling point and the combustion
temperatures, they can either be volatilized or remain a solid. Volatilized
metals will exit the stack as a gas or they will condense onto particles in
the stack gas stream. Non-volatilized metal particles can be fluidized and
swept up Into the combustion gas or leave the incinerator in the bottom ash.
The partitioning of a metal between the stack gas and the bottom ash is
primarily dependent upon the volatility of the metal. Metals with higher
volatility (e.g., mercury, selenium, antimony, cadmium, and lead) generally
have a higher proportion of the starting material exiting in the stack gas,
and lower volatility metals (e.g., nickel and chromium) tend to show
enrichment in the bottom ash (8). Because the combustion process provides no
inherent control over stack emissions of metals, air pollution control devices
such as venturi scrubbers or ionizing wet scrubbers are used to reduce the
atmospheric discharge of metals.
Particulate Matter-
The waste feed, auxiliary fuel, and combustion air can all serve as
sources for particulate emissions from an Incineration system. Particulate
emissions may result from inorganic salts and metals which either pass through
the system as solids or vaporize in the combustion chamber and recondense as
solid particles in the stack gas. High molecular weight hydrocarbons may also
contribute to particulate emissions through several possible mechanisms.
First, the molecule can self-nucleate and grow into a particle by adsorption
of other organic molecules (however, high temperatures tend to combust all
organic compounds to gases). Also, inorganic compounds such as halogens can
possibly dehydrate large organic molecules leading to nucleation and particle
growth. Finally, inorganic oxides may also adsorb high molecular weight
organics yielding a particle saturated with the adsorbed organic.
The molecular weight and geometry of particles is determined by the
incinerator operating conditions (temperature, residence time, and oxidizing
or reducing environment). Emissions of these particles are strongly affected
25
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by the waste and fuel compositions, incinerator type and operation, and the
effectiveness of the air pollution control devices. Participate loading in
uncontrolled combustion chamber exhaust gas varies with waste loading, but
generally ranges between 0.5 and 23 g/m3 (0.2 and 10 grains/dscf). Controlled
stack gas concentrations usually fall in the 34 to 110 mg/m3 (0.015 to 0.05
grains/dscf) range (9). Incinerators treating wastes from NPL sites will
generally be required to meet RCRA requirements governing particulate
emissions, I.e., requiring an emissions limit of 0.08 grains/dscf corrected to
7% of 02.
NOX-
Achieving high levels of destruction of organic wastes is directly
related to combustion chamber temperature: the higher the temperature, the
greater the ORE of organics. Unfortunately, the fixation of nitrogen and
oxygen to form NOX also increases with combustion temperature. Excess air and
high heat release are also contributors to NOX formation. NOX is generally
not a problem unless there are bound nitrogen atoms in the waste, e.g. amines.
In such cases, two stage combustion or emissions controls may be needed.
Carbon Monoxide--
Carbon monoxide emissions are generally low (<25 ppm) in commercial
incinerators due to the high operating temperatures and excess oxygen
maintained in the process. Elevated CO concentrations of (up to 800 ppm) have
been measured in several different types of incinerators (7). However, even
where carbon was not being fully oxidized, the destruction and removal
efficiencies were >99.99%.
Acid Gases--
Hazardous waste incineration may also produce acid gases. These include
oxides of sulfur (SOX), and halogen acids (HC1, HF, and HBr). The sulfur,
chlorine, fluorine, and bromine contents of the waste and fuel feed determine
the emission levels of their respective acid gases. The concentrations of
these elements range widely amongst different wastes; consequently, the
resulting acid gas emissions will also show wide variability. Incinerators
26
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treating wastes from NPL sites will generally be required to meet RCRA
requirements governing HC1 emissions.
Bottom Ash and APCD Residues--
Incineration of wastes containing substantial quantities of ash or
halogens will produce solids which will be found in the combustion chamber
bottom ash and in the residues collected by the APCDs. In the bottom ash and
APCD residues, the content of pollutants such as hazardous organics or metals
is dependent primarily upon the pollutant's waste feed concentration and
volatility. To determine the proper method of disposal, the residues must be
analyzed to characterize their hazardous properties.
Fugitive Emissions--
Fugitive emissions in an incineration facility are defined as
uncontrolled gas emissions coming from any operation or equipment other than
the exhaust stack. Sources for fugitive emissions include leaking valve and
pump fittings, flanges, storage tanks, and sampling and instrument
connections. Correlations have been developed which relate the fugitive
emission rate to number and size of each of these sources (10,11). Previous
studies of both predicted and measured emissions from incineration facilities
have indicated that atmospheric pollutant concentrations at close proximity to
a facility can be more strongly affected by fugitive losses than by stack
emissions (12,13). This is due in part to the low temperatures and proximity
to ground level of typical sources of fugitive emissions.
2.1.3 Possible Control Technologies
Three types of control strategies may be used for reducing the air
emissions from incineration. These are downstream treatment of the gases
produced during incineration, modification of operating parameters to reduce
the production of pollutant gases, and control of fugitive emission sources.
Each strategy is described, in turn, below.
27
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Incinerator air pollution control devices (APCDs) include venturi
scrubbers, packed bed scrubbers, electrostatic precipitators, ionizing wet
scrubbers, and fabric filters. Table 7 shows the applicable pollutants,
pressure drops, and descriptions for each of these APCDs (14). Methods for
controlling specific types of emissions by treatment of the flue gas exhausted
from the combustion chamber are discussed in the following paragraphs.
Organic Compounds--
Two recent EPA Incinerator studies in which combustion chamber ash and
scrubber water were analyzed found only very small quantities of organic
pollutants in these effluent streams (15,16). While these findings indicate
that the ORE for organic compounds is due primarily destruction rather than
capture and removal, the actual mechanism of capture is not well understood.
This is true also for dioxins and furans. Two likely modes of capture
include condensation and capture as a particle, as well as attack and capture
by caustic reagents. These modes of capture are enhanced by lowering flue gas
temperatures, scrubbing the flue gas with caustic reagents, and capturing the
partlculate matter in a high efficiency particle collector. Spray drying,
followed by fabric filtration, has been found to be effective and superior to
the spray drying/ESP system (17). Table 8 presents data on dioxins and furans
control device efficiencies.
Particulate Matter/Metals--
Vlet electrostatic precipitators, venturi scrubbers, and ionizing wet
scrubbers are frequently used in industry for particulate control. Wet ESPs
have high particulate control efficiencies. At high ratios of collector plate
surface area to gas volumetric flow rate (i.e. in the range of 170
minutes/meter), wet ESPs can control particulate emissions to less than 0.45
mg/m3 (0.02 gr/dscf). Venturi scrubbers are less effective and require very
high pressure drops to remove fine particles. They are capable of removing 80
to 95 percent of entrained particulate matter (17). Generally, scrubbers
control hazardous metals less efficiently than they do general particulate
28
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TABLE 7. INCINERATION SYSTEM AIR POLLUTION CONTROL DEVICES
Device
Pol1utant
Pressure Drop
(m of H20)
Description
Afterburner Gaseous
hydrocarbons
Venturl
scrubber
Particulate, 0.25 - 1.25
HC1, SO,, NO,,
HCN
Electrostatic Particulate <0.01
precipitator
Ionizing wet Particulate,
scrubber gases
Fabric filter Particulate 0.05 - 0.2
Completes combustion of
gases not destroyed 1n
primary Incineration.
Auxiliary fuel required.
High efficiency. High
energy requirement.
Requires downstream
mist eliminator.
/
Low operating cost.
High efficiency for
fine particles. Dust
resistivity problem.
Low energy consumption.
No dust resistivity
problem.
High efficiency for fine
particles. Not for
corrosive or hot gases
(>250'C).
Source: Reference 14
29
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TABLE 8. SPRAY DRYER CONTROL OF DIOXINS AND FURANS
Furans
tetra CDFb
penta CDF
hexa CDF
hepta CDF
octa CDF
Percent Removal
Compound
Dloxins
tetra CDDa
penta CDD
hexa CDD
hepta CDD
octa CDD
Spray Dryer
+ ESP
48
51
73
83
89
Spray Dryer
+ Fabric Filter
(High Temperature)
<52
75
93
82
NA
Spray Dryer
+ Fabric Filter
(Low Temperature)
>97
>99.6
>99.5
>99.6
>99.8
65
64
82
83
85
98
88
86
92
NA
>99.4
>99.6
>99.7
>99.8
>99.8
"CDD - chlorinated dlbenzo-para-dioxins.
bCDF - chlorinated dlbenzofurans.
30
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matter. For metals, the control efficiency 1s inversely dependent on the
metal's volatility, i.e., with decreasing control efficiency as the volatility
increases (8).
NOX--
Control of NOX in the flue gas is relatively difficult and expensive
because unreactive NO usually comprises up to 95 percent of the total NOX.
However, selective catalytic reduction (SCR) offers an effective means for NOX
reduction. Prior to SCR treatment, the stack gas must undergo acid gas and
heavy metals control. This method is capable of removing 80 to 90 percent of
the total NOX (17). The effectiveness of SCR can be enhanced further through
the use of special lower temperature catalysts which are resistant to HC1
(18).
Acid Gases--
Acid gases such as HP, HC1, and S02 may be controlled effectively with
wet, dry, and semi-dry scrubbers. Reactive acid gases including HP and HC1
are relatively easily controlled (water can be used as a sorbent). However,
efficient control of S02 requires an alkali sorbent. Table 9 discusses the
effectiveness of acid gas controls in various configurations.
Dry scrubbers are the least effective means of acid gas control because
the absorbent requires extended residence time in the gas. A more effective
means of control is spray drying or semi-dry injection. Wet scrubbing and
combined semi-dry/wet systems have the highest control effectiveness; however,
the advantages of these systems has to be balanced against possible higher
costs due to waste water treatment and increasing system complexity (17).
The following three paragraphs describe operational (in furnace) methods
of emission control for incineration.
31
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TABLE 9. EFFECTIVENESS OF ACID GAS CONTROLS (% REMOVAL)
Pol 1 utant
Control System
Dry Injection + Fabric Filter (FF)a
Dry Injection + Fluid-Bed Reactor + ESPb
Spray Dryer + ESP
(Recycle)0
Spray Dryer + Fabric Filter
(Recycle)0
Spray Dryer + Dry Injection + ESP or FFd
Wet Scrubber6
Spray Dryer + Wet Scrubber (s) + ESP or FFe
HC1
80
90
95+
(95+)
95+
(95+)
95+
99
99
HF
98
99
99
(99)
99
(99)
99
99
99
S02
50
60
50-70
(70-90)
70-90
(80-95)
90+
90+
90+
Source: Reference 17
«T - 160-180'C (320-356'F).
bT = 230*C (446*F).
°T - 140-160*C (284-320'F).
dT » 200'C (392°F).
eT = 40-50'C (104-122*F).
T <* the temperature at the exit of the control device.
32
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Organic Compounds--
Operational variables which have the most significant potential for
reducing organic emissions include combustion chamber temperature, residence
time, and oxygen content in the combustion atmosphere. Table 2-5 shows
typical temperatures and residence times at which various wastes might be most
completely destroyed.
Parti culates/Metals--
Incinerators have no inherent ability to destroy non-combustible
materials, therefore facilities burning wastes with a potential for high ash
or particulate emissions will generally route stack gases through air
pollution control devices such as scrubbers, wet electrostatic precipitators,
or fabric filters to prevent excessive emissions. Frequently, quench units
are used upstream from a venturi scrubber in order to cool the gases and
promote particle growth. When precipitators are used, a scrubber is often
placed downstream to absorb gaseous components.
NOX--
Most of the potential in-furnace process modifications (peak flame
temperature reduction, low excess air, and low rate of heat release) by which
NOX production could be reduced run contrary to achieving high ORE levels for
organic pollutants. However, staged combustion is one approach which can
reduce NOX emissions while still getting high DREs. Staged combustion, also
known as reburning, involves initial burning of waste under fuel rich
(reducing) conditions in the primary combustion zone followed by addition of
air to complete combustion in a secondary combustion zone. Another method
of NOX control involves ammonia injection in the upper combustion area.
Because the reaction of ammonia and NOX is quite temperature sensitive, this
method, known as Thermal DeNOx, requires careful selection of the ammonia
injection point (17).
33
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Fugitive emissions may also be a concern at incineration facilities.
The primary means of controlling or reducing fugitive emissions are through
equipment selection and the establishment of effective inspection and
maintenance programs.
2.2 AIR STRIPPING OF GROUND WATER
2.2.1 Emission Sources
Air stripping of ground water effectively transfers volatile organic
contaminants from the liquid-phase to the gas-phase. A typical ground-water
treatment facility may contain some or all of the following components:
1) Recovery wells;
2) Oil/water separator;
3) Storage/surge tank;
4) pH Adjustment;
5) Inorganic treatment;
6) Air stripping tower;
7) Off-gas treatment;
8) Semi-volatile organic compound treatment;
9) Filters; and
10) Injection wells.
Air stripping towers (see Figure 3) use packing media to optimize
the mass transfer of VOs in the ground water to the air. The upstream pH
adjustment serves to enhance removal efficiencies and to keep the packing
material in the tower clean. The water is introduced at the top of the tower
through spray nozzles and allowed to slowly flow down through the media. The
packing media acts to retard the water flow and increase the effective surface
area. A blower or blowers, forces air up from the bottom of the tower,
countercurrent to the direction of water flow. The saturated air containing
the volatiles is emitted at the top. The stripper exhaust may require
treatment, depending on the concentration and the nature of the VOs present in
the ground water.
34
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'LOW
-PACKING KCMOVAL
OOOH
INSPECTION »0«T
-BACKING ULL
OOOM
-PACKED COLUMN
AIM STNIFPC*
Figure 3. Typical Air Stripper and Blower
35
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The primary source of emissions from air stripping is the stripper
exhaust. However, other sources may exist. Any place upstream of the air
stripping tower where the water is in direct contact with the atmosphere, such
as separators, holding tanks, treatment tanks, or conduits, is an emission
source. Fugitive losses from pumps, valves, and flanges are usually not
significant due to the dilute nature of the ground-water contamination.
2.2.2 Kev Parameters Affecting Emissions
Air strippers are designed to maximize removal of VOs from ground
water leading to transfer of these contaminants into air and eventual
treatment in a control device or discharge to the atmosphere. The key
parameters affecting emissions from air stripping are:
• Ground-water VO concentration;
Volatility (Henry's Law Constant) of the VOs;
Ground-water temperature;
Air temperature;
• Air/water contact time;
Air/water ratio; and
Use and efficiency of control device.
Many of these parameters can be optimized and removal efficiencies in excess
of 99.5% for most volatile compounds have been demonstrated (20,21).
The design of a packed tower requires the evaluation of various
design parameters on the size of the packed towers. Kavanaugh and Russel (22)
have published a useful introduction to the topic which is summarized below.
Given the influent organic loading, the desired effluent water quality, system
flow rate, and design temperature, the design is as follows:
36
-------
1. Select an efficient packing material and determine Its headloss
and mass transfer characteristics from commercially available
data.
2. Select a stripping factor (e.g., 1.2-1.4).
3. Select a gas phase pressure drop (e.g., 100 N/m2 per m).
4. Determine the number of transfer units.
5. Using the headloss correlation, determine the allowable
superficial gas rate.
6. Based on items 2 and 5, determine the liquid loading rate and
the diameter of the column.
7. Evaluate the practicality of the liquid loading rate and, if
necessary, reduce the air headloss.
8. Optimize the cost of the system by evaluating various stripping
factors and air headlosses.
Reference 22 should be consulted for an explanation of the above terms.
Obviously, the design of a packed tower is a complex process and multiple,
interrelated variables must be considered.
Volatility increases with temperature, so heating the ground water
and/or the air stream enhances removal. The air blower heats the air during
compression; heat exchangers can be used to preheat the ground water.
The rate of volatilization is affected by the air-to-water contact
time and the air-to-water ratio. The contact time can be increased by
increasing the height of the tower, by slowing the rate of water percolation
through selection of packing material, or by increasing the effective surface
area of the tower through selection of packing material or decreasing the
37
-------
average droplet size. The spray pattern can be deleteriously altered by
plugging of Individual spray nozzles or if the distance between the nozzles
and packing is incorrect, and this may result in short circuiting of ground
water through the air stripper, thereby reducing removal efficiency.
Air-to-water ratios are typically 200:1 for effective removal.
For upstream emission sources, VO emission rates are dependent on similar
parameters to those affecting air stripper emissions such as VO concentration
in the ground water, ground water temperature, and volatility of the VOs.
Other key parameters for upstream emission sources are the surface area of the
exposed ground water, the degree of agitation of the water surface, and the
residence time of the water at any exposed location. Since air stripping is
typically a very efficient treatment process, any emissions that occur
upstream of the air stripper represent emissions that would otherwise occur at
the air stripper. Therefore, if emissions from the air stripper are
uncontrolled, then upstream emissions may generally be ignored. However, if
air stripper emissions are controlled, then consideration of upstream
emissions is warranted as these emission would otherwise be largely
controlled. Emissions from open tanks may be a significant emission source
and emissions can be measured or predicted as discussed in Section 5.
2.2.3 Control Technologies
The effect of air stripping of ground water is often to translate a
future health risk from drinking contaminated ground water, into an immediate,
albeit frequently lower, health risk from breathing contaminated air.
However, the air stripper exhaust can easily be routed through an emissions
control device. Two control technologies are typically used: carbon
adsorption and incineration. If an incinerator is in concurrent service, the
exhaust from the air stripping tower can be used as makeup air to the
combustion chamber. Otherwise, vapor-phase carbon adsorption with or without
steam regeneration is usually the most cost-effective treatment.
Carbon adsorption systems (CAS's) typically contain multiple beds of
granulated activated carbon. The exhaust gas from the air stripping must be
38
-------
first treated by a preheater to reduce the relative humidity of the gas stream
to below 50 percent. Very high humidities drastically reduce the adsorptive
capabilities of the activated carbon. A fan forces the vapor through the
carbon beds. Some type of diffuser or diaphragm baffle can be used to
Increase the flow path and the contact time. The flow may be In parallel or
In series with a second bed functioning as a polishing unit. The carbon beds
require either periodic replacement or cleansing with low pressure steam. The
solvent-laden steam from regeneration 1s passed through a condenser and the
condensate may be sent to a solvent recovery facility. The regeneration cycle
can be automatically activated based on the theoretical breakthrough of the
least adsorbed component, or operating cycles can be set in response to a
preset concentration monitored in the stack. Flammable or explosive
conditions may exist in the CAS and appropriate safety precautions are
required.
Typically, the adsorption capacity increases with the molecular weight of
the VO being adsorbed. Unsaturated compounds are usually more completely
adsorbed than saturated compounds, and cyclical compounds more than
straight-chain compounds. The adsorption capacity is increased by operating
at relatively low temperatures (50-55'C) and high VO concentrations. Carbon
adsorption can be used on gas streams with about 200 to 10,000 ppm of VOs.
The removal efficiency varies with concentration with removals of 95 to 99%
possible for inlet concentrations exceeding 1,000 ppm. CAS's do not work well
for two types of organic compounds: highly volatile compounds (molecular
weight < 45) do not adsorb readily on carbon, high molecular weight compounds
(molecular weight > 130) that have low volatility are strongly adsorbed on
carbon and are difficult to remove. Design information has been published by
the EPA (23). Control efficiencies, and thus emissions, will also be
dependent upon the manner of operation of the control system. For example, a
system that initiates regeneration when breakthrough is detected may have
higher emissions than a system that automatically regenerates more frequently.
Emissions from sources upstream of the air stripping tower can best be
controlled by covering or enclosing the source, to make the system as closed
as possible.
39
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2.3 IN-SITU VENTING
In-situ venting is a technique which uses soil aeration to treat
subsurface zones of contaminated soil for VOs. There are several techniques
available which either 1) remove the VOs from the soil or 2) cause migration
of the VOs away from a point of concern (the basement of a single structure,
for Instance, which is endangered by collection of explosive or toxic vapors).
Most of the discussion describing in-situ venting and key parameters affecting
emissions in this report is taken from Crow, et al. (24).
2.3.1 Emission Sources
Two basic types of aeration exist: active aeration, which uses
either vacuum or positive pressure pumping, and passive aeration, which
depends upon natural driving forces for soil gas displacement. Active
aeration through vacuum pumping is the only available means of actually
extracting the volatile constituents from the soil. Positive pressure and
passive aeration serve only to displace the VOs, causing migration away from
endangered structures. The latter two system types may not be suitable for
use at most NPL sites, except perhaps where the site is located adjacent to
basements, sewers, or other subsurface structures.
An example of a vacuum ventilation system is shown in Figure 4; it
consists of a vapor recovery well (i.e., a perforated pipe placed vertically
or horizontally into the subsurface soil for purposes of ventilation), a
vacuum source, and an emissions control device. A vacuum is applied to the
vapor recovery well by the vacuum source. The flow of gases results in a rich
mixture of VOs being pulled into the recovery well. The VO-rich gases pass
through the vacuum source and are treated in the emissions control device to
remove potential air pollutants.
40
-------
Figure 4. An Example of a Subsurface Ventilation System (Vacuum Type)
Source: Reference 24.
-------
As a vacuum is applied to a vapor recovery well, gas flows from the
soil Into the well and to the vacuum source. At the same time, air must enter
the soil to replace the soil gas removed by the ventilation system. Air flow
can be altered by an impermeable barrier at the surface and by an air intake
well. Air-flow patterns during vacuum aeration are illustrated in Figure 5.
These devices can be used to direct air flow and optimize performance of
subsurface ventilation systems.
Pressure systems are designed specifically to mitigate or avoid the
effects of contaminant vapors in the subsurface. Air is injected under
pressure to displace contaminated air and prevent vapors from encroaching upon
the protected structure. The systems are capable of maintaining very low
vapor concentrations in the immediate vicinity of the protected structure.
They are not amenable to emission control devices. There is no direct exhaust
from a pressure system; vapors are emitted to the air from a large surface
area of soil and are therefore not regulated. A typical pressure system is
illustrated in Figure 6.
Passive aeration systems perform the same task as pressure systems,
but at minimal expense. They rely on specially designed subsurface collection
systems to reduce the mean free path for molecular diffusion of gases through
the soil. No sources of pressure or vacuum are used other than that supplied
by natural forces such as diffusion, wind, temperature fluctuations, or
infiltrating water. Vapors in the soil diffuse to the surface with time. A
simple passive system is shown in Figure 7. Standpipes are used to emit the
extracted vapors above the roof. A wind turbine or similar apparatus can be
used to enhance recovery. Although inexpensive, such systems are relatively
slow in removing soil contamination and may not be amenable to controls.
Case studies reported by Crow, et al. (24) showed recovery rates
ranging from 1 to 110 kg of organic contaminants per day. However, recoveries
up to 900 kg/day of volatiles from ventilation of a single recovery well, have
been reported from an NPL site (25); this can be considered to be a maximum
rate.
42
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VACUUM
IMP€RMEABLE
STRUCTURE
INTAKE
\
Figure 5. Illustration of air-flow patterns active in subsurface ventilation
systems employing (a) vacuum, (b) impermeable barriers, and
(c) air intake wells.
Source: Reference 24.
43
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Mr Some*
Air Fto*
Figure 6. Pressure subsurface ventilation system designed to prevent
encroaching vapors from entering through the basement of a
dwel1i ng.
Source: Reference 24.
44
-------
Figure 7. Passive Subsurface Ventilation System Utilizing Horizontal Perforated Pipe.
Source: Reference 24.
-------
2.3.2 Key Parameters Affecting Emissions
The flow of gas through a subsurface environment Is governed by the
physics which pertain to the flux of gas through any porous medium. Natural
flow 1s affected by several parameters, such as gravity, pressure, tempera-
ture, wind, rainfall (Infiltrating water), and soil parameters such as
porosity, density, and moisture content. Active aeration using vacuum or
pressure is affected by these same factors; however, the effects of many of
the natural parameters are minimized by the pressure gradient induced by the
active aeration system.
Air permeability (ka) is a measure of the ability of soils to
transmit gases. It can be defined as the ratio of the flow volume to the flow
gradient. The flow gradient contains two components: pressure gradient and
gravitational gradient, although the pressure gradient is by far the primary
driving force. In active aeration, the gravitational gradient is overcome by
induced pressure gradients.
Pressure gradients can also result from several natural sources,
including temperature fluctuations, barometric pressure changes, wind, and
rainfall. For instance, warm air has a natural tendency to rise above cooler
air. As the soil surface cools, warmer gas in the underlying soil will rise
to the surface. An additional temperature effect occurs because gases expand
when heated and contract when cooled. The changing volume can create a
constant ebb and flow of gases in the soils. Both these mechanisms would only
be significant in situations of passive ventilation.
The contributions of barometric pressure, wind, and rainfall on gas
movement would also be minimal in the presence of subsurface ventilation
systems. Decreasing barometric pressure results in expansion of soil gases,
causing aeration. Wind blowing across the soil surface can cause mixing of
the upper few centimeters of soil gas by creating a small pressure gradient.
Infiltration of water through rainfall causes water to enter the soil pore
space and gas to be expelled.
46
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The most important external factors which affect soil gas movement
are the properties of the soil itself: porosity, density, and moisture
content. At a given soil density, the volume of soil solids is constant. The
balance of the soil volume 1s termed the pore space (porosity) and may be
filled with liquid or gas as shown in Figure 8. At a given soil density, the
pore space Is also constant. Since the mass flow of gas is restricted to the
gas volume, there is a complex interaction of density, water content, and
porous space available for gas flow.
In a dry soil, the porosity is equal to the gas volume and
proportional to the air permeability. However, it is the effective porosity,
or that calculated for connected pore space, that controls flow, since the
majority of gas flow is through large, continuous pores in the soil. Dense
soils, or those which have been remolded and compacted, are less permeable to
air than natural soils. Clay soils are less permeable than sandy soils, for
although many clay soils have porosities greater than sandy soils, the
effective porosities are smaller.
Moisture content is one of the most important parameters influencing
the air permeability of soils. Moisture in the soil resides in the pore space
with the gas, decreasing the space available for gas flow and therefore the
air permeability of soils. Air permeability decreases rapidly at relative
water saturation values greater than 50% (i.e., <50% air space). Large,
continuous pores are most effective at transmitting gas and are not filled
with water until the soil approaches saturation.
The water- to gas-filled pore space relationship can be related to
the water-holding capacity of the soil. Fine-textured soils have finer pores
and tend to hold more water against the force of gravity. The finer, less
continuous pores and greater water content make fine-textured soils much less
permeable to air than their coarse-textured counterparts. The coarser-
textured soils are more applicable to subsurface ventilation.
47
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a
LIQUID
souos
Figure 8. Cross-sectional view of the soil system. (The soil is a three-
phase system consisting of solids, liquids, and gases. Only the
gas space is available for movement of VOC vapors.)
48
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2.3.3 Possible Control Technologies
To prevent turning a subsurface pollution problem into an air
quality problem, some states regulate the emission of vent gas to the
atmosphere. Several options are available for emissions control of exhaust
from subsurface ventilation systems. The most effective techniques available
for control include condensation, carbon adsorption, and incineration.
Condensation is a means of recovering organic compounds from the
exhaust streams. The vent gas is cooled to decrease the vapor pressure of the
volatile organic compound and trigger condensation. Water also condenses at
these temperatures, and some form of separation process is necessary. In
addition, the temperature should be low enough to minimize vapors present in
the condenser which could potentially be released from the system. Even at
low temperatures, this method is not completely efficient at removing
contaminant vapors from the exhaust stream, and it is typically backed up with
another emission control such as carbon adsorption.
Carbon adsorption uses granular activated carbon to absorb
contaminant vapors. Two types of carbon adsorption systems are available.
The first uses disposable carbon, which is discarded when saturated with
organic compounds. The second reclaims the carbon using steam stripping to
volatilize the contaminants and strip them from the carbon. The steam is then
condensed and the immiscible organic products are separated from the water.
Carbon adsorption is discussed in more detail in Section 2.2.
Incineration, which is discussed in other sections in this manual,
is applicable to large venting projects which produce substantial quantities
of organics, or where incineration is a concurrent treatment. In the latter
case, the vented gas can be used as make-up air to the combustion chamber.
When properly operated, incineration is the most efficient technique for
treating hydrocarbon emissions.
49
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2.4 SOILS HANDLING
Remedial actions at NPL sites will very often involve handling of
contaminated soil. This handling may result in fugitive dust emission that
can carry inorganic and organic constituents which are contained in, or are
adhering to, the dust particles. Soils handling can also lead to enhancement
of volatile organic emissions due to exposure of the contaminated soil to the
atmosphere. Specific activities with emission potential include excavation,
transport, dumping, storage, or grading.
This section addresses participate and volatile organic emissions
from area-wide sources of fugitive emissions such as soils handling
activities. The discussion applies to any underlying, concentrated wastes as
well as to contaminated soils themselves. Stabilization and solidification
are remedial actions that are likely to involve the soil handling activities
discussed in this section, but also involve other unique soil processing
steps. Stabilization and solidification are covered separately in Section
2.5.
2.4.1 Emission Sources
Remedial activity at Superfund sites can produce air quality impacts
from the handling of contaminated soil, and this is one of the major types of
waste (by volume) handled during a typical remedial action. Digging and
relocating of soil causes fugitive dust emissions and enhances volatilization
of organic compounds to the atmosphere. Through entrapment in wind, fugitive
participates and organic compounds can be carried great distances away from
the site. Contaminated soil particles may also carry trace metals and
organics which have been adsorbed onto the particle surface.
It is important to discern which of the remedial operations have a
significant potential for air emissions, to quantify these emissions if pos-
sible, to weigh possible treatment alternatives with potential air hazards,
and to control these emissions when necessary. To this end, the various
50
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possible steps in soils handling during remedial treatment have been divided
into five broad categories: excavation, transport, dumping, storage, and
grading.
Excavation 1s the process of digging up contaminated soil and waste
from the dump. Common types of equipment used for excavation are backhoes,
draglines, bulldozers, front-end loaders, scrapers, etc. The machinery is
described in detail 1n an EPA handbook (26). Soil is stirred by the excava-
tion equipment and contributes to fugitive particulate emissions. Exposure of
the wastes to the atmosphere due to removal of the soil covering can also
increase volatile organic emissions from the site.
Transport in this report refers to travel of trucks between and
around storage piles, as well as travel on paved and unpaved roads. Unless
the wastes are transported to another site for disposal, Incineration, or
other remedial treatment, the fugitive dust emissions from travel on paved and
unpaved roads are expected to provide only a minor contribution to the overall
emission factor. Travel between, around, or on piles may present the more
serious emission problem because of the possibility of workers being exposed
to adsorbed contaminants on the particulate and the possibility of wind
entrainment. For long-distance transport, effective, inexpensive emission
controls are available.
Dumping of soil as a part of remedial action refers to both dumping
from excavating machinery into trucks and dumping from trucks onto storage
piles. Again, fugitive particulate emissions and volatilization will usually
be the main concerns. Storage in piles presents opportunity for fugitive
emissions through wind erosion and entrainment of particulate.
Grading refers to the leveling technique applied to the waste site
after remedial action has been completed. Usually, a tractor or dozer fitted
with a blade Is used for this, although at some sites pan scrapers or motor
graders are used (27).
51
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Typical ranges of particulate matter emissions for handling of con-
taminated soil are shown 1n Table 10. Estimated contributions of the more
common activities, expressed as percentages of overall fugitive dust emis-
sions, are as follows (28):
Loading onto piles (dumping) 12%
Equipment and vehicle movement (excav. and trans.) 40%
Wind erosion (storing) 33%
Loadout from piles (dumping) 15%
The contributions are estimated with data from the crushed rock industry.
2.4.2 Kev Parameters Affecting Emissions
Fugitive dust is usually the most ubiquitous type of emission from
remedial action, but depending on the waste present at the site, increased
amounts of volatile organic compounds (VOs) can escape into the air when the
wastes and soil covering are disturbed. Wind entrainment can carry the
particulates away from the site.
Theoretical drift distances, as a function of particle diameter and
mean wind speed, have been computed for fugitive dust emissions. Many of the
emission factors and equations obtained from USEPA (31) are given as a
function of particulate diameter to allow the computation of emissions in the
size range of interest. Large particles with diameters greater than 100
microns (urn) are likely to settle within 5 to 10 meters of the emissions
source. Those which are 30 to 100 microns in diameter are likely to settle
within a hundred meters or so of the source, except in cases of high
atmospheric turbulence. Smaller particles, especially those with diameters
less than 10 to 15 microns, are much more likely to stay adrift in the
atmosphere because of turbulence (32). Particles smaller than 10 to 15
microns are considered to be respirable; i.e., they can enter and lodge in
human lungs (26).
52
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TABLE 10. TYPICAL RANGES OF EMISSION FACTORS
Activity
Participate Matter3
Notes
Reference
Wl
CO
Excavation
Transport;
Unpaved Roads
Dry Industrial Paved Roads
Heavily-loaded Industrial Roads
Dumping
Storage:
Inactive Piles
Active Piles
Active/Inactive Piles
Grading
TSP
15 to 25 urn
<2.5 um
<15 um
0.002-0.086 kg/metric ton
0.015-0.22 kg/metric ton
1.3 kg/VKT
0.022-0.15 kg/VKT
0.093-0.12 kg/VKT
0.005-0.05 kg/metric ton
0.015-0.03 kg/metric ton
0.025-0.16 kg/metric ton
0.39 g/m2/day.
O.OBBpkg/metMc ton
1.5 g/m /day.
0.21 kg/metric ton
1.2 g/m /day.
0.16 kg/metric ton
0.006 kg/metric ton
5.4 kg/hr
2.5 kg/hr
0.03 kg/hr
2.6 kg/hr
Overburden 29.30
Topsoll 31.32
Estimated from equation
Medium & heavy vehicles 31
Light duty vehicles 31
Continuous 33
Batch 31
D1atom1te 30
Wind erosion only 28
8-12 hrs/day activity 28
5 active days/week 28
Overburden replacement 31
Grading spent dlatomlte 30
Grading spent dlatomlte 30
Grading spent dlatomlte 30
Grading spent dlatomlte 30
Units are kilograms per metric ton of soil moved, kilograms of emissions per vehicle kilometer
traveled (VKT). grams of emissions per square meter of storage pile surface area per day. or
kilograms of emissions per hour of grading.
-------
Organics and trace metals may also migrate or diffuse from the
underlying waste Into the soil covering and adsorb onto soil particles. When
present on resplrable particles, the metals or organics could enter the
bloodstream through the lungs and present additional health hazards.
For these reasons, site-specific Information on the composition of
the waste present 1s Important, particularly concentrations of organic
compounds and metals. At the same time, the emissions are also dependent on
other parameters In addition to the waste composition. For example,
meteorological conditions (e.g., wind speed, prevailing wind direction, amount
of precipitation), the amount of activity (e.g., excavation, dumping, storing
In piles), and soil/waste physical properties (e.g., silt content) must be
considered.
Table 11 contains a list of parameters that may effect the emissions
potential at a given site. Meteorological data can be obtained from a local
office of the National Weather Service. Operating characteristics of the
remedial activity are site-dependent and may be obtained through on-site
observation or from vendors and/or operators. Soil and waste characteristics
may be obtained from the remedial investigation for the site or from the Soil
Conservation Service. A few of the more important physical properties are
discussed in the following paragraphs. The dependence of air emissions on
these parameters is addressed in Section 3.6.
Silt content is defined as the weight fraction of the soil passing
through a 200-mesh screen, i.e., that which is less than 75 microns (urn). The
PM-10 portion is the weight fraction of the silt with a physical diameter (not
aerodynamic diameter) of less than 10 microns (urn). Percent moisture is
determined by gravimetric analysis, measured by the weight loss of the sample
after oven drying (27).
54
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TABLE 11. IMPORTANT PARAMETERS IN DETERMINING AND CONTROLLING
EMISSIONS FROM SOILS HANDLING
Parameter
Typical Importance to Emission Level
Particulates/Metals Volatile Organics
Meteorological Conditions
Wind Speed
Wind Direction/Variability
Temperature
Relative Humidity
Barometric Pressure
Precipitation
Solar Radiation
Medium
Low
Low
Low
Low
High
Low
Medium
Low
Medium
Low
Low
Medium
Low
Operating Characteristics
Area of Working Face
Agitation Factor
Drop Height
Storage Pile Geometry
Available Soil Cover
Medium
High
Low
Medium
High
High
High
Low
Low
High
Soil/Waste Characteristics
Physical Properties
Silt Content
PM-10 Content
Density
Permeability
Moisture Content
Organic Fraction
Metal Concentrations
High
Low
Low
Low
High
Low
High
Low
Low
Medium
High
Medium
High
Low
55
-------
The rationale for measuring the PM-10 parameter Is the hypothesis
that the hazardous constituents (e.g., heavy metals) In the contaminated soil
or surface material may tend to absorb preferentially on finer particles. The
finer particles are thought to remain airborne for longer periods of time, and
they may therefore be transported considerable distances from the site (27).
2.4.3 Possible Control Technologies
Measures to control fugitive participate and volatile organic
emissions are available for remedial action applications. Conventional
techniques include water sprays, surfactants or "wetting agents", dust
suppressants, windscreens, and slope and orientation of storage piles. New
technologies are also being developed and tested on smaller scales, but they
have not yet been accepted as conventional practices. These measures include
temporary and stabilized foams, membrane coverings, spray charging and
trapping systems, and road carpets. Each technology will briefly be discussed
in the following paragraphs. Table 12 shows the control technologies which
may be applied to each of the emission categories discussed previously.
The most common method of dust control at hazardous waste sites is
the use of water sprays. Surface wetting also inhibits volatilization by
filling available pore spaces with water and thereby decreasing diffusion
rates. This usually entails spraying the active working area (34), a process
which has to be repeated about every two hours to maintain effectiveness (26).
Another approach is to spray a curtain which would totally cover the bed or
box of a dump truck. This method has been tested by Rosbury and James (34).
One test was done with a continuously sprayed curtain; in another test, a
foaming agent was added to an intermittent water spray, where the spray was
only activated during the dump from an excavator into a truck box. Control
efficiencies for these and other technologies and applications are shown in
Table 13. Potential concerns with surface wetting are flushing contamination
down Into ground water and run-off to surface waters. When surface wetting at
56
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TABLE 12. CONTROL TECHNOLOGIES AVAILABLE FOR EACH
SOILS HANDLING EMISSION CATEGORY
Excavation
Transportation
Water sprays of active areas
Dust suppressants
Surfactants
Foam coverings
Water sprays of active areas
Dust suppressants
Surfactants
Road carpets
Road oiling
Speed reduction
Coverings for loads
Dumping
Storage
Grading
Water sprays of active areas
Water spray curtains over bed during dumping
Dust suppressants
Surfactants
Enclosure of dumping area for material
transfer
Windscreens and other enclosures
Orientation of pile
Slope of pile
Foam covering and other coverings
Dust suppressants
Light water sprays
Surfactants
57
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TABLE 13. EFFICIENCIES OF VARIOUS CONTROL TECHNOLOGIES
01
00
Dust Control Efficiency
Percent
Application
Spray of Active Excavation
Area. Front End Loader:
Water Spray
Water + Surfactant
Spray of Dumping Area.
Front End Loader to Truck:
Area Spray - Water
. Area Spray - Water +_ Surfactant
Water Curtain (continuous)
Foam Curtain (Intermittent)
Dust Suppressant
Unpaved Road
Wasteplle
Windscreens
Coal Pile
TSP «30 urn)
42
63
69
77
50
46
40-99
50-70
45-65
FP (<2.5 urn)
64
70
66
62
56
41
20-95
NA
NA
Vapor
Control
Efficiency Dosage
(J) (L/mz)
NA
NA
NA
NA
NA
NA
NA
NA
NA
4.1
3.4
4.1
4.1
6.8
1.8
Variable
Variable
-
Reference
34
34
34
34
34
34
35
36
37
"Beehive"-Type Enclosures
for Storage Piles
Orientation of Storage Pile
Length Perpendicular to
Prevailing Wind
100
60
NA
NA
NA
NA
NA = not available.
- = not applicable.
* First number 1s percent foam concentrate: second number 1s percent water.
36
36
Synthetic Covers
Temporary Foam (20 minutes)
Stabilized Foam (24 hours)
Rigid Foam (2 hours)
NA
NA
NA
NA
NA
NA
81
99
73
6/94*
6/94*
NA
38
38.39.40
40
-------
a hazardous waste site is being considered, the potential impact on surface
and ground waters as well as the potential benefit of reduced air emissions
should be considered.
Control efficiencies were measured for each of the water spray tests
performed by Rosbury and James (34). For the simple water spray of the active
working area, control efficiencies were 66-69% for the dumping area and 42%
for the travel and scraping area (excavation). It should be noted that the
ground was sprayed only twice a day during the testing. Also, the control
efficiencies are for total suspended participate (TSP), which includes all
particles with less than a 30 micron diameter. Water sprays on the travel and
scraping areas showed a 64% control efficiency during the study for fine
particulates (FP, with less than a 2.5 micron diameter).
When the dump truck box was sprayed with a continuous stream of
water, the control efficiency was 50% for TSP and 56% for FP. The author
noted that continuous spray could probably be replaced with intermittent spray
during dumping without a significant loss of control efficiency. Intermittent
spray was tested with a foaming additive. The calculated control efficiency
for that test averaged 46% for TSP and 41% for FP.
Chemical dust suppressants are sometimes used in conjunction with
water sprays for added control effectiveness. The purpose of dust
suppressants is to strengthen the bonds between soil particles. Their
effectiveness is dependent on maintaining an undisturbed soil-chemical crust.
Vegetation and traffic will break the crust and require more frequent
applications (26).
Several types of chemicals are available on the market. Surfactants
or surface wetting agents are also available. More detailed discussions,
complete with control effectiveness, recommended doses, and cost of the dust
suppressants and surfactants have been published (26,28,41). Rosbury and
James (34) tested the effectiveness of spraying the active working area with a
water spray containing a surfactant. The control efficiency in the travel and
59
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scraping area was 63% for TSP and 70% for FP. When tested In the dumping
area, the control efficiency averaged 77% for TSP and 62% for FP.
Water sprays, surfactants, and dust suppressants may be used to
control emissions from unpaved roads. Other available means of control
include oiling of roads (29), reduction of vehicle speed, and covering the
load with a tarp or other means of containment. The latter can be
particularly important in reducing emissions during long-distance
transportation, especially at high speeds.
Another type of control for fugitive particulate emissions is to
enclose the active area or storage piles with supported structures, such as
windscreens (26,37). Porous screens or other structures are designed to
deflect enough wind to lower the wind velocity below the threshold required to
stir soil. Windscreens are a mobile, low-cost method of reducing fugitive
particulate emissions. However, wind speed reduction is practical only when
the source is small (33).
Several studies have been performed to determine the control
efficiency of windscreens. At best, they are only partially effective in
controlling inhalable particulates (26), which are those particles with a
diameter less than 15 microns (41). Control efficiencies of about 60% for
inhalable particulate and 75% for TSP have been reported with wind speeds of
4.4 to 5.8 meters/sec (10 to 13 mph) and gusts of 8 to 8.5 meters/sec (18 or
19 mph). In another study, the results showed some effectiveness with
particles larger than inhalable particulate, but no consistent benefits were
apparent for particles in the 10-micron size range. The results of both
studies were summarized in USEPA (26).
A secondary form of wind-blown particulate control lies in the slope
and orientation of the storage pile. Keeping the slope of the pile less than
10 degrees in the direction of prevailing winds will help minimize emissions.
Also, if the long side of a pile is perpendicular to the prevailing wind,
emissions can be reduced by about 60% (36).
60
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Several new technologies also exist: spray foam coverings,
synthetic membranes, spray charging and trapping, and road carpets
(36,38,39,40,41,42). The term "new" does not necessarily mean that these
technologies have not been tried or tested, but that they have not yet been
accepted into conventional practice at hazardous waste sites for control of
fugitive particulate or volatile organic emissions. The technologies are
discussed 1n the following paragraphs. When available, control efficiency
data are included in Table 13.
Two types of foam coverings have been developed: temporary and
stabilized foams. Temporary foam is a slow-draining fluid foam with
approximately a 30-minute lifetime. It is usually used when immediate but
short vapor suppression 1s required, such as during excavation or dumping of
wastes. Stabilized foam, on the other hand, hardens 1-4 minutes after
spraying into a tough, elastic, nondraining surface cover. The stabilized
foam lasts as an effective vapor suppressant for about 24 hours. After
several days, the foam will dehydrate and collapse into an elastic membrane.
The aged foam seemed to consolidate particles very effectively, which should
reduce airborne particulate (38).
Both temporary and stabilized foams can be used during excavation at
active sites as vapor and dust-suppressive coverings (38,39,40). The foams
are environmentally compatible (39) and have been tested at several sites
under varying conditions, including an underground burning landfill (38), a
petroleum waste site (38,39), a floating roof petroleum storage tank (39),
sour refinery water (39), and acid fumes from a thin spill of oleum (39).
Membranes of the type used to control volatile emissions from land
treatment areas and surface impoundments have been considered for use at
remedial action sites. However, the cover would probably be punctured or torn
by equipment as waste is excavated from the site (36). Therefore, membranes
such as neoprene and polyvinyl chloride are probably not the most
cost-effective control alternative. Also, many membranes show poor
61
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performance for retaining organic compounds from landfills or surface
Impoundments (36). Results from control tests of volatile organics with
polyvinyl chloride membranes have reportedly been disappointing (42).
The Spray Charging and Trapping (SCAT) system controls fugitive
particulates by diverting them Into a charged spray scrubber located near the
emissions source. Different designs to accomplish this task are being
considered; one possibility is to use one or more high-velocity air streams,
produced by air jets, to entrain particulates and push them away from the
source. Downstream, a charged stream of water or an aqueous compound is
sprayed concurrently into the gas stream to remove the entrained dust. After
sufficient contacting time to allow capture of most of the gas stream
particles, a low-pressure drop entrainment separator is used to separate the
water spray drops from the gas stream. A system prototype has so far been
tested in cross-wind conditions and on a hot, buoyant plume of smoke (41).
Road carpets are fabrics which have been developed to stabilize and
contain particulates on unpaved roads, or surfaces such as those around
storage piles which are exposed to excessive traffic. Road carpets help to
spread the concentrated stress from heavy-wheeled traffic over a wide area,
siphon away groundwater, and contain fine soil particles (41).
Studies have shown that for unpaved road, application of a road
carpet material is not as cost effective as paving; however, a road
constructed with fabric Is less expensive than one that has to be continually
watered (41). Road carpets may therefore be a possible control measure for
use around storage piles, or for sections of the remedial action site which
receive heavy traffic, but are otherwise not disturbed (e.g., excavated).
2.5 STABILIZATION/SOLIDIFICATION
Stabilization/solidification differs from the soils handling steps
described above in that it is a treatment technology. It is more complex and
more costly than the other types of soils handling operations. Several types
62
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of stabilization and solidification processes exist as alternatives for
remedial action (43,44). Cost information for these processes may be found in
Cull inane (43). Except for emerging technologies that involve in-situ
treatment, the implementation of stabilization of solidification generally
involves several of the soil handling activities previously discussed. Thus,
consideration of emissions from stabilization or solidification must generally
address both the emissions that result directly from the treatment process and
the emissions from the associated soils handling activities.
Stabilization/solidification (encapsulation) processes are currently
being developed and evaluated for hazardous waste applications. Due to the
rapidly evolving nature of this technology, the material presented here is
preliminary and subject to revision.
2.5.1 Emission Sources
Stabilization processes reduce the hazard potential of a waste by
converting it to its least soluble, mobile, or toxic form. The physical
nature or handling characteristics of the waste are not necessarily changed by
the technique. Solidification processes (sometimes called encapsulation
processes) bind the waste in a structurally sound, uniform solid (43).
The basic steps in solidification and stabilization processes are
generally the same: wastes are loaded into the mix bin (wastes are sometimes
dried before addition to the bin), and other materials for the solidification
or stabilization are added. The contents of the bin are mixed and removed
from the bin (27,43). It is important to note that these basic steps describe
batch or continuous treatment of soil after it has been removed from its
original location. True 1n-s1tu treatment methods, such as vitrification by
applied voltage or injection of stabilizing agents are emerging technologies.
Many of the processes and materials are in common use, though not
necessarily at remedial action sites. The thermoplastic microencapsulation
process, for instance, was originally developed for disposal of radioactive
63
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waste (43). Typical raw materials used In stabilization processes (43,44) are
fly ash, cement kiln dust, lime kiln dust, or hydrated lime. Typical binding
agents for solidification/encapsulation processes are asphalt, paraffin,
polyethylene, or polypropylene.
It 1s important that the waste not react with the stabilizing or
binding agents in a way that Interferes with the solidification process.
Because of this restraint, the maximum organic chemical content of aqueous
wastes that can be solidified using cement 1s 2-3 percent (36). And, since
solidification processes usually require heating during the mixing step, they
are usually not suitable for combustible materials such as solid hydrocarbons
or sulfur, since the mixture can ignite at the elevated temperatures (120 to
260°C).
Possible sources of fugitive dust emissions from stabilization and
solidification processes are storage of raw materials, preparation of the
stabilization or binding agents, the dumping of wastes into the mixing bin,
removal of the material from the mixing bin, and replacement of the material
at the site after processing. The emissions data shown in Table 8 are not
from actual solidification or stabilization processes, but were taken instead
from the concrete batching and asphaltic concrete production industries,
respectively. Neither extraction or replacement are included in the Table 8
estimates, so emissions for these activities must also be added to obtain an
overall estimate.
Organics present in the wastes may be volatilized during the
solidification or stabilization processes. However, very little information
exists about the fate of the volatile constituents during these processes.
Typical ranges of particulate matter emissions for stabilization/
solidification are shown in Table 14. Very little data exist for VO emissions
from these processes. VO emissions from stabilization at the Kettleman Hills
waste facility have been estimated to be 5000 kg per year (45).
64
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2.5.2 Kev Parameters Affecting Emissions
The key parameters affecting PM and VO emissions are listed 1n Table
15. The effects of most parameters were discussed in the previous section on
soils handling. Indeed, much of Table 15 1s Identical to Table 11. The
differences relate to the effects of operating characteristics as discussed
below.
In general, VO emissions will depend on the duration and
thoroughness of the mixing, the amount of heat generated in the process, and
the average batch size. The longer or more energetic the mixing and
processing, the greater likelihood that organic compounds will volatilize.
The volatile losses will also increase as the temperature of the waste/binder
mixture increases. Binding agents with high lime contents generally cause
highly exothermic reactions. The batch size affects volatilization by
affecting the mean distance a volatilized molecule has to travel to reach the
air/solid interface at the surface of the stabilized waste. The larger the
block of material, the lower the rate of volatilization.
Particulate matter emissions from stabilization are usually not
significant relative to the emissions from handling the material.
2.5.3 Possible Control Technologies
Possible control technologies for stabilization/solidification of
hazardous wastes are listed in Table 16. Emissions controls generally require
enclosing the work areas to minimize air movement and subsequent windborne
losses. Venting of such enclosures using a baghouse with fabric filters to
collect the particulate matter may be necessary to avoid restrictive safety
requirements for workers in the enclosure.
65
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TABLE 14. TYPICAL RANGES OF EMISSION FACTORS
Activity
Participate Matter'
Notes
Reference
Stabilization/Solidification/ 0.27 kg/nT/month
Encapsulation
Stabilization**
Solidification/Encapsulation'
Replacement (for Stab/Solid)
0.31 kg/metric ton
0.41 kg/metric ton
0.006 kg/metric ton
Heavy construction
Concrete batching
Asphaltic concrete
production
Overburden
31
28.29
28.29
31
a Units are kilgrams of emissions per square meter of the soil surface area being processed per month.
or kilograms of emissions per metric ton of soil processed.
Includes excavation, transportation, dumping, replacement—rough estimate only.
c Does not include excavation of material or replacement of material back at waste site: does include
storage and traffic between piles and processing plant.
-------
TABLE 15. IMPORTANT PARAMETERS IN DETERMINING AND CONTROLLING
EMISSIONS FROM STABILIZATION AND SOLIDIFICATION
Parameter
Typical Importance to Emission Level
Partlculates/Metals Volatile Organics
Meteorological Conditions
Wind Speed
Wind Direction/Variability
Temperature
Relative Humidity
Barometric Pressure
Precipitation
Solar Radiation
Medium
Low
Low
Low
Low
High
Low
Medium
Low
Medium
Low
Low
Medium
Low
Operating Characteristics
Binder Type
Batch Size
Waste/Binding Agent Ratio
Mixing Time/Efficiency
Curing Time
Soil/Waste Characteristics
Physical Properties
Silt Content
PM-10 Content
Density
Permeability
Moisture Content
Organic Fraction
Metal Concentrations
Medium
Low
Medium
Low
Low
High
Low
Low
Low
High
Low
High
High
Medium
Medium
High
Low
Low
Low
Medium
High
High
High
Low
67
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TABLE 16. CONTROL TECHNOLOGIES FOR STABILIZATION AND SOLIDIFICATION
Remedial Operation
Control Technology
Mixing Area/Apparatus
Binder Preparation
Raw Material Storage
In-Situ Treatment
Enclosure
Venting of enclosures to fabric filter
Enclosure of binder preparation area
Storage pile controls
Suction hood
68
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SECTION 3
PROTOCOL FOR ESTIMATING EMISSIONS
This section presents a step-by-step protocol and associated equations
for estimating emissions from a variety of remedial operations during the
clean-up of Superfund (NPL) sites. The protocol is designed to allow the user
to make relative comparisons of the impacts on air quality from remedial
options being considered for implementation. Guidance on the types of
available control technologies for reducing air emissions and their typical
effectiveness are also presented.
The protocol is graphically presented in Section 3.1. A preliminary
screening approach for estimating emissions from a site is given in Section
3.2. The remaining subsections present equations and input values for each
specific remediation option considered in this manual.
3.1 PRESENTATION OF PROTOCOL STEPS
Estimating emissions is the focus of this manual, but it is only one
element of an air pathway analysis. Any emission estimate must also be
evaluated for its impact on potential receptors. A flow chart showing the
basic elements of an air pathway analysis is given as Figure 9. An
explanation of each step is beyond the scope of this manual; however, Volume I
of this series of manuals (1) does provide such an explanation. Also, a brief
description of each element is given in Appendix D of this manual.
69
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[ I. Define APA Objectives |
Z. Assess Existing Data/Records
| Collect Historical Data
I
3. Develop Conceptual Site
Model/Estimate Values
for Key Parameters
Yes
Conduct BI/FS
4. Divide site Into cells
of equivalent waste
V^. Unlts?^-^
^rT
, •
S. Identify Candidate
Remedial Actions
i
|6. Calculate EFs
No
7. Determine Average and Maximum
Emissions (mas W day)
Perform Steps 5. 6. and 7
for each operable unit
1
Select Control
Calculate Control
Efficiency
Remedial /Removal Actions
(Air Pollutants of Concern)
, (
1. Incineration (VO. *e*ais.
PM. NOX. SOX. CD
2. Soils Handling rvo. FM. .retsls)
a) Excavation
b) Short haul transport
c) Dumping
d) Storage
e) Long haul transport
f) Bulk operations
3. Stabilization (VO. PH. metals)
4. GU Stripping (VO)
5. In-sltu Venting (VO)
6. No Action
8. Estimate Pollutant Concentrations at
Receptors (e.g.. dispersion model)
9. Compare Concentration to
Regs/Standards
Yes
10. Input APA Results to FS/RD/ROD
Decision-making Process
Figure 9. Flow chart of air pathway analysis for remediation
70
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3.2 PRELIMINARY EMISSIONS ESTIMATION PROCEDURE
This subsection presents a simple procedure for making a gross estimate
of emissions due to remedial activities. It is intended to be used as a
screening tool to assess whether emissions from remediation may be significant
at a given site, using a given remedial technology. Sites that have the
potential for significant emissions, based on this screening, should have
their emissions potential subsequently evaluated using the more precise
estimation procedures for each remedial technology given in the following
subsections. The screening procedure is necessarily conservative, i.e., sites
with any likelihood of significant emissions are referred to the more precise,
but more time consuming, estimation procedures.
The necessity of evaluating air emissions for a given site is dependent
on the type of hazardous material(s) at the site, the size of the site, and
the proposed treatment options. The following information should be known to
initially assess the emissions potential of the site:
Estimate the volume (m3), mass (kg), and type of waste material to
be treated;
Estimate the concentration of VOCs, heavy metals, dioxins, asbestos,
and pesticides in the waste material (ug/g);
List the probable treatment options and control technologies; and
Estimate the operating rate for remedial activities.
Table 17 lists remedial options and their associated control technolo-
gies. Typical operational rates and air emission values for various remedial
options are presented in Table 18.
71
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TABLE 17. CONTROL TECHNOLOGIES AVAILABLE FOR EACH REMEDIAL OPTION
Remedial Operation Contaminant
Control Technology
Incineration
Hydrocarbons Afterburner, Operational (in-furnace)
methods
Particulate Venturi scrubber, Electrostatic
precipitator, Ionizing wet scrubber,
Fabric filter (baghouse)
Acid Gases Spray dryers, ionizing wet scrubber,
venturi scrubber
NOX Catalytic reduction, Operational
(in-furnace) methods
Fugitives Inspection/maintenance
Ground Water Stripping Hydrocarbons
In-situ Venting
Soils Handling
Excavation
Transportation
Dumping
Hydrocarbons
Particulates,
Hydrocarbons
Particulates,
Hydrocarbons
Particulates,
Hydrocarbons
Condensation
Carbon adsorption (disposable)
Carbon adsorption (regenerate)
Incineration
Condensation
Carbon adsorption (disposable)
Carbon adsorption (regenerate)
Incineration
Water sprays of active areas
Dust suppressants
Surfactants
Foam coverings
Water sprays of active areas
Dust suppressants
Surfactants
Road carpets
Road oiling
Speed reduction
Coverings for loads
Water sprays of active areas
Water spray curtains over bed during
dumping
Dust suppressants
Surfactants
(Continued)
72
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TABLE 17. (Continued)
Remedial Operation Contaminant
Control Technology
Soils Handling (Cont.)
Storage
Grading
Stabilization/
Solidification
Particulates,
Hydrocarbons
Particulates,
Hydrocarbons
Particulates,
Hydrocarbons
Windscreens and other enclosures
Orientation of pile
Slope of pile
Foam covering and other coverings
Dust suppressants
Light water sprays
Surfactants
Enclosure of mixing area/apparatus
Storage pile controls for raw
materi als
Enclosure of binder preparation area
Suction hood (in-situ treatment)
73
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TABLE 18. SUMMARY OF TYPICAL AIR EMISSION VALUES BY SOURCE TYPE
Remedial Option
Incineration
Air Stripping
In-s1tu Ventilation
Excavation
Backhoe
Dragline
Scraper
Bulldozer
Grading
Transport
Unpaved Roads
Paved Roads
Dumping
Storage
Stabilization
Typical
Operation
Rate
650 m3/m1na
50.000.000 BTU/hr
3500 L/m1n
0.15-0.85 m3/m1nd
900 m3/day
700 m3/dav
340-610 mVday
1100 or/day
5 trucks/hr
5 trucks/hr
24-270 m3/day
-
-
Uncontrolled Emissions Controlled Emissions
PM VOC PM VOC
0.5-23 g/m3 0.1-500 ug/m3 34-110 mg/m3 -
0 5-50 kg/day b 0 50-100 ppmc
0 1-110 kg/day 0 50-100 ppmc
0.002-0.22 kg/ - -e
metric ton
0.03-5.4 kg/hr - -e
1.3 kg/VKT - -!
0.022-0.15 kg/ - -
VKT
0.005-0.16 kg/ - -e
metric ton
0.39-1.5 g/m2/ - -e
day
0.31-0.41 kg/ - -e
metric ton
uExhaust gas rate.
•.Assume 1-10 mg/L pollutant.
95-99* efficiency for gas streams of 1000-10.000 ppm VO. Multiple treatment units may feed a single
.control system.
Exhaust gas rate per recovery well.
Assume control efficiency of 50%.
Note: •-• Implies Insufficient data to generate typical value.
-------
No clear-cut rules-of-thumb exist for screening which remedial actions
are likely to have significant emissions and which remedial actions are not.
Only a quantitative evaluation of emissions and their impacts can show the
significance of a remedial action. Nevertheless, considerations based on
common sense may be used to make qualitative judgments of potential
significance. If any of the conditions below are met, then a more rigorous
review is recommended.
1. Off-site receptors are near (e.g., within 1 km) of the emission
source.
2. The contamination includes any volume of dioxins or areas containing
highly concentrated pesticides, volatile carcinogens, or asbestos,
and the material will be handled or exposed.
3. The total contamination (mass x concentration) of pesticides, toxic
metals, volatile carcinogens, or asbestos at the site is substantial
(e.g., exceeds 100kg), and this material will be handled or exposed.
4. The total contamination (mass x concentration) of VOCs at the site
is substantial (e.g., exceeds 1,000 kg VOCs), and this material will
be handled or exposed.
5. Volatile organic contaminants are to be treated by incineration,
groundwater stripping, or in-situ ventilation, and no emissions
controls are to be used.
6. There is reason to believe that the control technology will not be
effective for some toxic compounds present in the waste.
7. The anticipated operating rate is relatively large (e.g., >10 times
the values given in Table 18).
Note that sites with insignificant impacts on any off-site areas may still
have an impact on the health and safety of on-site workers, and appropriate
75
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precautions should be followed. For sites that are judged to warrant a full
evaluation, Figure 9 suggests the components that such evaluations should
have, and subsequent subsections describe procedures for making detailed
emissions estimates.
3.3 ESTIMATION OF EMISSIONS FOR THERMAL DESTRUCTION DEVICES
As discussed in Section 2, a variety of thermal destruction devices
exist. Incinerators are by far the best known and most studied type of
thermal destruction devices. Other types of thermal destruction devices must
in most cases be assumed to have similar emissions characteristics as
incinerators.
Thermal destruction of wastes from NPL sites generally must meet
requirements of RCRA since these are generally considered applicable or
relevant and appropriate requirements (ARARs). The most prominent of these
requirements is a mandate that the principal organic hazardous components be
99.99% destroyed or removed. Additional requirements dictate a limit on
particulate emissions of 180 mg/standard m3 (0.08 grains/standard ft3).
Similarly, for wastes containing dioxins or polychlorinated biphenyls (PCBs),
TSCA requirements generally apply that dictate a destruction and removal
efficiency of 99.9999% of these pollutants.
A default approach to estimating emissions from thermal destruction of
hazardous waste is to assume that the above requirements of RCRA and TSCA will
be exactly met. If emissions are to be estimated in a feasibility study or
otherwise prior to incinerator design, then this default approach may be the
only option for estimating emissions. After the incinerator is designed,
three additional options for evaluating actual emissions more precisely may be
available. The first and most rigorous method for emissions estimation would
be to perform a trial burn on the waste in question or a similar waste and
sample the influent and effluent streams for the pollutant of concern. Where
this is not technically or economically feasible, a second approach using
theoretical or empirical equations correlating incinerator operating
parameters to pollutant emission rates is desirable. In the absence of
76
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applicable correlations, a third approach 1s to use data accumulated from the
various trial burns that have been conducted, and assume the results are
applicable to the site in question.
This section attempts to provide either correlations or typical data to
allow estimation of pollutant emissions from Incinerator operations. This
section also provides information to assist evaluation of whether specific
designs are likely to meet RCRA or TSCA requirements. Figure 10 Is a
flowchart delineating the sequence of steps by which emissions for a
Incineration of a given waste may be estimated. Estimation methods are
provided for various types of emissions Including: organic compounds,
metals/particulate matter, HC1, S02, HF, NOx, and fugitive emissions. The
general form of the emissions estimation equations are given in Table 19.
3.3.1 Organic Compounds
The Incinerator flue gas emissions of organic compounds is a function of
the destruction and removal efficiency (ORE) of the system. Currently, no
models exist for calculating the ORE for incineration of hazardous wastes.
This is a due to several factors Including the complex nature of the chemical
reactions taking place in an incinerator; the great diversity of wastes, each
with unique chemical and physical characteristics; and the variety of
incinerator types and operating methods.
Since 1981, EPA has evaluated the emissions from a large number and
variety of incineration facilities. Evaluation of data taken from these
studies indicate that virtually any properly designed and operated
incineration unit should be able to achieve at least 99.99% ORE for the
organic compounds present in the waste (6,7,9). Sufficient temperature,
retention time, oxygen, and feed control are necessary for high destruction.
Use of Tables 2 and 5 provide preliminary guidance for the selection of
incinerator type, residence time, and operating temperatures to maximize
destruction of the organic constituents in the waste.
77
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5. Ua»
Rflntodlfl
%yJ»nKln
liHfllPnr
Actions
Identify AD
Slate-of-the-Art
Disposal and
Treatment Options
Return to Figure 9.
Steps J
Obtain Waste Physical
Cnoinic&l An&lysls
Does
Waste Contain Dloxlns
orFurans?
Does
Waste Contain >SO
olPCBs?
Does Waste
>1000 ppm of
Detemilne the Healing
Value ol the Waste
(Worksheet A)
Incinerate with
an Auxiliary Fuel
For a Specific Incinerator Type,
Estimate (from Section 3.3.1):
Combustion Gas Ftowrate
Refractory Dimensions
Incinerator Cost
Incinerator S
Burner Size
Estimate Emissions for
Organlca (Table 19)
Metals (Table 20)
HO (Table 19)
HF (Table 19)
Paniculate Matter (Table 4)
Fugitives (Worksheet 0)
SO2 (Table 19)
Estimate Emissions
Reduction with Applicable
Control Eoiupinont
Select Incinerator Type,
Residence Time, and
Temperature
(Tables 2 and 7)
Figure 10. Flowchart for Incineration air emissions estimation.
78
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TABLE 19 EMISSION FACTOR (EF) EQUATIONS FOR INCINERATION SYSTEMS*
Emission Type
Emission Equation!- Metric
Emission Equation - English
Organic
Compounds
(>1000 ppm in
waste feed)
Particulate
Matter
(liquid
incinerators)
Metals
HC1
S02
HF
((I-IDRE/IOOJJ/IOOOHC^OO ((l-(DRE/100))/1000)(C,)(mJ
(m. (Ash/1000))(l-CE/100) (m^Ash/lOOOKl-CE/lOO)
C,OO(*MF/100)
CC1(1.028 kg HCl/kg C1K
Cs (2 kg S02/kg S)^
CF (1.053 kg HF/kg F)m,
Ci(mw)(%MF/100)
CC1(1.028 Ib HCl/lb
Cs(2 Ib S02/lb S)m,
CF( 1.053 Ib HF/lb FJm,,
' Equation provide mass of emission (kg/hr or Ib/hr) per mass of waste
incinerated (in kg/hr or Ib/hr). Equations are described in detail in text.
Symbols are defined and units given in the front matter of the document.
79
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As a first step towards estimating the appropriate Incinerator size, the
heating values of the waste (and auxiliary fuel when needed) need to be
calculated. Worksheet 4-11 1n Reference 46 provides a method for calculating
the thermal load on the Incinerator and whether auxiliary fuel Is needed.
Liquid Incinerators--
For liquid Incinerators, the following procedure is used to estimate an
Incinerator size suitable for achieving a minimum of 99.99 percent ORE
(thereby allowing confirmation of the adequacy of an existing unit or
specification of a new one):
1. Use Worksheet 4-2 in Reference 46 to calculate the total Volumetric
flow (Q) of combustion gases.
2. Calculate incinerator volume from:
V - RT * [(Q/(60 * P)) * ((T + 273J/298)] (Eq. 1)
where: V - volume (m3);
RT - retention time (seconds);
Q » combustion gas volumetric flow rate (std. m3/min);
P - combustion gas static pressure (atm); and
T • incinerating operating temperature (*C).
3. Determine the desired length-to-diameter ratio for the unit
(typically, this is 2:1 or greater).
4. Calculate Incinerator inside diameter and length from:
1d = (2 * Q * (RT)/60ff)1/3 (Eq. 2)
and
Length - 2 * 1d
where: 1d - incinerator Inside diameter (meters); and
Length « combustion chamber length (meters).
80
-------
To estimate the uncontrolled emissions of organic compounds from
this unit, use the following procedure:
5. The emission rate will then be:
ER, - ((HDRE/lOun/lOOOHCJOnJ (Eq. 3)
where: ER, = emission rate for pollutant 1 (kg/hr);
ORE = appropriate ORE value from Table 5;
n^ = mass flow rate for waste feed (kg/hr); and
C, - waste feed concentration for pollutant 1 (g/kg).
Rotary Kiln Incinerators--
For rotary kiln Incinerators, the following procedure Is used to estimate
an Incinerator size suitable for achieving a minimum of 99.99 percent ORE:
1. Use Worksheet 4-4 In Reference 46 to calculate the total volumetric
flow (q) of combustion gases in both the rotary kiln and the
afterburner.
2. Calculate combustion chamber and afterburner volumes using Equation
1 for liquid incinerators.
3. Determine the length/Id ratio for both the kiln and the afterburner.
Then for each, calculate Its dimensions using the equations in part
four above.
4. Finally, emissions can be estimated using Equation 3.
Multiple Hearth Incinerators--
No unit sizing worksheets have been published, but the steps should be
analogous to those for liquid and rotary kiln incinerators.
81
-------
Fluidized Bed Incinerators-
No unit sizing worksheets have been published, but the steps should be
analogous to those for liquid and rotary kiln incinerators.
3.3.2 Parti oil ate Matter
Emissions of particulate matter are dependent upon waste and fuel
compositions, incinerator type and operation, and the effectiveness of any air
pollution control devices. Consequently for most incinerator types, no
correlating equations exist for estimating particulate emissions. The one
exception is liquid incinerators because of their unique operating
characteristics. RCRA performance standards for hazardous waste incinerators
limit particulate emissions to a maximum of 180 ing/standard m3 (0.08 grains/
scf). These standards will generally be considered applicable or relevant and
appropriate requirements for the incineration of waste from NPL sites as well.
For all incinerator types, typical particulate matter emissions fall in the
following ranges (9):
Uncontrolled particulate emissions: 0.5 to 23 g/m3 (0.2 to 10
grains/dscf);
Controlled particulate emissions: 34 to 110 mg/m3 (0.015 to 0.05
grains/dscf).
These ranges indicate that systems with particulate emission control
devices tend to meet the standard while those without do not.
As a default value for assuming uncontrolled particulate emissions, the
average of the above-mentioned value may be used: 11,750 mg/m3 (5.1 grains/
scf). Similarly, the average value may be used for controlled emissions: 72
mg/m3 (0.033 grains/scf).
82
-------
Liquid Incinerator's--
Because liquid incinerators do not usually generate combustion chamber
bottom ash, it can be assumed that all particulate matter introduced to the
incinerator, as well as any generated in the unit, will exit in the exhaust
gases according to the equation (59):
' (Ash/1000)) ((100-CE)/100) (Eq. 4)
where: ER^ = particulate emission rate (kg/hr);
n^ = waste feed rate (kg/hr);
Ash = ash content of waste feed (g/kg); and
CE • Particulate removal efficiency of control system (%).
Rotary Kiln, Multiple Hearth, and Fluidized Bed Incinerators--
In addition to the introduction of particulate matter to the incinerator
via the waste feed stream, the mechanical operations of rotary kiln, multiple
hearth, and fluidized bed incinerators are also capable of generating
substantial particulate loads in the exhaust gases. No specific correlations
for particulate matter emissions from these units have been published.
3.3.3 Metals
Metals are not destroyed by the incineration process; therefore, they
leave the system via either the bottom ash, the solid or liquid control device
residues, or the stack gas. Depending on its volatility, a metal may be
present in the stack gas in either particulate or gaseous form. Figure 11
presents vapor pressure curves for various hazardous metals. There are
currently no correlations available for determining the partitioning of metal
emissions in incineration systems; however, a simplified and highly
conservative approach to estimating air emissions of hazardous metals is to
assume that all of the metals present in the feed are emitted in the stack
gas. In reality, however, a majority of the medium and lower volatility
metals would probably be trapped in the combustion chamber ash or control
devices. Actual data from incinerator tests may also be used to estimate
83
-------
Lo"wer Volatility Species
ts-
£
i
6OO
BOO
-------
metals emissions. Table 20 provides typical controlled and uncontrolled
emission ranges for five incinerators expressed as: (1) a function of total
particulate emissions, (2) actual metal emissions, and (3) a percentage of
metal fed. If the waste feed rate and the concentration of a given metal in
the waste feed are known, the uncontrolled or controlled emission rates for
that metal can be estimated from:
ER, = (CfMmJ^MF/lOO) (Eq. 5)
where: C, » concentration of metal i in the feed (g/kg);
n^ = mass flow rate of waste (kg/hr); and
% MF ° metal emitted expressed as a percentage of metal fed
(from Table 20).
3.3.4 Acid Gases
The production of acid gases, including HC1, S02, and HF, is determined
by the respective chlorine (Cl), sulfur (S), and fluorine (F) contents in the
waste and fuel feed streams. A conservative approach to calculating the air
emissions of these acid gases is to assume complete conversion of Cl, S, and F
into their respective acid gas products. The following uncontrolled emission
estimation calculations are based upon this assumption. These equations
follow the form:
ER, - (Cj/lOOOMR^K (Eq. 6)
where: ER, » emission rate for acid gas i (kg/hr);
Cj = concentration of element (Cl, S, or F) in waste (g/kg);
Rf/j » stoichiometric ratio of acid gas to element (kg/kg); and
n^ = mass flow rate of waste (kg/hr).
Table 4 presents the typical range for uncontrolled stack gas emissions of
acid gases.
85
-------
TABLE 20. RANGES OF PARTICULATE METALS EMISSIONS FOR FIVE HAZARDOUS WASTE INCINERATOR TESTS
00
Uncontrolled Emissions
Metal s
Antimony
Arsenic
Barium
Beryllium
Cadml urn
Chromium
Lead
Mercury
Nickel
Selenium
Silver
Thallium
ug Metal per
g Partlculate
300
NDa
250
NDa
140
950-47.500
3.100
NDa
650-49.000
9.200
620
NDa
g Metal
per Minute
o.z
NDa
0.12
NDa
0.069
0.19-0.47
KS
NDa
0.2-0.32
4.5
0.0025
NDa
X of Metal
Fed
I*
6.3
D
~K
U
34-56
7i
U
52-100
8Z
_u
Ib
Controlled Emissions
ug Metal per
g Partlculate
<12QO-15.200
NDa
41-3.090
0.32-6
140-4.300
0-2.770
5.300-96.100
0-56
0-5.170
<500-61.600
7.6-1.880
120-150
g Metal
per Minute
<0. 012-1. 2
NDa
0.0032-0.12
0-0.00013
0.0033-0.087
0-0.21
0.089-7.3
NDa
0.015-0.057
0.14-0.29
0-0.0064
0.011-0.012
% of Metal
Fed
0D53-9.1
0.038-13
0-2.2
0.94-50
0-2.0
0B2-51
ij
0.05-0.42
Or23
U
_b
a ND = not detected 1n all runs.
b All runs had either feed or emissions below detection limit.
Source: Reference 7.
-------
Equations for predicting uncontrolled emissions of acid gases are shown
in Table 19. Controlled emission rates for any acid gas species can be
estimated by using typical emission reduction values for various types of
emission control equipment and multiplying by the emission rate calculated
above:
ER, (controlled) - ER, (uncontrolled) (l-CE/100) (Eq. 7)
where: ER1 - emission rate for acid gas i (kg/hr); and
CE - control efficiency (% removal) from Table 6.
Of the acid gases, only HC1 is currently regulated under RCRA. The
performance standards for hazardous waste incinerators limit HC1 emissions to
a maximum of 1.8 kg/hr. If emissions from the incinerator exhaust exceed this
level, then RCRA requires 99% removal via control devices.
3.3.5 NQX
No Information on NOX emissions from incineration is currently available.
In general, Incinerators are not considered to be significant sources of NOX.
The form of nitrogen compound and its production rate can be controlled by
controlling the incineration temperature and air-to-waste ratio.
3.3.6 Fugitive Emissions
Fugitive emissions are any uncontrolled gas or particulate matter
emissions from any operation or equipment other than the exhaust stack.
Sources for these emissions include leaking valve and pump fittings, flanges,
storage tanks, and sampling and instrument connections. References 10 and 11
provide a series of detailed equations for estimating the fugitive emissions
from each of these sources.
Fugitive emissions from materials handling may be significant, both for
the waste feed into the incinerator and the ash out of it. These emissions
can be estimated using the procedure given in Section 3.6 for soils handling.
87
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3.4 AIR STRIPPING OF GROUND WATER
Estimation of emissions from air stripping of ground water Is relatively
simple. Air stripping towers can achieve nearly complete removal of volatile
organics from ground water, so emissions estimates can be based on the
slightly conservative assumption of 100% removal efficiency. The rate of
uncontrolled atmospheric emissions simply equals the rate of contaminant being
treated, which in turn equals the contaminant concentration in ground water
multiplied by the flow rate of the ground water being stripped. The
estimation of emissions becomes only slightly more complicated when
adjustments are made for emissions reductions resulting from the use of
control devices and for removal efficiencies that are less than 100%. With
these terms added, the equation for estimating emissions becomes:
ER, = (C1i1n)(Q1n)(10-6)(l-(CE/100))(RE/100) (Eq. 8)
where: ER, - emission rate for species i (g/min);
C, 1n = concentration of species i in influent ground water (ug/L);
Qln = flow rate (L/min);
RE ° removal efficiency (%); and
CE = control efficiency (%).
As discussed in Section 2, removal efficiencies for air stripping of
ground water will vary with numerous factors such as operating temperature,
tower height, and air-to-water ratio. The best emission estimates will
consider design parameters. Nevertheless, for volatile organic contaminants,
a reasonable default is to assume a removal efficiency of 99.5%, so Equation 8
reduces to:
ER, - ((^(QJO.gSxlO-'MHCE/lOO)) (Eq. 9)
A typical flow rate to assume for preliminary emissions estimates is 1000
liters per minute. If multiple air stripping towers are used, then the
emissions from each must be summed to determine the total emissions.
88
-------
For semi -volatile organic compounds or Inorganic contaminants, the
removal efficiency from air stripping may be assumed to be 0%. If site-
specific data are available, emissions can be calculated using Equation 10.
m (W(QJ - (c..,ut)«U)
106
where: C, out - concentration of species i in effluent (ug/L); and
Qout = effluent flow rate (L/min).
Note that the flow rates of the influent and effluent streams will differ due
to evaporative losses in the air stripping tower.
Control efficiency will vary with the inlet gas VO concentration and the
type of VOs present. Inlet streams of about 200-10,000 ppm VO can be treated,
with exhaust gas concentrations of 50-100 ppm VO obtainable. The following
values can be assumed:
Inlet
_ VO Tvoe _ VO Concentration (corny) Control Efficiency
Molecular Weight = <45 - 0%
Molecular Weight » 45-130 200-500 50%
1000-2000 95%
5000-10000 99%
Molecular Weight ° >130 - 100%
(permanently bound
to carbon)
3.5 IN-SITU VENTING
Emissions from in-situ venting are extremely site-specific. No
predictive equations exist. A theoretical framework for venting emissions is
presented below; however, not all variables shown are known for all or most
sites. Subsequently, equations for estimating recovery rates are given.
89
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The volumetric flow rate of VO- laden air vented from subsurface soils is
described by Darcy's law, an empirical law which states that the velocity
(volumetric flow through a cross-sectional area) is proportional to the
hydraulic gradient (the sum of pressure and gravity gradients). Darcy's law
is expressed through the following equation:
v = Q/A = -(ka/na)A(Pa + dagh) (Eq. 11)
where: v = discharge velocity (m/sec);
Q = volumetric flow rate through well (m3/sec);
A = cross-sectional area of well (m2);
ka = air permeability in soil (m2);
na = viscosity of air (N'sec/m2);
Pa = pressure of air (N/m2);
da = density of air (kg/m3);
g = acceleration due to gravity (m/sec2);
h = elevation (m); and
A = gradient (m"1).
During vacuum venting, the induced pressure gradient overwhelms the
gravity gradient, and Darcy's law reduces to:
v = Q/A= -(k./n.MPj-P!)/^ (Eq. 12)
where: P2 = air pressure at point 2 (low pressure);
P! - air pressure at point 1 (high pressure); and
112 ° distance from point 1 to point 2 as shown in Figure 12.
However, application of this equation to estimating the mass flow of
organics to the surface through the well is extremely complex. Air
permeability may be estimated roughly from site moisture and water
permeability data, although the margin of error may not be estimable without
air permeability data. Site-specific data from the Soil Conservation Service
on moisture content and water permeability are usually valid for depths of
90
-------
Vacuum
Source
Vapor
Recovery
Well
Well
Screen
Figure 12. Schematic of vapor recovery well and associated pressure gradient.
91
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only five or six feet; vapor recovery wells usually draw from much greater
depths. In addition, the actual moisture content of the soil is highly
variable, probably varying spatially and temporally at some sites. No
empirical means of estimating the air permeability from moisture or water
permeability data were found in the literature (47,48,49).
The pressure differential term is also difficult to estimate. Because
of the vacuum suction, air is constantly drawn into the soil while the VO-
laden air is withdrawn. The pressure drop varies across the diagonal shown in
Figure 12, and estimation of the pressure gradient would require some form of
integration or modeling.
Predictive models based on theory or empirical data may be possible if
enough site-specific data are available. However, no models were located in
the literature search. Because of the difficulty in applying Darcy's law to
the estimation of mass flow of gas through the well and the lack of models,
uncontrolled emissions from in-situ venting cannot be estimated at this time.
Hydrocarbon vapor recovery rates can be estimated as follows:
ER, = C,Q (Eq. 13)
where: ER, » emission rate of species i (g/min);
Q = venting rate (m3/nrin); and
C, = concentration of species i (g/m3).
The duration of ventilation is dictated by the remediation objectives and site
characteristics. The vented gas concentration typically decreases
exponentially over time. If the total mass of volatile species present is
known, then the duration of operation can be estimated from the vapor recovery
rate. If, as is usual, the amount of volatiles present is unknown, then
operation of the subsurface venting system for one year is a reasonable
assumption.
92
-------
The liquid product recovery rate can be computed as:
LPr - (ER,)/(1000 mL/L)dL (Eq. 14)
where: LPr - liquid product recovery rate (L/min); and
dL • density of liquid (g/mL).
If emissions control Is desired, the selection of a control method
should consider the VO concentration in the soil gas. If the VO concentration
Is greater than 10,000 ppm, it is recommended that the vent stream be
pretreated by condensing the VOs, as discussed 1n Section 2.1.3. When the VO
concentration 1s between 200 and 10,000 ppm, carbon adsorption should be
adequate to control organic emissions.
Efficiency of control varies depending on the VO concentration in the
gas to be treated, but carbon adsorption can usually reduce the VOs in the
exit gas to concentrations of 50 to 100 ppm. Carbon adsorption technology is
discussed in greater detail in Section 2.2 of this report under Air Stripping
of Groundwater.
3.6 SOILS HANDLING
3.6.1 Presentation of Equations and Steps in the Process
The steps necessary to calculate emission factors for soil handling
remedial activities are shown in the flowchart In Figure 13. The overall
process of estimating emissions requires determination of:
The activities required for soils handling;
• The potential for emissions of volatile organics and metals (the
emission of particulate matter 1s assumed by definition of soils
handling);
• The particulate size (diameter) of Interest;
93
-------
5.
U* Probable
Remedial Actions.
No
Determine steps In soils
handling end einount (mass(
volume) ol material
Involved In each step.
Determine H emissions po-
tential exists lor volatile
argantes and ntetah. (poferv
lal lor PM assumed to exist)
Volatile organkf*^ No
emissions possible?
to Flowchart B lor
volatile organic*
Determine partlculate
size range ol Interest
(le. total, inhalable. etc.)
Calculate control
eflldenciea (CEs) lor all
technologies used (or see
Table 13).
Flowchart C lor
excavation
emissions estimation.
Estimate Inputs tor
category (Table 31).
Estimate total controlled
•missions ol VOa, panic-
ulate matter, and metals:
EF . |massAlme|I1-CE/100].
Figure 13. Flowchart A: Soils handling emissions estimating methodology.
94
-------
The emission factors for organic, particulate, and metal
contaminants (if applicable) for each soils handling activity;
Which (if any) emission controls are necessary; and
The emission rate (mass per time), which is converted from the
emission factor (mass per unit operation).
Soils Handling Activities--
The development of emission factors is dependent on knowing which soils
handling activities will be necessary at the site and the mass or volume of
soil handled in each activity. The steps have been divided into six
categories which were discussed in greater detail in Section 2.1.2:
Excavation of soil from the site surface;
Transportation of the soil to storage or other sites;
Dumping of the soil into trucks, piles, etc.;
Storage of the soil in piles (wind erosion); and
Grading the treated or replacement soil.
Emissions Potential--
Data from site characterization studies such as those performed under
the RI should identify the organic and metal content of the soil. If the soil
contains organic compounds which could volatilize if the soil is disturbed,
then the potential for VO emissions exists, and potential emissions should be
estimated. If metal analyses of the soil have been performed, and heavy
metals are present in the soil covering, the potential exists for emissions of
metals adsorbed onto particulate surfaces. If no soil data are available, but
metals are present in the underlying wastes in forms that can diffuse into the
soil, the potential for metal emissions from the site may still exist. Small
inhalable particulates can carry adsorbed metals into the lungs and hence the
bloodstream.
95
-------
It should be noted that particulate matter is expected to be emitted
from soils handling operations; therefore, the potential for particulate
emissions is assumed to exist.
Particle Size of Interest--
It is important to determine the particulate size range of interest,
since emission factors/equations are available for several ranges. Most of
the equations determine TSP (total suspended particulate) emissions, which are
particles with an aerodynamic physical diameter of about 30 microns or less.
The primary equations are summarized in Table 21 with parameters defined in
Table 22. Equations for the dumping and transportation categories include
particle size multipliers (k) which allow the estimation of 15 micron and
smaller particulate emissions. Particle size multipliers are given in Table
23. Separate equations are used for the excavation and grading categories to
determine smaller particulate emissions; these equations are shown in Table
24. Table 25 has typical size ranges of emissions as percent of TSP for use
in estimating size ranges for storage emissions and comparing these to other
categories.
The user may extrapolate results to estimate emissions of particulate
matter of less than 10 microns.
Volatile Organic Emission Factors--
The search for existing estimation procedures turned up little in the
way of theoretically sound approaches for estimating VO emissions from dynamic
processes such as soils handling. However, many predictive models exist for
estimating VO emissions from static sources and EPA is currently working to
modify these models to address dynamic processes. Ultimately, it is hope that
predictive models will be developed that have the general form:
ER, - (Ci)(V)(A)(X-stripping rate)^)^) (Eq. 15)
where: ER, = emission rate for species i or total VOs (g/min-m2);
Ci = concentration of species i in soil (g/m3);
V = volume of soil handled (m3);
96
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TABLE 21. EMISSION FACTOR (EF) EQUATIONS FOR SOILS HANDLING (TOTAL SUSPENDED PARTICULATE)
ID
Category Emission Equations - Metric Metric EF Units Emission Equations - English English EF Units Rating*
Excavation
Bulldozer 2.6(s)It2(M)~1>3
Dragline 0.0046(d)l>1 (M)"0'3
Scraper 9.6xlO~6(s)1>3(H)2'4
Transport
12 48 2.7 4
Industrial Paved
Roads 0.022 I (-)(—)(—)(—)
Dry Ind. Roads.
Med. a Heavy Vehicles k(— )°'3
Uncovered Truck Bed O.OOlSu
Dumping k(0.0016)(— )ll3(5)"1-4
Storage (Active Piles)
Annual Estimate 1.9(— )( — )< — )
Short-Term (24-hour) 1.8u
Grading 0.0034(S>2-5
kg/hr 5.7(s)1>Z(M)"1>3
kg/m3 0.0021(d)1-1(M)~°-3
kg/VKT 2.7xlO~5(s)I-3(H)2-4
.5 365-p s S H 0.7 MO.
( 3M ) kg/VKT U5.9)(lf)(M)(sl (^
'7 kg/VKT 0.077 1 (-)(— ) (— — )(-)'
kg/VKT 3>5klOS35)° 3
kg/nz-hr O.OOOlSu
kg/Hg k (0.0032) (-)(-)"
kg/day/hectare 1.7( — )( -)(. — )
kg/hectare/hour 0.72u
kg/VKT 0.040(S)2-5
Ib/hr
lb/yd3
Ib/VMT
5 365-p
( 3M ) Ib/VMT
1-7 Ib/VMT
Ib/VHT
lb/ydz-hr
Ib/ton
Ib/day/acre of surface
Ib/acre/hour
Ib/VMT
C
C
8
A
B
A
NA
A
D
NA
C
Reference
31
31
31
31
31
31b
31b
31
33
31
a If parameters for transportation and dumping fall outside the range shown In Table 3-14. rating should be dropped one letter (A - highest confidence)
except for Industrial Paved roads, which should be dropped two letters.
b From 1987 Draft AP-42.
NA - not available.
- - not appllcable/dlmenslonless
NOTE: See Table 22 for units and explanation of variables.
-------
TABLE 22. DEFINITIONS OF PARAMETERS AND UNITS FOR SOILS HANDLING
EMISSION FACTORS
Parameter Definition Unit Category
s Silt content of material wt. % E,T
M Moisture content of material wt. % E,T,D
d Drop height m or ft E
W Mean vehicle weight Mg or tons E,T
w Mean number of wheels - T
S Mean vehicle speed km/hr or mph T,G
k Particle size multipler - T,D
p Number of days/yr with >0.254 mm - T
(0.01 inches) of precipitation
I Industrial augmentation factor - T
=1.0 traffic only on paved
roads
=3.5 industrial roadway,
unpaved shoulders, 20%
of vehicles forced to
travel temporarily with
one set of wheels on
shoulder
°7.0 paved industrial roadway,
traffic enters from
unpaved areas
n Number of traffic lanes - T
L Surface dust loading kg/km or Ib/mile T
U Mean wind speed m/sec or mph D,S
sL Road surface silt loading g/mz or oz/ydz T
u Sum of wind speed and vehicle m/sec or mph T
speed
f Percentage of time that the % s
unobstructed wind speed is
>5.4 m/sec (12 mph) at the
mean pile height
VkT Vehicle kilometer traveled km T
VmT Vehicle mile traveled mile T
E = excavation
T = transportation
D = dumping
S = storage
G = grading
- dimensionless
98
-------
TABLE 23. TYPICAL PARTICLE SIZE MULTIPLIERS (k, dimension!ess)
Size Range of Interest Unpaved roads Dry Industrial Roads Dumping
<30 urn, Stokes Diameter 1.0 NS NS
<30 urn 0.8 NS 0.74
<15 urn 0.5 0.28 0.48
<10 urn 0.36 0.22 0.35
<5 urn 0.20 NS 0.20
<2.5 urn 0.095 0.081 0.11
NS = not stated.
99
-------
o
o
TABLE 24. EMISSION RATE EQUATIONS FOR INHALABLE OR SMALLER PARTICULATES: EXCAVATION AND GRADING
Emission
Category Size Range Emission Equation - Metric Units Emission Equation - English Units
Excavation
Bulldozer <15 urn 0.45(s)1'5(M)"1'4
<2.5 urn (0.105)(2.6)(s)1'2(M)"1'3
kg/hr 1.0(s)1<5(M)"1'4 Ib/hr
kg/hr (0.105) (5.7) (s)1<2(M)"1'3 Ib/hr
Dragline
<15 urn
<2.5 urn
(0.0029)(d)°'7(M)~°-3
(0.017)(0.0046)(d)1'1(M)"°-3
kg/m
kg/m
0.0021 (d)°'7(M)"°-3
lb/yd
(0. 017) (0. 0021) (d)1'1(M)"°-3 lb/yd3
Scraper
Grading
<15 urn
<2.5 urn
<15 urn
<2.5 um
(2
0.
0.
0.
026(9.6xlO"6)(s)1'3(W)2'4
0056(S)2>0
031(0. 0034) (S)2'5
kg/VKT
kg/VKT
kg/VKT
kg/VKT
(6
0.
0.
0.
.2x10"
026(2.
051 (S)
031(0.
7xlO~5)(s)1'3(W)2'4
2.0
040) (S)2'5
Ib/VMT
Ib/VMT
Ib/VMT
Ib/VMT
NOTE: See Table 22 for units and explanation of symbols.
-------
TABLE 25. TYPICAL PARTICIPATE SIZE DISTRIBUTIONS
AS WEIGHT PERCENT OF EMISSIONS
Category
<3 urn <5 um 3-30 urn 5-30 urn >30 urn Reference
Aggregate Storage Piles
Paved Road/Surface
Unpaved Road/Surface
Gravel
Dirt
Mining Emissions
Overburden Removal
Truck Loading
Exposed Areas3
Other"
30
_
40
31
-
-
5
4.5
5
5.5
-
50
-
_
23
8
-
-
-
23
.
37
29
-
-
7
8.5
8
9.5
-
40
-
_
39
24
-
-
-
47
10
23
40
38
68
88
87
87
85
28,29
29
28
28
29
29
29
29
29
29
a Includes waste and reclamation areas prior to revegetation.
b Other mining activities include haul roads, truck dumping, and storage.
- = not applicable/not available.
101
-------
A = surface area of working area (m2);
X = stripping rate for remedial option X (% of species i/min);
KSF = lumped soil-related factors (unitless); and
KyF - lumped waste-related factors (unitless).
This approach, once fully developed and validated, would allow estimation of
organic emissions based primarily on knowledge of the average concentration of
VOs or individual compounds in a given area to be remediated.
Limited field data is available to support a second approach for
estimating VO emissions based on measuring a baseline emission rate and
multiplying this value by an "agitation factor" to account for the increase in
emission rate due to disturbance of the soil. This estimation procedure is
based on empirical data and provides only a very rough estimate of emissions.
The estimation procedure for any given waste cell is illustrated to Figure 14.
It should be kept in mind that the baseline emission estimate refers to
emissions from the exposed waste or contaminated soil. Any overburden will
greatly diminish emissions, as shown in Table 26, and make the estimation
problematic.
The initial step is to identify or estimate pertinent chemical and
physical properties of the waste. The key parameters are the type of VOs
present, their concentration, and the matrix surrounding the waste. An
additional parameter is the depth (and porosity) of any overburden. However,
during soils handling the waste is typically in direct contact with the
atmosphere.
Next, a baseline VO emission rate should be estimated. Detailed
guidance for this type of estimation is contained in a companion manual (2).
Three procedures for estimating baseline emissions are available. These are
in order of preference:
Use the site-specific emission rate collected during RI/FS;
Use an appropriate emission model; or
Use a value from Table 26.
102
-------
Identify/estimate chemical and
physic&l prapoftlos of ths w&sto.
Estimate baseline VO emission
rate In mass per lime per area
Calculate total baseline VO
emissions (BE) per unit time.
BE • [masi/lime*areal[aroa|
Multiply total baseline VO emissions
by agitation (actor (AF) tram
Table 27. Corrected BE . [BEIIAF]
Step 4 as necessary lor
soils handling activity.
Figure 14. Flowchart B: Estimating volatile organic emissions.
103
-------
TABLE 26. BASELINE VOC EMISSION FACTORS FOR HAZARDOUS WASTES
)n Rate
(ug/mz-nrin)
Site
Abandoned Landfill
Abandoned Landfill
Abandoned Landfill
Waste Type
Industri al/Petrol eum
Industri al/Petrol eum
Industri al/Petrol eum
Average
Covered
Waste
360
740
_29
380
Exposed
Waste
190,000
26,000
170.000
130,000
Source: Reference 2.
104
-------
Because such limited data is available in Table 26, the use of the average
value is the only reasonable option when selecting a value from this table.
Emission models are discussed briefly in Section 5.2 of this manual.
The emission models typically provide an emission rate in mass per unit
time per unit surface area. The applicable surface area should be estimated,
e.g., surface area of the truck bed. The surface roughness of the soil
material may double the actual soil surface area for a given size and should
be taken into account. A total baseline VO emission rate is calculated by
multiplying the emission rate derived from a model or other method by the
estimated surface area.
Soils handling increases the emission rate over baseline emissions.
This degree of enhancement (the agitation factor) is estimated in Table 27 for
each soils handling step. The agitation factors are not well characterized
and are further affected by the chemical and physical properties of the waste,
and by the applicable meteorological conditions.
Particulate Matter (PM) Emission Factors--
The equations and procedures for estimating particulate emissions during
soil handling are considerably more complicated than those for estimating
emissions for volatile organics. Each soils handling activity has its own set
of equations, and the steps for determining process emissions are broken into
separate flowcharts for each category. These are given in Figures 15 through
19. The silt fraction of soil generally has "enriched" concentrations of
metals relative to the soil as a whole due to the increased surface area to
weight ratio of the silt. Figure 20 contains a flowchart for determining the
enrichment of the eight RCRA metals on silt particles (<75 urn diameter).
These enrichment factors multiplied by the contaminant concentrations in a
total soil sample will provide an estimate of the metal concentration in the
emitted particulate matter.
105
-------
TABLE 27. INCREASE IN EMISSIONS DUE TO SOILS HANDLING
Soils
Handling
Category
Excavation
Backhoe
Dragline
Scraper
Bulldozer
Transport
Conveyor Belt
Truck
Dumpingb
Storage
Short -term0
Long-term
Stabilization
Gradingd
Agitation Factor8
2.5-28
36-63
36
42-72
10
1
-
4 (2-9)
2.5-38
Reference
50
51
51
51
51
Assumed
52
53
a Multiply agitation factor by baseline emissions estimate (BEE) to calculate
VOC emission factor.
b Values from crushing of ore.
c <4 days.
d Values from tilling of waste.
- = No data available
106
-------
EF - Z6(s)i < (M)-' * kgmr excavated
(or aquhr. equation lor smaller PM -
Table 24)
1.1 -o a a
EF-0.0046(10 (M) kg/kit
excavated (or equhr. equation lor
smaller PM - Table 24).
EF.05x10* (s) (W) kg/VKT
(or equlv. equation lor smaller PM
Table 24).
Estimate using emission
(actor (TaMelO).
Necessary
parameters
available?
Return to Flowchart A
and proceed to the
next step
Estimate using tables, perform
site survey, or contact Soil
Conservation Service.
Drop emission (actor rating
one tetter (Iran Table 21).
Figure 15. Flowchart C: Estimating excavation emissions.
107
-------
•chart A. jJL.
Estimate number and type of
vehicles needed tat volume of
waste and remedial activity.
Determine types ol roads (assume
unpavad lor morel case}. Estimate
mileage (Including travel between
storage piles) on each road type.
I— i
. fc(1.7Xa/12)(SAI8)(W/2.7)
ko/veMde km traveled (VKT)
«36&l»/p)
J
EF . 0.022 (l)(4/hXs/10)(LeaO)(W/2.7)
fcg/VKT
EF-k(sLfl2) kg/VKT
Estimate using (ablet, do sue survey, or con-
tact Soil Conservation Service (tor parame-
ters a A L) and National Weather Service (for p).
Drop confidence rating (Table 21) one toner.
Drop confidence rating 01
latter (from Table 21).
EF = 0.0018 (u) kgfeq. meter-hr
o . wind speed * vehicle speed.
(meters/second).
Assume 100% control
efliclency lor
partlculateg in bed
/Retur
V:
Return to Ftowchart A^\
and proceed lo ihe J
next step ^^/
Figure 16. Flowchart D: Estimating transport emissions.
108
-------
^
EF o k(0.0016XU/25) ' "(MO)'' * kg/Mg dumped
<
^t>^An net
•^^ PWW
-\^
1
^^^!re pa
^^^ i«Jthtr>
^^_^ wnran BBI
^^Xs^Jfc*
*»8aiy^x^^ N°
KMure ^^ •
tteT^"^
Yes
iwiwei^^^ No
^ZS\>^'^
Yes
Estimate using tables, do site survey.
or contact Soil Conservation Service
(M). and National Weather Service (U).
t
Drop confidence rating one letter
(from Table 21).
Drop confidence
(from Table 21)
rating one letter
Figure 17. Flowchart E: Estimating dumping emissions.
109
-------
EF - 1.9{a/1.5)«365-p)/235)(f/15) Kg/day/hectare
Return to Flowchart A
and proc66d to Iho
next step
Estimate Irem tables, do site survey.
or contact Soil Conservation Service
(s). or National Weather Service (l.p.U).
Drop eoniUen
rating one letter
(Irom Table 21).
Figure 18. Flowchart F: Estimating storage emissions.
110
-------
EF a 0.0034(8) kg/VeNde Km Traveled
(or equivalent equation lor smaller PM - Table 24).
Drop confio0no0 ruinQ ono lotto r
(Iram Table 21).
to Flowchart
and proceed to the
next step
Figure 19. Flowchart G: Estimating grading emissions.
Ill
-------
Figure 20. Flowchart I: Determination of RCRA metal enrichment on
fugitive particulate emissions.
112
-------
Emission equations for particulate matter are available for each
category, with the exception of the stabilization and solidification category,
for which only factors (estimated from other industries) are available. The
emission factor equations were summarized in Table 21. Definitions of the
parameters used in the equations were given in Table 22. Typical values are
shown in Tables 28 and 29. Local values for the soil parameters shown in
Table 28 will also commonly be available from the Soil Conservation Service of
the U.S. Department of Agriculture. A drawing of the continental U.S. and
Alaska showing the average number of wet days per day (>0.254 mm
precipitation) is included as Figure 21. This information is necessary for
estimating particulate matter emissions from transport.
Since the emission equations for particulate matter are empirical
equations, it is important that the site values of the parameters fall within
the same range as the original data, upon which the equations are based.
Values used to construct the equations are shown as ranges in Table 29.
Specific data for the site of interest should be compared to these values.
When site values fall outside the ranges given in Table 29, the confidence
rating (from Table 21) should be dropped one letter. The ranges in Table 29
may also be used as typical values for equation parameters if no site-
specific data are available.
Depending upon the remediation treatment employed at a particular site,
some special considerations may have to be accounted for which are not obvious
from the flowcharts in Section 3.6. For instance, the storage pile emissions
category does not account for emissions caused by vehicle traffic between
storage piles. The emission factor from this task should be calculated using
the unpaved road equation found in the transportation category. The value for
the silt content of the surface between the piles should be used if possible,
rather than the value for the silt content of the material in the storage
pile.
113
-------
TABLE 28. TYPICAL VALUES OF PHYSICAL PROPERTIES FOR VARIOUS MATERIALS WITH RANGES IN PARENTHESES
Material
Exposed Ground3
Topso11a
Sanda
Limestone3
Claya
Haul Truck Material
Overburden
Bulldozer
Dragline
Scraper
Rural Road
Gravel
Dirt
Crushed Limestone
Moisture
(X)
NO
ND
ND
ND
ND
ND
7.9 (2.2-16.8)
3.2 (0.2-16.3)
ND
ND
ND
ND
15.0
40
10
2
ND
364
6.9
ND
16.4
5.0
28.5
9.6
Silt Content
(Wt. *)
(5.1-21)
(34-2270) Ib/acre
(3.8-15.1)
(7.2-25.2)
(5.8-68)
(7.7-13)
Porosity
(%)
ND
51
32
ND
48
ND
ND
ND
ND
ND
ND
ND
Density
(g/mL)
ND
0.96
1.59
ND
1.34
ND
ND
ND
ND
ND
ND
ND
Reference
31
29/54
29/54
29
54
31
31
31
31
31
31
31
a Local values of the physical parameters in this table will commonly be available from the U.S.
Department of Agriculture's Soil Conservation Service.
Site loading, not silt fraction: given in Ib/acre.
ND = no data.
-------
TABLE 29. RANGES OF SOURCE CONDITIONS FOR TRANSPORT AND EXCAVATION
EQUATIONS WITH TYPICAL VALUES BY VEHICLE TYPE
Industrial
Unpaved Paved Dry Industrial
Road Road Dumping Road. Medium and Typical
Parameter Unit Equation Equation Equation Heavy Vehicles Value
s wt % 4.3- 20 5.1 - 92 0.44-19
U mg 3-142 3-12 - 6-42 22.0
51.3
23.0
20.2
11.2
23.2
12.9
6.8
2.6
7.9
1.8
S km/hr 21- 64 - - - 11.4
(8.0-19.0)
32.0
U -4-31 - - - 18.0
20
6
20
4
18
10
6
4
6
4
9
I - - 1 -
L kg/km - 42-2.000
n - - 2-4 -
M wt. 1 - - 0.25-4.8
u m/sec - - 0.58-6.7
sL g/m2 - - - 0.02-0.2
dm- - - - 8.6
(1.5-30)
3
1.5
Vehicle Type
Flatbed-over the road
Flatbed-low boy. coll
Scow
Trailer-dump
Straddle carrier
Tanker
Service Vehicle
(10-15 tons)
Utility
Passenger/Pickup
Bus
Misc. (<5 tons)
Grader
Haul Truck
Flatbed-over the road
Flatbed-low boy. coil
Scow
Trailer-dump
Straddle carrier
Tanker
Service Vehicle
(10-15 tons)
Utility
Passenger/Pickup
Bus
Misc. «5 tons)
Misc. <>5 tons)
Dragline
Haul Truck
Front-End loader
not applicable.
115
-------
01
so
ju -x. ; ,—,r-——•
70 70 "*•• V
0 100 200 300 400 SOO
lilt
120
210
Miles
-210
Mies
240
Figure 21. Mean number of days with *0.254 mm (0.01 in.) of precipitation per year.
Source: Reference 55.
-------
Metal Emission Factors--
If metals adsorbed onto the surface of the particulates are of interest
to the user, the flowchart shown in Figure 20 will enable the estimation of
the enrichment of the RCRA metals: arsenic (As), barium (Ba), cadmium (Cd),
chromium (Cr), lead (Pb), mercury (Hg), selenium (Se), and silver (Ag). Only
RCRA metals were studied in the report from which the enrichment ratios were
taken (27).
Note that knowledge of the average concentration of these metals in the
contaminated soil is necessary for this determination. Table 30 shows the
concentrations of these metals in the silt samples from the original study.
If no site-specific soil concentrations are available, the median silt
concentrations in Table 30 may be used as gross estimates. These
concentrations were obtained from only eight TSDF facilities, however, and are
not necessarily representative of any particular site.
Control of Emissions--
First, controls for both particulates and organics should be selected
for each category; a list of alternatives may be found in Table 12. Next, the
emission factors should be adjusted from uncontrolled to controlled emissions.
Control efficiencies for the technologies listed in Table 12 are summarized in
Table 13. If information more specific or more accurate than that found in
Table 13 is available, it should be used. The formula for calculating
controlled efficiencies is the following:
^.(controlled) = ^^(uncontrolled) ' (1-CE/lOO) (Eq. 16)
The controlled emission factor should be used for further analyses.
Conversion to Emission Rate--
After each category has been examined separately, then each emission
factor will need to be converted to an emission rate (i.e., from emissions per
mass, volume, mileage, or surface area of storage to emission per time).
Finally, the contribution from all cells of waste should be summed to arrive
at total VO, particulate, and metal emission factors. The total organic,
117
-------
TABLE 30. METAL CONCENTRATION AND ENRICHMENT DATA
Median Concentration Median Enrichment Ratios
In Silt (ug/g) Silt Cone.
over Background Cone.
Arsenic (As)
Barium (Ba)
Cadmium (Cd)
Chromium (Cr)
Lead (Pb)
Mercury (Hg)
Selenium (Se)
Silver (Ag)
Number of Samples
Number of Sites Sampled
8.7
222
4.9
142
146
0.40
0.90
8.9
26
8
1.28
1.85
1.31
4.72
7.34
3.00
2.00
1.0
26
8
118
-------
particulate or metal emissions from the remediation are the sum of all the
respective emission rates. Calculating one overall rate allows comparison
between different remedial alternatives.
The factors required for this conversion are shown in Table 31. Typical
operating rates are shown in Table 32; however, if better estimates are
available, they should be used instead. The conversion is described in
greater detail in Appendix D, under Step 7 of the protocol.
One limitation of scaling the factors to a per day basis is that most of
the equations are designed to estimate annual emissions rather than daily
emissions. Particulate emissions can vary from day to day because of rainfall
(hence moisture content) and in some cases, wind speeds. Seasonal variations
may in some cases be accounted for with data from the National Weather
Service, but only if the season in which remedial action will occur is known.
If so, then the number of seasonal dry days can be compared to the number of
annual dry days; a ratio of the two can be used to compensate the factor of
(365-p)/365 or (365-p)/235 in the equations. Likewise, daily or seasonal wind
speeds may be used in equations instead of yearly averages.
3.6.2 Data Assumptions and Limitations
Several of the equations, especially in the transportation and storage
categories, were designed to provide long-term (i.e., annual) estimates of
particulate emissions. Trying to break the emissions down to Ibs/min,
Ibs/hr, or even Ibs/day can result in a severe lack of reliability in the
equations or estimates, since they were formulated on the supposition that
yearly averages of rainfall and in some cases wind speed would be used. If
enough meteorological information is available from the National Weather
Service, it may be possible to offset the dependence on precipitation by
determining the average number of dry days during the season when remedial
action will most likely be instigated, and then adjusting the parameters
119
-------
TABLE 31. CONVERSION OF EMISSION FACTORS TO EMISSIONS PER UNIT TIME
Emission Factor
(EF) Units
Scaling Factor(s) Required'
To Determine Scaling Factor
ro
o
Excavation
kg/metric ton
kg/m3
VKT
Transport
kg/VKT
2
kg/m hour
Dumping
kg/metric ton
Storage 1n Piles
2
g/m day
g/m2'day
Grading
kg/VKT
Metric tons of material excavated/day
m of material excavated/day
Vehicle kilometers traveled by scraper/day
Vehicle kilometers traveled/day
2
Surface area covered by pile 1n truck (m ).
number of hours of transportation/day
Metric tons dumped/day
VMT = (miles traveled by each vehicle
x(no. of vehicles)
(Capacity of veh1cle)x(no. of
dumps/day)x(no. vehicles)
Area of surface covered by piles .
(not surface area of pile Itself). 24 hr/day
Area of surface covered by piles
Kilometers traveled by grading equipment/day
aEquat1on 1s designated to give annual estimates. Emissions could vary between days because of
rainfall (therefore moisture content of the soil).
Equation probably overpredicts for 24-hour periods with low wind speeds; probably underpredicts for
short periods and very high winds.
-------
TABLE 32. TYPICAL OPERATING RATES FOR SOIL HANDLING ACTIVITIES
Operation Frequency/Conversion Factor
Remedial
Option
Excavation
Dumping
Equipment
Type
Backhoe
Dragline
Front -End
Loader
Scraper
Dozer
Truck
Bucket
Capacity
0.8 ra3
1.1 m3
2.7 m3
O.B m3
2.3 m3
15 IB3
2.3 m3
11 m3
7.6 m3
4m3
5m!
5m3
9.2 m3
9.2 m3
To Obtain
Maximum
Emissions
37 m3
120 m3
390 m3
.
250 m3
To Obtain
Average
Emissions
275 m3/day
920 m3/day
700 mVday
.
600 m3
340 m3
1130 tn3/day
180 m3
65 m3
270 m3
24 m3
Haul
Di stance
-
-
.
460 m
1500 m
-
400 m RT
6500 m RT
400 m RT
32000 m RT
Source: EPA Handbook: Remedial Action at Waste Disposal Sites, EPA/625/6-
85/006, References 26 and 43.
RT - Round trip distance.
Maximum emissions for 15 minute period.
121
-------
(365-p)/365 and (365-p)/235 accordingly. Likewise, daily or seasonal wind
speeds may be used in equations instead of yearly averages. Such adjustments
(or use of assumed values) are particularly appropriate for evaluations of
worst-case, short-term impacts.
Conversion of the emission factors to emission rates is dependent upon
many parameters that will most likely have to be estimated: the mass of
material in storage (which may or may not be less than the total excavated,
depending upon the remediation employed), the number of vehicles needed for
transportation, the acreage of storage space required, the distance between
the excavation site and the storage area(s), etc. Estimation of these factors
will certainly affect the reliability and accuracy of the emission estimates.
However, this manual is designed to give only approximate estimates.
All of the emission factors and equations assume uniform contaminant
concentration, moisture content, and silt fraction throughout the soil.
Determination of the enrichment of metal on silt particles (<75 urn) was
based on only one study of eight TSDFs (27). Only RCRA metals were
considered, and concentrations varied significantly between sites. Also,
concentrations of cadmium, arsenic, and selenium were below detection limits
in more than half of the silt samples.
The unpaved road equation and other transportation equations do not
account for emissions from the load carried by the vehicles. This was
estimated using the short-term (24-hour) equation for wind erosion of a
storage pile, where the wind speed in this case would be the sum of vehicle
speed and wind speed. Instead of using the acreage of storage, the surface
area of the vehicle bed should be used. It is assumed in this manual that
covering the load, such as with a tarpaulin, would provide 100% control
efficiency. These considerations are diagrammed in Figure 13.
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3.7 SOLIDIFICATION/STABILIZATION
The process for estimating particulate matter solidification or
stabilization is given as Figure 22. The emission factor data for the
stabilization and solidification category are taken directly from other
industries, since fugitive particulate emissions from these processes have not
been studied. The emission factors for stabilization processes, which
normally blend the waste with fly ash, cement or lime kiln dust, silicic
materials, and/or lime, were taken from the batch concrete industry, as
reported in Orlemann (29). The emission factors for solidification processes,
which normally employ asphalt or hydrocarbon binding agents, were taken from
the asphaltic concrete industry, as given in Orlemann (29). The accuracy of
these estimates cannot be assessed at this time without actual emissions data
from remedial activities.
Several other emission processes must be considered. Use of
stabilization and solidification processes will more than likely require
storage on-site of raw materials such as fly ash, aggregate for asphalt
production, or silicic material. If these materials will be stored in piles,
the contribution from these sources must be accounted for using the storage
pile equations.
Furthermore, when stabilization or solidification processes are used, It
should be noted that the emission factors as shown in Figure 22 include steps
for the process only, such as mixing of the materials. Excavation, dumping
into storage piles, and storage of soil and raw material must all be taken
into account with the equations in Figures 15 through 19. Figure 22 gives the
best estimate of everything from transfer of the materials (from the storage
piles to the process), through production of the final solid product.
Replacement of the material is shown in another block in Figure 22; this data
point comes from replacement of overburden in western surface coal mining
(31).
123
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Assume process to similar to asphallic
concrete production. Estimate emissions
from mbdnQ AIM uniosdinQ BSI
EF-0.3 9*9 material.
Assume process Is slmHar to concrete batching plants.
ofRfsstofis lioni nnxfnQ flno OOCBQO bins BSI
EF. CDS a/kg materiaL
Estimate
Figure 22. Flowchart H: Estimating solidification and
stabilization emissions.
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Volatile organic emissions from solidification/stabilization have not
been extensively studied. An EPA pilot-scale study found roughly 10-60% of
volatiles were driven off during mixing and curing (56).
3.8 NO ACTION/POST CLEAN-UP EMISSIONS
Under some circumstances, no action will be required at an NPL site or
the type of remediation selected will not significantly increase the air
emissions from the site. In such cases, the emissions will be equivalent to
the baseline emissions for the undisturbed site. Baseline emissions can be
estimated using the protocol presented in Volume II of this series (2). In
many cases, the baseline emissions will be undetectable or too low to be a
concern. Overburden and vegetation over the contaminants can act to attenuate
or reduce air emissions. The upper layer of any organic waste contamination
may also lose its volatile fraction over time and create a cap layer to reduce
volatilization from underlying material.
Emissions after clean-up will vary depending on the remedial option
selected, its application, and on the target endpoint. Again, the protocol
presented in Volume II is the best approach for estimating post clean-up
emissions. By definition, if the remediation is properly performed, then no
post clean-up air problems will exist. In some cases, however, the treatment
or removal activities will leave low-level residual contamination at a site in
a state where post clean-up emissions may exceed the original baseline
emissions, at least until further depletion occurs and the emission rates
decay.
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SECTION 4
EMISSIONS ESTIMATION EXAMPLE
This section presents a hypothetical NPL site and gives example
calculations demonstrating the emissions estimation protocols from Section 3.
The example represents a program in the pre-ROD stage, where various potential
clean-up options are being evaluated.
4.1 SITE DESCRIPTION
No such thing as a "typical NPL site" exists, but the hypothetical site
is meant to exhibit a combination of factors that are individually charac-
teristic of many sites. The Erewhon Site is a 0.6 km2 (160-acre) abandoned
disposal area that is adjacent to an urban area. The site was used as a
dumping place for many years and received a combination of acidic refinery
sludge, used motor oil, and crushed batteries. The waste is uniformly found
in a layer, 0.9 m (3 feet) thick, across 0.16 km2 (40 acres) of the site. The
waste is covered with a 0.6 m (2-foot) layer of overburden. Beneath the waste
is a 4.6 m (15-foot) layer of unconsolidated silt and gravel. The depth to
ground water is 6.1 m (20 feet). The site is located directly above a
sole-source aquifer, with community drinking water wells located less than a
mile down gradient. The nearest downwind receptors are about 1 kilometer away
in the direction of the predominant winds.
The soil at the site is fairly uniformly contaminated across the entire
0.16 km2 (40 acres). The overburden contains 0.5% volatile organic compounds
(VOCs) and 10 ug/g lead. The waste itself is a black, asphalt-like material
that contains 10% VOCs and 1000 ug/g lead. The soil beneath the waste layer
1s contaminated with organic vapors, with the soil pore space VOC content
varying from 100,000 ppm near the ground-water table to 500 ppm directly below
the waste layer. A hydrocarbon lens, 0.3 m thick, is present on top of the
ground water. The water Itself contains 10 mg/L VOCs (benzene).
126
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The site RPM 1s Initially considering a number of clean-up options.
These Include:
1. Removing the overburden and sending 1t for off-site disposal at a
nearby (10 miles) hazardous waste disposal facility.
2. Digging up the waste layer and Incinerating it on site.
3. Installing an 1n-s1tu venting system to treat the subsurface vapor
contamination problem.
4. Removing the hydrocarbon lens, then using an air stripper to treat
the contaminated ground water.
The RPM assigned a contractor to evaluate each option. One of the factors to
be considered was the potential for significant air emissions.
4.2 PRELIMINARY ASSESSMENT OF EMISSIONS POTENTIAL
The contractor used the procedure given in Section 3.2 to do a
preliminary assessment of the air emissions potential for the site. Section
3.2 lists eight possible site-related conditions, any one of which indicate
that air emissions during remediation could be significant. All four
scenarios meet one or more of these conditions due to the proximity of
receptors, the handling of large volumes of contaminated material, and the
potential for a large mass of uncontrolled emissions from treatment
alternatives. This work indicated that air emissions were potentially a
significant concern, so a more precise emissions estimate was developed. The
estimate will focus on uncontrolled particulate matter emissions and
controlled and uncontrolled VOC emissions since these are thought to be the
greatest concerns based on the site description.
127
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4.3 EMISSIONS ESTIMATE FOR SCENARIO ONE
The basic approach taken to determine emissions from soils handling 1s to
divide the problem Into four basic steps:
1. Calculate emissions of VOCs caused by soils handling;
2. Calculate emission factors for particulate emissions;
3. Determine operation data needed to convert emission factors to
emission rates; and
4. Calculate emission rates In the desired units for use in dispersion
modeling.
Emission factors and rates will be calculated for each of the following
activities:
1. Excavation of soil overburden from the site;
2. Soil transport from the site to a hazardous waste facility 10 miles
away;
3. Dumping of soil from trucks at the hazardous waste facility; and
4. Grading of the replacement soil after other remedial activities are
completed.
Site parameters necessary for estimating emissions from soils handling
are listed in Table 33, along with the assumed value.
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TABLE 33. EREUHON SITE PARAMETERS
(To estimate emissions from soil handling.)
Site area 160 acres
Contaminated area 40 acres
Depth of soil overburden 2 feet
Lead (Pb) concentration in soil overburden 10 ppmw
VOC concentration in soil overburden 0.5%
VOC baseline emissions 400 ug/m -min
Site terrain Level
Nearest Downwind Receptors 0.25 mile
Number of days with >0.01 inches precipitation 140 days
Average wind speed 10 niph
Percent of time wind speed exceeds 12 mph
(at midpoint of soil storage pile height) 20%
Site Overburden
Silt content 10 wt. %
Moisture content 4 wt. %
Road Access
Site 1s accessible by paved roads
Distance from road to "hot" area 0.25 mile
Paved Road Information
Silt content of paved roads 6 wt. %
Dust loading of paved surface 280 kg/km
Number of lanes of traffic 2 lanes
129
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4.3.1 VOC Emissions from Soils Handling
The site RI/FS found the average VOC emission rate from the undisturbed
contaminated soil (not the exposed waste) to be 400 ug/m2-in1n. For the 0.16
km2 site, this results in baseline emissions of 3.84 kg/hr.
Excavation--
From Table 27, the average Increase In emissions (agitation factor) due
to excavation using a bulldozer 1s 50. Therefore, the VOC emission rate
during excavation Is:
EF - (400 ug/m2-min)(50)
EF - 20,000 ug/mz'min
= 0.02 g/m2-min
Assume that: (1) each truck has 17 m2 of exposed soil; (2) one truck at a
time Is filled and the soil Is exposed for 15 minutes; and (3) the exposed
waste beneath the topsoll Is covered with an Impermeable barrier after the
soil Is removed or Immediately excavated and hauled to the Incinerator.
EF - (0.02 g/mz-m1n)(17 m2)(15 min)
» 5.1 g VOC per truck load
It 1s estimated later 1n this section that 124 truck loads a day will be
required for 88 working days (8-hours each) to remove all the contaminated
soil. This corresponds to emissions of:
Dally Emissions - (5.1 g VOC/truck load)(124 truck loads/day)
- 632 g VOC/day or 0.079 kg/hr
Total Emissions - (632 g VOC/day)(88 days)
• 55,700 g VOC
- 55.7 kg VO
130
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From Table 13, temporary foams could be used for temporary emissions control
with 81% effectiveness. This would reduce emissions to:
(0.079 kg/hr)[(100-81)/100] - 0.015 kg/hr
Transport--
The trucks will certainly be covered during transport for dust and odor
control. Controlled emissions can be assumed to equal zero. Uncontrolled
emissions would depend on the length of the trip (assumed to be 2 hours for
this site).
EF - (0.02 g/m2-m1n)(l7 m2)(120 min)
= 40.8 g VOC/truck load
This corresponds to 5,060 g VOC/day (0.63 kg/hr) and 445 kg VOC for the 88-
day project.
Dumping--
From Table 27, the average increase in emissions (over the baseline
emission rate) due to dumping is 57. The emissions were already enhanced by
excavating, but since this agitation factor 1s larger, the new higher emission
factor will be used:
EF - (400 ug/m2-min)(57)
» 22,800 ug/m2'min
Assume that the soil will occupy the same 0.16 km2 at the landfill as It did
at the site (I.e., It Is spread as a thin layer). The emissions will stay
elevated for up to 4 days according to the storage data in Table 27. Assume a
linear decay in emissions over the four days back to the baseline emission
rate.
(400 ug/m2 min + 22,800 ug/m2'min)
EF (4 days)(1440 min/day)
2
- 6.68 x lp7 ug/m2
- 66.8 g/m2
131
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0.16 km2 - 160,000 m2, so the total VOC emissions from dumping are:
Total Emissions - (66.8 g/m2)(160,000 m2)
• 1.07 x 107 g VOC
- 10,700 kg VOC
Assuming the soil 1s dumped equally over 88 consecutive working days, the
dally VOC emission rate due to dumping 1s:
Dally Emissions « (10,700 kg)(1/88 days)
- 122 kg/day or 5.1 kg/hr
From Table 13, stabilized foams can achieve 99% vapor control efficiency. So,
the controlled emissions would be 1% of the uncontrolled emissions, i.e.,
0.152 kg/hr and 107 kg total. In actual practice, complete coverage by foams
is not usually possible and emissions will probably be higher.
Grading--
The Increase in emissions due to grading can range from 2 to 38 times the
baseline emission rate. Even the highest value is less than the increase due
to dumping. So, if the soil 1s graded within 1-2 days after dumping, grading
Is not expected to significantly increase the already elevated emission rates.
4.3.2 Particulate Emission Factors fromSoils Handling
The first step in estimating particulate emissions is to determine the
particle size of Interest. Since the soil 1s contaminated with lead, both
downwind receptor concentrations and worker exposure concentrations are
needed. Emission rates of particulates <30 urn in diameter are required for
downwind receptor modeling and worker safety. In addition, emission rates of
inhalable particulates (<15 urn) are necessary to determine worker safety
hazards. Inhalable emissions will be estimated for all appropriate on-site
activities. Equations shown are from Table 21 unless otherwise specified.
132
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Excavatlon--
1. Equipment used: one bulldozer for the 40 contaminated acres.
2. Emission factor for TSP, <30 urn:
EF - 2.6(s)1'2(M)-1-3 kg/hr
s - wt % silt - 10
N - wt % moisture - 4
EF - 2.6(10)1'2(4)-1-3
«6.8 kg/hr
3. Emission factor for Inhalable parti cul ate, <15 urn:
EF - O^Sfs)1-^)-- kg/hr (Table 28)
- 0.45(10)l'5(4)-1-4
- 2.0 kg/hr
Soil Transport--
Contaminated soil will require transport to a secure hazardous waste
disposal site. This site 1s 10 miles away and will require driving on 0.25
mile of unpaved roads (across part of the 160 -acre site without a contaminated
soil surface) to the nearest paved road. The remainder of the journey, 9.75
miles, Is on paved roadways. In addition, the trucks will have to drive on
the contaminated surface to retrieve the soil from the excavation equipment.
The average distance traveled per truck across contaminated soil is 0.2 mile
round-trip (RT).
1. Equipment used: trucks with a 12 cubic yard capacity, 6 wheels, and
weighing 36 Mg.
2. Transport over contaminated soil: 0.2 mile RT. Use unpaved road
equation and contaminated soil characteristics. Average truck speed
133
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Is 10 mph (16 km/hr). Calculate EF for TSP and inhalable
participates.
0.7/
kO.5/
EF - k(1.7)(s/12)(S/48)(W/2.7)°-7(w/4)°-!>(365 - p)/p kg/VKT
k - particle size multiplier - 0.8 for <30 urn
k - particle size multiplier • 0.5 for <15 urn
s • silt content, wt % - 10
S - average truck speed, km/hr « 16
VI - average weight of truck, M - 36
w • number of wheels - 6
p - number of wet days/year • 140
EF - 0.8(1.7) (10/12) (16/48) (36/2.7)°-7(6/4)°-5(365 - 140J/140
-4.6 kg/VKT for TSP, <30 urn
EF - 0.5(1.7)(10/12)(16/48)(36/2.7)°-7(6/4)°-5(365 - 140)/140
- 2.8 kg/VKT for Inhalable participate, <15 urn
Transport on unpaved "roads," over uncontamlnated site soil. Use
site soil characteristics. Average truck speed is 10 mph (16
km/hr), 0.5 mile RT. Only TSP emissions are of interest. Since all
parameters are the same as for contaminated soil, with the exception
of the metals and VOC content, the emission factor is the same:
EF - 0.8(1.7)(10/12)(16/48)(36/2.7)°-7(6/4)°-s(365 - 140J/140
= 4.6 kg/VKT for TSP, <30 urn
Transport on paved roads, 19.5 miles RT. Silt content of the road
shoulders Is 6%. Assume that since the nearest downwind receptors
are only 0.25 mile away, it is an urban area, and most or all of the
roads in the area are paved. Average truck speed is 35 mph (57
km/hr).
134
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EF - 0.022(I)(4/n)(s/10)(L/280)(W/2.7)°-7 kg/VKT
I • Industrial augmentation factor, explained in Table 26= 1.0
n - number of traffic lanes - 2
s • silt content, wt % « 6
L - surface dust loading, kg/km = 280
W • average weight of truck, Mg » 36
EF - 0.022(l)(4/2)(6/10)(280/280)(36/2.7)°-7
- 0.162 kg/VKT
5. Emissions from truck bed during transport: uncontrolled.
EF - 0.0018(u) kg/hr per square meter of surface area
u » sum of vehicle speed and wind speed, m/sec
35 mph + 10 mph - 45 mph
45 mph * (hr/3600 sec)(1000 m/0.62 mile) = 20 m/sec
EF - 0.0018(20) kg/hr m2
= 0.036 kg/hr m2
10 mph + 10 mph • 20 mph » 9.0 m/sec
EF - 0.0018(9) -0.016 kg/hr m2
From Tables 23 and 25, no Information 1s available on particle size
multipliers for this application. Assume that the multiplier for dumping
applies here, such that k - 0.50 for particulates <15 urn. The emission factor
for the inhalable particulates Is thus:
(0.5)(0.036) - 0.018 kg/hr m2 at 35 mph
(0.5)(0.016) - 0.008 kg/hr m2 at 10 mph
Controlled emissions for transportation can be assumed to be zero.
135
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Dump Ing--
Si nee the contaminated soil will be transported to another disposal site,
the emissions from dumping will not occur at the clean-up site, but rather at
the other site. However, emissions of both total and inhalable part icul ate
are of Interest at the other site, which has downwind receptors no closer than
10 kilometers away.
EF - kCO.OOlGHU/Z^j'-'CN/Z)'1-4 kg/Mg dumped
k - particle size multiplier « 0.74 for <30 urn
k « particle size multiplier - 0.48 for <15 urn
U - mean wind speed, m/sec = 4.5 (10 mph)
M - moisture content, wt % - 4
EF - 0. 74(0. 0016)(4. 5/2. 2)1-3(4/2)'1-4
- 0.0011 kg/Mg dumped, TSP <30 urn
EF - 0.48(0. 0016)(4. 5/2. 2)1-3(4/2)'1-4
• 0.00074 kg/Mg dumped, Inhalable <15 urn
Storage- -
Since the soil 1s not being stored on site, no storage piles will be
required.
NOTE: In circumstances where the emissions from storage piles are
important, the surface area per pile referred to Is not the surface area of
the pile Itself, but rather 1s the surface area covered by the pile (e.g., a
storage pile covering 0.5 acre of land).
Grading--
The contaminated soil will not be graded on site, but will be graded
after it is dumped at the certified hazardous waste disposal site. The total
and Inhalable part icul ate emissions are of interest there.
136
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1. TSP:
EF - 0.0034(S)2'5 kg/VKT
S - average grader speed, km/h -11.4 (Table 29)
EF - 0.0034(11.4)2'5
- 1.5 kg/VKT
2. Inhalable participate, 15 urn
EF • 0.0056(S)2'° kg/VKT (Table 24)
EF - 0.0056(11.4)2'°
- 0.73 kg/VKT
4.3.3 Partlculate_Em1sslon Rates from_So11s_Handl1nq
Conversion of emission factors to emission rates Is dependent upon the
operations at the site: the number of bulldozers and trucks, the distance
over which the soil Is transported, etc. Calculate all the necessary
operating parameters, then calculate emissions per hour and emissions per day
(assuming 8 hours of emissions per day).
Excavation--
One bulldozer used for the 40-acre site.
Bucket capacity: 5 yd3
Avg daily load: 1480 yd3/day (Table 18)
Volume of 40 acres with 2 feet of soil overburden:
(40 acre)(43,560 ft2/acre)(2 ft)(yd/3 ft)3 = 129,000 yd3
At 1480 yd3/day, number of days for excavation:
137
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129,000 yd3/1480 yd3/day - 87.2 days - 88 days
TSP Emission Rate:
ER - 6.8 kg/hr * 1 bulldozer - 6.8 kg/hr
ER « 6.8 kg/hr * 8 hr/day * 1 bulldozer - 54.4 kg/day
Inhalable Particulate Emission Rate:
ER « 2.0 kg/hr * 1 bulldozer - 2.0 kg/hr
ER - 2.0 kg/hr * 8 hr/day * 1 bulldozer » 16.0 kg/day
Soil Transport--
Assume that trucks are not the limiting factor, but that enough trucks
will be available to carry away all contaminated soil as It Is excavated.
Since each truck's capacity 1s 12 yd3, the number of loads per day required
would be:
(1480 yd3/day)/(12 yd3/load) - 123.333 • 124 loads/day
Since each trip will require 0.7 mile at 10 mph and 19.5 miles at 35 mph
(1.1 km at 16 km/hr and 31.5 km at 57 km/hr), the number of trips required,
and therefore the number of trucks (at 12 yd3 capacity each), is estimated as
follows:
(0.7/10) + (19.5/35) hours - 0.63 hours
Drivers will also require time for traffic signals, dumping, and decon-
tamination at both sites; therefore, allow 2 hours per trip.
(8 hours/day)/(2 hours/trip) - 4 trips/day per truck
(124 loads/day)/(4 trips/truck/day) » 31 trucks/day
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Vehicle kilometers traveled (VKT), and likewise vehicle miles traveled
(VMT), refers to the sum of the distances traveled along the road of Interest
by all vehicles traveling that road. Since three types of "road" surfaces are
employed (contaminated soil, uncontaminated soil, and paved roads), the total
kilometers (miles) traveled should be calculated for each surface.
Contaminated soil:
0.2 mile (0.3 km) for each round trip (RT) at an average speed
of 10 mph (16 km/hr)
0.3 km/trip * 124 trips/day = 37 VKT/day
Uncontaminated soil/unpaved road:
0.5 mile (0.8 km) per RT at an average speed of 10 mph (16
km/hr)
0.8 km/trip * 124 trips/day « 99 VKT/day
Paved road:
19.5 miles (31.5 km) per RT at an average truck speed of 35 mph
(57 km/hr)
31.5 km/trip * 124 trips/day = 3910 VKT/day
The emission rate for particulates lost from the bed of the truck during
transportation are dependent upon the surface area of the soil in the truck.
Assuming a 12 yd3 (9 m3) pile which is hemispherical in shape:
V - 0.5(4*R3)/3
9 - 0.5(4*R3)/3 > R = 1.6 m
A - 0.5(4*R2) - 17 m2
However, the truck is not always loaded, not always moving, and not
always moving at the same average speed:
139
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0.7 mile at 10 nph, 19.5 miles at 35 mph
4 trips per day per truck
31 trucks
loaded 50% of the time
(0.7/10) x 4 x 31 x 0.5 - 4.34 hr/day at 10 mph
(19.5/35) x 4 x 31 x 0.5 - 34.5 hr/day at 35 mph
ER - [(0.016 kg/hr mz)(4.34 hr/day) + (0.036 kg/hr m2)
(34.5 hr/day)](17 m2)
• 25 kg/day uncontrolled emissions
(25 kg/day)(day/8 hr) • 3.1 kg/hr
EF, Contaminated Soil, <15 urn: 2.8 kg/VKT * 37 VKT/day
- 104 kg/day
(104 kg/day)/(8 hr/day) - 13 kg/hr
Dumping--
To convert the emission factor to an emission rate, estimate the mass of
soil dumped at the new site. Use a bulk density of 1.5 g/cm3, which is equal
to 1.5 Ng/m3. Recall that the volume of soil excavated by the bulldozer is
1480 yd3 per day.
(1480 yd3/day) (0.9144 m/yd)3(1.5 Mg/m3) - 1700 Mg/day
Therefore, the emission rate Is:
(0.0011 kg/Mg}(1700 Mg/day) - 1.9 kg/day of TSP
(0.00074 kg/Mg)(1700 Mg/day) = 1.3 kg/day of <15 urn particulate
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On a mass per hour basis, assuming an 8-hour workday:
(1.9 kg/day)/(8 hr/day) - 0.24 kg/hr of TSP
(1.3 kg/day)/(8 hr/day) • 0.16 kg/hr of <15 urn
In reality, all of the emissions would take place In a few minutes during
and after each dump.
Grading--
The emission factor Is in units of kg/VKT (vehicle kilometers traveled}.
The average speed of the grader 1s 11.4 km/hr (from Table 29). The length of
an average work day is about 8 hours, but a significant amount of time will be
required for stops and starts, since several trucks will be dumping small
loads, and the grader will be spreading them over a small land area.
Therefore, assume that the VKT may be estimated based on four hours a day at
11.4 km/hr:
11.4 km/hr * 4 hr/day - 46 km/day
The emission rates may then be calculated:
1.5 kg/VKT * 46 km/day - 69 kg/day TSP
69 kg/day * day/8 hours = 8.6 kg/hour TSP
0.73 kg/VKT * 46 km/day - 33 kg/day of <15 urn
33 kg/day * day/8 hours - 4.1 kg/hour of <15 urn
141
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Summary of PM Emission Results-
Emission factors, rates, and conversion factors may be summarized In a
table and totaled, as shown In Tables 34 and 35. Controlled emissions may be
calculated by looking up the appropriate control efficiency (CE) 1n Table 13
and using It as follows:
Controlled ,k_/hri - Uncontrolled Emission 100-CE
Emissions Rate (kg/hr) 100
Lead Emissions - Soil Handling--
Lead content of soil - 10 ppm
Lead content of silt (<75 urn) • (10 ppm)(7.34) = 73.4 ppm
Assume that 73.4 ppm 1s the concentration of lead associated with all
fugitive particulate emissions from soil handling.
1. Lead associated with TSP emissions per 8-hour workday:
Excavation - (54 kg TSP/day)(73.4 x 10'6 kg Pb/kg TSP)
- 4.0 x 10'3 kg Pb/day
• 5 x 10'4 kg Pb/hr
Transportation (truck bed losses and soil transport over
contaminated soil)
Over contaminated soil - (169 kg/day)(73.4 x 1CT6 kg Pb/kg TSP)
- 1.2 x 10'2 kg Pb/day
From truck bed - (4.9 kg/day)(73.4 x 10'6 kg Pb/kg TSP)
- 3.6 x 10'4 kg Pb/day
Dumping - (1.9 kg/day)(73.4 x 10'6 kg Pb/kg TSP)
- 1.4 x 10'4 kg Pb/day
Grading = (69 kg/day)(73.4 x 10'6 kg Pb/kg TSP)
- 5.1 x 10'3 kg Pb/day
Total = 2.2 x 10'2 kg Pb/day
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TABLE 34. SUMMARY - EMISSIONS FROM SOILS HANDLING AT EREWHON SITE,
FOR TOTAL SUSPENDED PARTICULATE (TSP, <30 urn)
Type of Operation
Emission
Factor
Conversion
Factor
Emission Rate
leg/day kg/hour
Excavation
Soil Transport
Contaminated soil
Unpaved roads
Paved roads
From truck bed
Dumping
Storage
Grading
6.8 kg/hr
1 dozer
54
6.8
4.6 kg/VKT
4.6 kg/VKT
0.16 kg/VKT ,
0.052 kg/hr m2
0.0011 kg/Mg
N/A
1.5 kg/VKT
37 VKT/day
99 VKT/day
3906 VKT/day
17 m2,
38.8 hr/day
1700 Mg/day
N/A
46 km/day
Total
169
451
633
25
1.9
N/A
69
1402
21
56
79
3
0.24
N/A
8.6
175
143
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TABLE 35. SUMMARY - EMISSIONS FROM SOILS HANDLING INHALABLE PARTICULATE
um)
Type of Operation
Excavation
Soil Transport
Contaminated soil
Unpaved roads
Paved roads
From truck bed
Dumping
Storage
Grading
Emission
Factor
2.0 kg/hr
2.8 kg/VKT
0.026kg/hr m2
0.00074 kg/Mg
N/A
0.73 kg/VKT
Conversion
Factor
1 dozer
47 VKT/day
17 m2,
38.8 hr/day
1700 Mg/day
N/A
46 km/day
Total
Emission
Jig/day
16
104
17
1.3
N/A
33
171
Rate
kg/hour
2.0
13
2
0.16
N/A
4.1
21
144
-------
2. Lead associated with Inhalable participate emissions, <15 urn:
Excavation - (16 kg/day)(73.4 x 10'6 kg Pb/kg)
= 1.2 x 10'3 kg Pb/day
Transportation
Over uncontamlnated soil - (104 kg/day)(73.4 x 10'6 kg Pb/kg)
- 7.6 x 10'3 kg Pb/day
Dumping - (1.3 kg/day)(73.4 x 10'6 kg Pb/kg)
- 9.5 x 10'5 kg Pb/day
Grading - (33 kg/day)(73.4 x 10~6 kg Pb/kg)
- 2.4 x 1(T3 kg Pb/day
Total - 1.1 x lO'2 kg Pb/day
4.4 EMISSIONS ESTIMATE FOR SCENARIO TWO
Incineration emissions fall Into three categories:
Waste handling emissions;
• Stack emissions; and
Fugitive emissions.
Emission estimates for each of these three categories are developed below.
4.4.1 Waste Handling Emissions
The waste layer extends over 0.16 km2 and is 0.9 m thick. Assume the
waste will be removed concurrently with the soil removal by a second
bulldozer, and transported to a location on site and dumped onto one large
storage pile. The waste volume is 161,900 m3 and according to Table 18, a
bulldozer can excavate 1100 m3 of material per day. Hence:
145
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Days of Waste Removal - (161,900 m3)/(1100 m3/day)
- 147 days
Emissions of VOCs and partIculate matter will be of concern, with VOC
emissions almost certainly requiring some control measures.
The waste handling can be divided Into excavation, transport, dumping,
and storage steps.
Excavation, Transport, and Dumping--
The calculation of VOC and particulate matter emissions is analogous to
the steps used in Section 4.3 for soils handling, with the physical and
chemical characteristics of the material being different in some cases and
requiring different input values, e.g., silt content. It is important to
remember that excavation and dumping steps may be repeated to move waste from
the storage pile onto the feed mechanism of the incinerator.
Storage--
Emissions for particulate matter and VOCs are estimated.
Storage pile participate matter emissions (waste)--
Density - 1.5 g/cm3 - 1.5 Mg/m3
Silt content - 1% - s
Storage pile size - 0.5 acre
% time that unobstructed wind speed is greater than 12 mph at
mid-point • 20% « f
Particle sizes of Interest - <30 urn and <15 urn
1. Emission factor:
EF - 1.9(s/1.5)[(365 - f)/235](f/15) kg/day/hectare
- 1.9(1.0/1.5)[(365 - 140J/235](20/15)
»1.6 kg/day/hectare
146
-------
2. Surface area occupied by pile - 0.5 acre:
(0.5 acre)(hectare/2.417 acres) -0.20 hectare
3. Emission rate:
(1.6 kg/day/hectare)(0.2 hectare) • 0.32 kg/day
(0.32 kg/day)(day/24 hr) - 0.013 kg/hr
or, If the wind dies at night, assuming 12 hr of darkness:
(0.32 kg/day)(day/12 hr) - 0.03 kg/hr
Storage pile VOC emissions (wastel--
The site RI/FS found the average VOC emission rate from the exposed waste
to be 10,000 ug/m2'min. If all 0.16 km2 of the waste was exposed, this would
result In emissions of 96 kg/hr. This high value Is consistent with the 10%
VOCs 1n the waste. Assume that the waste pile Is one-half of a sphere that
has a radius of 42.6 m. The surface area would then be 1.1,400 m2. The
emission rate Is:
VOC Emission Rate - (10,000 ug/m2 min)(l 1,400 m2)(60 min/hr)
- 6.84 x 109 ug/hr
- 6.84 kg/hr
This value would decrease over time as the pile shrunk in size. More
importantly, the outer layer of waste would become depleted of VOCs over time
and Inhibit further volatilization from the waste underneath it. A worst-case
scenario would be that the emissions stayed constant over the entire 5060 days
required to incinerate the waste. Assuming a linear decrease in surface area
of the pile over time, the average-surface'area would be:
11,400 m2 + 0 m2
•» 5700 m2
147
-------
The worst-case total VOC emissions from storage are:
Total Emissions - (10,000 ug/mz-min)(5700 mz)(1440 min/day)(5060 days)
- 4.15 x 1014 ug
- 4.15 x 10s kg VOC
This value represents 1.7% of the total VOCs present in the waste. Emissions
control up to 99% could be obtained using stabilized foam, physical covers, or
by enclosing the waste In a building.
4.4.2 Stack Emissions
The pertinent input parameters are listed in Table 36.
Emissions from incineration and destruction efficiency are directly
dependent on the design of the Incineration system. For this example, it is
assumed that optimum values have been selected for:
• Combustion gas flow rates;
Auxiliary fuel requirements;
Incinerator size;
Burner size;
• Refractory dimensions; and
Incinerator cost.
The controlled and uncontrolled emissions are estimated using the equations
and/or assumed values from Section 3.3.
4.4.3 Organic Compounds
Assume that no control devices will be used that affect VOC emissions.
From Equation 3:
ER, - [1 - (DRE/100)](C1)(M,)(1/1000)
- [1 - (99.99/100)1(100 g/kg)(2000 kg/hr)(0.001 kg/g)
- 0.02 kg/hr
148
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TABLE 36. SITE PARAMETERS
Waste Parameters
Volume
Density
Mass
VOC Concentration
Pb Concentration
S Concentration
Btu Content
Inc1nerator Parameters
Type
Exhaust Gas Rate
ORE
Feed Rate
161,900 m3 (193,600 yd3)
1.5 g/cm3 - 1,500 kg/m3
2.43 x 10" kg
10% - 150 kg/m3
1000 ppm (ug/g) -1.5 kg/m3
1% - 15 kg/m3
23.2 kJ/g (10,000 Btu/lb)
Rotary Kiln
125 mVnrin
99.99%
2000 kg/hr
149
-------
Assuming that the Incinerator operates 24 hr per day, the dally emissions
would be 0.48 kg/day. At the specified flow rate, the Incinerator would need
to be operated 5060 days to destroy all the waste. Thus, the total organic
emissions would be 2430 kg.
4.4.4 Partlcul ate Matter JPM1
From Section 3.3.2, typical uncontrolled PM emissions are 11,800 mg/m3,
controlled PM emissions are 72 mg/m3, and RCRA performance standards limit PM
emissions to a maximum of 180 mg/m3. Assuming an exhaust gas rate of 125
ma/m1n, emission would be:
Uncontrolled - (11,800 mg/m3) (125 m3/min)(kg/106 ing)
- 1.475 kg/mi n
• 88.5 kg/hr
Controlled • (72 mg/m3) (125. mVmin) (kg/106 mg)
» 0.009 kg/mi n
• 0.54 kg/hr
4.4.5 Metal Emissions
From Equation 5:
XMF (metal emissions as a percentage of input metal mass) values for lead are
found in Table 20 and are 71% for uncontrolled emissions and average 26% for
controlled emissions. Thus,
Uncontrolled - (1 g/ kg) (2000 kg/hr) (71/100)
- 1420 g/hr
- 1.42 kg/hr
150
-------
Controlled • (1 g/kg)(2000 kg/hr)(26/100)
- 520 g/hr
- 0.52 kg/hr
4.4.6 Add Gas Emissions
From Equation 6, uncontrolled emissions are:
ER, - (Cj/lOOOMR/jJHJ
ER, • (10 g/kg)(l)(2000 kg/hr)
- 20,000 g/hr
- 20 kg/hr
From Table 13, dry Injection and fabric filter controls are 50% effective.
Therefore, uncontrolled emissions would be:
ER, - (20 kg/hr)(50/100)
- 10 kg/hr
The stack emissions due to incineration are summarized in Table 37.
4.4.7 Fugitive Emissions
From Table 4, fugitive emissions of all species but VOCs can be assumed
to be negligible. Taking the best and worst-case estimates of fugitive losses
(4% and 80% of stack emissions), emissions could range from 8xlO~4 to 1.6xlO"2
kg/hr. Fugitive particulate matter emissions can be assumed to be zero. This
does not include fugitive emissions from the waste feed and ash handling
operations.
151
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TABLE 37. STACK EMISSIONS DUE TO INCINERATION
Uncontrolled Emissions
Controlled Emissions
Species
VOCs
PM
Lead
SO,
Rate (kg/hr)
0.02
88.5
1.42
20
Total (kg)
2430
1.07 x 107
172,000
2.43 x 106
Rate (kg/hr)
0.02
0.54
0.52
10
Total (kg)
2430
65,600
63,100
1.21 x 10s
152
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4.5 EMISSIONS ESTIMATE FOR SCENARIO THREE
4.5.1 Uncontrolled Emissions
From Equation 13, the hydrocarbon vapor recovery rate per well is:
ERi - (
From Table 18, an average flow rate is 0.50 m3/min. From the site descrip-
tion, It is known that the subsurface vapors range from 100,000 to 500 ppm.
Assuming a linear distribution and an average molecular weight of 78 (ben-
zene), the average vapor concentration would be 173 g/m3. [Average concen-
tration • (100,000 + 500)/2 - 50,250 ppm and, for C6, 1 ppm • 3440 ug/m3.]
ER, - (173 g/m3) (0.50 m3/min)
= 86.5 g/min
• 5.19 kg/hr
For a site with coarse-textured soil, recovery wells may be located up to
60 m apart. Therefore, each recovery well would cover an area of:
Area = ffr2
= (3.14)(60 m)2
- 11,300 m2
For a 40 -acre site, the number of required wells would be:
No. of wells - (40 acres) (4097 m3/acre) (1/11, 300 m3)
» 14
Therefore, the overall uncontrolled emissions are:
ER - (5.19 kg/hr) (14)
- 72.7 kg/hr
153
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4.5.2 Control1ed_Em1ssions
From Table 18, controlled emissions for a carbon adsorption system
average 75 ppm. Assuming molecular weight - 78, this Is roughly 0.258 g/m3
(75 ppm x 3440 ng/m3/ppni). Emissions per recovery well are:
ER - (0.258 g/m3)(0.5 m3/min)
- 0.129 g/min
- 0.0077 kg/hr
For all 14 wells, this totals to 0.108 kg/hr. If emissions are controlled by
sending the vented gas to the incinerator, then emissions can be assumed to be
negligible.
4.6 EMISSIONS ESTIMATE FOR SCENARIO FOUR
Assume that the hydrocarbon layer on the ground water can be recovered
directly without incurring significant VOC losses. Air stripping of the
ground water could be used to clean up the 10 mg/L of benzene contamination.
From Table 18, 3500 L/min of water can typically be treated per unit. If one
unit 1s in use, the emissions can be calculated from Equation 8.
ER - (10,000 ug/L}(3500 L/min)(10'6)(99.5/100)
• 34.8 g/min
• 2.09 kg/hr
From Section 3.4, carbon adsorption control technology (CAS) can be expected
to get as low as 50% removal for compounds with benzene's molecular weight.
So the controlled emissions would be:
ER - (2.09 kg/hr)(50/100)
=1.05 kg/hr
If the air Is sent to the Incinerator Instead of a CAS, then the emissions can
be assumed to be negligible.
154
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4.7 SUMMARY AND AMBIENT IMPACT ASSESSMENT
The estimated emission rates for each scenario are summarized 1n Table
38.
Assessments of emissions are commonly followed by dispersion model
assessments of the ambient air quality Impacts of these emissions. The
selection of a dispersion model and the determination of model inputs are
discussed in Volume IV of this series and in other references, and are not
discussed here.
Nevertheless, to provide some perspective on the significance of given
levels of emissions from remedial actions, a modeling analysis was performed.
A range of inputs was used to provide an indication of the range of
concentrations that can result from a given rate of emissions. This analysis
used the ISCST model. Meteorological data from Albany, NY (1978 data) and
from Concord, NH (1981 to 1985 data) were used to represent the Northeastern
U.S. Meteorological data from Orlando, FL (1981 to 1985 data) and from
Atlanta, GA (1974 to 1979 data) were used to represent the Southeastern U.S.
These choices of meteorological data do not provide either the highest or the
lowest concentrations that might result from a given emission rate, but they
do indicate some of the range of emissions-to-concentration relationships
found in the United States.
The dispersion model runs were designed to indicate the downwind
concentrations (1n ug/m3) that could result per unit emission rate (1 kg/hr).
Results were obtained for both a short-term (1 hour) and a long-term (1 year)
average. For both averaging times, the valve below is the highest valve for
any time period and for any receptor direction:
155
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TABLE 38. SUMMARY OF EMISSION RATE ESTIMATES
(ft
VOC fka/hr)
1
2
3
4
Scenario
- Soil Removal
Excavation
Transportation
Dumping
Grading3
- Incineration
Waste Removal b
Waste Feed0
Storage
Stack Emissions
Fugitive Emissions
Ash Handling0
- In-SUu Ventilation
- Ground-Water
Stripping
Uncontrolled
0.07
0.63
5.1
5.1
--
6.84
0.02
0.016
--
72.7
2.09
Controlled
0.015
0
0.152
0.152
--
0.07
0.02
--
--
0.108
1.05
Uncontrolled
TSP <30 urn
(kg/hr)
6.8
159
0.24
8.6
--
0.03
88.5
0
• -
-c
..c
Uncontrolled
Inhalable
PM < 15 urn
(kg/hr)
2.0
15
0.16
4.1
—
--c
--^
0
--
--c
..c
Lead
(g/hr)
0.5
1.54
0.018
0.64
--
--c
1420
0
--
-c
__c
(kg/nV)
..c
__
__
--
--c
20r
--
--
-c
..c
aGrad1ng Is not expected to Increase emissions 1f performed soon after dumping,
so Grading ER = Dumping ER.
bNot calculated for this example. Emissions estimation 1s analogous to soil removal,
but VOC emissions would be about 20x higher due to higher VOC content.
°Not calculated, assumed to be insignificant.
-------
Downwind
Distance
10 m
100 m
500 m
1
2
3
5
km
km
km
km
NE U.S.
Peak
523,000
9,350
587
295
157
109
69
NE U.S.
Average
76,000
1,490
82
25
8
4
2
SE U.S.
Peak
508,000
9,070
682
362
192
133
84
SE U.S.
Average
59,900
893
48
14
5
2
1
These values may be multiplied by the emissions estimates to approximate
the Impact of a remedial action. For example, using the multipliers and the
emission rate estimates In Table 38, the Impact of the example scenario
emissions at various receptors can be evaluated. In Table 38, three values of
potential concern due to their large magnitude are:
uncontrolled TSP from transportation at 159 kg/hr;
lead from incinerator stack at 1.42 kg/hr; and
in-situ ventilation at 72.7 kg/hr (uncontrolled) and 0.108 kg/hr
(controlled).
Using the multipliers given above, the peak concentrations and annual average
concentrations of these contaminants can be calculated for receptors of
concern, say at 1 km for a site in the NE U.S. For example:
NE Peak Lead at 1 km - (295 ug/m3 / kg/hr) (1.42 kg/hr) = 419 ug/m3
Looking at the three values of potential concern, the concentrations at 1 km
equals (all values in ug/m3):
Criterion
Peak Annual Short Long
Contaminant Receotor=l km Receptor=l km Term Term
1. Uncontrolled TSP 46,900
2. Lead 419
3. Uncontrolled VOC 21,400
4. Controlled VOC 31.9
2,980
35.5
1,820
2.7
150 50 (for PM-10)
1.5
157
-------
Comparison of these Impacts to the National Ambient Air Quality Standards
for lead and participate matter Indicates that controls for these contaminants
may be warranted. No such standard exists for VOC. Instead, Individual
compound concentrations will generally be calculated for comparison to
compound-specific reference doses or for use in estimating cancer risks
(similar such calculations may be performed for particulate matter species as
well). Also, note that a PM1S concentration Is being compared to a PM10
standard; a more refined analysis should use PM10 emissions estimates.
The above calculations provide generalized approximations of ambient
Impacts of emissions. Analyses for particular sites would generally involve
running a dispersion model using locally-representative meteorological data.
Such analysis might consider the different locations of multiple sources and
the dimensions of the source area. Several other considerations may also
affect these analyses and their Interpretation. The principal utility of the
information in this section is to provide a means of evaluating whether a
given remedial action plan leading to a given emissions estimate is likely to
have a significant ambient Impact.
158
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SECTION 5
INPUT DATA COLLECTION
This section Is an Introduction to methods for collecting Input data for
use In the emissions estimation protocol. Data needs and data quality
objectives are discussed, followed by descriptions of data collection
approaches for assessing emission sources, ambient concentrations, or other
data needs. The companion volumes to this manual are excellent sources of
Information on certain input data collection topics: Volume I (1) for overall
air Issues, Volume II (2) for developing baseline emission estimates, and
Volume IV (3) for ambient air monitoring and dispersion modeling.
5.1 DATA NEEDS/DATA QUALITY OBJECTIVES
Collection of input data for the emissions estimation protocol may be
necessary to:
1) Fill an existing data gap;
2) Collect site-specific data to improve an existing emissions
estimate; or
3) Measure emissions to verify an emissions estimate.
Data gaps, if present, should be readily identified when executing the
protocol. In some cases, an emissions estimate can be improved by collecting
input data at the site, or at another similar site, and replacing generic
input data with the site-specific data. Verification of an emissions estimate
may be warranted for final selection of a remedial option, for atypical sites,
or for sites with sensitive receptors in close proximity.
159
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Once the need for input data to the protocol has been Identified, the
next step is to determine exactly what input parameters are needed, what
associated data quality (confidence) is required, and how the data should be
collected. The general steps in the process are illustrated in Figure 23.
The two pieces of data most needed for estimating emissions are usually
the amount of waste that is present and the average concentration of various
pollutants in the waste. An RI/FS usually must be performed at the field site
to collect these data. Other types of input data may also be collected from
the field site, but a number of alternative information sources may provide
the necessary data, Including:
• Predictive models;
• Published literature;
Other Superfund RPMs; and
Field data from other hazardous waste sites.
Other sources should be considered before committing to the time and expense
of a field study.
If field data are required, sampling and analytical methods must be
selected and a quality assurance/quality control program developed. Sampling
methods for determining air quality are discussed in Section 5.2. The
analytical methods and QA/QC program needs will depend directly on the data
quality needs. This dependence is summarized 1n Table 39. Data quality can
be Indicated by the PARCC (precision, accuracy, representativeness,
completeness, and comparability) parameters. A complete description of data
quality and QA/QC is beyond the scope of this manual. The EPA has published
guidance on these topics and they should be referred to for further
information (56,57,58).
160
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Define APA Objectives
Identify Types of Data
Needed for Protocol
X
Identify
Data Quality
Needs
Identify
Data Quantity
Needs
z.
Evaluate and Select
Sampling/Analytical and/or
Modeling Options
Implement
QA/QC Program
Collect Input
Data
Review Data Quality
Parameters
Yes
Apply Data
to Emissions
Estimation Protocol
Figure 23. Flowchart for Input data collection.
161
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TABLE 39. SUMMARY OF ANALYTICAL LEVELS APPROPRIATE TO DATA USES
Data Uses
Analytical
Level
Type of Analysis
Limitations
Data Quality
Site Characterization
Monitoring during
Implementation
Level I
Total organic/Inorganic
vapor detection using
portable Instruments
Field test kits
Instruments response to
naturally-occurring
compounds
If Instruments calibrated and
data Interpreted correctly.
can provide Indication of
contamination
Site Characterization Level II
Evaluation of Alternatives
Engineering Oeslgn
Monitoring during
Implementation
Variety of organic* by
GCi Inorganics by AA:
XRF
Tentative ID; Analyte-
Tentatlve ID
Techniques/Instruments
United mostly to
volatile*, metals
Dependent on QA/QC
steps employed
Data typically reported In
concentration ranges
specific
Detection limits vary
from low ppm to low ppb
cn
ro
Risk Assessment
PRP Determination
Site Characterization
Evaluation of Alternatives
Engineering Design
Monitoring during
Implementation
Level III Organlcs/lnorganlcs
Using EPA procedures
other than CLP can be
anilyte-speclflc
RCRA characteristic tests
Tentative ID In some
cases
Can provide data of
sane quality as
Levels IV. NS
Similar detection limits
to CLP
Less rigorous QA/QC
Risk assessment
PRP Determination
Evaluation of Alternatives
Engineering Oeslgn
Level IV
HSL organlcs/lnorganlcs
by GC/HS: AA: ICP
Low ppb Detection Limit
Tentative Identification
of non-HSL parameters
Some tine may be required
for valIdatlon of packages
Goal Is data of known
quality
Rigorous QA/QC
Risk Assessment
PRP Determination
Level V
Non-conventional
parameters
Method-specific
detection limits
Modification of
existing methods
Appendix 8 parameters
Hay require method
development/modification
Mechanism to obtain
services requires
special lead time
Method-specific
Source: Reference 56.
-------
5.2 DATA COLLECTION APPROACHES
This section introduces approaches for collecting data to assess air
quality and air quality Impacts. This subject is covered in more detail in
Volume II (2). Emission source assessments, ambient concentration
assessments, and other data needs are Included. The emphasis is on sampling
methods and modeling of contaminants in the atmosphere. Analytical methods
for measuring contaminant levels in gas, liquid, and solid samples have been
standardized and published elsewhere; this topic is therefore only briefly
discussed under other data needs.
5.2.1 Emission Source Assessments
Assessment of an emission source typically Involves measuring or modeling
an emission or production rate for each contaminant of interest. Emission
rate information for hazardous waste sites can be used for exposure
assessment, assessing air quality impacts under various meteorological con-
ditions, and developing suitable control strategies. Both direct and indirect
measurement techniques are available. The direct measurement techniques are
usually simpler, more accurate, and less expensive; however, the indirect
measurement techniques may be the only suitable approach for certain
applications (e.g., large heterogeneous area sources).
Direct measurement techniques include vent sampling (59) of ducts at
point sources, and the enclosure (flux chamber) (60-67) approach for sampling
area sources. Indirect measurement techniques include mass balance, transect
(68,69), and concentration profile (40,70,71) techniques.
A vast amount of research has been conducted to develop, validate, and
evaluate predictive models for hazardous waste sources, especially with
respect to VO emissions from area sources and transfer operations. The best
source of Information on this topic is EPA's Office of Air Quality Planning
and Standards (OAQPS). OAQPS has published an evaluation of mathematical
modeling techniques to predict volatile air emissions release from various
sources (72). This work has recently been revised (73) and the new report
163
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includes models on diskette for use on a microcomputer. Guidance for
estimating participate matter emissions was published by OAQPS in 1988. The
computer-compatible air emission models, referred to as CHEMOAT 6 models,
cover the following sources:
Surface impoundments (non-aerated), which for modeling purposes
include quiescent impounds and open-top tanks:
Disposal impoundments,
Storage impoundments;
• Land treatment:
Soil emissions subsequent to waste tilling,
Oil layer on soil (prior to tilling);
Closed landfills;
Open landfills;
• Uastepiles;
• Oil film on a liquid surface;
• Diffused air systems; and
• Mechanically aerated systems.
The Superfund Exposure Assessment Manual (74) and the companion volumes
to this manual (2,3) also contain guidance on selecting and using emission
models. Users should consult Reference 73 or the other citations for more
information.
Predictive models for emissions from incinerators, air strippers, and
in-situ venting systems are not currently available.
164
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5.2.2 Ambient Concentration Assessments
This manual has focused on the estimation of emissions from remedial
actions for cleaning up abandoned hazardous waste sites. Commonly, the
resulting emissions estimate is then used In an atmospheric dispersion
modeling analysis to estimate ambient concentrations of the emitted
pollutants. These ambient concentrations may then be evaluated using
available health data to determine the acceptability of the concentrations and
the need for emissions controls.
An alternative method often used for assessing ambient concentrations is
to measure the concentrations with monitoring equipment. The monitoring
alternative has several advantages and several disadvantages relative to the
emissions estimation/dispersion analysis alternative. The greatest advantage
of the monitoring alternative is that under some circumstances, viz. when
pollutant concentrations reflect representative circumstances (especially
representative meteorology), the measurements have greater reliability. This
advantage of relative reliability is particularly pronounced for some types of
cases such as soils handling where the emissions estimates are quite uncertain
and where even the existence of emissions of particular pollutants may be in
doubt.
The greatest advantage of the emissions estimation/dispersion analysis
alternative is the ability to predict impacts. Indeed, monitoring is simply
not an alternative for assessing concentrations before the emissions have
begun. Thus for example, in feasibility studies the emissions estimation/
dispersion analysis approach is the only feasible means of predicting the air
quality impacts of various remedial alternatives being considered.
Ambient monitoring and emissions estimation/dispersion analysis have
numerous other advantages and disadvantages. Ambient monitoring is clearly
advantageous for activities for which emissions estimation procedures are
unavailable. On the other hand, the emissions estimation/dispersion analysis
approach can provide more trustworthy results when background concentrations
are high, when concentrations are too low to measure, or when the monitoring
165
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study Is too short for measurements to provide a reliable, representative
assessment of remedial action Impacts. This advantage of emissions
estimation/dispersion analysis 1s particularly Important In the frequent
situation where monitoring detection limits are much higher than health-based
criteria. The emissions estimation/dispersion analysis approach has an added
advantage, for sites with multiple activities or multiple operable units, of
being readily able to distinguish separate Impacts of individual activities or
operable units. Furthermore, the emissions estimation/dispersion analysis is
a much less expensive alternative.
A more complete discussion of monitoring and of dispersion analysis is
provided elsewhere. Two companion volumes to this manual specifically address
procedures and purposes of monitoring and dispersion analysis in addressing
air Impacts of abandoned hazardous waste sites (2,3). Also of interest are
the overviews prepared for RCRA (75). Further references are available that
discuss monitoring and dispersion modeling 1n more detail, such as guidance on
developing data quality objectives (56), guidance on network design (76),
guidance on particular monitoring methods (e.g., 77 and 78), and the air
quality modeling guidelines (79).
This manual has sought to compile available Information to assist in
estimating emissions from various types of NPL site cleanup activities. This
concluding section has attempted to put such emissions estimation in the
broader perspective of assessing impacts of these emissions. A common
philosophy is that "If it can't be measured, it is not there". This
philosophy ignores the important role that emissions estimation, generally
followed by dispersion analysis, can play when monitoring is less reliable,
less practical, or even Impossible. This philosophy ignores the value of
emissions estimation and dispersion analysis in planning and in evaluation of
potential remedial actions, where monitoring 1s not a meaningful alternative.
It is hoped that this manual will provide the information and procedures
necessary to make this planning and evaluation of air quality impacts of
potential remedial actions a more reliable and more commonplace element of the
process for addressing abandoned hazardous waste sites.
166
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SECTION 6
REFERENCES
NOTE: Many of these references are synopsized in Appendix A.
1. NUS Corporation. Procedures for Conducting Air Pathway Analyses for
Superfund Applications - Volume I, Application of Air Pathway Analyses
for Superfund Activities. EPA Draft Manual, December 1988.
2. Radian Corporation. Estimation of Baseline Air Emissions at Superfund
Sites. EPA Interim Final Manual, January 1989.
3. NUS Corporation. Procedures for Conducting Air Pathway Analyses for
Superfund Applications - Volume IV, Procedures for Dispersion Modeling
and Air Monitoring for Superfund Air Pathway Analysis. EPA Draft Manual,
December 1988.
4. Lee, C. C., G. L. Huffman, and D. A. Oberacker. Hazardous/Toxic Waste
Incineration. Journal of the Air Pollution Control Association, Volume
36, Number 8. EPA, Cincinnati, OH. August 1986.
5. Cheremisinoff, P. N. Special Report: Hazardous Materials and Sludge
Incineration. Pollution Engineering, Volume 18, Number 12, pp. 32-38.
December 1986.
6. Trenholm, A. and D. Oberacker. Summary of Testing Program at Hazardous
Waste Incinerators. Proceedings--Annual Solid Waste Research Symposium,
Cincinnati, Ohio. Report No. CONF-8504112. Published by U. S.
Environmental Protection Agency, Cincinnati, Ohio. 1985.
7. Oppelt, E. T. Incineration of Hazardous Waste, A Critical Review.
Journal of the Air Pollution Control Association, Vol. 37, No. 5, May
1987.
167
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8. Wallace, D. D., A. R. Trenholm, and D. D. Lane. Assessment of Metal
Emissions from Hazardous Waste Incinerators. ProceedIngs--78th APCA
Annual Meeting, Detroit, Michigan. Published by APCA, Pittsburgh,
Pennsylvania. Paper 85-77. 1985.
9. Shen, T. T. Hazardous Waste Incineration: Emissions and Their Control.
Pollution Engineering, Volume 18, Number 7, July 1986.
10. Holton, G. A., and C. C. Travis. Methodology for Predicting Fugitive
Emissions for Incinerator Facilities. Environmental Progress Volume 3,
Number 2. Oak Ridge National Lab, Health & Safety Research Division, Oak
Ridge, Tennessee. May 1984b.
11. Travis, C. C., E. L. Etnier, G. A. Holton, F. R. O'Donnell, D. M.
Hetrick. Inhalation Pathway Risk Assessment of Hazardous Waste
Incineration Facilities. Oak Ridge National Lab, Tennessee. ORNL/TM-
9096. October 1984.
12. Harrington, E. S., G. A. Holton, and F. R. O'Donnell. Initial Emission
Assessment of Hazardous-Waste-Incineration Facilities. CONF-820418-20.
Prepared by Oak Ridge National Lab for Department of Energy, Washington,
D.C. 1982.
13. Staley, L. J., G. A. Holton, F. R. O'Donnell, and C. A. Little. An
Assessment of Emissions from a Hazardous Waste Incineration Facility.
Incineration and Treatment of Hazardous Waste: Proceedings of the Eighth
Annual Research Symposium, Ft. Mitchell, Kentucky, March 8-10, 1982,
EPA-600/9-83-003, U. S. EPA, Cincinnati, Ohio. 1983.
14. Sweet, W. E., R. D. Ross, and G. V. Veide. Hazardous Waste Management.
Journal of the Air Pollution Control Association. Volume 35, Number 2,
February 1985.
168
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15. Van Buren, D., G. Poe, and C. Castaldlnl. Characterization of Hazardous
Haste Incineration Residuals. Prepared for U. S. Environmental
Protection Agency. January 1987.
16. U. S. Environmental Protection Agency. Performance Evaluation of Full-
Scale Hazardous Waste Incineration. Five volumes, NTIS, PB 85-129500.
November 1984.
17. Brna, T. G. and C. B. Sedman. Waste Incineration and Emission Control
Technologies. EPA/600/D-87/147. U.S. Environmental Protection Agency,
AEERL, Research Triangle Park, NC. May 1987.
18. Ando, J. Recent Developments In S02 and NOX Abatement Technology for
Stationary Sources In Japan. Report No. EPA-600/7-85-040. September
1985. Section 5.
19. Stetson, J. R. The Remedial Investigation of a Toluene Spill Site and
the Design of a Groundwater Collection and Treatment System. In:
Proceedings of the Haztech International Conference, Denver, Colorado,
August 11-15, 1986. pp. 926-940.
20. lerardi, M., P. Brunner, and E. J. Cichon. Groundwater Restorations at
HcClellan AFB. In: Proceedings of Superfund '87. Hazardous Materials
Control Research Institute, Silver Springs, Maryland, 1987. pp. 204-
207.
21. Hale, D. W., M.J. Dent, and D. G. Van Arnam. Effective Startup and
Operational Procedures for Groundwater Remediation Systems. In:
Proceedings of Superfund '87 Hazardous Materials Control Research
Institute, Silver Springs, Maryland, 1987. pp. 223-227.
22. Kavanaugh, M. C. and R. R. Trussel. Air stripping as a Treatment
Process. In: Proceedings of AWWA Conference on Organic Chemicals in
Groundwater: Transport and Removal. June 7, 1981.
169
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23. U. S. Environmental Protection Agency. Control Technologies for
Hazardous Air Pollutants. AEERL/CERI, EPV625/6-86/014. September
1986.
24. Crow, U. L., T. J. Moore, J. Kovski, and E. P. Anderson. Guidelines for
Design, Installation, Operation, and Evaluation of Subsurface Ventilation
Systems. Draft report to confidential client. July 1987.
25. Applegate, J., J. K. Gentry, and J. J. Malot. Vacuum Extraction of
Hydrocarbons from Subsurface Soils at a Gasoline Contamination Site. In:
Proceedings of Superfund '87. Hazardous Materials Control Research
Institute, Silver Springs, Maryland, 1987. pp. 273-279.
26. U. S. Environmental Protection Agency. Handbook: Remedial Action at
Waste Disposal Sites (Revised) EPA/625/6-85/006. U. S. Environmental
Protection Agency, HWERL, Cincinnati, OH. October 1985.
27. Englehart, P. J., and D. Wallace. Assessment of Hazardous Waste TSDF
Particulate Emissions, Final Report. U. S. Environmental Protection
Agency, OAQPS, Research Triangle Park, NC. October 1986.
28. PEDCO Environmental, Inc. Technical Guidance for Control of Industrial
Process Fugitive Particulate Emissions. EPA-450/3-77-010, U. S.
Environmental Protection Agency, OAQPS, Research Triangle Park, NC.
March 1977.
29. Orlemann, J. A., and G. A. Jutze. Fugitive Particulate Dust Control
Technology. Book - Available from Noyes Publications, Mill Road at Grand
Avenue, Park Ridge, NJ, 07656. 1983.
30. Baxter, R. A., and D. M. Wilbur. Fugitive Particulate Matter and
Hydrocarbon Emission Factors from Mining, Handling, and Storing
Diatomite. Prepared for Confidential Client by AeroVironment, Inc.,
Pasadena, California. February 1983.
170
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31. U. S. Environmental Protection Agency. AP-42: Compilation of Air
Pollutant Emission Factors, Fourth Edition, U. S. Environmental
Protection Agency, OAQPS, Research Triangle Park, NC. September 1985.
32. Radian Corporation. Characterization of the Shirco Infrared Incineration
System at the Peak Oil Site, Brandon, Florida. Preliminary report
submitted to Enviresponse, Inc. November 1987.
33. Davis, E. A., J. H. Meyer, J. A. Kagan, and V. T. Freeman (The Johns
Hopkins University Applied Physics Laboratory). Fugitive Dust Emissions
from the Proposed Vienna Unit No. 9. Prepared for Maryland Power Plant
Siting Program. PB81-190175. Johns Hopkins University, Laurel, MD.
February 1981.
34. Rosbury, K. D., and S. C. James. Control of Fugitive Dust Emissions at
Hazardous Waste Cleanup Sites. In: Eleventh Annual Research Symposium
on Land Disposal of Hazardous Waste 8525035, Cincinnati, OH. 1985.
35. Cowherd, C. Jr., and J. S. Kinsey. Identification, Assessment, and
Control of Fugitive Particulate Emissions. Prepared for the U. S.
Environmental Protection Agency, AEERL, Research Triangle Park, NC.
August 1986.
36. Vogel, G. A. Air Emission Control at Hazardous Waste Management
Facilities. Journal of the Air Pollution Control Association, Volume 35,
Number 5, May 1985.
37. Stunder, B.J.B. and S.P.S. Arya. Windbreak Effectiveness for Storage
Pile Fugitive Dust Control: A Wind Tunnel Study. Journal of the Air
Pollution Control Association, Volume 38, pages 135-143. 1988.
38. Aim, R. R., K. A. Olson, and R. C. Peterson. Using Foam to Maintain Air
Quality During Remediation of Hazardous Waste Sites. Presented at the
Air Pollution Control Association's 80th Annual Meeting and Exhibition,
New York, NY. June 1987.
171
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39. Aim, R. R., K. A. Olson, and E. A. Reiner. Stabilized Foam: A New
Technology for Vapor Suppression of Hazardous Materials. Presented at
International Congress on Hazardous Materials Management, Chattanooga,
Tn. June 1987.
40. Aim, R. R., C. P. Hananska, K. A. Olson, M. T. P1ke. The Use of
Stabilized Aqueous Foams to Suppress Hazardous Vapors—A Study of Factors
Influencing Performance. Multi-Media, p. 480. Undated.
41. Calvert, S., and H. M. Englund, editors, Handbook of A1r Pollution
Control Technology. John Wiley and Sons, New York, NY. 1984.
42. Springer, C., K. T. Valsaraj, and L. J. Thibodeaux. In-S1tu Methods to
Control Emissions from Surface Impoundments and Landfills. EPA/600/S2-
85/124. U. S. Environmental Protection Agency, HUERL, Cincinnati, OH.
July 1986.
43. Hill, R. D. Stabilization/Solidification of Hazardous Waste.
EPA/600/D-86/028. U. S. Environmental Protection Agency, Hazardous Waste
Engineering Research Laboratory, Cincinnati, OH. January 1986.
44. Cull inane, M. J., L. W. Jones, and P. G. Malone. Handbook for
Stabilization/Solidification of Hazardous Waste. EPA/540/2-86/001.
U. S. Environmental Protection Agency, HWERL. June 1986.
45. Haigh, D.. Air Monitoring at the Kettleman Hills Facility. Presented at
the 81st Annual Meeting of APCA. June 1988.
46. U.S. EPA. Engineering Handbook for Hazardous Waste Incineration. EPA
Contract Number 68-03-3025. U.S. EPA/ORD. June 1981.
47. Holmes, J. W. and T. J. Marshall. Soil Physics. Cambridge University
Press, Cambridge, MA. 1981.
172
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48. Matyas, E. L. Air and Water Permeability of Compacted Soils. In
Permeability and Capillarity of Soils: A Symposium Presented at the
Sixty-Ninth Annual Meeting of the American Society for Testing and
Materials, Atlantic City, NJ, June 26-July 1, 1966.
49. Corey, A. T. A1r Permeability. In: A Klute (ed.), Methods of Soil
Analysis-Part 1: Physical and Mineralogical Methods. Second Edition.
Agronomy Monograph No. 9. American Society of Agronomy. Madison, WI.
1986. pp. 1121-1136.
50. Schmidt, C. E. McColl Phase II - Characterization of the Atmospheric
Contaminant Emissions from the McColl Site. Technical Memorandum to
California DHS. February 14, 1983.
51. Radian Corporation. Fugitive Volatile Hydrocarbon Emission Assessment
for Diatomite Mining Operations. Report to Confidential Client.
February 19, 1985.
52. Eklund, B. M., T. P. Nelson, and R. G. WetheroId. Field Assessment of
Air Emissions and Their Control at a Refinery Land Treatment Facility.
EPA Contract No. 68-02-3850, Task Assignment No. 15, September 1986.
53. Radian Corporation. Short-term Fate and Persistence of Motor Fuels in
Soils. Draft Report to Confidential Client. June 5, 1987.
54. Caravanos, J. and T. T. Shen. The Effects of Wind Speed on the Emission
Rates of Volatile Chemicals from the Open Hazardous WAste Dump Sites.
Air Monitoring, p. 68. 1984.
55. U. S. Environmental Protection Agency. User's Guide for Emission Control
Technologies and Emission Factors for Unpaved Road Fugitive Emissions.
EPA/625/5-87-022. U. S. Environmental Protection Agency. AEERL,
Research Triangle park, NC. September 1987.
173
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56. Esposlto, P., J. Hessling, B. B. Locke, M. Taylor, M. Szabo, R. Thurnau,
C. Rogers, R. Traver, and E. Barth. Results of Evaluations of
Contaminated Soil Treatment Methods In Conjunction with the CERCLA BOAT
Program. Presented at the 81st Annual Meeting of APCA. June 1988.
56. U. S. EPA. Data Quality Objectives for Remedial Response Activities--
Development Process. OERR and OWPE. EPV540/G-87/003. March 1987.
57. U. S. Environmental Protection Agency. Interim Guidelines and
Specifications for Preparing Quality Assurance Project Plans. QAMS-
005/80 OMSQA/ORD. Washington, D.C. December 19, 1980.
58. Schmidt, C. E., R. D. Cox, and M. R. Fuchs. Guidelines for Developing
Test Plans for Determining Atmospheric Emissions from Hazardous Waste
Disposal Facilities. EPA/IERL/ORD. EPA Contract No. 68-02-371, Task 63.
February 7, 1983.
59. Code of Federal Regulations, Volume 45, Number 9, Appendix A, January
1980.
60. D. F. Adams. Sulfur Gas Emissions from Flue Gas Desulfurization Sludge
Ponds. Journal of Air Pollution Control Association, Volume 29, Number 9
(1979). p. 963-968.
61. Eklund, B. M., W. D. Balfour, and C. E. Schmidt. Measurement of Fugitive
Volatile Organic Compound Emission Rates with an Emission Isolation Flux
Chamber. Environmental Progress, Volume 4, Number 3, August 1985.
62. Devitt, D. A., R. B. Evans, W. A. Jury, T. H. Starks, B. Eklund, and A.
Gholson. Soil Gas Sensing for Detection and Mapping of Volatile
Organics. National Water Well Association. 1987.
63. Radian Corporation. Validation of Flux Chamber Emission Measurements on
a Soil Surface. U. S. EPA, Environmental Monitoring Systems Laboratory,
EPA Contract Number 68-02-3889, Work Assignment 18, Las Vegas, NV.
174
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64. Klenbusch, M. R., D. Ranum, and B. Eklund. Evaluation of the Flux
Chamber Method for Measuring Air Emissions from Surface Impoundments.
EPA-OAQPS-EMB. EPA Contract No. 68-02-3889, WA 42. January 26, 1988.
65. U. S. Environmental Protection Agency. Measurement of Gaseous Emission
Rates from Land Surfaces Using an Emission Isolation Flux Chamber- User's
Guide. EPA/600/8-86-008. 1986.
66. Balfour, W. D., C. E. Schmidt, and B. M. Eklund. Sampling Approaches for
the Measurement of Volatile Compounds at Hazardous Waste Sites. Journal
Hazardous Materials, Volume 14, 1987. pp. 135-148.
67. C. E. Schmidt, W. D. Balfour, and R. D. Cox. Sampling Techniques for
Emissions Measurement at Hazardous Waste Sites. Proceedings from the
Third National Conference and Exhibition on Management of Uncontrolled
Waste Sites. Washington, D.C. 1982.
68. C. Cowherd, K. Axetell, C. M. Guenther, and G. A. Jutze. Development of
Emission Factors for Fugitive Dust Sources. EPA 450/3-74-037. U. S.
EPA, Cincinnati, OH. 1974.
69. W. D. Balfour, R. G. Wetherold, and D. L. Lewis. Evaluation of Air
Emissions from Hazardous Waste Treatment, Storage, and Disposal
Facilities. U. S. EPA, Hazardous Waste Engineering Research Laboratory,
EPA/600-52-85-057. Cincinnati, OH. 1985.
70. L. J. Thibodeaux, D. G. Parker, and H. H. Heck. Measurement of Volatile
Chemical Emissions from Wastewater Basins. U. S. EPA, Hazardous Waste
Engineering Research Laboratory, EPA/600/5-2-82/095. Cincinnati, OH.
1982.
71. R. D. Cox, et al., Evaluation of VOC Emissions from Wastewater Systems
(Secondary Emissions). U. S. EPA, Hazardous Waste Engineering Research
Laboratory. EPA/600/52-84/080. Cincinnati, OH. 1984.
175
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72. Evaluation and Selection of Models for Estimating A1r Emissions from
Hazardous Waste TSDF. U.S. EPVOAQPS/ESED. EPA-450/3-84-020. NTIS
IPB85-156115/AS. November 1984.
73. Hazardous Waste Treatment, Storage, and Disposal Facilities (TSDF) - Air
Emission Models. U.S. EPA/OAQPS/Chemlcal and Petroleum Branch. EPA
450-3-87-026. December 1987.
74. U.S. EPA. Superfund Exposure Assessment Manual. EPA-540/1-88-01. OSWER
Directive 9285.5-1. April 1988.
75. U.S. EPA. Ambient Air Monitoring at Hazardous Waste Treatment, Storage,
and Disposal Facilities. Phase I. EPA Contract No. 68-02- 4326. U.S.
EPA/OAQPS/ESED. 1987.
76. U.S. EPA. Network Design and Site Exposure Criteria for Selected Non-
Criteria Air Pollutants. EPA-450/4-84-022. EPA/OAQPS. September 1984.
77. U.S. EPA. Ambient Monitoring Guidelines for Prevention of Significant
Deterioration (PSD). EPA-450/4-80/012. EPA/OAQPS. November 1980.
78. U.S. EPA. Quality Assurance Handbook for Air Pollution Measurement
System: Volume IV. Meteorological Measurements. EPA-600/4-82-060.
EPA/ORD. February 1983.
79. U. S. EPA. Guideline on Air Quality Models (Revised). EPA/450/2-78-
027R. NTIS PB 86-245248, OAQPS, RTP, NC. July 1986.
176
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APPENDIX A
ANNOTATED BIBLIOGRAPHY
A-l
-------
BIBLIOGRAPHY
1. Aim. R.R.. C.P. Hananska. K.A. Olson. M.T. Pike. The use of Stabilized
Aqueous Foams to Suppress Hazardous Vapors—A Study of Factors
Influencing Performance. Multi-Media, p. 480. 1987(7).
Good reference explaining tests of a new control technology for VOC
emissions from landfills-foam. Paper gives some useful data shoving
effects of varying the percent of stabilizing chemical, percent of
foaming chemical, application weight, and expansion ratio. No cost
information, nor guidance as to when to select the method.
2. Aim. R.R., K.A. Olson, and E.A. Reiner. Stabilized Foam: A New
Technology for Vapor Suppression of Hazardous Materials. Presented at
International Congress on Hazardous Materials Management, Chattanooga,
TN. June 1987.
Focuses on foam as a control technology for accidental spills and
waste sties. In general, the less polar or water-soluble the
organic, the better the vapor suppression by the stabilized foam.
Environmental concerns of using the foam (toxicity, leachability.
biodegradation. photochemical degradation, etc.) are addressed.
3. Aim, R.R., K.A. Olson, and R.C. Peterson. Using Foam to Maintain Air
Quality During Remediation of Hazardous Waste Sites. Presented at the
Air Pollution Control Association's 80th Annual Meeting and Exhibition.
New York. NY. June 1987.
Describes field tests where foam was employed and successfully
mitigated the air pollution hazard. A burning landfill and a
petroleum waste site are discussed. Some minimal cost information
is presented.
4. Arthur D. Little. Inc. Evaluation of Emission Controls for Hazardous
Waste Treatment. Storage, and Disposal Facilities. PB85 163657.
Prepared for the U.S. Environmental Protection Agency, OAQPS, Research
Triangle Park. NC. November 1984.
This document covers volatile emissions from hazardous waste
handling via surface impoundments, treatment and storage tanks.
landfills, and landfarms. It gives an estimate of each category's
share of total, emissions. Depending on where it is applied, it
breaks controls into four classes: pretreatment, design and
operating practices, in-situ controls, and post-treatment. It
presents emission equations for each category and lists control
techniques for all classes and categories. It also estimates the
control efficiency for several techniques.
A-2
-------
5. Barnard. W.R.. D.F. Gatz, G.J.Stensland. Chemical Characterization of
Aerosols Emitted from Vehicle Traffic on Unpaved Roads. Presented at the
80th Annual Meeting of the Air Pollution Control Association, New York.
NT. June 11-26. 1987.
Depletion of some elements in fine and coarse aerosol fraction from
unpaved roads occurs relative to the road source material (<53 urn).
This study shoved that Si had the largest depletion of the following
elements: Ti. Si. Na. V. K. Cl. Mn. and Ca. Depletion was found to
be dependent both on participate size fraction and road surface
type.
Sampling of the road surface material and subsequent determination
of this elemental chemistry may not adequately represent the
ultimate chemistry of the aerosol derived from this source.
6. Barnard. W.R.. D.F. Gatz. and G.J. Stensland. Elemental Chemistry of
Unpaved Road Surface Materials. Presented at the 79th Annual Meeting of
the Air Pollution Control Association. Minneapolis. MN. June 22-27.
1986.
The study described in this paper was performed to determine if an
unpaved road surface could be characterized as to its elemental
contact, particularly minerals such as Ca and K. Impetus to perform
the study came from unexplained limestone components in the fugitive
dust in urban areas. The component was attributed to "soil" or
"entrained" dust, but the composition of the "soil" component is not
well known. This paper does not appear to contain any information
useful for assessing air emissions from NFL sites.
7. Barnard. W.R., G.J. Stensland, and D.F. Gatz. Alkaline Materials Flux
from Unpaved Roads: Source Strength. Chemistry, and Potential for Acid
Rain neutralization. Water. Air. and Soil Pollution, Volume 30, pp. 285-
293. 1986.
This paper contains no information useful for assessing air
emissions from NFL sites.
8. Barnard. W.R., G.J. Stensland. and D.F. Gatz. Development of Alkaline
Emissiolux Estimates from Unpaved Roads: Problems and Data Needs for
Modeling Potential Acid Rain Neutralization. Presented at the 79th
Annual Meeting of the Air Pollution Control Association, Minneapolis. MN.
June 22-27, 1986.
Describes study to predict alkaline emissions (Ca. Mg. K. Na) from
travel on unpaved roads. Discusses potential probems and
inconsistencies with the two methods (dispersion modeling and mass
balance approaches) used to develop the emission factor equations.
A-3
-------
Potential problems mentioned may be insightful to this project.
but no new emission factor equations are presented. Report uses
AP-42 unpaved road equation and introduces factors to account for
surface area of state, elemental abundance in the state, based on
U. S. Geological Survey data. etc.
9. Barnard. W. R.. G. J. Stensland. and D. F. Gatz. Evaluation of
Potential Improvements in the Estimation of Unpaved Road Fugitive
Emission Inventories. Presented at the 80th Annual Meeting of the Air
Pollution Control Association. New York, NY. June 21-26. 1987.
The paper addresses fugitive particulate inventories on a state-
wide level. Three parameters are introduced to the AP-42 equation
for unpaved road fugitive emissions in an attempt to increase the
accuracy of the state emission inventory. These corrections
pertain only to inventory on the state level and are not
applicable to individual hazardous waste sites.
10. Basden. L. S. Characterization of Fugitive Farticulate Emissions from
Industrial Sites. Proceedings—Fifth Symposium on the Transfer
and Utilization of Farticulate Control Technology, Volume 4, Kansas
City. MO. August 1984. F. A. Ayer. Compiler. Prepared by Research
Triangle Institute. Research Triangle Park. NC. February 1986.
Discusses accuracy and applicability of emissions data obtained by
hi-volume samplers and deposition gauges (i.e.. long sampling
period instruments). Doubts the accuracy of emissions estimates
that are "back-calculated" by modeling. Introduces current work
with portable cascade impactor and related instruments that use
shorter sampling times to determine more site-specific emission
rates as opposed to overall average values from long sampling
periods. Lists emission factors from long-term techniques for
haul trucks, blasting, truck loading and dumping, drilling, top
soil removal, and draglines.
11. Bonner. T. A.. C. L. Cornett. B. 0. Desai. J. M. Fullenkamp. and T. W.
Hughes. Engineering Handbook for Hazardous Waste Incineration. MRC-
DA-1090; EPA/SW-889. Prepared by Monsanto Research Corp. for U.S.
Environmental Protection Agency. Office of Solid Waste. Washington.
D.C. September 1981.
This is an engineering design handbook which provides suggested
minimums and/or acceptable ranges for incinerator performance
parameters. Discusses current practices; waste characterization;
and incineration facility design, operation, monitoring, and cost
estimating. Results from a number of trial burns are summarized.
A-4
-------
12. Brna, T. 6. and C. B. Sedman. Waste Incineration and Emission Control
Technologies. EPA/600/D-87/147. U.S. Environmental Protection Agency.
AEERL. Research Triangle Park. NC. May 1987.
Discusses various in-furaace and post-combustion technologies for
controlling pollutants such as POHCs. acid gases, trace heavy
metals, and particulates. Tabulated control efficiency data are
provided for acid gas control systems, spray dryer control of
dioxins and furans, and heavy metal control systems.
13. Calvert. S. and H. M. Englund. editors. Handbook of Air Pollution
Technology. John Wiley and Sons. New York. NY. 1984.
One section on control of fugitive emissions. Not very detailed
in areas of already viable technology (mostly wet spray methods).
More detail for "new concepts" such as spray charging and
trapping, charged fog spray, road carpets, improved street
sweepers, and windscreens. Some limited data on costs,
concentration reduction.
14. Caravanos. J. and T. T. Shen. The Effect of Wind Speed on the Emission
Rates of Volatile Chemicals from Open Hazardous Waste Dump Sites. Air
Monitoring, p. 68. 1984.
Equation relates emissions from the top layer of soil. Laboratory
data "based on benzene, carbon tetrachloride. and trichloroethylene
for clay. sand, and organic topsoil. Once the top layer of
chemically contaminated soil evaporates, other equations can be
used for subsurface emission.
15. Cheremisinoff, P. N. Special Report: Hazardous Materials and Sludge
Incineration. Pollution Engineering, Volume 18, Number 12, pp. 32-38.
December 1986.
GeneraJ. overview of hazardous waste incineration. Incinerator
types, waste and fuel characteristics, and new thermal destruction
technologies are discussed.
16. Cowherd, C. Jr. Measurement of Participate Emissions From Hazardous
Waste Disposal Sites. Paper 85-73. Proceedings—78th APCA. Annual
Meeting. Detroit. MI. Air Pollution Control Association, Pittsburgh.
PA. June 1985.
This paper discusses methods of measuring fugitive emissions from
hazardous waste sites and open waste piles. Methods include wind
erosion measurement by wind tunnel tests and emissions from
mechanical entrainment processes by upwind/downwind sampling.
Particle sizing by high-volume cyclone/cascade impactor combina-
tions is also discussed. More detail is provided here than in the
User's Guide for Unpaved Road Emissions.
A-5
-------
17. Cowherd. C. Jr. and J. S. Kinsey. Identification. Assessment, and
Control of Fugitive Participate Emissions. Prepared for the U. S.
Environmental Protection Agency. AEERL. Research Triangle Park. NC.
August 1986.
Does not contain any emission factors or equations—just methods
and important steps for preparing emissions inventories. Primary
purpose of document is to identify control alternatives and
estimate control system performance. Contains efficiency data
tables.
18. Davis. E. A., J. H. Meyer. J. A. Kagan. and V. T. Freeman. Fugitive
Dust Emissions from the Proposed Vienna Unit No. 9. Prepared for
Maryland Power Plant Siting Program. PB81-190175. Johns Hopkins
University. Laurel. MD. February 1981.
•
History of development of emission factor equations from storage
piles, and how different dependent variables were added. Applied
best available emission equations to a specific site (coal-burning
utility). Control methods are documented and efficiencies are
estimated. Also contains description of model simulation used and
results of simulation.
19. Dellinger, B.. et al. Determination of the Thermal Decomposition
Properties of 20 Selected Hazardous Organic Compounds. U.S. EPA. EPA-
600/2-84-138. August 1984.
Reports the thermal decomposition profiles and kinetic data for 20
hazardous organic compounds. These data were generated in the
laboratory and extrapolated to determine the temperature required
to achieve 99.99Z destruction. The analytical results are
discussed and explained in terms of possible chemical reactions
and mechanisms for destruction of POHCs. Parameters which
potentially affect incineration efficiency are discussed and four
methods of predicting relative incinerability of compounds are
reviewed.
20. Dellinger. B.. et al. Predicting Emissions from the Thermal Processing
of Hazardous Hastes. Hazardous Wastes and Hazardous Materials. Vol. 3.
No. 3. pp. 293-307. 1986.
Evaluates a number of "incinerability" ranking methods by
comparing each method's predicted results to the observed
incinerability for ten hazardous waste thermal destruction
systems. The only method which successfully predicted the field
results is based on laboratory determined thermal stability for
hazardous waste mixtures under oxygen deficient conditions.
Another finding of this study is that formation of POHCs in the
incineration process significantly affects DRE for all but the
most difficult to form POHCs.
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21. Englehart. P. J.. and C. Cowherd. Jr. Assessment of Fugitive
Participate Emissions From Hazardous Waste Treatment. Storage, and
Disposal Facilities: An Overview of Survey/Sampling Efforts with
Preliminary Analytical Results. Proceedings—79th APCA Annual Meeting.
Vol. 1. Air Pollution Control Association. Pittsburgh. PA. 1986.
A condensed version of a separate report prepared for EPA. May
1986. Program is not based on actual air sampling, but assumes
that existing model (AP-42) can be used in combination with
physical/chemical properties of surface material samples from
hazardous waste treatment, disposal, and storage facilities
(TSDFs). Samples were analyzed for the following parameters:
percent silt by weight, fraction by weight of silt that has a
physical diameter less than 20 urn. percent moisture by weight, and
concentrations of many metals, organics. and pesticides/PGBs on
the Hazardous Substances List. Metal concentrations were enriched
in the silt, and in the <20 urn silt particles. RCRA metal
concentrations are highest for landfill surface samples and lowest
for landtreatment units.
22. Frederick. E. R.. editor. A Specialty Conference on Fugitive Dust
Issues in the Coal Use Cycle. Pittsburgh. PA. Air Pollution
Control Association. April 11-13. 1983.
Two articles on measuring/modeling fugitive emissions; most of the
useful articles contain information on control technologies: dust
suppressants and weather dependency, micron-sized water particle
spray, windscreens, microfoam.
23. Gravitz. N. Derivation and Implementation of Air Criteria during
Hazardous Waste Site Cleanups. Journal of the Air Pollution Control
Association, Volume 35. Number 7. July 1985.
Gives brief regulatory overview and eztensive discussion of
modeling. Covers fence-line criteria and community exposure
standards. Does not address actual emissions.
24. Gregory. R. C. Design of Hazardous Waste Incinerators. Chemical
Engineering Progress. Volume 77, Number 4. pp. 43-47. April 1981.
Provides guidelines for designing hazardous waste incinerators.
Waste feed control, combustion control, afterburner operation.
emission control, and effluent gas monitoring are discussed.
25. Harrington. E. S., G. A. Holton. and F. R. O'Donnell. Initial Emission
Assessment of Hazardous-Waste-Incineration Facilities. CONF-820418-20.
Prepared by Oak Ridge National Lab for Department of Energy.
Washington. D.C. 1982.
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Discusses the results of an EPA study to quantify the emissions
from various operations at a typical hazardous waste incinerator
facility. Related work is discussed in Holton 1984a, Holton
1984b. and Travis 1984.
26. Hill, R. D. Stabilization/Solidification of Hazardous Waste.
EPA/600/D-86/028. Environmental Protection Agency. Hazardous Waste
Engineering Research Lab. Cincinnati. OH. January 1986.
Discusses such techniques as sorption, the lime-fly ash Pozzolan
process. Pozzolan-Portland cement processes, thermoplastic
microencapsulation. oacroencapsulation. and other techniques.
Gives some suggestions for determining which processes may be
unsafe for certain types of waste. Suggested physical and
chemical analyses to be performed to characterize the waste are
also included.
27. Holton, G. A.. C. C. Travis, E. L. Etnier. and F. R. O'Donnell.
Inhalation Pathway Risk Assessment of Hazardous Waste Incineration
Facilities. Proceedings—77th APCA Annual Meeting. Volume 6, San
Francisco. CA. Air Pollution Control Association. Pittsburgh. PA*
1984a.
Atmospheric transport modeling is used to estimate exposure risk
to two hypothetical incineration units. Fugitive emissions from
handling operations (valves, tanks, etc.) may be an important
contributor to total emissions, especially for small incinerators.
28. Holton, G. A., and C. C. Travis. Methodology for Predicting
Fugitive Emissions for Incinerator Facilities. Environmental Progress
Volume 3, Number 2. Oak Ridge National Lab, Health & Safety Research
Division. Oak Ridge. TN. May 1984b.
Studies of stack vs. fugitive emissions have shown that
atmospheric pollutant concentrations and population exposures at
close-in locations are more affected by fugitive releases. This
phenomena is attributed to the low temperature and ground level
emission characteristics of fugitives. There is wide variability
in fugitive emissions which includes those caused by leaky pump
fittings, sampling connections, flanges, storage tanks, and other
non-stack equipment. Error analysis and Monte Carlo modeling was
used to develop emissions predictions methods. Ten equations and
three parameter value tables are provided for emission
calculations.
29. Hwang, S. T. Measuring Rates of Volatile Emissions from Non-Point
Source Hazardous Waste Facilities. Proceedings—Annual Meeting - Air
Pollution Control Association, Volume 75 Number 4. U.S. Environmental
Protection Agency. Washington. DC. 1982.
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This paper develops the mathematics of a new method of measuring
toxic emissions from area sources. The method requires
concentrations and velocities simultaneously measured at different
heights above the sources. It is similar to the "Concentration
Profile Technique." but requires fewer data points. The method is
preliminary, and a comparison with the Concentration Profile
Technique was not available at the time the paper was presented.
If successful, the method could also be applied to landfills and
landtreatment facilities.
30. Hwang. S. T. Toxic Emissions from Land Disposal Facilities.
Environmental Progress Volume 1. Number (1). p. 46. February 1982.
Mass transfer equations ere given which allow estimation of toxic
emissions from landfills and landtreatment facilities. Data
needed to apply these equations include soil mass transfer
coefficients, porosity and tortuosity of cover material, air-phase
mass transfer coefficients, partial pressure of component i in
equilibrium with the waste, molecular weight of i. temperature.
and landfill area. Not all the variables in the equations are
well defined.
31. Johnson, L. D. Detecting Waste Combustion Emissions: Several Advanced
Methods are Useful for Sampling Air Contaminants from Hazardous Waste
Incinerator Stacks. Report No. EPA/600/J-86/010. Published in Envi-
ronmental Science and Technology. Volume 20. Number 3. Environmental
Protection Agency. Research Triangle Park. NC. 1986.
Discusses sampling and analytical methods for air contaminants in
hazardous waste incinerator stacks.
32. King, J.. compiler. Second Symposium on Fugitive Emissions: Measure-
ment and Control. (May 1977. Houston. Texas). EPA-600/7-77-148. U. S.
Environmental Protection Agency. IERL. Research Triangle Park. NC.
December 1977.
Three papers on measurement and monitoring. The first covers
exposure profiling technique for measuring fugitive particulate
emissions. The second gives preliminary findings of a grab-
sampling effort to monitor fugitive dust emissions at a large coal
cleaning plant. The monitoring was performed prior to operation
of the plant. The third article summarizes the results of a study
to determine the size of quench tower particulate emissions and
sampling methods. The other articles do not appear to contain any
information useful to the program.
33. Lee. C. C.. 6. L. Huffman, and D. A. Oberacker. Hazardous/Toxic Waste
Incineration. Journal of the Air Pollution Control Association, Volume
36. Number 8. EPA. Cincinnati. OH. August 1986.
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General overview of waste incineration technology. Discusses
advantages and disadvantages of liquid injection, rotary kiln, and
hearth incinerators. Air pollution control and monitoring
requirements are also discussed.
34. Oppelt, E. T. Hazardous Waste Destruction. Environmental Protection
Agency Hazardous Waste Engineering Research Lab. Cincinnati. OH.
Report No. EPA/600/J-86/107. Published in Environmental Science and
Technology, Volume 20, Number 4. 1986a.
Profiles current state of hazardous waste thermal destruction
technology in the U.S.. including facilities and typical wastes.
EPA performance test results presented in (Oppelt 1986c) are also
presented here. Also discussed are: incinerability ranking
methods. PIC emissions, and current and future thermal destruction
capacity.
35. Oppelt. E. T. Incineration of Hazardous Waste. A Critical Review.
Journal of the Air Pollution Control Association, Vol. 37. No. 5. Hay
1987.
Thorough overview of the current state of knowledge in the field
of hazardous waste incineration. Covers regulatory issues
pertinent to waste incineration, current incineration practices,
process performance measurement, emissions from hazardous waste
incineration, predicting incinerator performance, environmental
and public health implications, and remaining issues and research
needs.
36. Oppelt. E. T. Performance Assessment of Incinerators and High
Temperature Industrial Processes Disposing Hazardous Waste in the
United States. Environmental Protection Agency Hazardous Waste
Engineering Research Lab. Cincinnati. OH. Report No. EPA/600/D-86/133.
July 1986b.
Discusses EPA performance test results which indicate that
incinerators and many high temperature industrial processes are
capable of achieving existing performance and emissions standards
while burning organic hazardous wastes.
37. Oppelt. E. T. Thermal Destruction of Hazardous Waste. Environmental
Protection Agency Hazardous Waste Engineering Research Lab. Cincinnati,
OH. Report No. EPA/600/D-86/007. January 1986c.
Profiles thermal destruction technology, current practice in the
U.S.. design considerations, and summarizes the results of the EPA
performance assessments of hazardous waste thermal destruction
facilities in the U.S.
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38. Orlemann. J. A. and G. A. Jutze. Fugitive Dust Control Technology.
Book - Available from Noyes Publications. Mill Road at Grand Avenue.
Park Ridge. HI. 07656. 1983.
A compilation of emission factors and equations for several
industries. A section on general fugitive dust emission sources
includes equations for unpaved roads, storage piles (load-in,
erosion, activity, load-out), truck dumping, and area stripping by
equipment type: scraper or dragline.
39. PEDCo Environmental, Inc. Technical Guidance for Control of Industrial
Process Fugitive Participate Emissions. EPA-450/3-77-010. U. S.
Environmental Protection Agency. OAQPS. Research Triangle Park, NC.
March 1977.
A source of emission factors, but few equations—studies were
performed on fugitive emissions from several industries, including
smelting industries, grain transportation end storage, Portland
cement manufacturing, lime manufacturing, and also common dust
sources, including transfer, loading, roads, storage piles, and
waste sites. Description and costs of available control measures
are given.
40. Phillips. K., and J. Malek. Dredging as a Remedial Method for a
Superfund Site. Dredging and Dredged Material Disposal, Proceedings of
Conference held in Clearwater Beach, FL. November 14-16. 1984.
Prepared by U.S. Army Corps of Engineers. Environmental Resources
Section. Seattle, WA.
Discusses dredging a bay at Tacoma. Washington. One problem
encountered was disposal of the contaminated material after
dredging, and a few alternatives were discussed. While loss of
volatiles is usually not a problem in dredging, mechanical
dredging is preferred if this is a problem. Hydraulic dredging is
better for removal of sediment-bound contaminants.
41. Rosbury. K. D. and S. C. James. Control of Fugitive Dust Emissions at
Hazardous Waste Cleanup Sites. PEI Assoc., Inc. Eleventh Annual
Research Symposium on Land Disposal of Hazardous Waste 8525035, Cin-
cinnati. OH. 1985.
Control efficiencies of windscreens, water sprays, and surfactant
spray on wind erosion and fugitive particulates from activity.
Both storage piles and land plots were tested. Windscreen/storage
pile emission data limited because sampling equipment only picked
up particles smaller than 10 urn. Active site cleanup—control
efficiencies for front-end loader travel/scraping and dumping.
Surfactants found to be most effective control technologies.
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42. Rosbury. K. D.. W. Kemner. Quantification of Roadway Fugitive Duet at
a Large Midwestern Steel Mill. Proceedings—Fifth Symposium on
the Transfer and Utilization of Farticulate Control Technology,
Volume 4. Kansas City. MO. August 1984. F. A. Ayer, Compiler,
Prepared by Research Triangle Institute. Research Triangle Park. NC.
February 1986.
This paper quantified roadway emissions in a major Midwestern
steel mill which has over 80 miles of road. Data was collected in
a field survey, and emission factor equations were developed for
unpaved and paved roads. The emissions were functions of
parameters such as road silt content, speed, vehicle weight, and
rainfall.
43. Shen, T. T. Hazardous Waste Incineration: Emissions and Their
Control. Pollution Engineering, Volume 18, Number 7. July 1986.
Discusses the importance of physical and chemical characterization
of waste with respect to incineration system design. Emission
control techniques are also reviewed.
44. Shen, T. T. and 6. H. Sewell. Air Pollution Problems of Uncontrolled
Hazardous Waste Sites. Civil Engineering for Practicing and Design
Engineers. Volume 3. Number 3. pp. 241-252. 1984.
Identifies fugitive dust emissions and waste volatilization as
important mechanisms for transfer of hazardous materials to the
atmosphere. Gives predictive equations for unpaved roads, buried
wastes, dump sites with no covering material, and industrial
lagoons. Also includes control techniques for unpaved roads, as
well as discussions of various regulatory requirements.
45. Springer, C., K. T. Valsaraj. and L. J. Thibodeaux. In-Situ Methods to
Control Emissions from Surface Impoundments and Landfills. EPA/600/S2-
85/124. U. S. Environmental Protection Agency, HWERL, Cincinnati.
OH. July 1986.
Most of the control methods examined were employed over surface
impoundments (i.e., ponds); however, synthetic membranes over
landfills were tested. A 20-mil PVC membrane showed a high
permeability for a number of volatile organic vapors. Typical
results showed it to be the equivalent of only a few inches of
porous soil covering. Simple laboratory tests are available to
measure permeability of (other) specific membranes to specific
vapors.
46. Travis. C. C.. E. L. Etnier. 6. A. Holton. F. R. O'Donnell. D. M.
Hetrick. Inhalation Pathway Risk Assessment of Hazardous Waste
Incineration Facilities. Oak Ridge National Lab. TN. Report No.
ORNL/TM-9096. October 1984.
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Using two hypothetical incineration facility designs of three
sizes each, burning three different generic wastes, the relative
importance of plant design and waste physicochemical variables on
human inhalation exposure and health risk was evaluated. Air
concentrations were estimated for both stack and fugitive
emissions. Stack emissions were calculated using assumed values
for DRE; however, fugitives were calculated using equations which
relate incinerator facility operation and configuration to
fugitive emissions.
47. Trenholm. A.. R. Hathaway, and D. Oberacker. Products of Incomplete
Combustion from Hazardous Waste Incinerators: Proceedings of the Tenth
Annual Research Symposium held at Ft. Mitchell. Kentucky on April 3-5.
1984. Report No. EPA-600/9-84-022. September 1984.
Three mechanisms are proposed to explain the presence of POHCs in
the stack gas when the same POHCs are at less than 100 ug/g
concentrations in the waste feed. These mechanism are:
• Difficult to burn POHCs present in feed at concentrations
<100 ug/g (Relative Contribution - 0-68%).
• Compounds introduced from source other than waste feed
(Relative Contribution - 0-14%).
a) Trihalomethanes from the scrubbing liquid.
b) POHCs from ambient air inleakage (0-50% of total stack
air flow).
c) POHCS from the auxiliary fuel.
• Actual products of incomplete combustion or from complex side
reactions (Relative Contribution 32-100%). Common PICs
include benzene and chlorinated and non-chlorinated benzene
derivatives. PIC output rate rarely exceeds 0.01Z of POHC
input (i.e.. 99.99 DRE is achieved).
48. Trenholm. A., and D. Oberacker. Summary of Testing Program at
Hazardous Waste Incinerators. Proceedings—Annual Solid Waste Research
Symposium." Cincinnati. OH. Report No. CONF-8504122. Published by U.S.
Environmental Protection Agency, Cincinnati, OH. 1985.
Summarizes the results of tests conducted at eight full-scale
hazardous waste incineration facilities. Measurements were taken
on various pollutant emissions including EPA Appendix VII
compounds, particulates, HC1, CO, and total hydrocarbons. Data
analysis allowed evaluation of DRE, PIC formation, pollutant
emission levels, pollution control system performance, and
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relationships between operating conditions and ORE. The results
are summarized as follows:
POHCs - Three types of relationships between DRE and
operating parameters are addressed: 1) The waste feed
concentration correlated strongly with DRE. DRE increases with
increasing concentration. Linear regression techniques provided
the following relationships for penetration (1-DRE) versus waste
feed concentration (WFC):
Volatile Compounds: Log(1-DRE) = -0.79(Log(WPC))-1.585
Semivolatile Compounds: Log(1-DRE) = -0.81(Log(WFC))-l.49
2) There is no significant correlation between DRE and the heat
of combustion of the POHCs. 3) Of the operational parameters
such as combustion chamber temperature, residence time, and stack
gas oxygen content, the only operating variable strongly related
to DRE is the combustion chamber temperature. Also, carbon
monoxide and total hydrocarbon concentrations in the stack gas do
not appear to be good predictors of POHC concentrations.
PICs - PICs are compounds found in the stack gases, but not
detected in the waste feed stream. Three possible explanations
for these compounds are presented: 1) The PICs are present in the
feed stream in concentrations below detection limits, and
experience little or no destruction. The trend of decreasing DRE
with decreasing waste feed concentration supports this and could
explain the presence of many of the PICs detected. 2) Some PICs
are introduced from non-waste feed sources. Chloroform, for
example, has been shown to be introduced to the system from the
scrubber makeup water. Fuel oil can also be a source for PICs.
3) Compounds which are actually created in the combustion process.
The presence of simple stable compounds such as chlorinated
methanes, ethanes, and benzene compounds in most stacks supports
this hypothesis.
HC1 - Most hazardous waste incinerators which require add-on
HC1 control equipment use some type of countercurrent wet scrubber
for HC1 removal. Of the facilities tested, those equipped with
packed towers achieved 99% removal and emitted less than 1 kg/hour
of HC1. One unit equipped with a venturi scrubber and a mist
eliminator achieved a 97-98% removal and emitted 0.3 kg/hour.
Particulates - Complying with the particulate emission
standard of 180 mg/Nm3 (corrected to 7% 02) is difficult.
Facilities firing waste with greater than 0.5% ash content will
have difficulty. Contents of 0.2 to 0.5% may still create
emissions problems, but contents of less than 0.1% should not
cause failure to meet the standards.
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49. U. S. Environmental Protection Agency. AP-42: Compilation of Air
Pollutant Emission Factors. Fourth Edition. D. S. Environmental
Protection Agency. OAQPS. Research Triangle Park. NC. September 1985.
Reviewed Section 8.19.1 on sand and gravel processing. Section
8.19.2 on crushed stone operations. Section 8.2.4 on western
surface coal mining, and Section 11.2 on fugitive dust sources.
Sections contained several emission factors and emission
equations. In general, a predictive equation should include some
measure of source activity or expended energy (e.g., feed rate,
number of vehicles per day), properties of the material being
disturbed (e.g.. moisture content), and climactic conditions
(e.g.. wind speed).
50. U. S. Environmental Protection Agency. Handbook: Remedial Action at
Waste Disposal Sites (Revised) EPA/625/6-85/006. U. S. Environmental
Protection Agency. HWERL, Cincinnati. OH. October 1985.
Useful for understanding remedial technologies, selecting
potentially applicable technologies for a given waste site, and
planning for remedial action. Contains sections discussing on-
site and off-site disposal of wastes and soil, removal and
containment of contaminated sediments, and in-situ treatments.
51. U. S. Environmental Protection Agency. Hazardous Waste Treatment,
Storage, and Disposal Facilities (TSDF) — Air Emission Models (Draft
Report). D. S. Environmental Protection Agency, OAQPS. Research
Triangle Park. NC. April 1987.
Air emissions of volatile organic compounds from TSDFs (surface
impoundments, wastewater treatment ponds, landtreatment, and
landfills) are mathematically modeled. Model results are compared
with measured site emissions.
52. U. S. Environmental Protection Agency. User's Guide for Emission
Control Technologies and Emission Factors for Unpaved Road Fugitive
Emissions. EPA/625/5-87-022. U. S. Environmental Protection Agency.
AEERL. Research Triangle Park. NC. September 1987.
Explanation of factors, approach, use of factors, and control
systems for unpaved road fugitive emissions, in more detail than
the U. S. EPA's Compilation of Air Pollution Emission Factors
(AP-42).
53. Vogel. G. A. Air Emission Control at Hazardous Waste Management
Facilities. Journal of the Air Pollution Control Association.
Volume 35. Number 5. May 1985.
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Article covers several emission control methods that are
applicable to five waste management facilities' emission sources:
storage tanks, surface impoundments, landtreatment facilities.
and landfills. Also includes cost ranges for each control method.
It does not attempt to quantify emissions.
54. Wallace. Dennis D.. A. R. Trenholm. and D. D. Lane. Assessment of
Metal Emissions from Hazardous Waste Incinerators. Proceedings—78th
APCA Annual Meeting. Detroit. MI. Published by APCA. Pittsburgh. PA.
Pap 85-77. 1985.
MRI quantified emissions for specific metals at five incineration
facilities. These emissions are expressed as a fraction of total
particulate emissions and are not related to stack gas flow rates.
Conclusions:
• Hazardous metals emissions for H.W. Incinerators are:
Approximately equal to those for municipal solid waste units.
2-20 times those for sewage sludge units.
10-100 times those for coal-fired power plants.
• Control efficiencies for hazardous metals emissions achieved
by wet scrubbers will probably be less than overall
particulate control. This varies with specific metals.
55. Westbrook. W.. E. Tatsch. L. Cottone. and H. Freeman. Field Testing of
Pilot-Scale APCDs at a Hazardous Waste Incinerator. Proceedings of the
llth Annual Research Symposium on Incineration and Treatment of
Hazardous Waste, Cincinnati, OH.
Three pilot-scale a.p.c.d.s were tested at a PCS incinerator
facility. HC1 and particulate control was evaluated. Control
efficiencies for each are tabulated.
56. Wolbach. C. Dean. Prediction of Destruction Efficiencies. Environ-
mental Progress. Volume 1. Number 1. pp. 38-41. February 1982.
Discusses a model for predicting destruction efficiencies. The
model uses a destruction curve (time and temperature relationship
required to achieve a certain destruction for a given compound)
and a boiler curve (time and temperature relationship for the bulk
gases in the unit). Using a graphical overlay method, the model
determines whether there is sufficient time above a given
temperature in the unit to achieve the required destruction.
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APPENDIX B
SUPERFUND GLOSSARY OF TERMS
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Administrative Order on Consent: A legal and enforceable agreement signed
between EPA and potentially responsible parties whereby PRPs agree to perform
or pay the cost of site cleanup. The agreement describes actions to be taken
at a site and may be subject to a public comment period. Unlike a consent
decree, an administrative order on consent does not have to be approved by a
judge.
Administrative Record: All documents containing information the government
uses to 1} select response actions, and 2) impose administrative sanctions
for violations of CERCLA and Title III of SARA, the Emergency Planning and
Community Right- to- Know Act. This paper trail includes the RI/FS, the Record
of Decision, and public comments. SARA appears to limit judicial review of
the adequacy of a response action to the administrative record (CERCLA Sub-
section 113(j)).
ARAR: A Federal standard, or State standard that is more stringent, is
legally applicable to the substance, or relevant and appropriate under the
circumstances, that the cleanup must at least achieve (CERCLA Subsection
Air Stripping: A treatment system that removes, or "strips," volatile organic
compounds from contaminated ground water or surface water by forcing an air-
stream through the water and causing the compounds to evaporate.
Aquifer: An underground rock formation composed of materials such as sand,
soil, or gravel that can store and supply ground water to wells and springs.
Most aquifers used in the United States are within a thousand feet of the
earth's surface.
Carcinogen: A substance that causes cancer.
Carbon Adsoprtion: A treatment system where contaminants are removed from
ground water or surface water when the water is forced through tanks contain-
ing activated carbon, a specially treated material that attracts the contaminants.
Cleanup: Actions taken to deal with a release or threatened release of
hazardous substances that could affect public health and/or the environment.
The term "cleanup" is often used broadly to describe various response actions
or phases of remedial responses such as the remedial investigation/feasibility
study.
Comment Period: A time period during which the public can review and comment
on various documents and EPA actions. For example, a comment period is pro-
vided when EPA proposes to add sites to the National Priorities List. Also,
a minimum 3-week comment period is held to allow community members to review
and comment on a draft feasibility study.
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Community Relations: EPA's program to inform and involve the public in the
Superfund process and respond to community concerns.
Comprehensive Environmental Response, Compensation, and Liability Act: A
Federal law passed in 1980 and modified in 1986 by the Superfund Amendments
and Reauthorization Act. The Acts created a special tax that goes into a
Trust Fund, commonly known as Superfund, to investigate and clean up abandoned
or uncontrolled hazardous waste sites. Under the program, EPA can either:
Pay for site cleanup when parties responsible for the contamination
cannot be located or are unwilling or unable to perform the work.
Take legal action to force parties responsible for site contamina-
tion to clean up the site or pay back the Federal government for the
cost of the cleanup.
Consent Decree: A legal document, approved and issued by a judge, that formalizes
an agreement reached between EPA and potentially responsible parties (PRPs)
where PRPs will perform all or part of a Superfund site cleanup. The consent
decree describes actions that PRPs are required to perform and is subject to a
public comment period. The decree must be filed with and approved by a court.
Either a consent decree or an administrative order may be used in settlements
about RI/FSs (CERCLA Subsection 122(d)).
Contract Lab Program: Laboratories under contract to EPA which analyze soil,
water, and waste samples taken from areas at or near Superfund sites.
Cost-Effective Alternative: The cleanup alternative selected for a site on
the National Priorities List based on technical feasibility, permanence,
reliability, and cost. The selected alternative does not require EPA to
choose the least expensive alternative. It requires that if there are several
cleanup alternatives available that deal effectively with the problems at a
site. EPA must choose the remedy on the basis of permanence, reliability,
and cost.
Cost Recovery: A legal process where potentially responsible parties can be
required to pay back the Federal government for money it spends on any clean-
up actions.
De Minimis Settlement: A settlement EPA may reach with a PRP if EPA determines
that either 1) both the amount and the toxic or hazardous effects of the
substances the PRP contributed are minimal in comparison to other hazardous
substances at the facility; or 2) the PRP is the owner of the facility, did
not allow generation, transportation, storage, treatment, or disposal of any
hazardous substance at the facility, did not contribute to the release or
threat of release at the facility, and did not purchase the property knowing
that it was used for the generation, transportation, storage, treatment, or
disposal of any hazardous substances (CERCLA Subsection 122(g)).
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Emergency Plan: Required under Title III of SARA, the Emergency Planning
and Community Right-to-Know Act (Section 303(a)), for each emergency planning
district. Local emergency planning committees (see also Local Emergency
Planning Committees) will prepare the plans, which will include:
Identification of facilities, and routes likely to be used for the
transportation of extremely hazardous substances
Methods and procedures for responding to any release of extremely
hazardous substances
Designation of community and facility emergency coordinators to
help implement the plan
Procedures providing reliable, effective, and timely notification
Methods for determining the occurrence of a release, and the area
or population likely to be affected by it
A description of emergency equipment and facilities in the community
and at each facility, and list of the persons responsible for such
equipment and facilities
Evacuation plans
Training programs for local emergency response and medical personnel
Methods and schedules for exercising the emergency plan.
Endangerment Assessment: A study conducted as a supplement to a remedial
investigation to determine the nature and extent of contamination at a
Superfund site and the risks posed to public health and/or the environment.
EPA or State agencies conduct the study when legal action is pending to require
potentially responsible parties to perform or pay for the site cleanup.
Enforcement: EPA's efforts, through legal action if necessary, to force
potentially responsible parties to perform or pay for a Superfund site cleanup.
Enforcement Decision Document: A public document that explains EPA's selection
of a cleanup alternative at a Superfund site through an EPA enforcement action.
Similar to a Record of Decision.
Environmental Response Team: EPA hazardous waste experts who provide 24-hour
technical assistance to EPA Regional Offices and States during all types of
emergencies involving releases at hazardous waste sites and spills of
hazardous substances.
Extremely Hazardous Substance: A substance on a list EPA published in
November 1985 in Appendix A of the "Chemical Emergency Preparedness Program
Interim Guidance," Title III Section 302(a). This list was also published in
November 1986 (51 Federal Register 41.570) as an interim final rule under 40
CFR Part 300. EPA will revise the list from time to time.
B-4
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Facility: Under CERCLA Subsection 101(9), 1) any building, structure, installa-
tion, equipment, pipe or pipeline (including any pipe into a sewer or publicly
owned treatment works), well, pit, pond, lagoon, impoundment, ditch, land-
fill, storage container, motor vehicle, rolling stock, or aircraft; or 2) any
site or area where a hazardous substance has been deposited, stored, disposed
of or placed, or otherwise come to be located. Does not include any consumer
product in consumer use or any vessel.
Facility Notification: Notice to EPA under CERCLA Subsection 103(c) of cer-
tain facilities where hazardous substances are or have been stored, treated,
or disposed of. To provide a facility notification, you must complete and sub-
mit an EPA form identifying the facility; the amount and type of hazardous
waste to be found there; and any known, suspected, or likely releases of
such substances from the facility. Unless exempted (e.g., hazardous waste
management facilities with permits or interim status under RCRA), an individual
must file notice if the individual 1) presently owns/operates such a facility;
2) owned/operated such a facility at the time of disposal; or 3) accepted
hazardous substances for transport and selected such a facility for treatment,
storage, or disposal. Note that giving facility notification is different
from reporting a specific release.
Ground Water: Water found beneath the earth's surface that fills pores
between materials such as sand, soil, or gravel. In aquifers, ground water
occurs in sufficient quantities that it can be used for drinking water,
irrigation, and other purposes.
Hazard Ranking System: A scoring system used to evaluate potential relative
risks to public health and the environment from releases or threatened releases
of hazardous substances. EPA and States use the MRS to calculate a site
score, from 0 to 100, based on the actual or potential release of hazardous
substances from a site through air, surface water, or ground water to affect
people. This score is the primary factor used to decide if a hazardous
waste site should be placed on the National Priorities List.
Hazardous Chemical: Under Title III Section 311(e), any chemical which is a
physical hazard or a health hazard, except:
Any food, food additive, color additive, drug, or cosmetic regulated
by the Food and Drug Administration
Any substance present as a solid in any manufactured item to the
extent exposure to the substance does not occur under normal condi-
tions of use
Any substance to the extent it is used for personal, family, or
household purposes, or is present in the same form and concentration
as a product packaged for distribution and use by the general public
Any substance to the extent it is used in a research laboratory or
a hospital or other medical facility under the direct supervision of
a technically qualified individual
B-5
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Any substance to the extent it Is used in routine agricultural
operations or is a fertilizer held for sale by a retailer to the
ultimate customer.
Hazardous Substance Superfund: The fund, largely financed by taxes on
petroleum and chemicals, and a new "environmental tax" on corporations, that
provides operating money for government-financed actions under CERCLA. The
fund is a revolving fund in the sense that it enables the government to take
action and then seek reimbursement later, or to clean up sites where responsible
parties with sufficient cleanup funds cannot be found. Money recovered from
PRPs is returned to the fund rather than to the U.S. Treasury.
Hazardous Substances: Under CERCLA Subsection 101(14), any element, compound,
mixture, solution, or substance which, when released to the environment, may
present substantial danger to public health/welfare or the environment.
Also includes 1) any substance designated under Section 311(b)(2)(A) or any
toxic pollutant listed under Section 307(a) of the Federal Water Pollution
Control Act; 2) any hazardous waste having the characteristics identified
under or listed pursuant to RCRA Subsection 3001 (excluding any waste suspended
from regulation under the Solid Waste Disposal Act by Congress); 3) any
hazardous air pollutant listed under Section 112 of the Clean Air Act; and
4) any imminently hazardous chemical substance or mixture for which the
government has taken action under Section 7 of the Toxic Substances Control
Act. Excludes petroleum (including crude oil not otherwise specifically
listed or designated as a hazardous substance under any of the above laws),
natural gas, natural gas liquids, liquified natural gas, or synthetic gas
usable for fuel (or mixtures of natural gas and such synthetic gas). The
definition in CERCLA is broader than the definition of hazardous wastes under
RCRA.
Hazardous Wastes: Those wastes that are regulated or "listed" under RCRA
(40 CFR Part 261) or wastes that are ignitable, corrosive, reactive, or toxic.
Hydrology: The science dealing with the properties, movement, and effects
of water on the earth's surface, in the soil and rocks below, and in the
atmosphere.
Incinceration: Burning of certain types of solid, liquid, or gaseous
materials under controlled conditions to destroy hazardous waste.
Information Repository: A file containing current information, technical
reports, and reference documents regarding a Superfund site. The information
repository is usually located in a public building that is convenient for
local residents—such as a public school, city hall, or library.
Leachate: A contaminated liquid resulting when water percolates, or trickles,
through waste materials and collects components of those wastes. Leaching
may occur at landfills and may result in hazardous substances entering soil,
surface water, or ground water.
B-6
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Local Emergency Planning Committee: Under Title III Section 301(c), a
committee to include local and State officials; health, environmental, and
transportation personnel; and industry representatives, among others, will
be appointed by the State emergency response commission for each emergency
planning district. The local committee will prepare an emergency plan for
the district. (See also Emergency Plan and State Emergency Response Commis-
sion.)
Lead Agency: The Federal or State agency providing the On-Scene Coordinator
(OSC) or the responsible official for a CERCLA response action. (See also
On-Scene Coordinator.)
Mixed Funding Agreement: Allows EPA to reimburse parties for certain costs
(with interest) of actions parties have agreed to perform, but EPA has
agreed to finance. A mixed funding agreement can be used when some PRPs cannot
currently pay for response costs, and other PRPs want to perform response
action and be reimbursed for the nonparticipating PRPs1 share (CERCLA Subsec-
tion 122(b)).
Monitoring Wells: Special wells drilled at specific locations on or off a
hazardous waste site where ground water can be sampled at selected depths
and studied to determine such things as the direction in which ground water
flows and the types and amounts of contaminants present.
National Contingency Plan: The basic policy directive for Federal response
actions under CERCLA (Subsection 105). It sets forth the Hazard Ranking
System and procedures and standards for responding to releases of hazardous
substances, pollutants, and contaminants. The plan is a regulation (40 CFR
Part 300) subject to regular revision. (See also Hazard Ranking System.)
National Priorities List: A list of sites across the country slated for EPA
enforcement action or cleanup (CERCLA Subsection 105). EPA intends to revise
the NPL three times a year, in April, September, and December. SARA's schedules
for EPA to evaluate sites are likely to cause sites to be added to the NPL.
Note that many elements of the CERCLA/SARA program apply to sites regardless
of whether they are on the NPL. (See also Hazard Ranking System.)
National Response Center: The national communications center for activities
related to reponse actions. Individuals must notify the NRC if their facilities
or vessels release hazardous substances (other than Federally permitted releases)
in quantities considered reportable under CERCLA. Affected parties must notify
NRC regardless of whether they have notified the appropriate State or local
agency.
National Response Team: Representatives of 12 Federal agencies that coordinate
Federal responses to nationally significant pollution incidents and provide
advice and technical assistance to the responding agency(s).
Natural Resources: Land, fish, wildlife, biota, air, water, groundwater, drink-
ing water supplies, and other such resources belonging to, managed by, held
in trust by, or otherwise controlled by the U.S., any State or local govern-
ment, any foreign government, or any Indian tribe (CERCLA Subsection 101(16)).
B-7
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Nonbinding Preliminary Allocation of Responsibility: Determination EPA may
make of each PRP's share of responsibility for cleanup. Part of SARA, the
NBAR is an attempt to require EPA to provide more information to PRPs to
encourage settlement (CERCLA Subsection 122).
Notice Letter: EPA's formal notice to PRPs that CERCLA-related action is to
be undertaken at a site for which those PRPs are considered responsible.
Notice letters are generally sent at least 60 days prior to scheduled obliga-
tion of funds for an RI/FS at a designated site. The intent is to give
PRPs sufficient time to organize and to contact the government. A notice
letter is sent again prior to implementing the remedy.
On-Scene Coordinator: An individual, designated within an EPA region, who
directs Federal fund-financed reponse efforts and coordiantes all other Federal
actions at the scene of a release. The OSC is responsible for developing
contingency plans for Federal response in the OSC's area.
Operable Unit: A discrete response measure, consistent with a permanent
remedy, but not the permanent remedy itself. Hence actions formerly considered
initial remedial measures might now be preliminary operable units. The main
thrust of operable units is to facilitate faster action at sites; for example,
by encouraging responsible parties to take some action, without having to
agree to an entire remediation effort all at once.
Parts Per Billion/Parts Per Million: Units commonly used to express low con-
centrations of contaminants. For example, 1 ounce of trichloroethylene (TCE)
in 1 million ounces of water is 1 ppm: 1 ounce of TCE in 1 billion ounces of
water is 1 ppb. If one drop of TCE is mixed in a competition-size swimming
pool, the water will contain about 1 ppb of TCE.
Preliminary Assessment: The process of collecting and reviewing available in-
formation about a known or suspected hazardous waste site or release. EPA or
States use this information to determine if the site requires further study.
If further sutdy is needed, a site inspection is undertaken.
Potentially Responsible Parties: Those identified by EPA as potentially
liable under CERCLA for cleanup costs. PRPs may include generators and present
or former owners/operators of certain facilities or real property where
hazardous wastes have been stored, treated, or disposed of, as well as those
who accepted hazardous waste for transport and selected the facility.
Quality Assurance/Quality Control: A system of procedures, checks, audits,
and corrective actions used to ensure that field work and laboratory analysis
during the investigation and cleanup of Superfund sites meet established
standards.
Reauthorization: The Superfund Amendments and Reauthorization Act (SARA)
expanded the scope of CERCLA. Signed by the President on October 17, 1986,
SARA is a 5-year extension of the program to clean up toxic releases at un-
controlled or abandoned hazardous waste sites.
B-8
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Record of Decision: Written record deciding on the appropriate remedy selected
for the cleanup at a site relying generally on the Remedial Investigation/
Feasibility Study (RI/FS). Published by the government after completion of an
RI/FS, the ROD identifies the remedial alternative chosen for implementation
at a Superfund site. The ROD is part of the administrative record. Judicial
review of EPA cleanup decisions may be limited to the administrative record.
Regional Response Team: Representatives of Federal, State, and local agencies
who may assist in coordination of activities at the request of the On-Scene
Coordinator or Remedial Project Manager before and during response actions.
Release: Any spilling, leaking, pumping, pouring, emitting, emptying, dis-
charging, Injecting, escaping, leaching, dumping, or disposing into the envi-
ronment (CERCLA Subsection 101(22)). Includes the abandonment or discarding
of barrels, containers, and other closed receptacles containing any hazardous
substance, pollutant, or contaminant. Exclusions Include 1) releases solely
exposing workers in a work place, with respect to a claim they may bring
against the employer; 2) engine exhaust emissions from motor vehicles, rolling
stock, aircraft, vessels, or pipeline pumping station engines; 3) nuclear
releases subject to the Atomic Energy Act and financial requirements of the
Nuclear Regulatory Commission (also excludes any release of source, byproduct,
or special nuclear material from any processing site designated under Section
102(a) or 302(a) of the Uranium Mill Tailings Radiation Control Act); and
4) the normal application of fertilizer. Release also means substantial threat
of release.
Remedial Action: Under CERCLA Subsection 101(24), actions consistent with
permanent remedy taken Instead of, or in addition to, removal action to prevent
or minimize the release or threat of release so that hazardous substances will
not migrate to cause substantial danger to present/future public health, welfare,
or the environment. Includes a variety of on-site measures (storage, perimeter
protection, recycling or reuse, dredging, excavation, etc.), and required
monitoring, and the costs of permanent relocation of affected populations when
deemed necessary. Includes off-site measures such as transport, storage,
treatment, destruction, or secure disposition of hazardous substances and
associated contaminated materials.
Remedial Design: An engineering phase that follows the Record of Decision
when technical drawings and specifications are developed for the subsequent
remedial action at a site on the National Priorities List.
Remedial Investigation/Feasibility Study: Extensive technical studies conducted
by the government or by PRPs to investigate the scope of contamination (RI)
and determine the remedial alternatives (FS) which, consistent with the NCP,
may be implemented at a Superfund site. Government-funded RI/FSs do not
recommend a specific alternative for implementation. RI/FSs conducted by PRPs
usually do recommend and technically support a remedial alternative. An RI/FS
may include a variety of on- and off-site activities such as monitoring,
sampling, and analysis.
B-9
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Remedial Project Manager: An individual, designated within an EPA region,
who directs Federal fund-financed remedial actions and coordinates all other
Federal actions at the scene. The counterpart of the On-Scene Coordinator
for removal actions. (See also On-Scene Coordinator.)
Remedial Response: A long-term action that stops or substantially reduces a
release or threatened release of hazardous substances that is serious, but does
not pose an immediate threat to public health and/or the environment.
Removal, Remove, or Removal Action: Under CERCLA Subsection 101(23), actions
taken to respond promptly to an urgent need. With regard to hazardous sub-
stances, the cleanup or removal of released substances from the environment;
actions in response to the threat of release; actions that may be necessary to
monitor, assess, and evaluate the release or threat; disposal of removed
material; or other actions needed to prevent, minimize, or mitigate damage to
public health or welfare or to the environment. Removal also includes,
without being limited to, security fencing or other measures to limit access;
provision of alternative water supplies; temporary evacuation and housing of
threatened individuals not otherwise provided for; and any emergency assistance
provided under the Disaster Relief Act.
Reportable Quantity: Quantity of a hazardous substance considered reportable
under CERCLA in the event of a release. Reportable quantities are identified
in 40 CFR Subsection 302.5 and may be 1, 10, 100, 1000, or 5000 pounds.
Quantities are to be measured over a 24-hour period.
Resource Conservation and Recovery Act: A Federal law that established a
regulatory system to track hazardous substances from the time of generation
to disposal. The law requires safe and secure procedures to be used in
treating, transporting, sorting, and disposing of hazardous substances. RCRA is
designed to prevent new, uncontrolled hazardous waste sites.
Response Action: A CERCLA-authorized action at a Superfund site involving
either a short- term removal action or a long-term remedial response that may
include, but it not limited to the following activities:
Removing hazardous materials from a site to an EPA approved, licensed
hazardous waste facility for treatment, containment, or destruction
Containing the waste safely on-site to eliminate further problems
Destroying or treating the waste on-site using incineration or
other technologies
Identifying and removing the source of ground-water contamination
and halting further movement of the contaminants.
Responsiveness Summary: A summary of oral and/or written public comments
received by EPA during a comment period on key EPA documents, and EPA's
responses to those comments. The responsiveness summary is especially valuable
during the Record of Decision phase at a site on the National Priorities List
when it highlights community concerns for EPA decision-makers.
B-10
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Risk Assessment: An evaluation performed as part of the remedial investigation
to assess conditions at a Superfund site and determine the risk posed to
public health and/or the environment.
Site Inspection: A technical phase that follows a preliminary assessment
designed to collect more extensive information on a hazardous waste site.
The information 1s used to score the site with the Hazard Ranking System to
determine whether response action Is needed.
State Emergency Response Commission: A commission State governors will appoint
as required by Title III Section 301(a). The commission will appoint local
emergency planning committees, supervise and coordinate their activities, and
designate emergency planning districts.
Special Notice Procedures: The government may use these procedures under
SARA'S settlement provisions (Section 122) to attempt to reach agreement with
PPRs to conduct RI/FS and other remedial actions. When it wants to begin such
negotiations, the government must notify the PRP, and provide the following
information: 1) names and addresses of other PRPs, 2) volume and nature of
substances each PRP contributed, and 3) a ranking of the substances by volume.
Superfund: The common name used for the Comprehensive Environmental Response.
Compensation, and Liability Act, also referred to as the Trust Fund.
Superfund Amendments and Reauthorization Act: Modifications to CERCLA enacted
on October 17, 1986.
Surface Water: Bodies of water that are above ground, such as rivers, lakes,
and streams.
Superfund Comprehensive Accomplishments Plan: Document EPA uses as a central
planning and mangement tool for budgeting expenditures and technical support
of enforcement actions at Superfund sites. The SCAP, maintained at Federal
and regional EPA offices, indicates planned expenditures for Superfund sites
on a quarter-by-quarter basis for each fiscal year.
Toxic Chemicals: Listed in Committee Print Number 99-169 of the Senate Com-
mittee on Environment and Public Works ("Toxic Chemicals Subject to Section
313 of the Emergency Planning and Community Right-to-Know Act of 1986"). This
list of 329 chemicals was published by EPA on February 4, 1987 (52 Federal
Register! 3479). EPA may add or delete chemicals from the 11st. In addition,
Title III establishes a procedure citizens and governors can use to petition
EPA to add or delete a chemical.
Treatment, Storage, and Disposal Facility: Any building, structure, or installa-
tion where a hazardous substance has been treated, stored, or disposed. TSD
facilities are regulated by EPA and States under the Resource Conservation
and Recovery Act.
Trust Fund: A Fund set up under the Comprehensive Environmental Response,
Compensation, and Liability Act to help pay for cleanup of hazardous waste
sites and to take legal action to force those responsible for the sites to
clean them up.
B-ll
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Volatile Organic Compound: An organic (carbon-containing) compound that
evaporates (volatilizes) readily at room .temperature.
Water Purveyor: A public utility, mutual water company, county water
district, or municipality that delivers drinking water to customers.
REFERENCES
1. Superfund Glossary, WH/FS-86-007 Winter 1986.
2. Superfund Handbook, ERT and Sldley and Austin Law offices.
B-12
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APPENDIX C
ADVANTAGES AND DISADVANTAGES
OF VARIOUS INCINERATION TECHNOLOGIES
C-l
-------
TABLE C-l. ADVANTAGES AND DISADVANTAGES OF VARIOUS INCINERATION TECHNOLOGIES
FOR SLUDGES AND HAZARDOUS MATERIALS DISPOSAL
Type
Design Features and Advantages
Limitations
Liquid Injection
r>
i
IS)
Rotary Kilns
Can be designed to burn a wide range
of pumpable waste.
Also used 1n conjunction with other
Incinerator systems as a secondary
afterburner for combustion of
volatlles.
Hot refractory minimizes cool
boundary layer at walls.
HC1 recovery possible.
No secondary combustion chamber 1s
needed If the primary combustor has
enough residence time--2 seconds as
a general rule of thumb.
No continuous ash removal system 1s
required other than for downstream
air pollution control systems.
Capable of a fairly high turndown
ratio.
Virtually no moving parts.
Low maintenance costs.
Can accommodate great variety of
waste feeds: solids sludges.
liquids, and some bulk waste con-
tained In fiber drums.
Limited to destruction of pump-
able waste of viscosity of less
than 20 stokes.
Usually designed to burn specific
waste streams.
Smaller units can have problems
with clogging of Injection
widely used design.
Rotary kilns are expensive but
have economy of scale.
High capital cost for Instal-
lation, because of the need for
the secondary combustor.
(Continued)
-------
TABLE C-l. (Continued)
Type
Design Features and Advantages
Limitations
Rotary Kilns
(Cont.)
o
I
10
Cement Kilns
Boilers (usually
a liquid In-
jection design)
Rotation of combustion chamber en-
hances mixing of waste by exposing
fresh surfaces for oxidation.
Can maintain a high retention or
residence time.
Continuous ash removal which does not
Interfere with the waste oxidation.
The retention or residence time of
the nonvolatile component can be
controlled by adjusting the rota-
tional speed.
Rotary kilns can be operated at
1.400°C (2.550°F). making them well
suited for the destruction of toxic
compounds that are difficult to
thermally degrade.
Attractive for destruction of harder-
to-burn waste, due to very high
residence times, good mixing, and
high temperatures.
Alkaline environment neutralizes
chlorine.
Energy value recovery and fuel
conservation.
Availability on sites of waste
generators reduces spill risks
during hauling.
Spherical or cylindrical Items
may roll through kiln before
complete combustion.
High partlculate loadings.
Problems 1n maintaining seals
at either end of the kiln are
a significant operating
difficulty.
Drying of aqueous sludge wastes
or melting of some solid wastes
can result 1n cylinder or ring
formation on refractory walls.
Burning of chlorinated waste
limited by operating require-
ments, and appears to Increase
particle generation.
Cool gas layer at walls result
from heat removal. This con-
strains design to high-
efficiency combustion within
the flame zone.
(Continued)
-------
TABLE C-l. (Continued)
Type
Design Features and Advantages
Limitations
Boilers (Cont.)
Multiple Hearth
o
I
Fluldlzed-bed
Incinerators
Passage of waste onto progressively
hotter hearths can provide for long
residence times for sludges.
Able to handle wide variety of
sludges.
Large quantities of wastebound water
can be evaporated.
Can utilize many types of fuels In-
cluding coal dust, waste oils and
solvents.
Fuel burners can be added to any of
the hearths to maintain a desired
temperature profile.
For multlzone configuration hearths.
fuel efficiency 1s nigh and Improves
with the number of hearths used.
Turbulence of bed enhances uniform
heat transfer and combustion of waste
Nozzle maintenance and waste
feed stability can be critical.
Where HC1 1s recovered, high
temperatures must be avoided.
Tiered hearths usually have
some relatively cold spots
which Inhibit even and complete
combustion.
Opportunity for some gas to
snort circuit and escape
without adequate residence time.
Not suitable for wastestreams
which produce fusible ash when
combusted.
Units have high maintenance re-
quirements due to moving parts
1n high-temperature zone.
Need a secondary combustor.
Solid wastes generally require
pretreatment.
Potentially high particulate
loading.
(Continued)
-------
TABLE C-l. (Continued)
Type
Design Features and Advantages
Limitations
Flu1d1zed-bed
Incineration
(Cont.)
At-Sea
Incineration
r»
in
Pyrolysls
Molten Salt
Mass of bed Is large relative to the
mass of Injected waste.
Large economy of scale.
Minimum scrubbing of exhaust gases
required by regulations on assumption
that ocean water provides sufficient
neutralization and dilution.
This could provide economic advantages
over land-based Incineration methods.
Also. Incineration occurs away from
human populations. Shipboard In-
cinerators have greater combustion
rates.
A1r pollution control needs minimum:
air-starved combustion avoids
volatilization of any Inorganic com-
pounds. These and heavy metals go
Into Insoluble solid char.
Potentially high capacity.
Molten salts act as catalysts and
efficient heat transfer medium.
Self-sustaining for some wastes.
Reduces energy use and reduces
maintenance costs.
Not suitable for waste that are
shock sensitive, capable of
spontaneous combustion, or
chemically or thermally unstable
due to the extra handling and
hazard of shipboard environment.
Some wastes produce a tar which
1s hard to dispose of.
Potentially high fuel maintenance
costs.
Commercial-scale applications
face potential problems with
regeneration or disposal of
ash-contaminated salt.
Not suitable for high ash
wastes.
(Continued)
-------
TABLE C-l. (Continued)
Tvoe
Deslan Features and Advantaaes
Limitations
Molten Salt
(Cont.)
High-
Temperature
Fluid Hall
r>
ot
Plasma Arc
Wet Oxidation
Units are compact; potentially
portable.
Minimal air pollution control needs;
some combustion products, e.g., ash and
acidic gases are retained in the melt
Waste is efficiently destroyed as it
passes through cylinder and is exposed
to radiant heat temperatures of about
2,200'C (4,000'F).
Cylinder 1s electrically heated; heat
Is transferred to waste through inert
gas blanket, which protects cylinder
wall.
Mobile units possible.
Very high energy radiation breaks
chemical bonds directly, without series
of chemical reactions.
Simple operation, very low energy
costs, mobile units planned.
Applicable to aqueous waste too dilute
for incineration and too toxic for
biological treatment.
Lower temperatures requrled, and energy
released by some wastes can produce
self-sustaining reaction.
Chamber corrosion can be a problem.
Core diameters and cylinder length limit
throughout capacity.
Scale-up may be difficult due to thermal
stress on core.
Potentially high costs for electrical
heating.
Limited throughput.
High use of NaOH for scrubbers.
Not applicable to highly chlorolnated
organics, and some wastes need further
treatment.
Used as pretreatment to biological
wastewater treatment.
-------
TABLE C-l. (Continued)
Type
Design Features and Advantages
Limitations
Wet Oxidation (Cont.)
Super Critical Water
No air emissions.
Applicable to chlorinated aqueous
waste which are too dilute to
Incinerate.
Takes advantage of excellent solvent
properties of water above critical
point for organic compounds.
Injected oxygen decomposes smaller
organic molecules to C02 and water.
No air emissions.
Probable high economy of scale.
Energy needs may Increase on
scale-up.
o
I
Sources: References (Cherem1s1noff 1986) and (Lee 1986).
-------
APPENDIX D
DESCRIPTION OF PROTOCOL
FOR ESTIMATING EMISSIONS
AND ASSESSING AIR
QUALITY IMPACTS
-------
APPENDIX D
DESCRIPTION OF PROTOCOL FOR ESTIMATING EMISSIONS
AND ASSESSING AIR QUALITY IMPACTS
This appendix presents a step-by-step protocol for estimating emissions
from a variety of remedial operations during the clean-up of Superfund (NPL)
sites. The protocol is designed to allow the user to make relative
comparisons of the impacts on air quality from remedial options being
considered for implementation. The protocol is graphically presented and each
step of the process is discussed. The mathematical equations and calculations
common to assessments of air quality impacts for all remediation options are
then presented. Equations and input values for each specific remediation
option considered in this project may be found in Section 3 of the main body
of the manual.
D.I DISCUSSION OF PROTOCOL STEPS
A flow chart showing the steps of the protocol is given as Figure D-l.
Each step is discussed below.
D.I.I Step 1 - Define Air Pathway Analysis (APA) Objectives
Performance of an air pathway analysis for remediation may be useful
during the Feasibility Study (FS). Remedial Design (RD). Record of Decision
(ROD) or Remedial Action (RA) phase of a Superfund project: and is most
critical during the RD phase. However, the objectives of the APA will vary
depending on the phase of the project. In general, the objectives of the APA
are to assess the impact on downwind receptors from the implementation of a
given remedial technology at a given operating rate. Therefore, the first
protocol step is to clearly define what objectives are to be met for a given
APA. The intended uses of the analysis results dictate the type, quantity.
D-l
-------
1. Define APA Objectives |
| 2. Assess Existing Data/Records |
3. Develop Conceptual Site
Model/Estimate Values
for Key Paraneters
Yes
Conduct RI/FS
4.
Divide site Into cells
of equivalent waste
\Un1
5. Identlf
Renedlt
•
**lS Perfor
(^ for e
NO
•'
y Candidate
1 Actions
|6. Calculate EFs |
"v^wi
i
k
rolTX Yes S
fT
Cl
NO
7. Determine Average and HaxiBun
Emissions Duiplng
d> Storage
elect Control f) Bull operations'
Technology
3 Stabilization (VO Pit mettli)
leulate Control
Efficiency 5. In-sUu Venting (VO)
~ I 6. No Action
10.
Input APA Results to FS/RO/ROO
Decision-making Process
Figure D-l. Flow chart of air pathway analysis for remediation.
D-2
-------
and required confidence level of the Input data to the APA. In general, as
the Superfund process for a given NPL site advances, more details are
available for Input to the APA. but more specific and more accurate outputs
are required.
The following steps are recommended:
• Recognize the stated CERCLA objective to characterize the nature and
extent of contamination Including the air contamination pathway.
• Review the characteristics of the site and surrounding area, then
formulate site-specific objective(s). Consider:
- Technical feasibility:
Program resources;
Community involvement;
Bioreceptor location;
Waste characteristics:
Disposition of wastes;
Other factors.
• Circulate the stated site-specific objectives for review and modify
as necessary.
D.I.2 Step 2 - Assess Existing Data and Records
At the point where remedial options and their associated air quality
impacts are being evaluated, extensive information about the site should
already have been collected as part of the initial steps of the Remedial
Investigation/Feasibility Study (RI/FS) process. Site files should be
examined to determine if adequate quantity and quality of data are available.
Historical information may be obtained from EPA enforcement and technical
files. USGS and SCS files, state and local regulatory agency files, files of
the potentially responsible parties (PRPs). personal interviews, etc. See
Section 2.0 of Reference D-l for further Information regarding potential data
D-3
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sources. A site Inspection(s) should also have been performed to confirm and
update the historical Information, as well as to conduct a preliminary
assessment of health and safety concerns for both on-site workers and the
surrounding community. In many cases, a remedial investigation (RI) will also
have been performed to characterize the site. The field Investigations
typically involve collecting a series of surface and subsurface solid and
liquid samples, making limited air quality measurements and screening the
samples using a phased analytical approach. Detailed Information on site
characterization has been published by the EPA (D-2).
The existing data should be reviewed and the adequacy of the data
assessed. The user should be acquainted with the steps of this protocol and
the required inputs to the various emission factor equations (see Table
D-3) prior to evaluating the existing data set. The data review will
typically involve a systematic search of the site files to identify and record
all pertinent Information for the APA for remediation. Not all necessary
inputs to the protocol may be available in the site files; further historical
data collection from primary sources may be required. Under certain
circumstances, an APA may need to be performed despite existing data gaps.
Therefore, the equations in this protocol for estimating emissions contain
default inputs, i.e.. typical values to use for a given parameter when no
site-specific information is available. However, site-specific information is
always preferable and should be used whenever possible.
The available data will rarely all be intrinsically equal in quality: it
is therefore necessary to assess the adequacy of the data. Major
consi derati ons 1nclude:
• Age of the data;
• Sampling and analytical procedures used:
• Analytical detection limits; and
• QA/QC procedures and documentation.
The uncertainty associated with each data measurement must be known to
evaluate the existing data set. The data validation process should identify
0-4
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and delete Invalid data and qualify the usefulness of the remaining data. Two
types of data quality must be considered. First, each Individual data point
has an associated confidence level or uncertainty. These Individual data
points are then typically compiled Into statements regarding the volume, type.
distribution, etc. of the pollutant that Is present. Second, remediation
decisions are delineated based on specific action levels, and the confidence
level for a given decision Includes both the confidence in Individual
measurements as well as the confidence level for estimations based on the
Individual measurements, e.g.. the estimate of the area requiring remediation.
Determining the confidence level for a given decision requires that a detailed
statistical evaluation of the data be performed. The EPA has published
guidance for assessing data quality for the RI/FS process (D-3) and has
published an example scenario (D-4).
D.I.3 Step 3 - Estimate Values for Key Parameters
During the RI process, a conceptual model of the site is typically
developed. This model should be reviewed and updated, or developed if none
currently exists. A conceptual model describes a site and Its environs and
presents the best available hypotheses regarding the pollutants present at the
site, the possible routes of migration, and the potential impact on receptors.
Elements of a conceptual model are shown in Figure D-2. The conceptual model
must be detailed enough to qualify the potential or suspected sources, types.
and concentrations of pollutants, affected media, migration routes and rates.
and location and sensitivity of receptors.
A 11st of all necessary input parameters for performing the air pathway
analysis for remediation should be available from the Step 2 activities
described above. The conceptual model and existing data/records can then be
consulted to determine the quantitative value to assign to each input
parameter. It is advisable to develop two sets of values: a best-guess
single value, and a probable range (confidence interval) surrounding the
single value. Not all input parameters are equally important for determining
air quality impacts, and having ranges of values will permit sensitivity
analyses to be performed. The list of input parameters should next be
D-5
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Source
Contaminants
Concentration
Time
Location
Media
Rate of Migration
Time
Loss Functions
Type
Sensitivity
Time
Concentration
Number
Hypothesis
to be
Tested
• Source Exists
• Source Can Be
Contained
• Source Can Be
Removed and
Disposed
• Source Can Be
Treated
• Pathway Exists
• Pathway Can Be
Interrupted
• Pathway Can Be
Eliminated
Receptors are Not
Impacted by Migration
of Contaminants
Receptor Can Be
Relocated
Institutional Controls
Can Be Applied
Receptors Can Be
Protected
Figure D-2. Elements of a conceptual evaluation model (D-3).
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evaluated. If significant data gaps exist (e.g.. waste type, volume, or
distribution) or the data quality 1s unacceptable, then a site Investigation
may be necessary to procure the required data. As stated earlier, this
protocol Includes default Inputs for use when further data collection Is not
cost effective.
D.I.4 Step 4 - Divide Site Into Equivalent Units
NPL sites containing mixed wastes or having other types of Inherent
variability may require separate remedial options to be considered for each
equivalent area. The site should be theoretically divided Into units of
equivalent waste for evaluating remedial options. For example, a hypothetical
site mitigation may Involve the clean-up of burled wastes, contaminated ground
water, and sludge pits. This hypothetical site would thus have at least three
distinct units and perhaps more. If the type, concentration, or distribution
of a given form of contamination varies widely, then further subdivision of
the units should be considered. Similarly. 1f the soil media (soil type.
porosity, contaminant level, etc.) varies significantly either laterally or
with depth, or the proximity of receptors varies significantly across the
site, then further subdivisions of the units may be necessary.
The air quality impacts from remediation of each unit should be evaluated
using Steps 5 and 6 of this protocol. An iterative process may be necessary
to Identify the most efficient method(s) from an air emissions standpoint of
treating a contaminated site (i.e.. it may require several attempts to make
the most appropriate selection of waste cells, remedial options, and control
technologies).
D.I.5 Step 5 - Identify Candidate Remedial Actions
A large number of possible technologies are available for remediating NPL
sites. The generic technology groups addressed in this protocol were listed
in Figure D-l. These are thought to represent the most commonly used and the
most viable of the available options. However, new remedial options are
undergoing rapid research and development (e.g.. biodegradation). and new
D-7
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technologies should be considered once their effectiveness has been
demonstrated and sufficient Information 1s available to develop emission
factors for them.
The best options for treating a given site are. of course, site specific.
The EPA recommends that the following be assessed during development of the
conceptual model to determine the appropriate remedial and/or removal actions
at a site (D-3):
• Population, environmental, and welfare concerns at risk:
• Routes of exposure:
• Spatial distribution of contaminants:
• Atmospheric dispersion potential and proximity of targets;
• Amount, concentration, hazardous properties, environmental fate and
form of the substance(s) present:
• Hydrogeological factors:
• Climate:
• Extent to which the source can be adequately identified and
characterized:
• Potential for reuse, recycling, or treatment of substances at the
site:
• Likelihood of future releases if the substances remain on site:
• Extent to which natural or man-made barriers currently contain the
substances and the adequacy of the barriers:
D-8
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• Assessment of the potential pathways of migration and a model of
such:
• Extent to which the substances have migrated or are expected to
migrate from their source and whether migration poses a threat to
public health, welfare, or the environment: and
• Extent to which contamination levels exceed applicable or relevant
and appropriate federal or state requirements (ARARs) relating to
public health or environmental standard and criteria.
When selecting one or more remedial options to consider for a given
situation, the primary evaluation criterion should be the short- and long-
term effect of the option on the health and safety of on-s1te workers and
surrounding receptors.
In most cases, the viable remedial options can be limited to two or three
options per waste cell. Further guidance for selecting remedial options is
present in Sections 2 and 3 of this protocol under the discussions of the
specific technologies. This protocol assists in evaluating these options in
terms of their impact on air quality: other considerations also apply as
indicated in the discussion of Step 10.
D.I.6 Step 6 - Calculate Emission Factors
For each unit and remedial option, the appropriate emission factor should
be determined. Specific calculation steps for each remedial activity are
outlined beginning in Section 3.3.
D.I.7 Step 7 - Determine Average and Maximum Emissions
The emission factors from the previous step are given in terms of mass of
pollutants per unit operation or per given time frame. Emissions during
several time frames may be of concern including:
D-9
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1) Maximum emissions during any 15-minute period:
2) Maximum emissions during any 60-m1nute period:
3) Average emissions during an 8-hour work period:
4) Average emissions during a 24-hour period:
5) Total emissions during remediation; and
6) Average post clean-up emissions during a 24-hour period.
To determine average, maximum, or overall emissions, follow the steps
given below.
First, select the time frame of interest from the above 11st.
Second, convert all emission factors into mass per unit time using
Equation D-l and values listed in Table 0-1. In some cases, separate emission
factor equations are available for a given remedial activity for calculating
peak and average EF^ values.
Operable Unit 1: XEFi>t = (XEF1tUO)(CF) (D-l)
where: XEF1>t = emission factor for species i during remedial option X
(mass/time):
XEFj.uo = emission factor for species i during remedial option X
(mass/unit operation): and
CF = conversion factor from Table D-l (unit operation/time).
Equation D-l will provide maximum and average emissions from a given
operable unit for a given remedial option directly. 1f the appropriate
operating frequency/conversion factor are selected. If multiple remedial
options are practiced in the same in the same time frame, then the
contributions from each option must be summed using Equation D-2.
Operable Unit 1: XEF1§t + YEFiit + ZEF1
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TABLE D-l. CONVERSION FACTORS FOR CALCULATING TIME-BASED
EMISSION FACTORS FOR NON-CONTINUOUS PROCESSES
Remedi al
Option
Emission
Factor
Units
Typical
Operation
Frequency
Conversion Factor
Maximum
Emissions
Average
Emissions
Incineration kg/hr
kg/kg of feed
kg/m3 off-gas 125 m3/m1n 1875 m3/15 mln 60.000 m3/8hr
Air Stripping g/mln
In-s1tu Venting g/mln
3.500 L/m1n 52.500 L/15 mln 5.04x10° L/day
0.5 m3/m1n 7.5 m3/15 mln 720 m3/day
Soils Handling - VOC
Excavation
Dumping
kg/tonc
kg/tonc
50 ton/hr
8 hr/day
8 ton/load
1 load/5 min
5 loads/hr
8 ton/load
5 load/hr
8 hr/day
50 tons/hr
1.6 ton/5 mln
8 ton/60 mln
Soils Handling - Partlculates
(see Section 3.6.1.8)
400 ton/day
40 ton/hr
320 ton/day
Substitute site-specific frequency, if known.
K O O
Assume 1 m = 1.000 kg. average scoop = 4 m .
C 3 3
Assume 1 m = 1.000 kg. average scoop = 8 m .
D-ll
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where: X = remedial option X:
Y = remedial option Y: and
Z = remedial option Z.
Third, for total emissions from a given unit during remediation, use
Equation D-3 and output of Equation D-l.
Operable Unit 1: E1 = (XEF1>t)(tx) + (YEFift)(ty) ... (D-3)
where: E1 = total emissions during remediation for species i (kg):
XEF.j>t = average emissions for species 1 during remedial option X
(kg/day); and
tx = number of days remedial option X is performed.
Fourth, if multiple units exist, then emissions for the entire site can
be determined by inputting the results of Equations D-l. D-2. or D-3 as
required into Equation D-4. For summing the contributions of multiple units
using Equation D-l or D-2 outputs, the time dependence of the remedial
activities must be taken into account. The maximum emissions for different
units may not coincide, or remedial activities may not take place 1n all the
units during a given time frame.
Site Emissions = Unit 1 Emissions + Unit 2 Emissions + ... (D-4)
D.I.8 Step 8 - Estimate Pollutant Concentrations at Receptors
The emission factors provide an emission rate per unit time or unit
operation. It is usually necessary to convert this emission rate to a
concentration at the receptors of interest, in order to assess health and
safety concerns arising from air quality impacts. The most valid means to
accomplish this is to use the emission factor as a source term (input) to an
atmospheric dispersion model. The models recommended by the EPA (49) are
listed In Table D-2. PC-compatible versions of some of the dispersion models
D-12
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TABLE D-2. RECOMMENDED AIR QUALITY (DISPERSION) MODELS
Buoyant Line and Point Source Dispersion Model (BLP)
Caline 3
Climatological Dispersion Model (CDM 2.0)
Gaussian-Plume Multiple Source Air Quality Algorithm (RAM)
Industrial Source Complex Model (ISC)
Multipoint Point Gaussian Dispersion Algorithm with Terrain
Adjustment (MPTER)
Single Source (CRSTER) Model
Urban Airshed Model (UAM)
D-13
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are readily available. For urban or Industrial areas, the ISC model 1s an
appropriate choice. Both long-term and short-term versions are available.
Dispersion modeling Is discussed In more detail 1n Volume IV (3).
In addition to a source term, the models generally require Information
regarding:
• Size and geometry of source:
• Location and profile of adjacent structures:
• Wind speed:
• Wind variability;
• Temperature:
• Dispersion coefficients:
• Atmospheric stability:
• Receptors: and
• Particle size distribution.
The models are typically independent of the chemical and physical properties
of the pollutant (though the actual rate of dispersion is dependent on the
molecular weight of the pollutant). Therefore, the models need to be run only
once per given set of meteorological conditions and receptors, and the
downwind concentrations can then be ratioed to various source terms. In some
cases, contributions from background sources must also be considered.
For particulate matter, the same dispersion models listed in Table D-2
can be used. The model should include a settling velocity term or other
factor to account for gravitational effects on the particles. The potential
distance a particle may drift before being deposited 1s affected by the
starting height of the particle, its terminal settling velocity, and the
degree of atmospheric turbulence. Predictive models have been developed that
use particle diameter and mean wind speed as the key Inputs (50). Particles
with diameters greater than 30 urn generally settle out within a short
distance.
D-14
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The downwind concentrations determined from the dispersion modeling
should be compared to any existing downwind ambient air data collected during
trial or pilot-scale remediation activities, as a check of the modeling
results. Obviously, the predicted downwind concentrations for full-scale
remediation should exceed measured downwind concentrations during limited
remediation activities or those at baseline conditions. If not. the model
Inputs should be re-examined and background sources of contamination assessed.
D.I.9 Step 9 - Compare Concentration at Receptors to Applicable
Regulati ons/Standards
The modeling results should be compared to established action levels to
determine if the site emissions pose a potential health or safety risk. The
results may also be used as input to long-term risk assessment work. If
exceedances are noted, then three options are available:
• Re-evaluate the control technologies to be used during remediation;
• Re-evaluate the selected remedial options and their operating rates:
or
• Increase the level of personal protective clothing worn by site
workers (if they are the only receptors affected by the exceedance).
Action levels will vary depending on the location of the NPL site and the
proximity and orientation of sensitive receptors. A number of health
standards exist and the applicable regulatory agency may select some fraction
of an existing health standard to serve as an action level (i.e.. a trigger
point where steps are taken to reduce the exposure of sensitive receptors).
Information sources for air standards are available (D-5.D-6.D-7.D-8. and D-
9).
Emissions of certain compounds pose an odor problem at levels below the
point of health and safety concerns. This is particularly true for organic
compounds that contain sulfur (e.g.. thiophenes and mercaptans). Odor
D-15
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threshold values can be obtained from ACGIH's Threshold Limit Values
publication, the TOXNET computerized database, or other sources. The odor
potential of remediation should be evaluated for sites: 1) with past
histories of odor complaints. 2) having nearby receptors, or 3) containing
contaminants likely to produce odorous compounds. In general, the control
technologies discussed for each remedial option will reduce odorous emissions
commensurate with reductions 1n total emissions. However. 1n some cases.
complete odor control 1s not possible and education of the Impacted public as
to the risks/benefits of remediation Is Imperative.
D.I.10 Step 10 - Input A1r Pathway Analysis Results to Record of Decision
Process
This protocol 1s intended for use in evaluating the air pathway transport
mechanism during remediation. The results of the APA should be one of many
factors that are considered when preparing Feasibility Studies. Remedial
Designs, and Record of Decisions. The overall ROD process must consider
myriad other site-specific factors, both objective and subjective, including:
ground-water and surface water pathways, existing exposure/
contact hazards, long-term risk assessments, overall cost effectiveness of
remedial alternatives, site hazard ranking, etc.
D-16
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APPENDIX D: REFERENCES
0-1. U. S. EPA. Guidance on Remedial Investigations under CERCLA.
HWERL/OERR and OUPE, EPA/540/G-85/002. June 1985.
D-2. U. S. EPA. Characterization of Hazardous Waste Sites—A Methods
Manual. Volume I - Site Investigation. EPA/600/4-84/075. 1985.
0-3. U. S. EPA. Data Quality Objectives for Remedial Response
Activities-'Development Process. OERR and OWPE. EPA/540/G-87/003.
March 1987.
D-4. U. S. EPA. Data Quality Objectives for Remedial Response
Activities-- Example Scenario: RI/FS Activities at a Site with
Contaminated Soils and Ground Water. OERR and OWPE.
EPA/540/G-87/004. March 1987.
D-5. NIOSH Pocket Guide to Chemical Hazards. National Institute for
Occupational Safety and Health, Cincinnati, OH. 1985.
D-6. Chemical Rubber Company. Handbook of Chemistry and Physics. 55th
Edition, Robert Weast Ed., pp. D-85-86. CRC Press. 1974.
0-7. National Fire Protection Association (NFPA). Fire Protection Guide
on Hazardous Materials, 8th Edition, NFPA, Boston, MA. 1985.
0-8. Threshold Limit Values for Chemical Substances and Physical Agents
in the Workroom Environment and Biological Exposure Indices with
Intended Changes for 1985-86. American Conference of Governmental
Industrial Hygienists, 6500 Glenway Avenue, Building D-5,
Cincinnati, Ohio, 45211. 1985.
0-9. OSHA. 29 CFR Part 1910. (OSHA standards are legally binding.)
0-17
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NOTICE TO THE READER - IF YOU WOULD LIKE TO RECEIVE
UPDATED AND/OR REVISED COPIES OF THIS VOLUME IN THE
NATIONAL TECHNICAL GUIDANCE STUDIES SERIES, PLEASE
COMPLETE THE FOLLOWING AND MAIL TO:
Mr. Joseph Padgett
U.S. Environmental Protection Agency
MD-10
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Volume No.
Title
Name
Address
Telephone No. ( )
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