r/EPA
United States
Environmental Protection
Agency
Office of Air Quality
Planning and'Standards
MD-14
EPA-454/R-97-004D
July 1997
EIIP Volume II
Point Sources
Preferred and Alternative
Methods
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PREFACE
As a result of the more prominent role given to emission inventories in the 1990 Clean
Air Act Amendments (CAAA), inventories are receiving heightened priority and
resources from the U.S. Environmental Protection Agency (EPA), state/local agencies,
and industry. More than accountings of emission sources, inventory data are now
providing the prime basis for operating permit fee systems, State Implementation Plan
(SIP) development (including attainment strategy demonstrations), regional air quality
dispersion modeling assessments, and control strategy development. This new emphasis
on the use of emissions data will require significantly increased effort by state/local
agencies to provide adequate, accurate, and transferrable information to meet various
agency and regional program needs.
Existing emission inventory data collection, calculation, management, and reporting
procedures are not sufficient or of high enough quality to meet all of these needs into
the next century. To address these concerns, the Emission Inventory Improvement
Program (EIIP) was created. The EIIP is a jointly sponsored endeavor of the State and
Territorial Air Pollution Program Administrators/Association of Local Air Pollution
Control Officials (STAPPA/ALAPCO) and the U.S. EPA, and is an outgrowth of
recommendations put forth by the Standing Air Emissions Work Group (SAEWG) of
STAPPA/ALAPCO. The EIIP Steering Committee and technical committees are
composed of state/local agency, EPA, industry, consultant, and academic representatives.
In general, technical committee participation is open to anyone.
The EIIP is defined as a program to develop and use standard procedures to collect,
calculate, store, and report emissions data. Its ultimate goal is to provide cost-effective,
reliable, and consistent inventories through the achievement of the following objectives:
• Produce a coordinated system of data measurement/calculation methods as
a guide for estimating current and future source emissions;
• Produce consistent quality assurance/quality control (QA/QC) procedures
applicable to all phases of all inventory programs;
• Improve the EPA/state/local agency/industry system of data collection,
reporting, and transfer; and
• Produce an integrated source data reporting procedure that consolidates
the many current reporting requirements;
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EIIP goals and objectives are being addressed through the production of seven guidance
and methodology volumes. These seven are:
• Volume I: Introduction and Use of EIIP Guidance for Emissions
Inventory Development
Volume II: Point Sources Preferred and Alternative Methods
Volume III: Area Sources Preferred and Alternative Methods
Volume IV: Mobile Sources Preferred and Alternative Methods
Volume V: Biogenics Sources Preferred and Alternative Methods
Volume VI: Quality Assurance Procedures
Volume VII: Data Management Procedures
The purpose of each volume is to evaluate the existing guidance on emissions estimation
techniques, and, where applicable, to identify the preferred and alternative emission
estimation procedures. Another important objective in each volume is to identify gaps in
existing methods, and to recommend activities necessary to fill the gaps. The preferred
and alternative method findings are summarized in clear, consistent procedures so that
both experienced and entry-level inventory personnel can execute them with a reasonable
amount of time and effort. Sufficiently detailed references are provided to enable the
reader to identify any supplementary information. Users should note that the number of
source categories or topics covered in any volume is constantly expanding as a function
of EIIP implementation and availability of new information.
It is anticipated that the EIIP materials will become the guidance standard for the
emission inventory community. For this reason, the production of EIIP volumes will be
a dynamic, iterative process where documents are updated over time as better data and
scientific understanding support improved estimation, QA, and data management
methods. The number of individual source categories addressed by the guidance will
grow as well over time. The EIIP welcomes input and suggestion from all groups and
individuals on how the volumes could be improved.
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1
VOLUME II: CHAPTER 1
INTRODUCTION TO STATIONARY
POINT SOURCE EMISSION
INVENTORY DEVELOPMENT
July 1997
Prepared by:
Eastern Research Group, Inc.
Prepared for:
Point Sources Committee
Emission Inventory Improvement Program
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DISCLAIMER
This document was furnished to the Point Sources Committee, Emission Inventory
Improvement Program and the U.S. Environmental Protection Agency by Eastern Research
Group, Inc., Morrisville, North Carolina. This report is intended to be a final document and
has been reviewed and approved for publication. The opinions, findings, and conclusions
expressed represent a consensus of the members of the Emission Inventory Improvement
Program.
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ACKNOWLEDGMENT
This document was prepared by Eastern Research Group, Inc., Morrisville, North Carolina,
for the Point Sources Committee of the Emission Inventory Improvement Program and for
Dennis Beauregard of the Emission Factor and Inventory Group, U.S. Environmental
Protection Agency. Members of the Point Sources Committee contributing to the preparation
of this document are:
Dennis Beauregard, Co-Chair, Emission Factor and Inventory Group, U.S. Environmental Protection Agency
Bill Gill, Co-Chair, Texas Natural Resource Conservation Commission
Denise Alston-Guiden, Galson Consulting
Bob Betterton, South Carolina Department of Health and Environmental Control
Paul Brochi, Texas Natural Resource Conservation Commission
Alice Fredlund, Louisiana Department of Environmental Quality
Gary Helm, Air Quality Management, Inc.
Paul Kim, Minnesota Pollution Control Agency
Toch Mangat, Bay Area Air Quality Management District
Ralph Patterson, Wisconsin Department of Natural Resources
Jim Southerland, North Carolina Department of Environment, Health and Natural Resources
Eitan Tsabari, Omaha Air Quality Control Division
Bob Woolen, North Carolina Department of Environment, Health and Natural Resources
EIIP Volume II 111
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CHAPTER 1 -INTRODUCTION 7/1/97
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IV CUP Volume II
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CONTENTS
Section Page
Abbreviations, Acronyms, and Symbols xi
Definitions of Commonly Used Terms xvi
1 Introduction 1.1-1
1.1 Background 1.1-1
1.2 Purpose of Chapter 1 1.1-3
1.3 Organization of Chapter 1 1.1-5
2 Purposes for Assessing Emissions 1.2-1
2.1 Federal Requirements 1.2-1
2.1.1 Clean Air Act Requirements 1.2-1
2.1.2 Requirements under Other EPA Regulations 1.2-23
2.1.3 Federal Requirements Outside of EPA 1.2-25
2.2 State Requirements 1.2-25
3 Emissions Inventory Planning 1.3-1
3.1 Preliminary Planning Activities 1.3-1
3.1.1 End Use of the Data 1.3-1
3.1.2 Scope of the Inventory 1.3-1
3.1.3 Availability and Usefulness of Existing Data 1.3-2
3.1.4 Strategy for Data Collection 1.3-6
3.2 Inventory Work Plan 1.3-6
3.3 Training 1.3-7
3.4 Data Handling 1.3-8
3.5 Documentation Requirements 1.3-9
3.6 Schedule 1.3-9
EIIP Volume II V
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CONTENTS (CONTINUED)
Section Page
4 Emission Estimation Procedures 1.4-1
4.1 Source Tests 1.4-1
4.2 Material Balances 1.4-5
4.3 Emission Factors 1.4-6
4.3.1 Calculation of Emissions Using Emission Factors 1.4-7
4.3.2 Role of Throughput in Emission Factor Estimates 1.4-8
4.3.3 Role of Capture and Control Device Efficiencies in Emission Factor
Estimates 1.4-9
4.3.4 Process-Specific Empirical Relationships 1.4-10
4.4 Emission Models 1.4-10
4.5 Best Approximation or Engineering Judgement 1.4-11
4.6 Other Considerations 1.4-11
4.6.1 Rule Effectiveness 1.4-11
4.6.2 Control Devices 1.4-13
5 Data Collection 1.5-1
5.1 Level of Detail 1.5-1
5.1.1 Plant Level 1.5-1
5.1.2 Point/Stack Level 1.5-1
5.1.3 Process/Segment Level 1.5-2
5.2 Availability and Usefulness of Existing Data 1.5-2
5.3 Data Collection Methods 1.5-2
5.3.1 Questionnaires 1.5-2
5.3.2 Plant Inspections 1.5-8
5.3.3 Accessing Agency Air Pollution Files 1.5-8
5.3.4 Emissions Estimates Conducted by Plant Personnel 1.5-8
VI EHP Volume II
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CONTENTS (CONTINUED)
Section Page
6 Inventory Reporting and Documentation 1.6-1
6.1 Written Documentation 1.6-1
6.2 Computerized Data Reporting 1.6-2
7 Quality Assurance/Quality Control 1.7-1
7.1 Quality Control 1.7-1
7.2 Quality Assurance 1.7-2
7.3 QA/QC Procedures for Specific Emission Estimation Methods 1.7-3
7.3.1 Source Tests and Continuous Emissions Monitoring (CEM) .... 1.7-3
7.3.2 Material Balances 1.7-5
7.3.3 Emission Factors 1.7-5
7.3.4 Modeling 1.7-7
7.4 Data Attribute Rating System (DARS) 1.7-8
8 References 1.8-1
Appendix A: Table of Contents from AP-42, 5th Edition
Appendix B: Conversion Factors from Appendix A, AP-42, 5th Edition
Appendix C: Contact and Resource Information
Appendix D: Annual Emissions Inventory Checklist for Stationary Point Sources
Appendix E: Test Methods
Appendix F: Emission Estimation Tools
EIIP Volume II Vll
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FIGURES
Page
1.1-1 Point Source Inventory Development Process 1.1-4
1.2-1 Key Relationships for Industry Air Pollutant Emission Estimation 1.2-2
1.4-1 Emission Estimation Hierarchy 1.4-2
1.5-1 Example of Point Source Surveying 1.5-3
EHP Volume II
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TABLES
Page
1.2-1 Overview of Key Federal Emission Estimation Requirements 1.2-3
1.2-2 Comparison of Emissions Reporting Program Data Elements 1.2-10
1.2-3 Inventory Requirements of the Clean Air Act Amendments for Ozone
and CO 1.2-15
1.2-4 Emission Cutoffs for Determining Applicability of Title V Operating
Permits Program in Nonattainment Areas 1.2-19
1.3-1 Potential Point Sources and Pollutants 1.3-3
1.4-1 Air Pollution Control Technologies 1.4-14
1.4-2 Control Techniques Guidelines Documents (Groups I, II, III) 1.4-15
1.4-3 Alternative Control Techniques Documents 1.4-18
1.7-1 Methods for Achieving Emission Inventory Data Quality Objectives 1.7-4
EI1P Volume II IX
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ABBREVIATIONS, ACRONYMS, AND
SYMBOLS
ABBREVIATIONS
ACT Alternative Control Technology Guideline
AFS AIRS Facility Subsystem
AFSEF AIRS Facility Subsystem Emission Factors Database
AIRS Aerometric Information Retrieval System
ALAPCO Association of Local Air Pollution Control Officials
AMS AIRS Area and Mobile Subsystem
APA Air Pathway Analysis
API American Petroleum Institute
APPCD Air Pollution Prevention and Control Division
APTI Air Pollution Training Institute
AQS AIRS Quality Subsystem
ARDS Acid Rain Data System
ASTM American Society for Testing and Materials
BACT best available control technology
BTU British thermal unit
CAA Clean Air Act
CAS Chemical Abstract Services
CD-ROM compact disc read-only memory
CEM Continuous Emissions Monitoring
CFC Chlorofluorocarbon
CFR Code of Federal Regulations
CERCLA Comprehensive Environmental Recovery and Comprehensive Liability Act
CHIEF Clearinghouse for Inventories and Emission Factors
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ABBREVIATIONS, ACRONYMS, AND
SYMBOLS (CONTINUED)
CMS Continuous Monitoring System
CO carbon monoxide
CTC Control Technology Center
CTG Control Techniques Guideline
DARS Data Attribute Rating System
DECIM Defense Corporate Information Management
DoD Department of Defense
DOE Department of Energy
EA Environmental assessment
EFIG Emission Factor and Inventory Group
EIIP Emission Inventory Improvement Program
EIS Environmental Impact Statement
EMTIC Emission Measurement Technical Information Center
EPA U.S. Environmental Protection Agency
FIP Federal Implementation Plan
FR Federal Register
FIRE Factor Information Retrieval System
HAP hazardous air pollutant
HCFC hydrochlorofluorocarbon
ID identification
JEIOG Joint Emission Inventory Oversight Group
LAER lowest achievable emission rate
LAEEM Landfill Air Emissions Estimation Model
Ib pound
LDP locational data policy
EIIP Volume II xi
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ABBREVIATIONS, ACRONYMS, AND
SYMBOLS (CONTINUED)
MACT maximum achievable control technology
MSDS material safety data sheets
MWC municipal waste combustors
NAAQS National Ambient Air Quality Standard
NEC not elsewhere classified
NEDS National Emissions Database System
NEPA National Environmental Policy Act
NATICH National Air Toxics Information Clearinghouse
NADB National Allowance Database
NOX nitrogen oxides
NPL national priority list
NSPS New Source Performance Standard
NSR new source review
NTIS National Technical Information Service
OAQPS Office of Air Quality Planning and Standards
OMB Office of Management and Budget
ORD Office of Research and Development
PC personal computer
PC-BEIS Personal Computer-Biogenic Emissions Inventory System
PL Public Law
PM particulate matter
PM10 particulate matter of aerodynamic diameter less than or equal to 10 micrometers
PM2.5 particulate matter of aerodynamic diameter less than or equal to 2.5 micrometers
POTW publicly owned treatment works
PPM parts per million
xn
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ABBREVIATIONS, ACRONYMS, AND
SYMBOLS (CONTINUED)
PSD prevention of significant deterioration
QA quality assurance
QC quality control
RACT reasonably available control technology
RCRA Resource Conservation and Recovery Act
RE rule effectiveness
RFP reasonable further progress
RVP Reid vapor pressure
SARA Superfund Amendments and Reauthorization Act
SAEWG Standing Air Emissions Work Group
STAPPA State and Territorial Air Pollution Program Administrators
SCC Source Classification Code
SIC Standard Industrial Classification
SIP state implementation plan
SO2 sulfur dioxide
TAP toxic air pollutant
tpy tons per year
TRAC Tracking Responses to Acid Rain Compliance
TRIS Toxic Chemical Release Inventory System
TSDF treatment, storage, and disposal facility
U.S. United States
U.S.C. United States Code
UTM universal transverse mercator
VOC volatile organic compound
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XIV EHP Volume II
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DEFINITIONS OF COMMONLY USED
TERMS
Actual Emissions are the actual rate of emissions of a pollutant from an emissions unit
calculated using the unit's actual operating hours, production rates, and types of materials
processed, stored, or combusted during the selected tune period.
Allowable Emissions are the emissions rate that represents a limit on the emissions that can
occur from an emissions unit. This limit may be based on a federal, state, or local regulatory
emission limit determined from state or local regulations and/or 40 Code of Federal
Regulations (CFR) Parts 60, 61, and 63.
Ambient Standards limit the concentration of a given pollutant in the ambient air. Ambient
standards are not emissions limitations on sources, but usually result in such limits being
placed on source operation as part of a control strategy to achieve or maintain an ambient
standard.
Area Sources are smaller sources that do not qualify as point sources under the relevant
emissions cutoffs. Area sources encompass more widespread sources that may be abundant,
but that, individually, release small amounts of a given pollutant. These are sources for which
emissions are estimated as a group rather than individually. Examples typically include dry
cleaners, residential wood heating, auto body painting, and consumer solvent use. Area
sources generally are not required to submit individual emissions estimates.
Carbon Monoxide (CO) is a colorless, odorless gas that depletes the oxygen-carrying capacity
of blood. Major sources of CO emissions include industrial boilers, incinerators, and motor
vehicles.
Class I Substances as defined in Title VI of the Clean Air Act Amendments include
chlorofluorocarbons (CFCs), halons, carbon tetrachloride, and methyl chloroform. According
to the CAAA, all of these compounds must be phased out of production by the year 2000 with
the exception of methyl chloroform, which must be phased out of production by the year 2002.
Provisions are also made that allow for acceleration of this phaseout.
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CHAPTER 1 - INTRODUCTION 7/7/37
Class II Substances as defined in Title VI of the Clean Air Act Amendments include
hydrochlorofluorocarbons (HCFCs). These substances must be phased out of production by
the year 2015.
Continuous Emissions Monitoring (CEM) is any monitoring effort that "continuously"
measures (i.e., measures with very short averaging times) and records emissions. In addition
to measuring and recording actual emissions during the time of monitor operation, CEM data
can be used to estimate emissions for different operating periods and longer averaging times.
Criteria Pollutants are carbon monoxide (CO), lead (Pb), nitrogen oxides (NOX), sulfur
dioxide (SO2), volatile organic compounds (VOCs), and particulate matter of aerodynamic
diameter less than or equal to 10 micrometers (PM10). The National Ambient Air Quality
Standards (NAAQS) were mandated by the Clean Air Act of 1970, and are based on criteria
including adverse health or welfare effects. NAAQS are currently used to establish air
pollutant concentration limits for the six air pollutants listed above that are commonly referred
to as criteria pollutants.
Design Standards impose certain hardware requirements. For example, a design standard
might require that leaks from compressors be collected and diverted to a control device.
Design standards are typically used when an emissions limit is not feasible.
Emission Concentration Standards limit the mass emissions of a pollutant per volume of air.
Emission concentration standards are expressed in terms such as grams per dry standard cubic
meter (g/dscm) or other similar units.
Emission Factors are ratios that relate emissions of a pollutant to an activity level at a plant
that can be easily measured, such as an amount of material processed, or an amount of fuel
used. Given an emission factor and a known activity level, a simple multiplication yields an
estimate of the emissions. Emission factors are developed from separate facilities within an
industry category, so they represent typical values for an industry, but do not necessarily
represent a specific source. Published emission factors are available in numerous sources.
Emissions Reduction Standards limit the amount of current emissions relative to the amount
of emissions before application of a pollution control measure. For example, an emission
reduction standard may require a source to reduce, within a specified tune, its emissions to
50 percent of the present value.
Emission Standards are a general type of standard that limit the mass of a pollutant
that may be emitted by a source. The most straightforward emissions standard is a simple
limitation on mass of pollutant per unit time (e.g., pounds of pollutant per hour).
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Engineering Estimate is a term commonly applied to the best approximation that can be made
when the specific emission estimation techniques such as stack testing, material balance, or
emission factor age are not possible. This estimation is usually made by an engineer familiar
with the specific process, and is based on whatever knowledge may be available.
Equipment Standards require a specific type of equipment to be used in certain processes.
Equipment standards are typically used when an emissions limit is not feasible.
Fugitive Emissions are emissions from sources that are technically infeasible to collect and
control (e.g., storage piles, wastewater retention ponds).
Hazardous Air Pollutants (HAPs) are listed in Section 112(b) of the 1990 Clean Air Act
Amendments (CAAA). These pollutants are generally emitted in smaller quantities than
criteria pollutants but may be reasonably anticipated to cause cancer, developmental effects,
reproductive dysfunctions, neurological disorders, inheritable gene mutations, or other
chronically or acutely toxic effects in humans. The CAAA specifies an initial list of
189 HAPs to be subject to further regulation. The list of HAPs includes relatively common
pollutants such as formaldehyde, chlorine, methanol, and asbestos, as well as numerous less-
common substances. Pollutants may, under certain circumstances, be added to or deleted from
the list.
Lead (Pb) is an element that causes several types of developmental effects in children
including anemia, neurobehavioral alterations, and metabolic alterations. Lead is emitted from
industries such as battery manufacturing, lead smelters, and incineration. Although regulated
in highway fuels, lead may also be emitted from unregulated off-highway mobile sources.
Material Balance or Mass Balance is a method for estimating emissions that attempts to
account for all the inputs and outputs of a given pollutant. If inputs of a material to a given
process are known and all outputs except for air emissions can be reasonably well quantified,
then the remainder can be assumed to be an estimate of the amount lost to the atmosphere for
the process.
Maximum Achievable Control Technology (MACT) Standards in addition to National
Emissions Standards for Hazardous Air Pollutants (NESHAP), are promulgated under Section
112 of the Clean Air Act Amendments (CAAA). Technically NESHAP and MACT standards
are separate programs. MACT standards differ from older NESHAPs because MACT
standards are mandated by law to require the maximum achievable control technology.
MACT standards are source category-specific, and each standard covers all the pollutants
listed in Section 112 of the CAAA that are emitted by that source category. The first MACT
standard promulgated (for the Synthetic Organic Chemical Manufacturing Industries) was
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CHAPTER 1 - INTRODUCTION 7/1/97
originally developed as a NESHAP and is still referred to as the Hazardous Organic NESHAP
(HON).
Means of Release to the Atmosphere is the mechanism by which emissions enter the
atmosphere. Environmental agencies usually classify release mechanisms into three
categories: process emissions, fugitive emissions, and process fugitive emissions. This
characteristic of an emission source is important because emission factors and other estimation
methods are specific to the type of release.
Mobile Sources include all nonstationary sources, such as automobiles, trucks, aircraft, trains,
construction and farm equipment, and others. Mobile sources are a subcategory of area
sources, and are generally not required to submit individual emissions estimates.
National Ambient Air Quality Standards (NAAQS) are the main ambient standards for the
following six criteria pollutants: carbon monoxide (CO), lead (Pb), nitrogen oxides (NOX),
sulfur oxides (SOX), ozone (O3), and particulate matter of aerodynamic diameter less than or
equal to 10 micrometers (PM10).
National Emissions Standards for Hazardous Air Pollutants (NESHAP) are a class of
standards limiting emissions of HAPs. The common usage of NESHAP actually refers to two
different sets of standards. First, there are 22 emissions standards promulgated prior to the
1990 Clean Air Act Amendments (CAAA). Some of these standards are pollutant-specific
(e.g., the NESHAP for vinyl chloride), others are source-category specific (e.g., the NESHAP
for benzene waste operations), and still others are both pollutant- and source-category specific
(e.g., the NESHAP for inorganic arsenic emissions from glass manufacturing plants).
New Source Performance Standards (NSPS) are promulgated for criteria, hazardous, and
other pollutant emissions from new, modified, or reconstructed sources that the
U.S. Environmental Protection Agency (EPA) determines contribute significantly to air
pollution. These are typically emission standards, but may be expressed in other forms such
as concentration and opacity. The NSPS are published in 40 Code of Federal Regulations
(CFR) Part 60.
Nitrogen Oxides (NOX) are a class of compounds that are respiratory irritants and that react
with volatile organic compounds (VOCs) to form ozone (O3). The primary combustion
product of nitrogen is nitrogen dioxide (NO2). However, several other nitrogen compounds
are usually emitted at the same time (nitric oxide [NO], nitrous oxide [N2O], etc.), and these
may or may not be distinguishable in available test data. They are usually in a rapid state of
flux, with NO2 being, in the short term, the ultimate product emitted or formed shortly
downstream of the stack. The convention followed in emission factor documents is to report
the distinctions wherever possible, but to report total NOX on the basis of the molecular weight
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of NO2. NOX compounds are also precursors to acid rain. Motor vehicles, power plants, and
other stationary combustion facilities emit large quantities of NOX.
Opacity Standards limit the opacity (in units of percent opacity) of the pollutant discharge
rather than the mass of pollutant.
Operational Standards impose some requirements on the routine operation of the unit. Such
standards include maintenance requirements or operator training certification requirements.
Operational standards are typically used when an emission limit is not feasible.
Ozone (O3) is a colorless gas that damages lungs and can damage materials and vegetation. It
is the primary constituent of smog, and is formed primarily when nitrogen oxides (NOX) and
volatile organic compounds (VOCs) react in the presence of sunlight. It is also emitted in
insignificant quantities from motor vehicles, industrial boilers, and other minor sources.
Particulate Matter of aerodynamic diameter less than or equal to 10 micrometers (PM10) is a
measure of small solid matter suspended in the atmosphere. Small particles can penetrate
deeply into the lung where they can cause respiratory problems. Emissions of PM10 are
significant from fugitive dust, power plants, commercial boilers, metallurgical industries,
mineral industries, forest and residential fires, and motor vehicles.
Particulate Matter of aerodynamic diameter less than or equal to 2.5 micrometers (PM25) is
a measure of fine particles of particulate matter that come from fuel combustion, agricultural
burning, woodstoves, etc. On November 27, 1996 the U.S. Environmental Protection Agency
proposed to revise the current primary (health-based) PM standards by adding a new annual
PM2.5 standard.
Plant Level Emissions are consolidated for an entire plant or facility. A plant may contain
one or many pollutant-emitting sources.
Plant Level Reporting is generally required if total emissions from a plant (which may be
composed of numerous individual emission points) meet the point source cutoff. These data
can be used by the state to conduct a detailed estimate of emissions from that plant. The plant
level reporting used by most air pollution control agencies generally requires that the facility
provide data that apply to the facility as a whole. Such data include number of employees and
the Standard Industrial Classification (SIC) code designation for the plant. A plant usually has
only one SIC code denoting the principal economic activity of the facility. For the purpose of
clearly identifying and tracking emissions data, each plant is generally assigned a plant
(alternatively, "facility") name and number. The plant is also identified by geographic or
jurisdictional descriptors such as air quality control region, county, address, and universal
transverse mercator (UTM) grid coordinates (or latitude/longitude) that identify a coterminous
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location. An owner or operator engaged in one or more related activities is also identified. In
some cases, plantwide emissions may be reported at the plant level.
Point Level Emissions typically represent single stacks or vents individually large enough to
be considered point sources.
Point Level Reporting includes specific data for individual emission points (typically stacks).
These data are more detailed than that submitted in Plant Level Reporting and may include
emission-related and modeling information such as stack height of the release point, diameter
of the stack, emission rate, method of determination, fugitive emissions, gas exit velocity from
a stack, gas temperature, and operating schedule. Source identification information, as
previously described under Plant Level Reporting, is usually also required at the point level to
ensure that emission data for a single plant remain clearly identified. Regulatory agencies
generally maintain individual emission-related records at the point level.
Point Sources are large, stationary, identifiable sources of emissions that release pollutants
into the atmosphere. Sources are often defined by state or local air regulatory agencies as
point sources when they annually emit more than a specified amount of a given pollutant, and
how state and local agencies define point sources can vary. Point sources are typically large
manufacturing or production plants. They typically include both confined "stack" emission
points as well as individual unconfmed "fugitive" emission sources.
Within a given point source, there may be several emission points that make up the point
source. Emissions point refers to a specific stack, vent, or other discrete point of pollution
release. This term should not be confused with point source, which is a regulatory distinction
from area and mobile sources. The characterization of point sources into multiple emissions
points is useful for allowing more detailed reporting of emissions information.
For point sources, the emission estimate reporting system used by most state and local air
regulatory agencies groups emission sources into one of three categories and maintains
emission-related data in a different format for each. The three categories are plant level, point
level, and process or segment level.
Potential Emissions are the potential rate of emissions of a pollutant from an emissions unit
calculated using the unit's maximum design capacity. Potential emissions are a function of the
unit's physical size and operational capabilities.
It is important to note that annual potential emissions from a unit are not necessarily the
product of 8760 hours per year times the hourly potential emissions. For most processes, the
operation of one piece of equipment is limited in some way by the operation of another piece
of equipment upstream or downstream. For example, consider a batch process involving
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vessels X, Y, and Z in series (i.e., the output from Vessel X is the feed to Vessel Y, and the
output from Vessel Y is the feed to Vessel Z) where the residence time for each vessel is
different. In this process, Vessel Y may not operate 8760 hours per year because either the
output from Vessel X is not feeding Vessel Y at all times or Vessel Z may not always be
available to accept the output from Vessel Y.
It is also possible for the emission rate to vary over tune. For instance, if a reaction requires
6 hours to reach completion, the emissions from the reaction vessel during the first hour will
be different than those during the last hour. Thus, the highest hourly emission rate is not
sustained during the entire cycle or for the entire year.
Process-based Emission Standards limit the mass emissions per unit of production. These
standards may limit mass emissions per unit of material processed or mass emissions per unit
of energy used. As process rate increases (e.g., an increase in tons of ore processed per
hour), the allowable emissions increase (e.g., an increase in pounds of pollutant per hour).
Process Emissions are emissions from sources where an enclosure, collection system, ducting
system, and/or stack (with or without an emission control device) is in place for a process.
Process emissions represent emissions from process equipment (other than leaks) where the
emissions can be captured and directed through a controlled or uncontrolled stack for release
into the atmosphere.
Process Fugitive Emissions occur as leaks from process equipment including compressors,
pump seals, valves, flanges, product sampling systems, pressure relief devices, and open-
ended lines. Emissions from the process that are not caught by the capture system are also
classified as process fugitive emissions.
Process or Segment Level Emissions usually represent a single process or unit of operation.
Process or Segment Level Reporting involves each process within a plant being identified by a
U.S. Environmental Protection Agency (EPA) source classification code (SCC). For point
sources, reporting guidelines may require that a plant identify, for each process or operation
(designated by SCC), the periods of process operation (daily, weekly, monthly, annually);
operating rate data including actual, maximum, and design operating rate or capacity; fuel use
and fuel property data (ash, sulfur, trace elements, heat content, etc.); identification of all
pollution control equipment and their associated control efficiencies (measured or design); and
emissions rates. Source identification information, as previously described under Plant Level
Reporting, is usually also required at the process level to ensure that emissions data for a
single plant are clearly identified.
EIIP Volume II XXI
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CHAPTER 1 - INTRODUCTION 7/1/97
•
Process-specific Empirical Relationships are similar to emission factors in that they relate
emissions to easily identifiable process parameters. However, these relationships are
represented by more detailed equations that relate emissions to several variables at once, rather
than a simple ratio. An example is the estimate for volatile organic compound (VOC)
emissions from storage tanks that is based on tank size and throughput, air temperature, vapor
pressure, and other variables.
Reported Emissions are those emission estimates that are submitted to a regulatory agency.
Emissions inventories can be used for a variety of purposes such as State Implementation Plan
(SIP) base year inventories, environmental compliance audits, air quality rule applicability,
and reporting information hi an air quality permit application. Emissions can be reported on
an actual, potential, or maximum basis. Many state and local ah" pollution control agencies
have rules and regulations that define an allowable emission value for a particular piece of
equipment. Because of this, a facility should first define the purpose of the inventory and then
choose the appropriate means of reporting emissions to the regulatory agency. For example,
SIP base year inventories for point sources would contain actual emissions. However,
regulatory applicability and air quality permit applications can require that actual, allowable,
and potential emissions be reported.
Source Tests are short-term tests used to collect emissions data that can then be extrapolated to
estimate long-term emissions from the same or similar sources. Uncertainties arise when
source test results are used to estimate emissions under process conditions that differ from
those under which the test was performed.
Stratospheric Ozone-depleting Compounds are chlorofluorocarbons (CFCs), halons, carbon
tetrachloride, methyl chloroform, and hydrochlorofluorocarbons (HCFCs). These pollutants
are regulated by Title VI of the Clean Air Act Amendments (CAAA) because they may
destroy stratospheric ozone. Title VI is primarily designed to limit the manufacture of these
materials, not their use. The pollutants are divided into two classes (Class I and Class II)
based on the dates by which their manufacture must be discontinued. Methods to estimate
emissions of ozone-depleting compounds are not discussed in Emission Inventory Improvement
Program (EIIP) documents. Information on emissions of ozone-depleting compounds can be
obtained from the U.S. Environmental Protection Agency (EPA) Office of Atmospheric and
Indoor Air Programs, Global Climate Change Division, located at EPA Headquarters in
Washington, D.C.
Sulfur Oxides (SOX) are a class of colorless, pungent gases that are respiratory irritants and
precursors to acid rain. Sulfur oxides are emitted from various combustion or incineration
sources, particularly from coal combustion.
XXll EUR Volume II
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7/1/97 CHAPTER 1 - INTRODUCTION
Volatile Organic Compounds (VOCs) react with nitrogen oxides (NOX) in the atmosphere to
form ozone (O3). Although not criteria pollutants, VOC emissions are regulated under criteria
pollutant programs because they are ozone precursors. Large amounts of VOCs are emitted
from motor vehicle fuel distribution, chemical manufacturing, and a wide variety of industrial,
commercial, and consumer solvent uses.
The use of certain photochemical models requires estimation of methane, ethane, and several
other less photochemically reactive compounds and particulates. While not regulated as
VOCs, these compounds may need to be estimated for certain modeling inventories or to meet
certain state inventory requirements. For this reason, the term total organic compounds
(TOCs) is used to refer to this broader class of chemicals.
Work Practice Standards require some action during the routine operation of the unit. For
example, volatile organic compound (VOC) monitoring of a compressor might be required on
a quarterly basis to ensure no leaks are occurring. Work practice standards are typically used
when an emission limit is not practical.
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XX1V EIIP Volume II
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1
INTRODUCTION
1.1 BACKGROUND
The Clean Air Act, as amended in 1990 (hereafter referred to as the CAA), has expanded the
continuing role of the U.S. Environmental Protection Agency (EPA) in its effort to improve
air quality in the United States. Among the mandates set forth in the CAA is the requirement
that the EPA improve the quality of emission estimates of air pollutants.
Over the last two decades, the CAA and numerous other federal, state, and local programs
have required industry to report the amount of air pollutants emitted. With the CAA in place,
it is useful for industry to understand the methods used to estimate emissions in order to
comply with regulations.
The Emission Inventory Improvement Program (EIIP) is a joint program of the EPA, Standing
Air Emissions Work Group (SAEWG), and the State and Territorial Air Pollution Program
Administrators and the Association of Local Air Pollution Control Officials
(STAPPA/ALAPCO). The ultimate goal of the EIIP is to provide cost-effective, reliable
inventories by improving the quality of emissions data collected and provide for uniform
reporting of this information. These emissions-related data will be made available to state and
local agencies, the regulated community, the public, and EPA. The EIIP has been designed to
increase the likelihood that acceptable quality emission inventory data will be available. The
use of these procedures will promote consistency in these activities among the emission
inventory reporting groups.
Using standardized approaches enables federal, state, and local agencies to generate data of
known quality at acceptable or reasonable costs. The EIIP has implemented this concept by
selecting preferred and alternative methods for use in determining emissions for various source
categories of interest. Their findings are reported in the following series of guidance
documents:
• Volume I: Introduction and Use of EIIP Guidance for Emissions Inventory
Development
• Volume II: Point Sources Preferred and Alternative Methods
• Volume III: Area Sources Preferred and Alternative Methods
• Volume IV: Mobile Sources Preferred and Alternative Methods
EIIP Volume II 1.1-1
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CHAPTER 1 - INTRODUCTION
7/1/97
• Volume V: Biogenic Sources Preferred and Alternative Methods
• Volume VI: Quality Assurance Procedures
• Volume VII: Data Management Procedures
Volume II in the series of EIIP guidance documents is intended to familiarize the private and
government sectors with the basic concepts and procedures involved in estimating air pollutant
emissions from point sources. Volume II should also be used to provide state agencies with
instructional guidance on preferred methods for developing emission inventories for point
sources.
Point sources are those facilities/plants/activities for which individual source records are
maintained in the inventory. Under ideal circumstances, all sources would be considered point
sources. However, in practical applications, only sources that emit (or have the potential to
emit) more than some specified cutoff level of emissions are considered point sources.
Area sources, in contrast, are those activities for which aggregated source and emissions
information is maintained for entire source categories rather than for an individual source.
Sources not treated as point sources should be included in an area source inventory. Area
sources are addressed in Volume III of the EIIP series of guidance documents.
Volume II consists of various combustion, manufacturing, and production activities that
comprise point sources. The major chapters within Volume II at various stages of production
are as follows:
Chapter 1: Introduction to Stationary Point Source Emission Inventory Development
Chapter 2: Preferred and Alternative Methods for Estimating Air Emissions from
Boilers
Chapter 3: Preferred and Alternative Methods for Estimating Air Emissions from
Hot-Mix Asphalt Plants
Chapter 4: Preferred and Alternative Methods for Estimating Fugitive Air Emissions
from Equipment Leaks
Chapter 5: Preferred and Alternative Methods for Estimating Air Emissions from
Wastewater Collection and Treatment
Chapter 6: Preferred and Alternative Methods for Estimating Air Emissions from
Semiconductor Manufacturing Facilities
1.1-2
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7/7/57
CHAPTER 1 - INTRODUCTION
Chapter 7: Preferred and Alternative Methods for Estimating Air Emissions from
Surface Coating Operations
Chapter 8: Preferred and Alternative Methods for Estimating Air Emissions from
Paint and Ink Manufacturing Facilities
Chapter 9: Preferred and Alternative Methods for Estimating Air Emissions from
Metal Production Facilities
Chapter 10: Preferred and Alternative Methods for Estimating Air Emissions from Oil
and Gas Field Production and Processes
Chapter 11: Preferred and Alternative Methods for Estimating Air Emissions from
Plastic Products Manufacturing
Each industry- or source-specific document contains a brief process description; identification
of emission points; an overview of methods available for estimating emissions; example
calculations for each technique presented; a brief discussion on quality assurance and quality
control; and the source classification codes (SCCs) needed for entry of the data into a database
management system. The SCCs included in each volume apply to the process emission points,
in-process fuel use, storage tank emissions, fugitive emissions, and control device fuel (if
applicable).
1.2 PURPOSE OF CHAPTER 1
Chapter 1 provides an introduction to air pollutant emission assessment, the basic procedures
involved in estimating emissions, and industry-specific techniques for estimating emissions.
This introductory chapter of Volume II is intended to introduce the information applicable to
all stationary point sources as well as identify basic concepts of emission estimation
techniques. Practical, detailed calculations and procedures applicable to a specific category
are found within subsequent chapters (documents). These later chapters present several
different estimation scenarios and provide example calculations to aid in actual emission
estimation. Figure 1.1-1 is included to assist readers tasked with inventory preparation in
decision making and to refer them to the applicable chapters within this volume and other
volumes in the EIIP series. Cumulatively, the chapters of Volume II provide a comprehensive
series of manuals which should successfully serve the user in generating a point source
emissions inventory.
EIIP Volume II
1.1-3
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CHAPTER 1 - INTRODUCTION
7/1/97
Federal/State
Agency
Determine which sources
will be inventoried
Define level of detail needed: choose
appropriate data collection method
Chapter 1
Set data quality objectives;
prepare QA plan
Volume VI
Distribute
Follow-up with
non respondents
Make a list of all sources
of emissions within the facility
Chapter 1
Identify appropriate method
for calculating emissions
and collect data needed
For
each
emission
unit
within
facility
Complete and return questionnaire
and/or inventory
1.1-4
FIGURE 1.1-1. POINT SOURCE INVENTORY DEVELOPMENT PROCESS
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7/7/37 CHAPTER 1 - INTRODUCTION
1.3 ORGANIZATION OF CHAPTER 1
Section 2 of this chapter identifies several purposes for industry to generate emissions
estimates including federal and state regulations, and plant initiatives. Section 3 discusses the
emission inventory planning effort, including data handling and documentation requirements.
Section 4 describes the basic techniques employed to estimate emissions, including emission
factors, source tests, models, and material balances. Section 5 describes the basic procedures
followed for data collection and the types of data available for estimating emissions. Section 7
describes quality assurance and quality control procedures and Volume VI of the EIIP series
describes quality assurance and quality control procedures in detail. References are provided
in Section 8.
Appendix A includes the table of contents from AP-42, 5th Edition and Appendix B provides
useful conversion factors. Appendix C provides various contact and resource information, and
Appendix D presents an example checklist to use to guarantee the completeness of the
emissions inventory. Appendix E provides a brief description of the test methods described in
individual chapters throughout Volume II. Information on emission estimation tools are
presented in Appendix F.
EIIP Volume I I . 1.1-5
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1-1-6 El I P. Volume II
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PURPOSES FOR ASSESSING
EMISSIONS
In order to comply with various federal and state regulations, sources must initiate an
emissions estimation effort. This section primarily focuses on the federal requirements for
reporting emissions, while typical state requirements are also briefly discussed. Figure 1.2-1
provides an overview of some of the key emissions estimation relationships among industry,
and state and federal agencies (EPA, 1993a).
2.1 FEDERAL REQUIREMENTS
Various federal requirements are linked to emissions estimation requirements. The major
federal requirements for both sources and states, with emphasis on those requirements that are
likely to lead to emissions estimation requirements for industry, are discussed in this section.
Requirements discussed stem mainly from the Clean Air Act, and from other legislation such
as the National Environmental Policy Act (NEPA), the Comprehensive Environmental
Recovery and Comprehensive Liability Act (CERCLA), the Super fund Amendments and
Reauthorization Act (SARA), the Resource Conservation and Recovery Act (RCRA), and the
Pollution Prevention Act. Additional requirements stem from policy issued by the EPA, the
Department of Energy (DOE), and the Department of Defense (DoD). The form and content
of the specific emissions information varies with each requirement. A useful source for
identifying which specific data elements are necessary under each requirement is the document
entitled Integrated Reporting Issues: Preliminary Findings (EPA., 1992e). Table 1.2-1
provides an overview of the key federal emissions estimation requirements. In addition,
Table 1.2-2, taken from the Integrated Reporting Issues document, provides an overview of
the data elements contained in the major emissions reporting programs described in this
section.
2.1.1 CLEAN AIR ACT REQUIREMENTS
The Clean Air Act is the major legislation addressing air pollution in the United States. It
mandates a wide variety of programs to manage air quality. The federal air quality
management effort begins with the national ambient air quality standards (NAAQS). The
NAAQS set nationwide minimum air quality goals. Each state must assess all areas' air
El IP Volume 11 1.2-1
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CHAPTER 1 - INTRODUCTION
7/1/97
Plant
Level
Engineer
Design/
Specifications for
Emitting Processes
and Control
Systems
Production
and Control
Recordkeeping;
Material
Tracking
Sampling/
Analysis of
Process and
Waste
Streams
Emission Estimation
Permit
Applications and
Renewals
(Periodic)
Emission
Statements
(Annual)
Other State Implementation
Plan. (SIR) Activities
State Implementation
PJan_(SlP.)_lnvejilocies
State Agency
ventory/System
Control Strategy Development
Air Quality Modeling
Regulatory Development
Initial Submittals
Tracking
State Programs/
Activities
EPA SIP
Review and
Approval
Federal
Level
Permit Fee
Determination
I
State Review/
Approval
(EPA Permit |
Review/Approval I
FIGURE 1.2-1. KEY RELATIONSHIPS FOR INDUSTRY AIR POLLUTANT
EMISSION ESTIMATION
1.2-2
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^
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^
TABLE 1.2-1
OVERVIEW OF KEY FEDERAL EMISSION ESTIMATION REQUIREMENTS
Statutory Requirement
and Agency
Pollutant
Due Date
Size Cutoff
Data Requirements
Annual AIRS Update
40 CFR 51.321
Agency: State to EPA
PM10, sulfur oxides,
VOC, NOX, CO, and lead
July 1 , annually
Facility- 1 00 tpy PM10, sulfur
oxides, VOC, and NOx;
100 tpy CO; 5 tpy lead.
Point-25 tpy PMIO, sulfur
oxides, VOC, and NOx;
250 tpy CO; and 5 tpy lead
General plant information, year of
inventory, general operating parameters,
emissions data, and control equipment
data
Emission Inventory (base year and periodic)
Clean Air Act
Section 172(c)(3)
Section 182(a)(l)a
Section 182(a)(3)(A)a
Section 187(a)(l)b
Agency: State to EPA
All criteria pollutants
November 15, 1992
and every 3 years
thereafter
Point sources- 10 tpy VOC;
100 tpy PM10 moderate;
70 tpy PM10 serious
General plant information; year of
inventory, source operating data, physical
data (i.e., stack height, process rate data,
source emissions data, and emission
limitation data)
Emission Statement
Clean Air Act
Section 182(a)(3)(B)c
Agency: Source to state
VOC, NOX
April 15, annually;
25 tpy VOC or NOX; in
nonattainment area; 50 tpy
VOC or 100 tpy NOx in
attainment portion of transport
region
Source identification, source emissions
data (annual and typical summer day),
control equipment data, process rate data
and a certification that the data are
accurate
i
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Is)
TABLE 1.2-1
(CONTINUED)
Statutory Requirement
and Agency
Pollutant
Due Date
Size Cutoff
Data Requirements
Title V Operating Permits
Clean Air Act Title V
Agency: Source to state
All criteria pollutants, all
HAPs, CFCs, HCFCs
At time of initial
Title V permit
application submittal,
which is generally one
year after EPA
approval of state
permit program.
Annual submission
according to state
schedule to determine
fee basis.
Potential to emit "major"
amounts of regulated air
pollutantsd.e
General company information, plant
description, emissions information,
regulatory requirements and compliance
information
New Source Review
Clean Air Act
Section 172(c)(5)
Agency: Source to state
Criteria pollutants,
fluorides, sulfuric acid
mist, hydrogen sulfide,
total reduced sulfur,
reduced sulfur
compounds, MWC
organics, metals and
gases, ozone-depleting
substancesf
Prior to construction or
operation of a new or
modified major source
Potential to emit "major"
amounts for new sources,
significant net emissions
increase for modified sources
Legal authority, technical specifications,
potential emissions, emission compliance
demonstration, definition of excess
emissions, administrative and other
conditions
Economic Incentive Programs (EIP)
40CFRPart51 (some
required, some optional)
Agency: Source to state
All criteria pollutants
Specific to individual
EIP
Majord
Specific to individual EIP. Emissions
must be "quantifiable."
I
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TABLE 1.2-1
(CONTINUED)
XI
Statutory Requirement
and Agency
Pollutant
Due Date
Size Cutoff
Data Requirements
Early Reductions Program
Clean Air Act
Section U2(i)(5)
Agency: Source to state
All HAPs as defined in
Section 112(b)
Reduction must be
achieved before
January 1, 1994,
therefore
demonstration must
come before then
Any stationary source
Same as permit with the early reduction
demonstration
Urban Air Toxics Program
Clean Air Act
Section 112(k)
Agency: EPA to Congress
All HAPs as defined in
Section 112(b)or(k)
EPA must report by
November 15, 1993
Any source of HAPs
contributing to urban
concentrations, with emphasis
on area sources
Data as necessary to characterize
emissions of HAPs and prioritize threats
to public health in urban areas
Great Lakes and Coastal Waters Program
Clean Air Act
Section 112(m)
Agency: EPA to Congress
All HAPs as defined in
Section 112(b)
EPA must report by
November 15, 1993,
and biennially
thereafter
Any source contributing to
deposition of HAPs
Data as necessary to determine sources
and deposition rates of HAPs
Accidental Release Program
Clean Air Act
Section 112(r)
All extremely hazardous
substances as defined in
regulation developed
under Section 112(r)
As specified in
Section 112(r)
regulations to be
published
Sources emitting amounts
above threshold quantities as
specified in Section 1 12(r)
regulations to be published
Risk management plan including estimate
of potential release quantities,
determination of downwind effects,
previous release history, and an
evaluation of the worst case accidental
release
i
t)
§
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TABLE 1.2-1
(CONTINUED)
Statutory Requirement
and Agency
Pollutant
Due Date
Size Cutoff
Data Requirements
New Source Performance Standards
40 CFR Part 60
Agency: Source to state
agency or EPA
SO2, NOX, total reduced
sulfur, hydrogen sulfide,
CO, opacity, VOC, PM
30 days after reporting
period ends
As specified in standard
Pollutant, reporting period, general
company information, emission
limitation, monitor manufacturer and
model number, data of last CMS
certification or audit, process units
description, total source operating time,
emissions data, CMS performance data
Acid Rain Allowance Trading (Title IV)
Title IV Clean Air Act
S02, NOX
30 days after end of
quarter (beginning
January 30, 1994 for
Phase I and April 30,
1995 for Phase II)
Any facility listed in Table A
or B of Title IV or any facility
that opts-in (Phase I approx.
110 sources, Phase II approx.
800 sources). Also applies to
any new fossil-fuel
combustion device that
supplies electricity for sale or
serves an electricity-
generating device that
supplies electricity for sale.
General plant information, emissions
data, fuel use data
Section 114 General Requirements (i.e., "Section 114 letter")
Clean Air Act Section 114
Agency: Source to EPA
As specified by EPA
As specified by EPA
Determined case-by-case by
EPA
General company information, pollutant,
compliance information, operating
information
i
t!
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TABLE 1.2-1
(CONTINUED)
Statutory Requirement
and Agency
Pollutant
Due Date
Size Cutoff
Data Requirements
Section 114 Compliance Certification
Clean Air Act
Section 114(a)(3)
Agency: source to EPA
All criteria pollutants and
all hazardous air
pollutant as defined in
Section 112(a)(l)
30 days after quarter
ends, on a quarterly or
annual basis
Majord
General company information, pollutant,
emission information, description of
enhanced monitoring system, summary of
compliance demonstration, deviation
description, violation information, and
operation data
National Air Toxics Information Clearinghouse (NAT1CH)
Clean Air Act
Section 11 2(1 )(3)
Agency: State/local agency
to EPA
Any hazardous air
pollutant (i.e., any
noncriteria air pollutant)
Voluntary
Voluntary
Agency name, general plant information,
year permit issued, control equipment
data, pollutant names, emission limit
data, actual emission rate data, source
testing data
Best Available Control Technology (BACT)TLowest Achievable Emission Rate (LAER) Clearinghouse
N.A.
Agency: State/local agency
to EPA
Criteria pollutants
Voluntary - after
issuance of a BACT or
LAER determination
Voluntary
General company information, plant
description, year permit issued, emissions
data, control technology data, compliance
data
National Environmental Policy Act (NEPA)
PL 91-190
Agency: EPA
Anything that may result
in a "significant
environmental impact"
Prior to
implementation of any
federal agency action
NA
Description of the proposed action,
alternatives to the action, and
environmental, social, and economic
impacts of the proposed action and
alternatives. May lead to specific
requests from EPA to industry
1
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TABLE 1.2-1
i
(CONTINUED)
Statutory Requirement
and Agency
Pollutant
Due Date
Size Cutoff
Data Requirements
Comprehensive Environmental Recovery and Comprehensive Liability Act (CERCLA)
PL 96-510, amended SARA
42 U.S.C. Section 9601
Agency: Source to state
Chemicals listed in
Sections 307, 311 of
Clean Water Act, Section
3001 of RCRA,
Section 112ofCAA,
Section 7 of Toxic
Substances Control Act,
others designated by
EPA under Superfund
Upon release
Releases to the environment
that exceed the reportable
quantity for that material
Report on release of the toxic substance,
including substance and quantity
released. (See SARA Section 304.)
Superfund Amendments and Reauthorization Act (SARA)
SARA Title III Section 313
("right to know")
Agency: EPA and states
SARA Section 304
(hazardous releases)
Agency: Source to public
EPA designated "toxic
chemicals" (329 on
original list; 284 added
1995)
Hazardous substances as
defined by CERCLA,
extremely hazardous
substances as defined by
EPA
July 1 , annually
Immediately upon
release
Chemicals used z 10,000 Ib/yr,
chemical manufactured or
processed 225,000 Ib/yr
Any episode that releases
more than published
reportable quantity
Chemical identify, name, location and
principal business identity, certification
by senior officials of business, use of
each listed chemical, maximum on-site
quantity at any time, amount (Ib/yr)
released to the environment of each
chemical, amount (Ib/yr) transferred
offsite, method of waste treatment and
disposal including treatment efficiency,
release data (fugitive air emissions in
Ib/yr, stack/point air emissions in Ib/hr,
wastewater discharges, releases to land,
transfers to off-site locations,
underground injection)
Chemical name or identity, quantity
released, time and duration of release,
media into which released, anticipated
health risks, medical attention
requirements, precautions, evacuation
information, name of person to contact
for more information
1
§
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TABLE 1.2-1
(CONTINUED)
Statutory Requirement
and Agency
Pollutant
Due Date
Size Cutoff
Data Requirements
Resource Conservation and Recovery Act (RCRA)
40 CFR Subtitle C
Agency: Source to EPA
Pollution Prevention Act
PL 101 -508 Section 6607
Agency: Source to EPA
Hazardous waste as
defined by 40 CFR
261.31, acutely defined
by 40 CFR 26 1.33
EPA designated "toxic
chemicals"
Biennially
Annually
Small generators: 100-1000 kg
non-acutely hazardous
waste/month; large generators
>1 kg acutely hazardous
waste, >1000 kg non-acutely
hazardous waste/month
Chemicals used i 10,000 Ib/yr,
chemical manufactured or
processed i25,000 Ib/yr
EPA ID number, record of hazardous
waste transfers (manifests), records of any
test results, waste analyses, etc., waste
minimization plan
Toxic chemical source reduction and
recycling report
Source: EPA, 1993a.
a For ozone.
b For CO.
c The periodic inventory requirement is only for ozone nonattainment areas.
d Definition of major and significant net emissions increase depends on pollutant (e.g., for ozone it depends on an area's classification).
e Additional nonmajor sources may be added by EPA rule expected in late 1990s.
f Applicability determination is based on emissions of all pollutants regulated under the Act. However, emission inventory submitted to
the state is generally on pollutants listed to determine control technology requirements.
CMS = Continuous Monitoring System.
NADB = National Allowance Database.
ARDS = Acid Rain Data System.
TRAC = Tracking Responses to Acid Rain Compliance.
NA = Not applicable.
1
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CHAPTER 1 - INTRODUCTION
7/1/97
TABLE 1.2-2
COMPARISON OF EMISSIONS REPORTING PROGRAM DATA ELEMENTS
Data Element
Triennial
Inventory
(State to
EPA)
AIRS
Annual
Update
(State to
EPA)
Permit
Program3
(Source to
State)
Emission
Statement
(Source to
State)
Plant - General Level
FIP State Code
FIP County Code
Year of Record
Plant AFS/NEDS ID
Plant Name
Plant Address
FIP City Code
Plant Zip Code
UTM Zone, Easting, and
Northing or Latitude and
Longitude
Primary SIC Code
Type of Inventory
Annual Nonbanked Emissions
(Estimated Actual)
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
Point - General Level
FIP State Code
FIP County Code
Plant AFS ID
Point AFS ID
Operating hours/day
Operating days/week
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
1.2-10
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7/7/57
CHAPTER 1 - INTRODUCTION
TABLE 1.2-2
(CONTINUED)
Data Element
Operating hours/year
Percent throughput: Dec-Feb
Percent throughput: Mar-May
Percent throughput: Jun-Aug
Percent throughput: Sep-Nov
Triennial
Inventory
(State to
EPA)
/
/
/
/
/
AIRS
Annual
Update
(State to
EPA)
/
/
/
/
/
Permit
Program3
(Source to
State)
Emission
Statement
(Source to
State)
/
/
/
/
/
Stack Level
FIP State Code
FIP County Code
Plant AFS ID
Stack AFS ID
Stack Height
Stack Diameter
Plume Height
/
/
/
/
/
/
/
/
/
/
/
/
/
/
Segment - General Level
FIP State Code
FIP County Code
Plant AFS ID
Point AFS ID
Segment AFS ID
SCC Number
Process Rate Units
Actual Annual Process Rate
/
/
/
/
/
/
/
^
/
/
/
/
/
/
/
/
/
/
/
/
/
/
Vo/yme //
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CHAPTER 1 - INTRODUCTION
7/1/97
TABLE 1.2-2
(CONTINUED)
Data Element
Ozone Season Daily Process
Rate
CO Season Daily Process Rate
Stack ID for Segment
Triennial
Inventory
(State to
EPA)
/
/
/
AIRS
Annual
Update
(State to
EPA)
Permit
Program3
(Source to
State)
Emission
Statement
(Source to
State)
/
Segment - Pollutant Level
FIP State Code
FIP County ID
Plant AFS ID
Point AFS ID
Segment AFS ID
Pollutant/CAS Number
Primary Control Device Code
Secondary Control Device
Code
Control Efficiency
SIP Regulation in Place
Compliance Year for Segment
Emission Limitation
Description
Emission Limitation Value
Emission Limitation Units
Emission Estimation Method
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
^
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
^
/
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7/7/37
CHAPTER 1 - INTRODUCTION
TABLE 1.2-2
(CONTINUED)
Data Element
Emission Factor
Annual Nonbanked Emissions
(Estimated Actual)
Rule Effectiveness
Ozone Season Daily Emissions
CO Season Dailv Emissions
Triennial
Inventory
(State to
EPA)
/
7
/
/
/
AIRS
Anneal
Update
(State to
EPA)
/
7
Permit
Program"
(Source to
State)
Emission
Statement
(Source to .
State)
/
'
/
/
Source: EPA, 1992e.
a Proposed AFS permit enhancements.
EIIP Volume II
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CHAPTER 1 - INTRODUCTION 7/7/57
quality relative to the NAAQS. For those areas meeting the standard, the state is required to
submit plans showing prevention of significant deterioration (PSD).
For nonattainment areas, the state must develop and submit to EPA a detailed, comprehensive
and legally binding plan to meet the NAAQS by a specified date and to continue to meet the
NAAQS beyond that date. This legally binding plan is called a state implementation plan
(SIP). In the SIP, each state has the responsibility for selecting a control strategy that
determines which sources must control emissions and the degree of control needed to achieve
and/or maintain the NAAQS. States that have been totally or partially designated as
nonattainment areas must develop emissions inventories as part of their SIP to reduce
emissions. If the state fails to submit an adequate plan, the EPA will impose its own plan,
called a federal implementation plan (FIP).
In addition to those requirements related to maintenance of the NAAQS, other federal-state
programs addressing emissions of various air pollutants have also been established to improve
air quality. These include emissions standards for hazardous air pollutants (HAPs), emission
and fuel standards for motor vehicles, provisions for control of acid deposition, requirements
for operating permit programs, and stratospheric ozone protection. The following sections
briefly describe these programs.
SIP Requirements (CAA Amendments, Title I)
The CAA requires that the base year SIP inventories be prepared according to a set of
minimum standards. The requirements for ozone and CO SIP inventories are listed in
Table 1.2.3.
Operating Permits Program (CAA Amendments, Title V)
Title V of the Clean Air Act mandates that states establish operating permits programs
requiring the owners or operators of major and other sources to obtain permits addressing all
applicable pollution control obligations under the CAA. These obligations include emissions
limitations and standards, and monitoring, recordkeeping, and reporting requirements. Such
requirements are to be contained in an operating permit which is issued to the source for a
period of no more than five years, before renewal. EPA has published its final regulations on
operating permits in a new Part 70 of Title 40 of the Code of Federal Regulations. In general,
the operating permits program as defined in the Part 70 regulations includes the following
sources regulated under the Clean Air Act:
• Major sources of air toxics as defined in Section 112 with the potential to emit
10 tpy or more of any single HAP listed in Section 112(b); or 25 tpy or more of
any combination of HAPs; or a lesser quantity if specified by the EPA.
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CHAPTER 1 - INTRODUCTION
TABLE 1.2-3
INVENTORY REQUIREMENTS OF THE CLEAN AIR ACT AMENDMENTS
FOR OZONE AND CO
Activity
Requirement
Date
Ozone Base Year
Inventory—Basis For
All Other
Inventories
Comprehensive, accurate inventory for
1990
Include VOC, NOX, and CO from point,
area, and mobile sources
Include anthropogenic and biogenic
sources
Same requirements for all nonattainment
classifications
11/15/92
Adjusted Ozone
Base Year Inventory
• Needed to demonstrate 15% VOC
reduction by 1996
• Excludes.biogenic emissions and
emissions reductions required before
CAAA
11/15/93
CO Base Year
Inventory
Comprehensive, accurate inventory for
1990
Include CO emissions from point, area,
and mobile sources for a 24-hour period
For moderate and serious areas
11/15/92
PM
10
Comprehensive, accurate inventory due
with the attainment plan
Most significant inventory will be for
serious areas—due later
11/15/92
Inventory Work Plan
The EPA requires states to submit plans
to explain how they will develop,
document, and submit their inventories
10/01/91
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CHAPTER 1 - INTRODUCTION
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TABLE 1.2-3
(CONTINUED)
Activity
Requirement
Date
Periodic Inventories
for Ozone and CO
Same information as base year
1993 base for first year
Purpose is to track emissions reductions
for all nonattainment classifications
Ozone-11/15/96
CO-09/30/95
Update every
3 years until
attainment
Ozone Modeling
Inventory
Required for all areas using
photochemical grid model and other
moderate areas making an attainment
demonstration
Requires base year and projected
inventory
Photochemical grid model requires
allocated, speciated, and spatially gridded
inventory
Areas using a
photochemical
grid model-
inventory due
11/15/94. Other
modeling
approaches-
inventory due
11/15/93.
CO Modeling
• Needed for nonattainment areas with
design values exceeding 12.7 ppm
• Requires base year and projected
inventory
• Detail will reflect model used
(proportional rollback or gridded
dispersion model)
• Used for determining whether proposed
SIP control strategies are adequate to
reach attainment by specified date.
• Moderate areas demonstration plan for
attainment.
• Serious areas demonstration plan for
attainment.
11/15/93
12/31/95
12/31/00
1.2-16
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CHAPTER 1 - INTRODUCTION
TABLE 1.2-3
(CONTINUED)
RFP Projection
Inventory for 3 %
per year VOC
Reduction
Serious and above areas show 3% per
year VOC reduction after 1996
Continue until attainment
Base year will be final year of
demonstration (i.e., 1999, 2002, 2005,
2008, 2010)
Based on allowable emissions reflecting
regulatory limits
11/15/94
Emission Statements
For all nonattainment classifications
Annual statements from owners of
stationary sources showing actual
emissions of NOX or VOCs
Certify information is accurate
Sources less than 25 tpy can be waived if
included in inventory and the EPA
emission factors used
11/15/93
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CHAPTER 1 - INTRODUCTION 7/7/57
• Any other source, including an area source, subject to the HAP provisions of
Section 112. An area source is any source not considered to be a major source.
• Major sources in nonattainment areas as defined in Part D of Title I with potential
to emit pollutants hi the amounts shown in Table 1.2-4.
• Any source subject to the new source performance standards (NSPS) under
Section 111.
• Sources subject to the preconstruction permits requirements of the Prevention of
Significant Deterioration (PSD) program under Title I, Part C or the nonattainment
area NSR program under Title I, Part D.
• Major sources as defined in Section 302 of the Act with the potential to emit
100 tpy or more of any pollutant.
• Sources subject to the acid rain provisions contained in Title IV.
• Any source designated by the EPA in whole or in part, by regulation, after notice
and comment.
The Part 70 regulations specify the requirements under Title V of the Act for permitees, as
well as the administrative duties required of state air permitting agencies. The minimum
requirements for information to be submitted by subject sources in the permit application,
which include certain emissions-related information, are listed in 40 CFR 70.5(c). Emissions-
related information required to be in the application includes the following: (1) all emissions
of pollutants for which the source is major [including unregulated Section 112(b) pollutants],
and all emissions of regulated air pollutants from all emissions units; (2) identification and
description of all emissions points; (3) emissions rate in tpy and in any other units necessary to
establish compliance with standards; (4) fuels, fuel use, raw materials, production rates, and
operating conditions used to determine emissions, fees, or compliance; (5) pollution control
and compliance monitoring activities; (6) limitations on source operation affecting emissions;
(7) other relevant information, including stack height limitations; and (8) calculations on which
any of the above are based. A state's permit program may also require additional information
under its own laws.
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7/1/97 CHAPTER 1 - INTRODUCTION
TABLE 1.2-4
EMISSION CUTOFFS FOR DETERMINING APPLICABILITY OF
TITLE V OPERATING PERMITS PROGRAM IN NONATTAINMENT AREAS
Pollutant
Ozone (VOC and NOX):
Serious nonattainment area
Transport region not severe extreme in nonattainment
Severe nonattainment area
Extreme nonattainment area
Carbon monoxide - serious nonattainment area
Particulate matter - (PM10) serious nonattainment area
tpy
<50
<50
^25
< 10
<50
< 70
New Source Review (CAA Amendments, Title I)
Section 172(c)(5) of the CAA states that SIPs for nonattainment areas will require
preconstruction permits for the construction and operation of new or modified major stationary
sources anywhere within the nonattainment area. Likewise, Section 165(a)(l) of the CAA
requires that new or modified sources in attainment areas must also secure preconstruction
permits. These permits must contain certain basic elements, including legal authority,
technical specifications (including an estimate of emissions of each pollutant that the source
would have the potential to emit in significant amounts), emission compliance methods, a
definition of excess emissions, and other administrative and miscellaneous conditions (EPA,
1992e). Once the source begins operation it will be necessary to determine source emissions
under design operating conditions in order to demonstrate compliance or noncompliance with
the allowable levels of emissions. Sources obtaining permits for new sources often use trading
transactions, which also require emissions estimations.
Emissions Statements (CAA Amendments, Title I)
Section 182(a)(3)(B) of the CAA requires that states with areas designated as nonattainment for
ozone obtain emissions statement data from VOC and NOX sources in the nonattainment areas.
Emissions statements are derived from point source data through plant contacts. A revision to
a state's SIP to include emissions statements should have been submitted within 2 years of the
CAA Amendments enactment date.
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CHAPTER 1 - INTRODUCTION 7/1/97
The emissions statement requirement applies to all ozone nonattainment areas, regardless of
their classification, and to stationary sources that emit, or have the potential to emit, 50 tons
per year (tpy) or more of VOC or 100 tpy or more of NOX in attainment areas within ozone
transport regions. A state may, with the EPA's approval, waive the requirement for emissions
statements for classes or categories of sources with less than 25 tpy of actual plantwide NO x or
VOC emissions in nonattainment areas if the class or category is included in the base year and
periodic inventories and emissions are calculated using emission factors established by the
EPA (such as those found in AP-42) or other methods acceptable to the EPA. Whatever
minimum reporting level is established, if either VOC or NOX is emitted at or above this level,
the other pollutant should be included in the emissions statement, even if it is emitted at levels
below the specified cutoffs.
At a minimum, emissions statements should include: (1) certification of data accuracy,
(2) operating schedule, (3) emissions information (to include annual and typical ozone season
day emissions), (4) control equipment information, and (5) process data. Agencies are
responsible for reviewing the consistency of the emissions statement data with other available
data sources and resolving any inconsistencies (EPA, 1992c).
The emissions statement reporting format provides for two data collection mechanisms.
Traditional sources (i.e., those with emissions data already in the AIRS database) should
review and/or correct their Aerometric Information Retrieval System (AIRS) AFP644 report.
Nontraditional sources (i.e., those that do not have emissions data in AIRS) should submit an
"Emissions Statement Initial Reporting Form." In both cases, an explanatory letter and
detailed instructions should be included. Agencies have the option of developing their own
emissions statement reporting format, in which case care should be taken to ensure that the
minimum emissions statement data elements are requested and that the emissions statement
data are provided to the EPA via the AIRS system.
Facilities must submit their first emissions statement within three years of the CAA
Amendments enactment date, and annually thereafter. The first emissions statement will be
based on 1992 emissions. The EPA strongly recommends that agencies require a submittal
date of April 15 to allow use of the emissions statement data in the preparation of the annual
point source inventory. Adequate records of emissions statement data and source certifications
of emissions should be maintained by an agency for at least three years to allow for review or
verification of the information, as needed.
Agencies should provide the EPA with a status report that outlines the degree of compliance
with the emissions statement program. Since July 1, 1993, agencies are required to report the
total number of sources affected by the emissions statement provisions, the number that have
complied with the emissions statement provisions, and the number that have not. This report
is a quarterly submittal until all the regulated sources have complied for the reporting year.
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7/7/37 CHAPTER 1 - INTRODUCTION
The status report also includes the total annual and typical ozone season day emissions from all
reporting sources, both corrected and non-corrected for rule effectiveness. Agencies should
include in their status report a list of sources that emit 500 tpy or more of VOC or 2,500 tpy
or more of NOX and that are delinquent in submitting their emissions statements.
Agencies are recommended to enter emissions statement data into AFS by July 1 of each year,
as of 1993. This activity should be coordinated with other reporting requirements to avoid
deleting valuable data in the AIRS database.
The emissions statement data elements were developed to be consistent with other source and
agency reporting requirements. This consistency is essential to assist agencies with an avenue
to check emissions estimates and to facilitate consolidation of all EPA reporting requirements.
Thus, emissions statement data will provide information useful for the development, quality
assurance, and completion of several emissions reporting requirements, including tracking of
RFP, periodic inventories, annual AFS submittals, the operating permit program of the CAA,
emissions trends, and compliance certifications. The goal of emissions statement reporting in
the future is to consolidate all these reporting requirements into one annual effort.
Hazardous Air Pollutants (CAA Amendments, Title III)
Section 112 of the CAA requires EPA to promulgate regulations for reducing the emissions of
HAPs. Section 112(b) contains a list of 189 pollutants which are to be regulated as HAPs.
Section 112(d) requires that emissions standards be established for each source category listed.
A draft schedule for issuance of these standards was published on September 24, 1992 (57 FR
44147) and the emissions standards must be technology-based and must require the maximum
achievable degree of reduction possible in emissions of HAPs from the source category. This
technology is referred to as maximum achievable control technology (MACT) and the
emissions standards are called MACT standards. In general, MACT standards may include
process changes; material substitutions; reuse or recycling; enclosure of systems or processes
to eliminate emissions; pollution collection, capture or treatment systems; design, equipment,
work practice or operational methods; operator training requirements; or a combination of
these methodologies.
Section 112 may lead to additional emission estimation or inventory requirements for sources.
All sources subject to Section 112 are also subject to the Title V requirements. As such,
sources of HAPs must include emissions estimates in their operating permits. In addition, four
special programs under Section 112 may lead to additional requirements for emissions
estimates. These are: the early reductions program under Section 112(i)(5), the Urban Air
Toxics Study under Section 112(k), the Great Lakes and Coastal Waters program under
Section 112(m), and the accidental releases program under Section 112(r).
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Under Section 112(s), EPA is required to maintain a database on pollutants and sources subject
to Section 112. This database will be required to contain information from all of the programs
described above, as well as information from standard development projects under
Section 112(d). EPA is planning to consolidate this data into a "MACT database."
Information and guidance on this database will be available in future rulemakings pertaining to
Section 112.
Early Reduction Program. Under the early reduction program, existing sources may opt to
apply for a 6-year extension of the regular 3-year MACT compliance deadline if such sources
can demonstrate a 90 percent reduction (or 95 percent reduction for paniculate emissions) or
more of HAPs prior to the proposal of the applicable MACT standard. As a condition of the
compliance extension, states may require additional emission reductions from such sources.
Such reductions generally must be based on actual and verifiable emissions in a base year no
earlier than 1987. The source must provide a one-tune demonstration of the required
reduction, which will require estimation and comparison of current emissions and emissions
during the relevant base year. It should be noted that the emissions reductions used to qualify
under this extension will be federally enforceable, and hence also require a Title V permit
revision.
Urban Air Toxics Study. Under the Urban Air Toxics Study, EPA is required to conduct a
program of research on sources of HAPs in urban areas. This program must include an
analysis to characterize sources of such pollution with a focus on area sources. EPA, in
implementing this program, may request specific emissions estimates and other relevant
information from sources.
Great Lakes and Coastal Waters Program. Under the Great Lakes and Coastal Waters
program (often referred to as the Great Waters Program), EPA is required to assess the extent
of atmospheric deposition of HAPs into the Great Lakes, Chesapeake Bay, Lake Champlain,
and coastal waters. In addition to numerous monitoring and sampling efforts, this assessment
will include an investigation of the deposited chemicals and their precursors and sources. This
investigation will likely lead to emissions estimation requirements for sources which emit
HAPs that could be deposited into these waters.
Accidental Release Program. Under the accidental release program, sources which emit
HAPs above certain threshold quantities must submit risk management plans designed to detect
and prevent accidental releases of HAPs. The risk management plan must assess the potential
effects of an accidental release, which will include an estimate of potential release quantities,
determination of downwind effects, previous release history and an evaluation of the worst
case accidental release. The plan must also include an accidental release prevention program
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7/7/97 . CHAPTER 1 - INTRODUCTION
and an emergency response program to be implemented in the event of such a release. Such
plans must be submitted to EPA, the Chemical Safety and Hazard Investigation Board, and
State and local air pollution control agencies.
Section 114 Reporting Requirements, Compliance Certifications and Compliance
Monitoring. Section 114 of the CAA gives EPA the authority to require sources to, on a one-
time, periodic, or continuous basis, report to EPA information which EPA deems necessary
for developing standards or SIPs, determining compliance, or meeting other provisions of the
Act. Under Section 114, EPA can require sources to establish recordkeeping; make reports;
sample emissions; keep production, control technology, or other operations data; or provide
other necessary information. The EPA may include emissions estimates as part of these
information requirements. Information collected under Section 114 is publicly available except
non-emissions-related data which may be held as confidential by the EPA, rather than
divulging proprietary product information.
Allowance Trading (CAA Amendments, Title IV)
In order to control sources of acid deposition, Title IV of the CAA Amendments establishes
the allowance trading program. This program seeks to reduce emissions of SO2 by 10 million
tpy, relative to 1980 levels. Three databases, National Allowance Database (NADB), Acid
Rain Data System (ARDS) and Tracking Responses to Acid Rain Compliance (TRAC), are set
up under this program to track emissions, allowance trading, and compliance, respectively.
Sources affected by Title IV (i.e., those listed in Table A, Title IV, of the CAA Amendments),
or those that opt in will be responsible for reporting to these databases. These reports will
include general plant information, emissions data, and fuel use data. It should also be noted
that sources subject to Title IV requirements are also subject to Title V operating permit
provisions (EPA, 1993a).
2.1.2 REQUIREMENTS UNDER OTHER EPA REGULATIONS
A number of other EPA requirements which are not directly related to the CAA require some
form of emissions estimation. These requirements are a result of the following federal laws:
NEPA, CERCLA, SARA, RCRA, and the Pollution Prevention Act. This subsection briefly
highlights these requirements.
National Environmental Policy Act (NEPA) of 1969
The National Environmental Policy Act (NEPA) requires that, where a federal agency action
may result in a significant environmental impact, an environmental assessment be prepared
before such policy can be implemented. An environmental assessment (EA) is a study that
provides background information and preliminary analyses of the potential impact of a new
EllP Volume II 1.2-23
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CHAPTER 1 - INTRODUCTION ; 7/7/37
policy. If the results of an EA indicate that significant environmental impact may result, EPA
will prepare an Environmental Impact Statement (EIS). The EIS examines, in detail, the
potential impact of a proposed agency action. Generally, industries are not required to prepare
EISs, but EPA may require industry input, including emissions estimates, for its evaluation of
the impact of proposed rulings (EPA, 1993a).
Comprehensive Environmental Recovery and Comprehensive Liability Act of 1980
Under CERCLA, facility managers are required to perform an Air Pathway Analysis (APA) in
order to assess the potential for exposure of personnel to toxics in the ambient air at National
Priority List (NPL) sites and to provide input to the Superfund risk assessment process. Air
pathway analysis involves a combination of modeling and monitoring methods to assess actual
or potential emissions from a hazardous waste site. The APA has three major components:
(1) characterization of air emission sources (e.g., estimation of contaminant emission rates) for
the control and recordkeeping process; (2) determination of the effects of atmospheric
processes (e.g., transport and dilution) on the personnel at a site; and (3) evaluation of
receptor exposure potential (i.e., what air contaminant concentrations are expected at receptors
of interest for various exposure periods) (EPA, 1989).
Superfund Amendments and Reauthorization Act (SARA) of 1986
SARA, which was passed in 1986 to amend CERCLA, contains two requirements likely to
lead to emissions estimation. First, Section 313 of SARA requires that companies that
process, manufacture, or otherwise use toxic compounds listed in Section 313 of the Act report
to EPA the annual quantities used of those compounds and any releases to the environment
(including air emissions) that result from their use. The Section 313 "Right-to-Know"
requirements were enacted by Congress to increase public awareness and information on toxic
emissions. The EPA has made Section 313 data publicly available. A database has been
established, known as the Toxic Release Inventory System (TRIS), which contains information
from SARA toxic chemical release reports (EPA, 1993a).
Second, Section 304 of SARA requires that any source which emits amounts in excess of
threshold levels of any "hazardous" or "extremely hazardous" substance as defined by EPA
pursuant to CERCLA must report the quantities of the substance(s) released. These reports
are to be filed with the National Response Center, and are due immediately upon release of the
substance (EPA, 1993a).
Resource Conservation and Recovery Act (RCRA) of 1976
RCRA was established to minimize the generation of hazardous waste, and to aid in the
management of such hazardous waste. Sections 3001 and 3002 of RCRA require hazardous
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7/7/37 CHAPTER 1 - INTRODUCTION
waste generating facilities to report and analyze their generation of certain hazardous wastes.
Such an analysis could include estimation of emissions of certain substances. These facilities
must report biennially to EPA.
Pollution Prevention Act of 1990
The Pollution Prevention Act is designed to facilitate the reduction of pollution at the source,
rather than to mandate "end-of-pipe" controls. In general, this Act requires several EPA
activities to facilitate pollution prevention, including establishing a clearinghouse for pollution
prevention information, a grants program, reports to Congress, and others. It also imposes a
specific reporting requirement on certain sources. Specifically, sources that are required to
file an annual toxic release form under Section 313 of SARA must also file an annual toxic
chemical source reduction and recycling report. Section 6607 of the Pollution Prevention Act
describes the specific requirements for this report. For many sources, meeting these
requirements will require some form of emissions estimation (EPA, 1991c).
2.1.3 FEDERAL REQUIREMENTS OUTSIDE OF EPA
In addition to EPA, two other federal agencies have requirements that may lead to emissions
estimates for certain sources. The Department of Energy (DOE) requires electric power plants
to report information on fuels, cooling equipment, environmental control equipment, and other
information from which air emissions may be estimated. The Department of Defense (DoD) is
in the process of establishing a central air emissions database which is to be part of the
Defense Corporate Information Management (DECIM) system. This database may require
additional emissions reporting. It should also be noted that each facility subject to any DOE
or DoD requirements is also subject to any relevant EPA requirements.
2.2 STATE REQUIREMENTS
As previously described, the EPA places several requirements on states which may indirectly
lead to reporting requirements for sources. These include the requirements that the states
update emissions inventories on an annual basis for AIRS, that the states submit base year and
periodic inventories for SIP development, and that the states develop Title V Operating
Permits programs.
Although states must comply with federal requirements, states are not restricted from
establishing their own, more stringent requirements. While the federal laws and regulations
identify a minimum set of requirements, states may choose to develop additional estimating
and reporting requirements. Individual state agencies can provide assistance to sources on
identifying and complying with individual state requirements.
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EMISSIONS INVENTORY PLANNING
3.1 PRELIMINARY PLANNING ACTIVITIES
Prior to initiating the actual compilation of an emissions inventory, an agency or facility must
plan a basic approach for collecting, handling, and reporting emissions data. Careful
consideration of the approach to be used in developing the emissions inventory program will
greatly facilitate the inventory process and can prevent major revisions to the inventory during
review. As part of the preliminary planning activities, the inventory preparer should consider
the following:
• End use of the data;
• Scope of the inventory;
• Availability and usefulness of existing data; and
• Strategy for data collection and management.
Each of these issues is discussed in more detail below.
3.1.1 END USE OF THE DATA
A basic consideration in planning the inventory is establishing the end uses of the completed
inventory. For the regulatory agency, the end uses of all inventories fall into three general
categories: (1) air quality control strategy development, (2) air quality maintenance, and
(3) air quality research. For an individual facility, the inventory may be the measure of
progress towards a corporate goal for emission reductions and/or a means of identifying
opportunities for process improvements. Possible future use of the inventory, as well as
immediate objectives, should be considered in determining inventory procedures and data
needs.
3.1.2 SCOPE OF THE INVENTORY
In defining the scope of the inventory, the primary considerations are the desired level of
detail, the desired number of sources, and the pollutant(s) of interest. Point sources can be
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CHAPTER 1 - INTRODUCTION 7/7/37
inventoried at three levels of detail: (1) the plant level, which denotes a plant or facility that
could contain several pollutant-emitting activities; (2) the point/stack level, where emissions to
the ambient air from stacks, vents, or other points of emission are characterized; and (3) the
process/segment level, representing the unit operations of specific source categories. The
appropriate level of detail will be a function of the intended use of the data.
Under ideal circumstances, all stationary sources would be considered point sources for
purposes of emission inventories. In practical applications, however, only sources that emit
more than a specified cutoff level of pollutant are considered point sources. In general, the
higher the cutoff level, the fewer the facilities that are included in an inventory of point
sources; a lower cutoff level would result in the inclusion of more sources. As a rule, the
lower the cutoff level, the greater the cost to develop the inventory. However, a low cutoff
level will increase user confidence in the source and emissions data, and the inventory will
have a greater number of applications.
The pollutants to be inventoried are a major element in determining the scope of the inventory.
The pollutants of interest for ozone inventories are VOCs, NOX) and CO. For other criteria
pollutants, only the criteria pollutant itself is of interest in the inventory. For HAP inventories
on the federal level, the CAA list of 189 HAPs determines the pollutants to be inventoried.a
States and local agencies may have additional toxic pollutants on their state/local toxic air
pollutant (TAP) lists.
Table 1.3-1 presents source categories that should be considered for inclusion in point source
emission inventories. The table also indicates the types of pollutants emitted from these
categories. In defining the scope of an inventory, the emphasis should be on those source
categories that are located in the geographic area covered by the inventory and that are
addressed by regulations applicable to point sources. The selected sources and source
categories should be compatible with available information and be of sufficient detail to
facilitate control strategy projections.
3.1.3 AVAILABILITY AND USEFULNESS OF EXISTING DATA
A major inventory planning consideration is whether, and to what extent, existing information
can be used. Existing inventories should be examined to determine whether the appropriate
sources have been included and whether the emissions data represent current conditions.
Existing inventories can serve as a starting point for developing extensive data and support
information, such as documentation of procedures. Information may also be drawn from other
regulatory agency operations such as permitting, compliance, and source inspections and from
aCaprolactam was delisted as a HAP (Federal Register, Vol. 61, page 30816, June 18, 1996).
1.3-2 Eup Volume II
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I
TABLE 1.3-1
POTENTIAL POINT SOURCES AND POLLUTANTS
XI
Source Name
Fuel Combustion, Electric
Utilities
Fuel Combustion, Industrial
Fuel Combustion, Other
Chemical and Allied Product
Mfg.
Description
Coal
Oil
Gas
Other
Internal Combustion
Coal
Oil
Gas
Other
Internal Combustion
Commercial/Institutional Coal
Commercial/Institutional Oil
Commercial/Institutional Gas
Misc. Fuel Comb. (Except Residential)
Residential Wood
Residential Other
Organic Chemical Mfg.
Inorganic Chemical Mfg.
Polymer and Resin Mfg.
Agricultural Chemical Mfg.
Paint, Varnish, Lacquer, Enamel Mfg.
Pharmaceutical Mfg.
Other Chemical Mfg.
POLLUTANTS
VOC
X
X
X
X
X
X
CO
X
X
X
X
™°K
X
X
X
X
X
X
X
X
X
X
X
SO2
X
X
X
X
X
X
X
PMin
X
X
X
X
X
X
X
X
X
Lead
X
X
X
X
X
X
X
X
X
X
HAPs
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
I
o
CD
8
o
-------
U)
TABLE 1.3-1
(CONTINUED)
i
Source Name
Metals Processing
Petroleum and Related Industries
Other Industrial Processes
Solvent Utilization
Description
Non-Ferrous Metals Processing
Ferrous Metals Processing
Metals Processing Not Else Classified (NEC)
Oil and Gas Production
Petroleum Refineries and Related Industries
Asphalt Manufacturing
Agriculture, Food, and Kindred Products
Textiles, Leather, and Apparel Products
Wood, Pulp and Paper, and Publishing Products
Rubber and Miscellaneous Plastic Products
Mineral Products
Machinery Products
Electronic Equipment
Transportation Equipment
Construction
Miscellaneous Industrial Processes
Degreasing
Graphic Arts
Dry Cleaning
Surface Coating
Other Industrial
Nonindustrial
POLLUTANTS
VOC
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
CO
X
X
X
X
NOX
X
SO2
X
X
X
X
X
PMln
X
X
X
X
X
X
X
X
X
X
X
X
X
Lead
X
X
X
X
HAPs
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
§
i
<0
XJ
-------
TABLE 1.3-1
(CONTINUED)
Source Name
Storage and Transport
Waste Disposal and Recycling
Miscellaneous
Description
Bulk Terminals and Plants
Petroleum and Petroleum Product Storage
Petroleum and Petroleum Product Transport
Service Stations: Stage I
Service Stations: Stage II
Service Stations: Breathing and Emptying .
Organic Chemical Storage
Organic Chemical Transport
Inorganic Chemical Storage
Inorganic Chemical Transport
Bulk Materials Storage
Bulk Materials Transport
Incineration
Open Burning
Publicly Owned Treatment Works (POTW)
Industrial Waste Water
Treatment, Storage, and Disposal Facility
(TSDF)
Landfills
Other
Agriculture and Forestry
Other Combustion
Catastrophic/Accidental Releases
Repair Shops
Health Services
Cooling Towers
Fugitive Dust
POLLUTANTS
VOC
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
CO
X
X
X
NOY
X
S02
X
X
PM,n
X
X
X
X
X
X
X
X
X
X
X
X
X
Lead
X
X
X
X
HAPs
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
i
1
§
1
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CHAPTER 1 - INTRODUCTION 7/7/37
other facility resources such as corporate reporting or compliance report submittals. For
effective use of resources, an agency or facility should plan to fulfill specific emissions
inventory requirements by building upon and improving the quality of regularly collected data.
For effective use of resources, an agency or facility should plan to fulfill specific emissions
inventory requirements by building upon and improving the quality of regularly collected data.
3.1.4 STRATEGY FOR DATA COLLECTION
Another key decision in inventory planning regards what particular data collection procedures
will be followed. Alternatives include questionnaires, plant inspections, and review of existing
agency permit and compliance files. Depending on the approach selected, the data available
may be in various forms such as source tests, material balances, purchasing records, or actual
emission estimates. The amount of staff and budget that will be needed to actually gather the
data and then manipulate it into the desired inventory will also vary depending on the selected.
approach. The inventory preparer must keep these considerations hi mind during the
preliminary planning phase in order to decide on the strategy that best matches the data needs
and the available resources.
Because it is not always certain whether a category will be considered a point or an area
source for the purpose of the inventory, data collection efforts should always include as much
detailed information as possible. For example, employment by standard industrial
classification code may not be used in a point source inventory, but would be helpful for
preparing an area source inventory.
Once the strategy for data collection is known, the inventory preparer needs to consider how
these data will be handled and managed, including QA/QC procedures. Emissions inventory
data for a single point source or area source category may be minimal enough to be handled
using spreadsheets or by hand calculations. For large sets of data, some type of electronic
database will be needed to organize, manipulate, and simply store the collected data. There
are a wide variety of available software packages designed for the tracking of environmentally
related emissions and release information. The system used should be able to handle the types
of information being collected as well as have the ability to export information for state and
federal reporting requirements.
3.2 INVENTORY WORK PLAN
The inventory work plan is a concise, to-the-point document that declares how an agency or
plant intends to develop and present its inventory. It allows a line of communication between
the inventory preparer, his/her management, and the receiving agency to ensure that the
inventory is conducted effectively. The work plan should include inventory objectives and
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general procedures and should address all sources (regardless of size) of all the target
pollutants.
Although no specific format is usually required, the work plan should, at a minimum:
• Define how the inventory work plan is structured and what it contains;
• Define the inventory area by nonattainment status;
• Provide the background/basis for the inventory (i.e., previous efforts that are
viable and related);
• Specify who is responsible for the inventory, with a detailed organization chart
of key personnel/consultants;
• Specify the quality assurance (QA) coordinator (who must be different than the
inventory management or technical staff);
• Describe the approach to be used to estimate emissions, including plans for data
collection, analysis, and storage; and
• Describe how the plant or agency plans to present and document the inventory
for submittal.
For point sources, an agency must define how all pertinent emissions sources will be identified
and located. The work plan should describe how point source activity levels and associated
parameters will be developed, and how these data are used to calculate emissions estimates. It
should also describe the type of source surveys that are planned and the use of existing data
contained in systems such as the Aerometric Information Retrieval System (AIRS), state
emission inventory systems, or state permitting files.
3.3 TRAINING
Training is an important component of the facility's or agency's preliminary planning
activities. The extent of training needed will depend on the staff chosen to prepare the
inventory and the number of new procedures required by the inventory process.
Training courses for the critical components of an emissions inventory are provided annually
by the EPA's Air Pollution Training Institute (APTI). These courses provide detailed
instruction in:
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CHAPTER 1 - INTRODUCTION 7/7/97
• Inventory planning;
• Inventory management;
• Point source emissions;
• Emissions calculations;
• Projection techniques; and,
• Data reporting.
These courses are available to any individuals with the education, experience, or employment
responsibilities involving enforcement or compliance with regulatory programs for
achievement of air quality standards. Further information can be obtained by contacting the
APTI (see Appendix C).
3.4 DATA HANDLING
Inventory data can be managed almost entirely by computer. During the inventory planning
stages, the inventory preparer should anticipate the volume and types of data-handling needed
in the inventory effort and should weigh the relative advantages of manual versus
computerized systems. If the inventory preparer must deal with large amounts of data,
maximizing the use of computerized inventory data-handling systems will allow them to spend
more time gathering, analyzing, and validating the inventory data, as opposed to manipulating
the data.
Computerized data handling becomes significantly more cost-effective as the database, the
variety of tabular summaries, or the number of iterative tasks increases. In these cases, the
computerized inventory requires less overall time and has the added advantage of forcing
organization, consistency, and accuracy.
Some activities that can be performed efficiently and rapidly by computers include:
• Printing mailing lists and labels;
• Maintaining status reports and logs;
• Calculating and summarizing emissions;
• Performing error checks and other audit functions;
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7/7/37 CHAPTER 1 - INTRODUCTION
• Storing source, emissions, and other data;
• Sorting and selectively accessing data; and
• Generating output reports.
Additional information on data handling is presented in Volume VII of the EIIP series of
guidance documents.
3.5 DOCUMENTATION REQUIREMENTS
Documentation is an integral part of an emissions inventory. Before submittal, internal review
of the written documentation provides an opportunity to uncover and correct errors in
assumptions, calculations, or methods. Following submittal of the inventory, the
documentation allows the results of the inventory to be clearly understood and the quality of
the inventory to be effectively judged.
Although documentation requirements may evolve during data collection, the calculation and
reporting steps of the emissions inventory development process should be anticipated during
planning. Planning the level of documentation required will: (1) ensure that important
supporting information is properly developed and maintained; (2) allow extraneous information
to be identified and discarded, thereby reducing the paperwork burden; (3) help determine data
storage requirements; and (4) aid in identifying aspects of the inventory on which to
concentrate the QA efforts.
3.6 SCHEDULE
If the development and maintenance of an emissions inventory is conceptualized as a network
of activities or events with a definite start and end, various techniques can be used to formulate
a project schedule. One method is to graphically present the inventory tasks, their estimated
completion tunes, major project milestones, and labor requirements. This is a useful way to
visualize the activities and their relationships to one another. By identifying the "critical path"
events at this early point in the schedule-planning activities, the inventory preparer can
anticipate potential bottlenecks in the process and avoid delays that might affect the timely
submittal of the final inventory.
It is important to remember that a schedule must be frequently compared to the actual progress
of the inventory effort. By closely tracking the activities, the preparer can: (1) ensure that
each task is being completed expeditiously; (2) revise labor commitments to reflect schedule
and data changes; and (3) learn from experience so that this knowledge can be applied towards
future inventory efforts.
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EMISSION ESTIMATION PROCEDURES
Air pollutant emissions may be released from numerous sources within a facility. Depending
on the facility size, the nature and number of processes, and the emission control equipment in
place, emission estimation may be very simple or extremely difficult. The inventory preparer
should consider the types of emissions to be reported (i.e., actual, potential, or allowable), the
availability of data, and the cost when selecting which method of emissions estimation is
appropriate.
Figure 1.4-1 (from/4P-42) depicts various approaches to emission estimation that should be
considered when analyzing the costs versus the quality of the results (EPA, 1995a). Ideally,
plants needing emissions estimates would use continuous emissions monitoring (CEM) to
obtain actual emissions measurements over very short time intervals. Some facilities currently
do this. The CEM concentration data can be easily converted to mass emission rates provided
the air volume through the monitor is also known. In cases where CEM or parametric
monitoring data are unavailable, however, another method must be used to estimate emissions.
The three principal methods for estimating emissions in such cases are source tests, material
balances, and emission factors. If none of these three methods can be employed to estimate
emissions for a specific process, an approximation or engineering estimate based on available
process, physical, chemical, and emission knowledge may be used.
Where risks of adverse environmental or regulatory effects are high, the more sophisticated
and costly emission determination methods such as CEM or source tests may be necessary.
Conversely, where the risks are low, less expensive estimation methods such as the use of
emission factors and emission models may be acceptable.
4.1 SOURCE TESTS
The source test is a common method of estimating process emissions. Source tests are
short-term emission measurements taken at a stack or vent. Due to the substantial time and
equipment involved, a source test requires more resources than an emission factor or material
balance emission estimate. Typically, a source test uses two instruments: one to collect the
pollutant in the emission stream and one to measure the emission stream flow rate. The
essential difference between a source test and CEM is the duration of tune over which
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CHAPTER 1 - INTRODUCTION
7/1/97
RISK SENSITIVITY EMISSION ESTIMATION APPROACHES
i
INCREASING
COST
GEM
PARAMETRIC SOURCE TESTS
SINGLE SOURCE TESTS
MATERIAL BALANCE
SOURCE CATEGORY EMISSION MODEL
STATE/INDUSTRY FACTORS
EMISSION FACTORS (AP-42)
ENGINEERING JUDGEMENT
INCREASING RELIABILITY OF ESTIMATE
FIGURE 1.4-1. EMISSION ESTIMATION HIERARCHY
1.4-2
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7/1/97 CHAPTER 1 - INTRODUCTION
measurements are conducted. A source test is conducted over a discrete, finite period of time,
while CEM is continuous.
If the use of source test data reduces the number of assumptions regarding the applicability of
emissions data to a source (a common consideration when emission factors are used), as well
as the control device efficiency, equipment variations, and fuel characteristics. Thus, source
tests typically provide better emission estimates than emission factors or material balances, if
correctly applied (Southerland, 1991). However, source test data should be used for emission
estimation purposes only if the data were obtained under conditions which are representative of
or related to operating conditions normally encountered at the source in question.
Two items should be noted when using source test data to calculate emissions. First, because
most source tests are only conducted over several hours or days at most, adjustments may need
to be made when using these data to estimate emissions over longer tune intervals. Emission
data from a one-tune source test can be extrapolated to estimate annual emissions only if the
process stream does not vary and if the process and control devices are operated uniformly.
Second, a source test may not adequately describe a given facility's annual or seasonal
operating pattern. For example, there may be variations in process operation throughout the
year or the efficiency of control device performance may vary due to fluctuations in ambient
temperature or humidity. In such cases, multiple tests must be conducted for source testing to
be useful in generating an emission estimate for extended periods that are longer than the test
period. If facility operation and test methods employed during the source test cannot be
adequately characterized, the source test data should not be used.
If a source test is used to estimate emissions for a process, test data gathered on-site for that
process is generally preferred. The second choice is to use test data from similar equipment
and processes on-site, or to use pooled source tests or test data taken from literature. The
reliability of the data may be affected by factors such as the number of tests conducted and the
test methodology used.
The EPA has published reference methods for measuring emissions of PM, SO2, NOX, CO,
and VOC. The reference methods, given in Title 40, Code of Federal Regulations, Part 60,
Appendix A, define and describe the test equipment, materials, and procedures to be used in
stack tests for the various criteria pollutants. Reference methods for estimating HAP
emissions are published in Title 40, Code of Federal Regulations, Part 61, Appendix B (EPA,
1986; EPA, 1988). The EPA publication, Screening Methods for the Development of Air
Toxics Emission Factors, presents an overview of the use of these reference methods for
specific HAPs (EPA, 1992d). A brief description of several EPA methods is given in
Appendix E. For further information, the reader can consult with the Emission Measurement
Technical Information Center (EMTIC), which provides technical guidance on stationary
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CHAPTER 1 - INTRODUCTION 7/1/97
source emission testing. Industry personnel may access EMTIC on the EPA's Technology
Transfer Network bulletin board system, or by calling EMTIC staff directly. Appendix C
contains EMTIC contact information.
Most source test reports summarize emissions for each pollutant by expressing them in terms
of: (1) a mass loading rate (weight of pollutant emitted per unit of time); (2) an emission
factor (weight of pollutant emitted per unit of process activity); or (3) a flue gas concentration
(weight or number of moles of pollutant per some weight or volume of flue gas). Generally,
when a mass loading rate or flue gas concentration is provided, the resulting emission factor
can easily be calculated with knowledge of equipment size or operating parameters, as in the
example below (EPA, 1993a):
• Example. A single-line paper coating plant has been subjected to an emission test
for VOC emissions. Since the coating solvent is primarily toluene, the emission
concentrations were measured as toluene. The data averaged for three test runs are
as follows:
Stack flow rate (Qs) = 10,000 scf
Emission concentration (Ce) = 96 ppm (as toluene)
Fugitive emission capture (Effcap) =0.90 (90 percent, as required by
reasonably available control technology
(RACT)
Other information needed to complete the calculations include:
Plant operation =16 hour/day, 312 days/year
Solvent input rate (Mj) = 500 ton/year
Rule effectiveness (RE) =0.80 (80 percent)
Molecular weight (toluene) = 92
Unit correction factor (f) = 1.58 x 10~7 (lb-mole-min)/(hr-ppm-scf)
The emission calculation begins with determination of the average mass loading rate
(Mo):
M0 = (f)(MW)(CeXQs)
= (1.58 x 10-7)(92)(96)(10,000)
= 14 Ib/hr
The emission control efficiency (Effcon) is calculated:
= (Mi-M0)/Mi
= [500 - ((14)(16)(312)/2,000)]/500
= 0.93 (93 percent control)
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7/7/37 CHAPTER 1 - INTRODUCTION
4.2 MATERIAL BALANCES
The material balance (also known as a mass balance) is a method commonly used for
estimating emissions from many source categories. In this method, emissions are estimated as
the difference between material input and material output across a vessel, process, or entire
facility. The material balance method can be used where source test data, emission factors, or
other developed methods are not available. For example, emissions from evaporation sources
are commonly estimated using this approach as are sources where testing of low-level,
intermittent, or fugitive exhaust streams would be very difficult, costly, and uncertain. The
material balance is most appropriate to use in cases where accurate measurements can be made
of all but the air emission component, or when the emission estimate will be used for
screening purposes if reasonable assumptions can be made about the fate of compounds.
Use of material balances involves the examination of a process to determine whether emissions
can be estimated solely on knowledge of operating parameters, material compositions, and
total material usage. The simplest material balance assumes that all solvent used in a process
will evaporate to become air emissions somewhere at the facility. For instance, for many
surface coating operations, it can be assumed that all of the solvent in the coating evaporates to
the atmosphere during the application and drying processes. In such cases, emissions equal
the amount of solvent contained in the surface coating plus any added thinners.
Material balances are greatly simplified and very accurate in cases where all of the consumed
solvent is emitted to the atmosphere. But many situations exist where a portion of the
evaporated solvent is captured and routed to a control device such as an afterburner
(incinerator) or condenser. In these cases, the captured portion must be measured or estimated
by other means and the disposition of any recovered material must be accounted for. As a
second example, in degreasing operations, emissions will not equal solvent consumption if
waste solvent is removed from the unit for recycling or incineration. A third example is
cutback asphalt paving where some fraction of the diluent used to liquefy the asphalt is
believed to be retained in the substrate (pavement) rather than evaporated after application. In
these examples, a method of accounting for the non-emitted solvent is required to avoid an
overestimation of emissions.
Material balances cannot be accurately employed at a reasonable cost for some evaporation
processes because the amount of material lost is too small to be determined accurately. As an
example, applying material balances to petroleum product storage tanks is not generally
feasible because the losses are too small relative to the uncertainty of any metering devices. In
these cases, AP-42 emission factors or equations can be used (EPA, 1995a).
The material balance method should not be used for processes where material is reacted to
form products or where the material otherwise undergoes significant chemical change. If a
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CHAPTER 1 - INTRODUCTION 7/7/37
material balance method is used to estimate emissions and if the actual emissions are a small
fraction of the throughput, the throughput estimate or measurement can be even more critical.
Because the emissions are estimated to be the difference between the material input and the
known material output, a small percentage error in estimating the input or output can result in
a much larger percentage error in the emission estimate. For this reason, material balances
are sometimes inappropriate for estimating small losses.
Available test methods are published through the American Society for Testing and Materials
(ASTM) and have focused on providing information on material balance and gravimetric
determinations for various industrial processes (ASTM, Volumes 06.01 and 15.05). The use
of a mass or material balance to determine total emissions from a process is usually simple and
affordable. Total VOC emitted from a batch paint mixing process, for example, would be
calculated as follows (according to ASTM Method D 2369):
VOCadded to mixing vessel (Ib/gal) - VOCin fmal paint mixwre (Ib/gal) = VOCemitted (Ib/gal) (1.4-1)
4.3 EMISSION FACTORS
One of the most useful tools available for estimating emissions from point sources is the
emission factor. An emission factor is a ratio that relates the quantity of a pollutant released to
the atmosphere to the activity level associated with the release of that pollutant
(e.g., production rate or amount of fuel combusted). If the emission factor and the
corresponding activity level for a process are known, an estimate of the emissions can be
made. In most cases, emission factors are expressed simply as a single number, with the
underlying assumption that a linear relationship exists between emissions and the specified
activity level over the probable range of application. The use of emission factors is
straightforward when the relationship between process data and emissions is direct and
relatively uncomplicated. The primary reference for criteria pollutant emission factors for
industrial sources is AP-42 (EPA, I995a).
Because emission factors are averages obtained from data of wide range and varying degrees
of accuracy, emissions calculated this way for a given facility are likely to differ from that
facility's actual emissions; factors will indicate higher emission estimates than are actual for
some sources, and lower for others. Only specific source measurement can determine the
actual pollutant contribution from a source, under conditions existing at the tune of the test.
For the most accurate emissions estimate, it is recommended that source-specific data be
obtained whenever possible. If factors are used to predict emissions from new or proposed
sources, the latest literature and technology should be reviewed to determine whether such
sources would likely exhibit emission characteristics different from those sources from which
the emission factors were derived.
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In addition to presenting emission factors, AP-42 gives a quality indicator for each emission
factor rated "A" through "E," with "A" being the best; and Ul through U5, published with
varying degrees of uncertainty (EPA, 1995a). The lower the quality indicator, the more likely
that a given emission factor may not be representative of the source type. When an emission
factor for a specific source or source category may not provide a reasonably adequate emission
estimate, it is always better to rely on actual stack test data, where available. Conversely, if
an emission factor does provide reasonably adequate emission estimates, stack testing may
represent an ineffective use of time and resources.
The EPA continues to update and expand the factors in AP-42, including a more detailed
speciation of VOC and other organic emissions by compound or compound class, where data
are available (EPA, 1995a). The EPA databases and documents that contain emission factors
for use in inventory development are discussed in more detail in Appendix F. The EPA's
procedure for assigning emission factor quality ratings is described in the document, Technical
Procedures for Developing AP-42 Emission Factors and Preparing AP-42 Sections
(EPA, 1993b).
4.3.1 CALCULATION OF EMISSIONS USING EMISSION FACTORS
In order to calculate emissions using emission factors, various inputs to the estimation
algorithm are required:
• Activity information for the process as specified by the relevant emission factor;
• Emission factors to translate activity information into uncontrolled or controlled
emission estimates; and
• Capture device and control device efficiencies to provide the basis for
estimation of emissions to the atmosphere after passage through the control
device(s) if using an uncontrolled emission factor ("Controlled" emission
factors already take this into account).
The basic emission estimation algorithm for an uncontrolled emission factor is:
E = A * EF * (1 - ER/100) (1.4-2)
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where:
E = emission estimate for source (at the process level)
A = activity level (such as throughput)
EF = "uncontrolled" emission factor (such as Ib emitted/throughput)
ER = overall emission reduction efficiency, expressed in percent; equal to the
capture device efficiency multiplied by the control device efficiency
If a controlled emission factor is being used, the emission factor already incorporates the
control system effectiveness term (1 - ER/100); therefore, the form of the algorithm is:
E = A*EF (1.4-3)
where:
E = emission estimate for source (at the process level)
A = activity level (such as throughput)
EF = controlled emission factor (such as Ib emitted/throughput)
The accuracy of the emission estimate is equally dependent upon the relative accuracy of each
of these individual components. Errors introduced into any one of these components will
affect the final emission estimate.
4.3.2 ROLE OF THROUGHPUT IN EMISSION FACTOR ESTIMATES
The activity level (also referred to as throughput rate) is the second component of an estimate
developed using an emission factor. For industrial processes, activity data are generally
reported as process weight rates (e.g., pound, ton, gallon or barrel per hour). Similarly, for
fuel-burning equipment, activity data are reported as fuel consumption rates (tons, 103 gallons,
106 ft3, or 106 Bru per hour). The optimum activity data are hourly values, although in some
cases only shift, daily, weekly or even monthly data are available. If hourly values are not
known, the hourly average value can be calculated from the actual operating schedule.
In many instances, conversion factors must be applied to convert reported consumption or
production values into units that correspond to the emission factor throughput units (tons,
barrels, etc.). For example, an emission factor for fuel oil consumption may be given in Ibs
per MMBtu while the activity data are available only in gallons of oil per hour. In order to
estimate emissions, a conversion factor is needed. The heating value of the fuel in MMBtu per
gallon provides the necessary conversion. In this case, the emission equation would be:
E = AxEFxC (1.4-4)
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7/1/97 CHAPTER 1 - INTRODUCTION
where:
E = emission estimate in Ibs/hr
A = activity level = fuel consumption in gal/hr
EF = emission factor in Ibs/MMBtu
C = conversion factor = heating value in MMBtu/gal
If the emission factor or activity data involve electrical power output or steam generation, an
additional correction factor (i.e., the fractional efficiency of the fuel burning equipment) must
be applied to account for conversion of heat input to power output (electrical) or steam
production (thermal).
Occasionally, additional process data are required to ensure that the correct conversion factors
are applied. For example, a production rate for plywood boards might be given as the number
of boards manufactured per hour, while an emission factor relates emissions to the number of
tons manufactured, rather than the number of boards. In this case, the weight of the product
per board must be known. Errors associated with the conversion of activity data to emission
factor units can be avoided by clearly specifying the required units throughout a calculation
(EPA, 1993a; EPA, 1991d).
4.3.3 ROLE OF CAPTURE AND CONTROL DEVICE EFFICIENCIES IN EMISSION FACTOR
ESTIMATES
Control effectiveness is the third element of the emission factor approach. Control
effectiveness is a product of the capture device efficiency (including the duct system between
the capture device and the control device) and the control device efficiency. The capture
device efficiency indicates the percentage of the emission stream that is taken into the control
system, and the control device efficiency indicates the percentage of the air pollutant that is
removed from the emission stream before release to the atmosphere (EPA, 1993a;
EPA, 1991d).
Control device efficiency may be determined for specific equipment by source tests measuring
pollutant concentrations before and after application of the control device. However, because
of possible variation in control device operation, control device malfunction, and deterioration
over tune, etc., the measurement is subject to the potential limitations of all source tests.
Capture device efficiency can be quantified by more complex methods. Often, capture device
efficiency is estimated on the basis of tests performed on similar equipment at other facilities,
rather than by tests performed at the facility for which emissions are being estimated.
When test data are not available for a specific control device, a second approach using
literature values to estimate control efficiency is often employed. AP-42 includes efficiencies
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for control devices which are commonly encountered in industrial applications (EPA, 1995a).
However, these control efficiency estimates may not be precisely applicable to specific control
devices. In addition, a control device may be improperly sized for effective control of the
process under consideration. Therefore, knowledge of the process and engineering judgement
should be used along with the literature value.
A third method of obtaining a control device efficiency is to employ the manufacturer's design
specification or guaranteed performance specification subject to field verification. However,
the design efficiency reported by manufacturers is the efficiency obtainable under optimum
conditions and may not represent actual conditions. Some assessment of design efficiency may
be required to adjust for source-specific conditions.
It may also be necessary to modify the control device efficiency estimate based on
considerations such as downtime or gradually deteriorating conditions (e.g., degradation of
fabric filter bags). If the devices are shut down periodically for maintenance or by upset
conditions, the emissions released in a given hour may far exceed those released in the
controlled mode over many hours of operation. Failure to account for excess emissions
resulting from downtime and deteriorated efficiency can be a large source of error in the
emission estimate. Although regulations and permitting conditions often exempt emissions
occurring when control equipment is inoperative or malfunctioning, these emissions should be
quantified and reported for emission inventory purposes.
4.3.4 PROCESS-SPECIFIC EMPIRICAL RELATIONSHIPS
In addition to the emission factors described above, AP-42 also provides empirically developed
process equations for estimating emissions from certain sources (EPA, 1995a). These
equations, like emission factors, are based on throughput and control efficiency. However,
they are often more complex than the simple ratio used for emission factors. Typically, these
equations include such variables as air temperature, vapor pressure, and others. For example,
VOC emissions from some sources, including storage tanks, vary as a function of tank size,
tank color, temperature, barometric pressure, throughput, and properties of the material
stored.
4.4 EMISSION MODELS
Emission models may be used to estimate emissions in cases where the calculational approach
is burdensome, or in cases where a combination of parameters have been identified which
affect emissions but, individually, do not provide a direct correlation. For example, the
TANKS program incorporates variables such as tank color, temperature, and windspeed to
obtain an emissions estimate.
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Emission models may be based on measured or empirical values. The computer model may be
based on theoretical equations that have been calibrated using actual data, or they may be
purely empirical, in which case the equations are usually based on statistical correlations with
independent variables. :
Appendix F provides information on some of the more commonly used emission estimation
models.
4.5 BEST APPROXIMATION OR ENGINEERING JUDGEMENT
A best approximation or engineering judgement is a final option for estimating emissions,
although it is considered the least desirable method. A best approximation or engineering
judgement is an emission estimate based on available information and assumptions.
If emissions must be estimated by best approximation, a few guidelines may be used to reduce
the potential error. Published emission factors may be used to place order-of-magnitude
boundaries on possible emissions from the process in question.
4.6 OTHER CONSIDERATIONS
4.6.1 RULE EFFECTIVENESS
Inventories performed before 1987 assumed that regulatory programs would be implemented
with full effectiveness, achieving all required or intended emissions reductions and maintaining
the reduction level over time. However, experience has shown regulatory programs to be less
than 100 percent effective for most source categories in most areas of the country.
Rule effectiveness (RE), expressed as a fraction or percent, is an adjustment which reflects the
ability of a regulatory program to achieve the required emissions reductions. The intent
behind the RE factor is to account for the fact that most emission control equipment does not
achieve emission reductions at the designed rates at all times and under all conditions, and that
some intentional noncompliance exists. Process upsets, control equipment malfunctions,
operator errors, equipment maintenance, and other nonroutine operations are typical examples
of times when control device performance is expected to be less than optimal.
Rule effectiveness is especially important for VOC and CO control programs because of the
small size, large number, and relative complexity of most regulated sources. It is necessary to
apply rule effectiveness when preparing emissions inventories because the effectiveness of
existing regulations is directly related to emissions levels. Rule effectiveness must also be
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considered in planning for the expected effect of further regulations. Rule effectiveness should
be applied for all applicable regulations: federal, state, and local.
A default fraction of 0.80 (equal to 80 percent effectiveness) has been established by the EPA
to estimate rule effectiveness in the base year inventories. This fraction is a representative
estimate of the average effectiveness values, based on a survey of selected state and local
personnel on the perceived effectiveness of their regulatory programs for a wide range of
source categories. The 80 percent default value or local category-specific rule effectiveness
factor is applied if the emissions data were determined using emission factors, results of
emissions tests, or estimated control efficiencies, even if the data were obtained from a survey
of the source.
Although the 80-percent rule effectiveness value may generally be valid, it can vary
significantly among source categories and can have a dramatic impact on sources assumed to
be controlled at a high efficiency (e.g., 99.9 percent). Use of the default rule effectiveness
factor should be carefully reviewed under these circumstances. A rule effectiveness of
100 percent may be applicable in some cases, but sources should be sure that no equipment
downtime or emergency releases have occurred during the inventory period.
For the purpose of base year inventories under the CAA, the EPA allows the use of the
80-percent default value, but also gives agencies the option to derive local category-specific
rule effectiveness factors through the use of a survey. Also, if rule effectiveness can be
determined for a source category in a particular region using the protocol defined by the
EPA's Office of Enforcement and Compliance Assurance, this rule effectiveness can be used.
If a particular facility disagrees with the rule effectiveness factor used in an inventory, a
case-by-case assessment of emissions can be performed to determine whether there is adequate
data for emissions to be directly determined. If a facility can provide the explicit source data
required by EPA, such as continuous source monitoring and control equipment functioning
records for the inventory period, then emissions can be determined directly.
Where controls are not used, there is no need to apply rule effectiveness. The rule
effectiveness factor should be applied to the estimated control efficiency in the calculation of
emissions from a source. However, if emissions are estimated properly, there is no need to
apply rule effectiveness. An example of the application is given below.
• Example:
Uncontrolled emissions = 50 pounds (Ib) per day
Estimated control equipment efficiency = 0.90 (90 percent)
Rule effectiveness factor = 0.80 (80 percent)
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Emissions after control = 50[1-(0.90)(0.80)]
= 50(1-0.72)
= 14 Ib per day
Note: The EIIP Point Sources Committee is currently evaluating the application of the rule
effectiveness policy. The committee will present Iheir findings in an issues paper to the EIIP
Steering Committee upon completion of their study.
4.6.2 CONTROL DEVICES
A basic description of the techniques typically used by industry to control PM10, VOCs, SO2,
NOX, and HAPs can be found in the Handbook: Control Technologies for Hazardous Air
Pollutants (EPA, 199Id). The handbook briefly describes the efficiencies commonly achieved
by major types of control devices in current use and describes how to estimate emission
reductions using control systems. Table 1.4-1 lists several control devices commonly used for
emission reduction at stationary point sources. For each control device listed, the table
identifies the pollutants controlled by the device and presents expected efficiency ranges.
In order to determine removal efficiencies of HAPs from the air stream, it is necessary to
know the nature of the HAPs involved, including such parameters as particle size, volatility,
or combustibility. Control techniques guidelines (CTG) documents have been written for
numerous VOC-emitting source categories; some of these documents contain information
relevant to the control of HAPs. A list of several CTGs is presented in Table 1.4-2.
Information on available CTG documents can also be obtained via the Control Technology
Center (CTC) assistance line (see Appendix C). Another source of information on control
devices for a particular source is a series of documents collectively referred to as alternative
control techniques (ACT) documents. These documents provide background information on
controls, but do not provide reasonably available control technology (RACT) analysis
information as do the CTGs. A list of available ACT documents is presented in Table 1.4-3.
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CHAPTER 1 - INTRODUCTION
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TABLE 1.4-1
AIR POLLUTION CONTROL TECHNOLOGIES
Method
Cyclones
Fabric filter
Wet scrubbers
Electrostatic
precipitators
Carbon adsorption
Fluidized-bed systems
Absorption
Condensation
Thermal incineration
Catalytic incineration
Pollutant Type
Organic
Vapors
Xb
Xc
xd
xe
X
X
X
Inorganic
Vapors
X
X
Xf
Particulates
X
X
X
X
Efficiency
(%)
98a
80-99
95
99.5-99.9
50-99
—
90-99
50 - 95s
;>99
95-99
Sources: EPA, 1991d; and Cooper, et al., 1994.
a The greatest amount of control would be achieved for particles larger than 5 //m.
b Depends on material, should be miscible in water.
c Carbon adsorption or fired-bed systems.
d Not widely used.
e Material must be readily soluble in water or other solvents.
f Depends on vaporization point of material.
g Highly dependent on the emission stream characteristics.
-- No data available.
1.4-14
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CHAPTER 1 - INTRODUCTION
TABLE 1.4-2
CONTROL TECHNIQUES GUIDELINES DOCUMENTS
(GROUPS I, II, III)
Source Description
Surface Coating Operations
Coating of Cans, Coils,
Paper, Fabrics, Automobiles,
and Light-Duty Trucks
Surface Coating of Metal
Furniture
Surface Coating of Insulation
of Magnet Wire
Surface Coating of Large
Appliances
Surface Coating of
Miscellaneous Metal Parts
and Products
Factory Surface Coating of
Flat Wood Paneling
Graphic Arts - Rotogravure
and Flexography
Bulk Gasoline Plants
Storage of Petroleum Liquids
in Fixed Roof Tanks
Refinery Vacuum Producing
Systems, Wastewater
Separators, and Process Unit
Turnarounds
EPA Report
Number
450/2-76-028
450/2-77-008
450/2-77-032
450/2-77-033
450/2-77-034
450/2-78-015
450/2-78-032
450/2-78-033
450/2-77-035
450/2-77-036
450/2-77-025
NTIS Report
Number
PB-260 386
PB-272 445
PB-278-257
PB-278-258
PB-278-259
PB-286-157
PB-292-490
PB-292-490
PB-276-722
PB-276-749
PB-275-662
Date of
Publication
1976
1977
1977
1977
1978
1978
1978
1978
1977
1977
1977
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TABLE 1.4-2
(CONTINUED)
Source Description
Use of Cutback Asphalt
Tank Truck Gasoline
Loading Terminals
Design Criteria for Stage I
Vapor Control Systems-
Gasoline Service Stations
Control of Volatile Organic
Compound Leaks from
Petroleum Refinery
Equipment
Petroleum Liquid Storage in
External Floating Roof
Tanks
Perchloroethylene Dry
Cleaning Systems
Leaks from Gasoline Tank
Trucks and Vapor Collection
Systems
Volatile Organic Liquid
Storage in Floating and
Fixed Roof Tanks, Draft
Large Petroleum Dry
Cleaners
Synthetic Organic Chemical
Polymer and Resin
Manufacturing Equipment
EPA Report
Number
450/2-77-037
450/2-77-026
—
450/78-036
450/2-78-047
450/2-78-050
450/2-78-051
—
450/3-82-009
450/3-83-006
NTIS Report
Number
PB-278-185
PB-275-060
—
PB-286-158
PB-290-579
PB-290-613
PB-290-568
—
PB 83-124-875
PB-84-161-520
Date of
Publication
1977
1977
1975
1978
1978
1978
1978
1981
1982
1984
1.4-16
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CHAPTER 1 - INTRODUCTION
TABLE 1.4-2
(CONTINUED)
Source Description
Equipment Leaks from
Natural Gas/Gasoline
Processing Plants
Solvent Metal Cleaning
Manufacture of Synthesized
Pharmaceutical Products
Manufacture of Pneumatic
Rubber Tires
Control Techniques for
Volatile Organic Emissions
from Stationary Sources
Air Oxidation Processes in
Synthetic Organic Chemical
Manufacturing Industry
Manufacture of High-Density
Polyethylene, Polypropylene,
and Polystyrene Resins
Fugitive Emissions Sources
of Organic Compounds -
Additional Information on
Emissions, Emissions
Reductions, and Costs
EPA Report
Number
450/2-83-007
450/2-77-022
450/2-78-029
450/2-78-030
450/2-78-022
450/3-84-015
450/3-83-008
450/3-82-010
NTIS Report
Number
PB-84-161-520
PB-274-557
PB-290-580
PB-290-557
PB-284-804
PB-85- 164-275
PB-84-134-600
PB-82-217-126
Date of
Publication
1983
1977
1978
1978
1978
1984
1983
1982
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TABLE 1.4-3
ALTERNATIVE CONTROL TECHNIQUES DOCUMENTS
Source Description
Halogenated Solvent
Reduction of Volatile
Organic Compound
Emissions from the
Application of Traffic
Markings
Ethylene Oxide
Sterilization/Fumigation
Operations
Reduction of Volatile
Organic Compound
Emissions from
Automobile
Organic Waste Process
Vents
Industrial Wastewater
Volatile Organic
Compound
Emissions-Background
Information for
BACT/LAER
Determinations
Polystyrene Foam
Manufacturing
EPA Report
Number
450/3-89-030
450/3-89-007
450/3-88-009
450/3-91-007
450/3-90-004
450/3-90-020
NTIS Report
Number
PB 90-103268
PB 89-148274
PB 90-131434
PB 89-148282
PB 91-148270
PB 90-194754
PB 91-1021 11
Date of
Publication
1989
1988
1989
1990
1990
1990
1.4-18
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DATA COLLECTION
This section describes effective procedures for obtaining data for emissions inventories.
Questionnaires, plant inspections, and agency air pollution files are some of the methods that
are useful in collecting emissions data as well as source activity and control data. Selection of
the appropriate method of data collection should include consideration of the desired level of
detail of the inventory.
5.1 LEVEL OF DETAIL
Point sources can be inventoried at three levels of detail: (1) the plant level, which denotes a
plant or facility that could contain several pollutant-emitting activities; (2) the point/stack
level, where emissions to the ambient air from stacks, vents, or other points of emission are
characterized; and (3) the process/segment level, representing the unit operations of specific
source categories. A discussion of these three levels follows and includes the minimum
information that will be needed for the inventory regardless of the method selected for
collecting the data.
5.1.1 PLANT LEVEL
In a plant-level survey, each plant within the area should be identified and assigned a plant
number. The plant should be further identified by geographic descriptors such as
nonattainment area, state, county, city, street and/or mailing address, and UTM grid
coordinates (or latitude/longitude). A plant contact should also be identified to facilitate
communication and interaction with the plant. Additional information gathered regarding the
facility should include annual fuel consumption, process throughput, hours of operation,
number of employees, and the plant's standard industrial classification (SIC) code. The SIC
codes are prepared and published by the U.S. Office of Management and Budget (OMB). A
facility can have more than one SIC code denoting the secondary economic activities of the
facility.
5.1.2 POINT/STACK LEVEL
In an inventory conducted at the point/stack level, each stack, vent, or other release point that
meets or exceeds a specified minimum emission rate should be identified as an emission point.
Information obtained at the point/stack level is used in application of mathematical models to
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correlate air pollutant emissions with ambient air quality. Thus, in addition to the facility
identification, location, and plant contact, release characteristics for each emission point are
necessary for establishing a comprehensive inventory and performing evaluations with
modeling programs. The necessary emission point parameters include location (latitude/
longitude), stack height, stack diameter, emission rate, and gas exit velocity.
It is recommended that the location of point sources be reported with a resolution of
+1 second at 30 meters. This level of resolution is consistent with existing data specifications
in EPA emissions inventory databases. However, such a high degree of precision in
specifying location may only be necessary in a limited number of applications
5.1.3 PROCESS/SEGMENT LEVEL
A plant may include various processes or operations. Each process can usually be identified
by an SCC that is used to enter emissions data into a database management system. The
information necessary to establish an inventory at this level includes facility identification;
facility location; plant contact; process identification information; point level data; applicable
regulations; operating rate data, including actual, maximum, and design operating rate or
capacity; fuel use and properties data (e.g., ash content, sulfur content, level of trace
elements, heat content, etc.); and identification of all pollution control equipment and its
associated control efficiency (measured or design).
5.2 AVAILABILITY AND USEFULNESS OF EXISTING DATA
A major inventory planning consideration is whether, and to what extent, existing information
can be used. Existing inventories can serve as a starting point for developing extensive data
and support information, such as documentation of procedures. Information may also be
drawn from other regulatory agency operations such as permitting, compliance, and source
inspections and from other facility resources such as corporate reporting or compliance report
submittals. For effective use of resources, an agency or facility should plan to fulfill specific
emissions inventory requirements by building upon and improving the quality of regularly
collected data.
5.3 DATA COLLECTION METHODS
5.3.1 QUESTIONNAIRES
The survey questionnaire is a technique commonly used by state and local agencies for
gathering point source emissions inventory data. Figure 1.5-1 shows an example of point
1.5-2
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CD
Develop Questionnaire
Complete Questionnaire
for Each Point Source
Industrial Plant #3
Survey All Facilities
Estimate Facility
Emissions for Surveyed
Point Sources
i
"0
Ul
FIGURE 1.5-1. EXAMPLE OF POINT SOURCE SURVEYING
1
§
c:
o
y
i
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CHAPTER 1 - INTRODUCTION 7/7/57
source surveying. The primary purpose of a survey is to obtain source and emissions data by
means of a questionnaire that can be mailed or otherwise delivered to each facility. In order
to conduct this type of data-gathering operation, the facilities to be surveyed must be
identified; mailing lists must be prepared; questionnaires must be designed, assembled, and
either mailed or delivered; data-handling procedures must be prepared and organized; and
response-receiving systems must be established. Recently, it has become common to use
computer media (floppy disks or electronic transmission) instead of paper to return
questionnaire responses to the regulatory agency. This technique can also include the use of
standardized computer forms or software so that data submitted to the agency is in a format
easily handled by agency personnel.
The sections below provide additional detail regarding the steps involved in collecting data via
questionnaires. The information is applicable regardless of whether the data is collected on
paper or electronic media. See the document Development of Questionnaires for Various
Emission Inventory Uses for more information about questionnaires (Holman and
Collins, 1979).
Preparing the Mailing List
A necessary step in the mail survey is the preparation of a mailing list that tabulates the name,
address, and general process category of each facility to be surveyed. The basic function of
the mailing list is to identify those sources to which questionnaires will be sent. The mailing
list may also serve other functions. For example, the general process category information
obtained from the mailing list can assist an agency in determining those categories for which
questionnaires must be designed. In addition, the size of the resulting mailing list gives an
agency an indication of the numbers and types of sources that can effectively be considered in
the point source inventory within resource limitations. In this regard, the mailing list can be
used to help an agency determine whether the resources allocated for the compilation effort
will be sufficient.
The mailing list is compiled from a variety of information sources, including:
• Existing inventories;
• Other inventories such as the Toxic Chemical Release Inventory System
(TRIS);
• Air pollution control agency files;
• Other government agency files; and
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• Other local information sources such as local industrial directories, yellow pages,
manufacturers and suppliers, and national publications such as those listed below;
Dun and Bradstreet,b Million Dollar Directory: Companies with sales
over $1,000,000 per year are compiled by SIC and county.
Dun and Bradstreet,a Middle Market Directory: Companies with sales
between $50,000 and $1,000,000 per year are compiled by SIC and
county. '
Dun and Bradstreet,a Industrial Directory.
National Business Lists: Companies are listed by SIC and county with
information on financial strength and number of employees.
Trade and professional society publications: Names and addresses of
members are listed along with their type of business.
The mailing list should be organized to facilitate the necessary mailing and follow-up
activities. A logical order in which to list companies is by city or county, then by SIC, and
finally, alphabetically. Ordering the list in this manner will increase the efficiency of all
subsequent data-handling tasks and will allow a quicker QC check of the list.
Limiting the Size of the Mail Survey
If more sources are identified on the mailing list than can be realistically handled with
available resources, an agency should screen the mailing list in some manner to reduce the
number of facilities to be sent questionnaires. This can be done in a number of ways. One
way is to limit the mailout to only those sources believed to be above certain emissions levels.
The cutoff level distinction is especially important in the VOC inventory because there are so
many more small sources of VOC than of most other pollutants. The cutoff level for NO x and
CO is less critical because of the usually significant contribution from the larger emitters. In
general, if too high a cutoff level is chosen, many facilities will not be considered individually
as point sources, and, if care is not taken, emissions from these sources may not be included
in the inventory at all. Techniques are available for "scaling up" the inventory to account for
missing sources; however, such procedures are invariably less accurate than point source
methods. If too low a cutoff level is chosen, the result will be a significant increase in the
a Dun and Bradstreet data can be accessed through the FACTS database on the EPA
mainframe National Computing Center. Contact (919) 541-4506 to set up an account.
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number of plant contacts of various sorts that must be made and the size of the point source
file that must be maintained. While a low cutoff level may increase the accuracy of the
inventory, the tradeoff is that many more resources are needed to compile and maintain the
inventory.
Designing the Questionnaires
A questionnaire should be prepared for each source category type to be contacted. This can
be done either by preparing industry-specific questionnaires for each source category or by
preparing more general questionnaires that encompass many source categories. The use of
general questionnaires may be advisable if the mailing list is long, if an agency is unfamiliar
with many of the sources on the list, or if an agency's resources are limited. Often in
practice, a general questionnaire is merely a collection of process-specific questionnaires. If
sufficient resources are available, the use of industry-specific questionnaires is advantageous
for certain sources.
Developing a questionnaire involves identifying and writing the appropriate questions,
establishing a suitable format, and developing a cover letter and instructions for filling out the
questionnaire. The basic rule is to design the questionnaire for the person who will be asked
to complete it. An agency should consider that the person who will complete the
questionnaire may not have the benefit of a technical background in air pollution, engineering,
or physical sciences. Hence, questionnaires and instructions should be designed to be
understood by persons without specialized technical training. Each question should be self-
explanatory or accompanied by clear directions.
All necessary information should be solicited on the questionnaire, thus avoiding later
requests for additional data. In addition to general source information such as location,
ownership, and nature of business, the request should include the following:
• Process information-Because activity levels, including indicators of production
and fuel consumption, are generally used with emission factors, appropriate
activity levels must be obtained for each type of source. The types of activity
levels needed to calculate emissions from point sources are defined for sources
in AP-42, 5th Edition.
• Source information-Some of the emission equations in AP-42 require
information on the operation or physical characteristics of the individual point
source. For example, emissions from petroleum product storage and handling
operations are dependent on a number of variables, including liquid
temperature, tank size, tank color, roof type, and product vapor pressure.
1.5-6
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Appropriate values for these variables should be obtained to allow an agency to
use the emission equations given mAP±42, 5th Edition.
• Control device information-Many of the emission factors in AP-42 represent
emissions hi the absence of any controls. Thus, data on control devices is
helpful for determining potential emission reductions resulting from applying
various control strategies, especially for those source categories for which
CTG documents have been published. •
• Modeling data-Application of dispersion and photochemical models requires
input data characterizing the emission stream as it exits the stack or vent.
These parameters include stack height, stack diameter, exit temperature, exit
velocity, and geographic location in the form of latitude/longitude or UTM
coordinates. [NOTE: These example parameters are appropriate for
dispersion modeling but may not be representative of the types of information
needed for photochemical models. Please review carefully.]
Mailing and Tracking the Questionnaires and Logging Returns
Each questionnaire sent out should be accompanied by a cover letter stating the purpose of the
inventory and citing any statutes that require a response from the recipient. Cooperation in
filling out and returning the questionnaire should be respectfully requested. In addition, each
questionnaire should be accompanied by a set of general procedures and instructions telling
the recipient how the questionnaire should be completed and the date it should be returned to
the agency.
After the final mailing list has been compiled and questionnaire packages are assembled
(including mailing label, cover letter, instructions, questionnaires, and self-addressed stamped
envelope), an agency should proceed with the mailout activities. It is important to develop a
tracking system to determine the status of each step of the mail survey. Such a tracking
system should tell an agency: (1) to which companies questionnaires were mailed; (2) the
dates the questionnaires were mailed; (3) the dates that each response was returned;
(4) corrected name, address, and SIC information; (5) preliminary information on the type of
the source; (6) whether recontacting is necessary; and (7) the status of the follow-up contact
effort. Tracking can be accomplished manually through the use of worksheets or through the
use of a simple computer program. A computer printout of the mailing list can be formatted
for use as a tracking worksheet.
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5.3.2 PLANT INSPECTIONS
During plant inspections, agency personnel usually examine the various processes at a
particular facility and interview appropriate plant personnel. If an agency's resources allow,
source testing may be conducted as a part of the plant inspection.
The major advantage of the plant inspection is that it should provide more thorough and
accurate information about an emitter than does the questionnaire alone. Errors resulting
from a company's misinterpretation of the questionnaire, or an agency's misinterpretation of
the response, are also minimized. Finally, in cases where a process is unique or complex, the
only realistic way for an agency to gain an adequate understanding of the emitting points and
the variables affecting emissions is to observe the plant equipment personally and to review
the operations and process schematics with the appropriate plant personnel.
5.3.3 ACCESSING AGENCY AIR POLLUTION FILES
An agency may have special files or databases that can be accessed for use in emissions
inventory development. These files may include permit files, compliance files, or emissions
statements. Permits are typically required for construction, startup, modifications, and
continuing operation of an emissions source. Permit applications generally include enough
information about a potential source to describe the nature of the source and to estimate the
magnitude of emissions that will result from its operations. Some permits also include source
test data.
Some agencies may also maintain a compliance file which records the agency's dealing with
each source on enforcement matters. A compliance file might contain a list of air pollution
regulations applicable to a given source, a history of contacts made with that source on
enforcement matters, and an agreed-upon schedule for the source to effect some sort of
control measures. Such information may be helpful in the preparation of an inventory.
5.3.4 EMISSIONS ESTIMATES CONDUCTED BY PLANT PERSONNEL
The number and complexity of processes within a given plant, In addition to the difficulty of
accessing all the data necessary to complete emission calculations, can make emissions
estimation a complex task, with significant opportunity for error. A few general guidelines
for conducting overall emissions estimates for a plant are listed below:
• Identify and document the emission sources;
• Identify the types of pollutants and quantify the emissions;
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• Compile the source and emissions data into a useable format;
• Design and implement a quality assurance plan; and
• Seek assistance from EPA, state, and local agencies.
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INVENTORY REPORTING AND
DOCUMENTATION
Documentation is an integral part of an emissions inventory. Before submittal, internal review
of the written documentation of an inventory's data sources and procedures may uncover
errors in assumptions, calculations, or methods. Early correction of these errors will result in
a more reliable and technically defensible database, which is essential in some critical aspects
of the inventory such as source impact assessments and development of emissions control
strategies.
Following submittal of the inventory, the documentation allows the quality of the inventory to
be effectively judged. An emissions inventory that is documented according to standardized
guidelines enables the receiving agency to review the inventory in a consistent manner.
Because it is recognized that some variability is needed to meet the specific needs of each
inventory region, standardization is emphasized for the types of data reported, but not the
format hi which they are reported. Inventories not meeting the minimum data reporting and
documentation standards may be deemed unacceptable and returned to the preparer for
modification before any further review of technical quality is performed.
The reporting steps of the emissions inventory development process should be anticipated
during planning. Planning the level of documentation required will: (1) ensure that important
supporting information is properly developed and maintained; (2) allow extraneous information
to be identified and discarded, thereby reducing the paperwork burden; (3) help determine data
storage requirements; and (4) aid in identifying aspects of the inventory on which to
concentrate the QA efforts.
6.1 WRITTEN DOCUMENTATION
Written documentation should include summary tables and a report discussing the inventory
development procedures and point source results. Large volumes of detailed data should be
put into appendices but clearly linked to the text discussion in terms of how they were used to
determine emissions.
For inventories prepared by a plant, emissions may be summarized by pollutant, equipment/
source, and/or stack. For larger inventories prepared by a state or local agency, the
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CHAPTER 1 - INTRODUCTION 7/7/37
presentation may be more broadly focussed by source category and/or county. Graphics may
be useful to illustrate the contribution of point sources to areawide emissions.
The report should address data collection methods and tools, how the inventoried sources were
identified, the completeness of source coverage, and procedures for estimating emissions. If
any source categories are excluded, they should be listed and a reason for the exclusion should
be provided. If applicable, an explanation should be included on how emissions were
temporally allocated and on what basis. The methodology by which activity levels and
emissions were determined for each plant should also be explained.
The appendices should contain the results of all information surveys that have been conducted.
All sources inventoried should be listed according to their source category type (e.g., storage
tank, process vent, petroleum refinery, graphic arts, degreasing, etc.). All references and
other data sources should also be included or, if they are too voluminous, they should be
clearly cited in the inventory submittal and kept in a readily accessible location on site.
For a more detailed discussion of documentation requirements, consult the EPA document
Example Documentation Report for 1990 Base Year Ozone and Carbon Monoxide SIP
Emissions Inventories (EPA, 1992b).
6.2 COMPUTERIZED DATA REPORTING
Along with the written documentation of the inventory, an electronic submittal inventory is
also recommended. State and local agencies may submit their data to EPA, using one of the
data transfer options available. Specific information on the data transfer options may be
located on the EPA's 1996 Emission Inventory World Wide Website (expected to be available
mid-July 1997).
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QUALITY ASSURANCE/
QUALITY CONTROL
The development of a reasonable and comprehensive emissions inventory requires the
implementation of quality assurance/quality control (QA/QC) procedures throughout the entire
inventory process. The main objective of the QA and QC for emissions inventories is the
development of accurate, useful, and reliable data. These procedures should be applied
consistently by the state or local agency in preparing or reviewing inventories.
Prior to establishing a quality program or plan, the meaning of quality as it relates to the
inventory should be clarified. Quality control is the overall system of routine technical
activities that are designed to measure and control the quality of the inventory as it is being
developed. Quality assurance is an integrated system or program of activities involving
planning, QC, quality assessment, reporting, and quality improvements which are designed to
help ensure that the inventory meets the data quality goals or objectives established prior to
developing the inventory.
7.1 QUALITY CONTROL
Quality control is the performance of standardized activities during the course of inventory
preparation to ensure data quality. Quality control activities include technical reviews,
accuracy checks, and the use of approved standardized procedures for emissions calculations.
These internal activities are designed to provide the first level of quality checking and should
be included in inventory development planning, data collection, data analysis, emissions
calculation, and reporting. Quality control is best implemented through the use of
standardized checklists that assess the adequacy of the data and procedures at various intervals
in the inventory process. Specifically, QC checklists are used to monitor the following
procedures and tasks:
• Data collection;
• Data calculation;
• Emission estimates;
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• Data validity;
• Data reasonableness;
• Data completeness;
• Data coding and recording; and
• Data tracking.
The checklist can aid the preparer hi finalizing the inventory prior to submittal to a reviewing
agency. An example QC checklist for stationary point sources is included in Appendix D.
This checklist includes questions concerning completeness (e.g., questions whether all the
VOC point sources ^ 10 tpy have been accounted for); use of approved procedures
(e.g., questions as to which model was used to estimate wastewater treatment emissions); and
reasonableness (e.g., questions whether all stack heights are greater than 50 feet and all stack
diameters between 0.5 and 30 feet). For additional information and guidance on applying
reasonableness or reality checks to an inventory, please refer to Chapter 3, Volume VI of the
EIIP series.
7.2 QUALITY ASSURANCE
Quality assurance activities include helping inventory preparers identify critical phases of the
inventory development process that will affect the technical soundness, accuracy, and
completeness of the inventory. After identifying these phases of the process, QC procedures
are developed to monitor the quality of the data and work to help ensure the generation of an
accurate and complete inventory. Other QA activities include the evaluation of the
effectiveness of these QC procedures by conducting data and procedural audits at critical
phases of the inventory development process.
If quality concerns are found during QA audits, they should be discussed with the personnel
involved so that actions can be taken immediately to resolve the issues. The quality concerns,
recommendations for corrective actions, and satisfactory aspects of the QC program should be
summarized in an audit report. Inventory development personnel are responsible for the
resolution of the quality concerns in a timely fashion so that the work progresses as planned
and the quality of the data is always being optimized.
The keys to the success of a QA/QC program are proper planning and the involvement of QA
personnel to help design the QC program. An essential part of proper planning is the
specification of the data quality objectives. Much of the data used for inventories are not
sufficient to establish quantitative goals. Therefore, qualitative goals must be specified.
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Table 1.7-1 lists six important quality goals for inventories and gives general methods for
achieving those goals.
7.3 QA/QC PROCEDURES FOR SPECIFIC EMISSION ESTIMATION
METHODS
7.3.1 SOURCE TESTS AND CONTINUOUS EMISSIONS MONITORING (CEM)
The main objective of any QA/QC effort for any program is to independently assess and
document the precision, accuracy, and adequacy of data. In an emissions inventory developed
from source tests and CEM, the data of interest will be that generated during sampling and
analysis. As a first step, a QA Plan should be developed by the team conducting the test prior
to each specific field test. Next, it is essential to the production of valid test data that the
emissions measurement program be performed by qualified personnel using appropriate and
properly functioning test equipment. Sampling equipment, such as flow meters and gauges,
must be properly calibrated and maintained. Emphasis is placed upon these standard practices
as means of ensuring the validity of results. Deviations from standard procedures must be
kept to a minimum and applied only when absolutely necessary to obtain representative
samples. For compliance testing, deviations from standard procedures may be used only with
approval of the regulatory agency. Any changes hi methodology must be based on sound
engineering judgement and must be thoroughly documented.
Thorough descriptions of stack sampling procedures, source sampling tools and equipment,
identification and handling of samples, laboratory analysis, use of the sampling data, and
preparation of reports are available in several references, such as the Quality Assurance
Handbook for Air Pollution Measurement Systems: Volume III. Stationary Source Specific
Methods (EPA, 1984). This document also contains a detailed discussion of interpretations of
CEM data, required accuracy calculations, specific criteria for unacceptable CEM data, and
indications that a CEM is out of control.
A systems audit should be conducted on-site as a qualitative review of the various aspects of a
total sampling and/or analytical system to assess its overall effectiveness. The systems audit
should represent an objective evaluation of each system with respect to strengths, weaknesses,
and potential problem areas. The audit provides an evaluation of the adequacy of the overall
measurement system(s) to provide data of known quality which are sufficient, in terms of
quantity and quality, to meet the program objectives.
Quality control procedures for all instruments used to continuously collect emissions data are
identical. The primary control check for precision of the continuous monitors is daily analysis
of control standards.
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TABLE 1.7-1
METHODS FOR ACHIEVING EMISSION INVENTORY DATA QUALITY OBJECTIVES
Data Quality Objectives
Methods
Ensure correct implementation of EPA
guidance.
Review inventory documentation, comparing
actual procedures used to those required.
Where EPA guidance was not used or
unavailable, assess bias by evaluating
the reasonableness of the approach
used.
Technical review of approach used.
Compare with results from other methods.
Ensure accuracy of input data.
• Check accuracy of transcription of data.
• Check any conversion factors used.
• Assess validity of assumptions used to calculate
input data.
• Verify that the data source was current and the
best available.
Ensure accuracy of calculations.
Reconstruct a representative sample (or all) by
hand.
Assess comparability and
representativeness of inventory.
Compare emissions to those from similar
inventories.
Cross-check activity data by comparing it to
surrogates.
Assess completeness of inventory.
Compare list of source categories or emission
points to those listed in EPA guidance.
Cross-check against other published inventories,
business directories, etc.
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The emission rates of a particular pollutant are a function of a number of stack gas parameters
such as concentration and flow rate which are measured during testing. Sensitivity and error
analyses illustrate the extent to which the emission estimate may be affected by variability in
the measured values. See Volume VI of the EIIP series of guidance documents for additional
information on evaluating how the quality of the calculated emission rates are affected by the
accuracy of the measurements.
7.3.2 MATERIAL BALANCES
The accuracy and reliability of emission values calculated using the material balance approach
are related to the quality of material usage and speciation data, and knowledge of the different
fate pathways for the material.
The quantity of material used in an operation is often "eye-balled," a procedure that can easily
result in an error of as great as 25 percent. This level of uncertainty can be reduced by using
a standardized method of measuring quantities such as a gravimetric procedure (e.g., weighing
a container before and after using the material) or use of a stick or gauge to measure the level
of liquid hi a container. For certain applications (e.g., those where very small quantities of
materials are used), it may be more accurate to make these types of measurements monthly or
annually, rather than after each application event. Another technique for determining usage
quantities would be to use purchase and inventory records.
Uncertainty of emissions using the material balance approach is also related to the quality of
material speciation data, which is typically extracted from Material Safety Data Sheets
(MSDSs). If speciation data are not available on the MSDS, the material manufacturer should
be contacted. Finally, a thorough knowledge of the amount of a material exiting a process
through each fate pathway is needed. Typical fate pathways include product, recycle/reuse,
solid waste, liquid waste, and air emissions.
7.3.3 EMISSION FACTORS
Realizing that site specific test or CEM data are not always available or the most cost effective
means for estimating air emissions from a facility, emission factors are often used as an
alternative method for calculating emissions. Data used to develop emission factors available
in AP-42 or the FIRE system, for example, are obtained from source tests, material balance
studies, and engineering estimates. AP-42 and FIRE identify any qualifications or limitations
of the data. AP-42 and FIRE emission factors represent the best available information on
average emissions from the identified source categories as of the date of factor publication.
Each emission factor published in AP-42 or FIRE receives a quality rating, which serves as an
assessment of the confidence the generator of that value places in the quality of the emission
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factor. When using existing emission factors, the user should be familiar with the criteria for
assigning both data quality ratings and emission factor ratings as described in the document
Technical Procedures for Developing AP-42 Emission Factors and Preparing AP-42 Sections
(EPA, 1993b).
The data quality ratings for source tests are as follows:
• A-Rated Test - Excellent - The test(s) was performed by a sound methodology
and reported in enough detail for adequate validation. These tests are not
necessarily EPA reference test methods, although such reference methods are
certainly to be used as a guide.
• B-Rated Test - Above Average - The test(s) was performed by a generally
sound methodology but lacked enough detail for adequate validation.
• C-Rated Test - Average - The test(s) was based on a nonvalidated or draft
methodology or lacked a significant amount of background data.
• D-Rated Test - Below Average - Test(s) was based on a generally unacceptable
method but may provide an order-of-magnitude value for the source.
Once the data quality ratings for the source tests are assigned, these ratings along with the
number of source tests available for a given emission point are evaluated. Because of the
almost impossible task of assigning a meaningful confidence limit to industry-specific variables
(e.g., sample size versus sample population, industry and facility variability, method of
measurement), the use of a statistical confidence interval for establishing a representative
emission factor for each source category is usually not practical. Therefore, some subjective
quality rating is necessary. The following factor quality ratings are used for the emission
factors found in AP-42, FIRE, or any EPA published document:
• A - Excellent - The emission factor was developed only from A-rated test data
taken from many randomly chosen facilities in the industry population. The
source category is specific enough to minimize variability within the source
category population.
• B - Above Average - The emission factor was developed only from A-rated test
data from a reasonable number of facilities. Although no specific bias is
evident, it is not clear if the facilities tested represent a random sample of the
industry. As with the A-rating, the source category is specific enough to
minimize variability within the source category population.
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• C - Average - The emission factor was developed only from A- and B-rated test
data from a reasonable number of facilities. Although no specific bias is
evident, it is not clear if the facilities tested represent a random sample of the
industry. As with the A-rating, the source category is specific enough to
minimize variability within the source category population.
• D - Below Average - The emission factor was developed only from A- and
B-rated test data from a small number of facilities, and there may be reason to
suspect that these facilities do not represent a random sample of the industry.
There also may be evidence of variability within the source category
population.
• E - Poor - The emission factor was developed from C- and D-rated test data,
and there may be reason to suspect that the facilities tested do not represent a
random sample of the industry. There also may be evidence of variability
within the source category population.
• U - Unrated or Unratable - The emission factor was developed from suspect
data with no supporting documentation to accurately apply an "A" through "E"
rating. A "U" rating may be applied in the following circumstances (FIRE):
Ul - Mass Balance (for example, estimating air emissions based on raw
material input, product recovery efficiency, and percent control).
U2 - Source test deficiencies (such as inadequate quality assurance/quality
control, questionable source test methods, only one source test).
U3 - Technology transfer.
U4 - Engineering judgement.
U5 - Lack of supporting documentation.
7.3.4 MODELING
When a model or other software program is used to calculate emissions, manual verification
(by hand) of each type of calculation should be performed. If the calculations are complex and
can not be easily reconstructed, an alternative approach is to try to duplicate the results using
another calculation method. The input data should also be verified for accuracy. For
additional guidance on QA/QC procedures for using models, refer to Chapter 3, General
QA/QC Methods (EIIP, 1996). *
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7.4 DATA ATTRIBUTE RATING SYSTEM (DARS)
The EPA has developed a Data Attribute Rating System (DARS) to assist in evaluating data
associated with emission inventories (Beck, et al., 1994). The system disaggregates emission
inventories into emission factors and activity data, then assigns a numerical score to each of
these two components. Each score is based on what is known about the factor and activity
parameters, such as the specificity to the source category and the measurement or estimation
techniques employed. The resulting emission factor and activity data scores are combined to
arrive at an overall confidence rating for the inventory.
The DARS defines certain classifying attributes that are believed to influence the accuracy,
appropriateness, and reliability of an emission factor or activity and derived emission
estimates. This approach is semiquantitative in that it uses numeric scores; however, scoring
is based on qualitative and often subjective assessments. The proposed approach, when
applied systematically by inventory analysts, can be used to provide a measure of the merits of
one emission estimate relative to another.
The DARS provides the means for determining the comparability and transparency of rated
inventories. The inventory with the higher overall rating is likely to be a better estimate given
the techniques and methodologies employed in its development. Several methods of
combining the values are discussed and compared in the paper entitled A Data Attribute Rating
System (Beck, et al., 1994).
The DARS is currently being developed into a PC-based system which will enable users to
import emissions inventories for scoring.
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REFERENCES
ASTM, Annual Book ofASTM Standards, Volumes 06.01 and 15.05. September 1992.
Washington, D.C.
Beck, L. L., R. L. Peer, L. A. Bravo, and Y. Yan. November 3, 1994. A Data Attribute
Rating System. Presented at the Air and Waste Management Association Specialty Conference
on Emission Inventory Issues. Raleigh, North Carolina.
Clean Air Report. June 15, 1995. "Status of EPA's Enhanced Monitoring Rule-Results of the
First Stakeholders' Meeting." Washington, DC.
Code of Federal Regulations, Title 40, Part 60, Appendix A.
Code of Federal Regulations, Title 40, Part 61, Appendix B.
Cooper, C.D., and F.C. Alley. Air Pollution Control, A Design Approach. Second Edition,
1994. Waveland Press, Inc. Prospect Heights, Illinois.
Dobie, N. 1992. Procedures for Emission Inventory Preparation, Volume IV: Mobile
Sources (Revised). EPA-450/4-81026d. U.S. Environmental Protection Agency. Research
Triangle Park, North Carolina.
EPA. 1978. Technology Transfer Handbook-Industrial Guide for Air Pollution Control.
EPA-625/6-78-004. U.S. Environmental Protection Agency, Environmental Research
Information Center. Cincinnati, Ohio.
EPA. 1984. Quality Assurance Handbook for Air Pollution Measurement Systems:
Volume III. Stationary Source Specific Methods. EPA-600/4-77-027b. U.S. Environmental
Agency. Cincinnati, Ohio.
EPA. 1986. Test Methods for Evaluating Solid Waste, SW-846, Third Edition.
U.S. Environmental Protection Agency, Office of Solid Waste and Emergency Response.
Washington, DC.
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EPA. 1988. Compendium of Methods for the Determination of Toxic Organic Compounds in
Ambient Air, EPA-600/4-89-017, [Supplements: 600/4-87-006 and
600/4-87-013] U.S. Environmental Protection Agency, Office of Research and Development,
Washington, DC.
EPA. 1989. Air/Superfund National Technical Guidance Study Series, Volume I: -
Application of Air Pathway Analyses for Superfund Activities; Interim Final,
EPA-450/1-89-001. U.S. Environmental Protection Agency, Office of Air Quality Planning
and Standards. Research Triangle Park, North Carolina.
EPA. 1991a. Emission Inventory Requirements for Carbon Monoxide State Implementation
Plans. EPA-450/4-91-011. Office of Air Quality Planning and Standards. U.S. Environmental
Protection Agency, Research Triangle Park, North Carolina.
EPA. 1991b. Emission Inventory Requirements for Ozone State Implementation Plans. EPA -
450/4-91-010. U.S. Environmental Protection Agency. Office of Air Quality Planning and
Standards. Research Triangle Park, North Carolina.
EPA. 1991c. Pollution Prevention Grants Program. U.S. Environmental Protection Agency,
Office of Pollution Prevention. Washington, DC.
EPA. 1991d. Handbook: Control Technologies for Hazardous Air Pollutants.
EPA-625/6-91-014. U.S. Environmental Protection Agency, Office of Research and
Development, Center for Environmental Research Information. Cincinnati, Ohio.
EPA. 1992a. AIRS User's Guide Volume XI: AFS Data Dictionary. U.S. Environmental
Agency, Office of Air Quality Planning and Standards. Research Triangle Park, North
Carolina.
EPA. 1992b. Example Documentation Report for 1990 Base Year Ozone and Carbon
Monoxide State Implementation Plan Emissions Inventories. EPA-450/4-92-005a.
U.S. Environmental Protection Agency. Office of Air Quality Planning and Standards.
Research Triangle Park, North Carolina.
EPA. 1992c. Guidance on the Implementation of an Emission Statement Program. (Draft)
U.S. Environmental Protection Agency. Office of Air Quality Planning and Standards.
Research Triangle Park, North Carolina.
EPA. 1992d. Screening Methods for the Development of Air Toxics Emission Factors.
EPA-450/4-91-021. U.S. Environmental Protection Agency, Office of Air Quality Planning
and Standards. Research Triangle Park, North Carolina.
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EPA. 1992e. Integrated Reporting Issues: Preliminary Findings. EPA-454/R-92-022.
U.S. Environmental Protection Agency, Office of Air Quality Planning and Standards.
Research Triangle Park, North Carolina.
EPA. 1993a. Introduction to Air Pollutant Emission Estimation Techniques For Industry,
final report. Office of Air Quality Planning and Standards, EPA Contract No. 68-D9-0173,
Work Assignment No. 3/316. Research Triangle Park, North Carolina.
EPA. 1993b. Technical Procedures for Developing AP-42 Emission Factors and Preparing
AP-42 Sections. EPA-454/B-93-050. U.S. Environmental Agency, Office of Air Quality
Planning and Standards. Research Triangle Park, North Carolina.
EPA. 1993c. VOC/PM Speciation Data System Documentation and User's Guide,
Version 1.5. EPA-450/4-92-027. U.S. Environmental Protection Agency, Office of Air
Quality Planning and Standards. Research Triangle Park, North Carolina.
EPA. 1995a. Compilation of Air Pollutant Emission Factors - Volume I: Stationary Point
and Area Sources, Fifth Edition and Supplements A-B, AP-42, U.S. Environmental Protection
Agency. Research Triangle Park, North Carolina.
EPA. 1995b. Factor Information Retrieval System (FIRE), Version 4.0. U.S. Environmental
Protection Agency, Office of Air Quality Planning and Standards. Research Triangle Park,
North Carolina.
EPA. 1995c. TANKS Software Program, Version 3.0. U.S. Environmental Protection
Agency, Office of Air Quality Planning and Standards. Research Triangle Park,
North Carolina.
Federal Register, Vol. 39, p. 37119. Procedures for Voluntary Preparation of Environmental
Impact Statements. October 21, 1974.
Federal Register, Volume 58, No. 203, Friday, October 22, 1993.
Holman, P., and C. Collins. June 1979. Development of Questionnaires for Various Emission
Inventory Uses. EPA-450/3-78-122. U.S. Environmental Protection Agency. Research
Triangle Park, North Carolina.
Hunt, W.F., Jr. May 17, 1995. Telefax Letter from William F. Hunt, Jr., Director,
Emissions, Monitoring, and Analysis Division, U.S. Environmental Protection Agency, To
Stakeholders. Research Triangle Park, North Carolina.
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EIIP. 1996. General QA/QC Methods, Final Report, Volume VI, Chapter 3, Quality
Assurance Committee, Emission Inventory Improvement Program, Research Triangle Park,
North Carolina.
Radian Corporation. 1996. Emissions Inventory Development: Point Sources, Draft.
Prepared for the Mexico Emissions Inventory Development Program under Contract to the
Western Governors Association. Radian Corporation. Sacramento, California.
Russell, John J., Managing Editor. 1992. National Trade and Professional Associations of
the United States. 27th Annual Edition. Columbia Books, Inc., Washington, D.C.
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Presented at the Air and Waste Management Association Specialty Conference on Emission
Inventory Issues in the 1990s. Durham, North Carolina.
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APPENDIX A
TABLE OF CONTENTS
FROM AP-42, STH EDITION
Source: EPA. January 1995. Compilation of Air Pollutant Emission Factors, Volume I:
Stationary Point and Area Sources, Fifth Edition and Supplements A-B, AP-42. U.S.
Environmental Protection Agency, Office of Air Quality Planning and Standards. Research
Triangle Park, North Carolina.
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CONTENTS
Page
INTRODUCTION 1
1. EXTERNAL COMBUSTION SOURCES l.O-l
1.1 Bituminous And Subbituminous Coal Combustion 1.1-1
1.2 Anthracite Coal Combustion 1.2-1
1.3 Fuel Oil Combustion 1.3-1
1.4 Natural Gas Combustion 1.4-1
1.5 Liquefied Petroleum Gas Combustion 1.5-1
1.6 Wood Waste Combustion In Boilers 1.6-1
1.7 Lignite Combustion 1.7-1
1.8 Bagasse Combustion In Sugar Mills 1.8-1
1.9 Residential Fireplaces 1.9-1
1.10 Residential Wood Stoves 1.10-1
1.11 Waste Oil Combustion 1.11-1
2. SOLID WASTE DISPOSAL 2.0-1
2.1 Refuse Combustion 2.1-1
2.2 Sewage Sludge Incineration 2.2-1
2.3 Medical Waste Incineration 2.3-1
2.4 Landfills -. 2.4-1
2.5 Open Burning 2.5-1
2.6 Automobile Body Incineration 2.6-1
2.7 Conical Burners 2.7-1
3. STATIONARY INTERNAL COMBUSTION SOURCES 3.0-1
3.1 Stationary Gas Turbines For Electricity Generation 3.1-1
3.2 Heavy-duty Natural Gas-fired Pipeline Compressor Engines 3.2-1
3.3 Gasoline And Diesel Industrial Engines , . . 3.3-1
3.4 Large Stationary Diesel And All Stationary Dual-fuel Engines 3.4-1
4. EVAPORATION Loss SOURCES 4.0-1
4.1 Dry Cleaning . . 4.1-1
4.2 Surface Coating 4.2-1
4.2.1 Nonindustrial Surface Coating 4.2.1-1
4.2.2 Industrial Surface Coating 4.2.2-1
4.2.2.1 General Industrial Surface Coating 4.2.2.1-1
4.2.2.2 Can Coating 4.2.2.2-1
4.2.2.3 Magnet Wire Coating 4.2.2.3-1
4.2.2.4 Other Metal Coating 4.2.2.4-1
4.2.2.5 Flat Wood Interior Panel Coating 4.2.2.5-1
4.2.2.6 Paper Coating 4.2.2.6-1
4.2.2.7 Polymeric Coating Of Supporting Substrates 4.2.2.7-1
4.2.2.8 Automobile And Light Duty Truck Surface Coating Operations 4.2.2.8-1
1/95 Contents iii
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4.2.2.9 Pressure Sensitive Tapes And Labels 4.2.2.9-1
4.2.2.10 Metal Coil Surface Coating 4.2.2.10-1
4.2.2.11 Large Appliance Surface Coating 4.2.2.11-1
4.2.2.12 Metal Furniture Surface Coating 4.2.2.12-1
4.2.2.13 Magnetic Tape Manufacturing 4.2.2.13-1
4.2.2.14 Surface Coating Of Plastic Parts For Business Machines 4.2.2.14-1
4.3 Waste Water Collection, Treatment And Storage 4.3-1
4.4 Polyester Resin Plastic Products Fabrication 4.4-1
4.5 Asphalt Paving Operations 4.5-1
4.6 Solvent Degreasing 4.6-1
4.7 Waste Solvent Reclamation 4.7-1
4.8 Tank And Drum Cleaning 4.8-1
4.9 Graphic Arts 4.9-1
4.9.1 General Graphic Printing 4.9.1-1
4.9.2 Publication Gravure Printing 4.9.2-1
4.10 Commercial/Consumer Solvent Use 4.10-1
4.11 Textile Fabric Printing 4.11-1
5. PETROLEUM INDUSTRY 5.0-1
5.1 Petroleum Refining 5.1-1
5.2 Transportation And Marketing Of Petroleum Liquids 5.2-1
5.3 Natural Gas Processing 5.3-1
6. ORGANIC CHEMICAL PROCESS INDUSTRY 6.0-1
6.1 Carbon Black 6.1-1
6.2 Adipic Acid 6.2-1
6.3 Explosives 6.3-1
6.4 Paint And Varnish 6.4-1
6.5 Phthalic Anhydride 6.5-1
6.6 Plastics 6.6-1
6.6.1 Polyvinyl Chloride 6.6.1-1
6.6.2 Polyethylene terephthalate) 6.6.2-1
6.6.3 Polystyrene 6.6.3-1
6.6.4 Polypropylene 6.6.4-1
6.7 Printing Ink . 6.7-1
6.8 Soap And Detergents 6.8-1
6.9 Synthetic Fibers 6.9-1
6.10 Synthetic Rubber 6.10-1
6.11 Terephthalic Acid 6.11-1
6.12 Lead Alky! 6.12-1
6.13 Pharmaceuticals Production 6.13-1
6.14 Maleic Anhydride 6.14-1
6.15 Methanol 6.15-1
6.16 Acetone And Phenol 6.16-1
6.17 Propylene 6.17-1
IV
-------
7/1/97 CHAPTER 1 - INTRODUCTION
6.18 Benzene, Toluene And Xylenes 6.18-1
6.19 Butadiene 6.19-1
6.20 Cumene 6.20-1
6.21 Ethanol 6.21-1
6.22 Ethyl Benzene 6.22-1
6.23 Ethylene 6.23-1
6.24 Ethylene Dichloride And Vinyl Chloride 6.24-1
6.25 Ethylene Glycol 6.25-1
6.26 Ethylene Oxide 6.26-1
6.27 Formaldehyde 6.27-1
6.28 Glycerine 6.28-1
6.29 Isopropyl Alcohol 6.29-1
7. LIQUID STORAGE TANKS 7.0-1
7.1 Organic Liquid Storage Tanks 7.1-1
8. INORGANIC CHEMICAL INDUSTRY 8.0-1
8.1 Synthetic Ammonia 8.1-1
8.2 Urea 8.2-1
8.3 Ammonium Nitrate 8.3-1
8.4 Ammonium Sulfate 8.4-1
8.5 Phosphate Fertilizers 8.5-1
8.5.1 Normal Superphosphates 8.5.1-1
8.5.2 Triple Superphosphates 8.5.2-1
8.5.3 Ammonium Phosphate 8.5.3-1
8.6 Hydrochloric Acid 8.6-1
8.7 Hydrofluoric Acid 8.7-1
8.8 Nitric Acid 8.8-1
8.9 Phosphoric Acid 8.9-1
8.10 Sulfuric Acid 8.10-1
8.11 Chlor-Alkali 8.11-1
8.12 Sodium Carbonate 8.12-1
8.13 Sulfur Recovery 8.13-1
8.14 Hydrogen Cyanide 8.14-1
9. FOOD AND AGRICULTURAL INDUSTRIES 9.0-1
9.1 Tilling Operations 9.1-1
9.2 Growing Operations 9.2-1
9.2.1 Fertilizer Application 9.2.1-1
9.2.2 Pesticide Application 9.2.2-1
9.2.3 Orchard Heaters 9.2.3-1
9.3 Harvesting Operations 9.3-1
9.3.1 Cotton Harvesting 9.3.1-1
9.3.2 Grain Harvesting 9.3.2-1
9.3.3 Rice Harvesting 9.3.3-1
1/95 Contents
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CHAPTER 1 - INTRODUCTION 7/1/97
9.3.4 Cane Sugar Harvesting 9.3.4-1
9.4 Livestock And Poultry Feed Operations 9.4-1
9.4.1 Cattle Feedlots 9.4.1-1
9.4.2 Swine Feedlots 9.4.2-1
9.4.3 Poultry Houses 9.4.3-1
9.4.4 Dairy Farms 9.4.4-1
9.5 Animal And Meat Products Preparation 9.5-1
9.5.1 Meat Packing Plants 9.5.1-1
9.5.2 Meat Smokehouses 9.5.2-1
9.5.3 Meat Rendering Plants . . . 9.5.3-1
9.5.4 Manure Processing 9.5.4-1
9.5.5 Poultry Slaughtering 9.5.5-1
9.6 Dairy Products 9.6-1
9.6.1 Natural And Processed Cheese 9.6.1-1
9.7 Cotton Ginning 9.7-1
9.8 Preserved Fruits And Vegetables 9.8-1
9.8.1 Canned Fruits And Vegetables 9.8.1-1
9.8.2 Dehydrated Fruits And Vegetables 9.8.2-1
9.8.3 Pickles, Sauces And Salad Dressings 9.8.3-1
9.9 Grain Processing 9.9-1
9.9.1 Grain Elevators And Processes 9.9.1-1
9.9.2 Cereal Breakfast Food 9.9.2-1
9.9.3 Pet Food 9.9.3-1
9.9.4 Alfalfa Dehydration 9.9.4-1
9.9.5 Pasta Manufacturing • 9.9.5-1
9.9.6 Bread Baking 9.9.6-1
9.9.7 Corn Wet Milling 9.9.7-1
9.10 Confectionery Products 9.10-1
9.10.1 Sugar Processing 9.10.1-1
9.10.1.1 Cane Sugar Processing 9.10.1.1-1
9.10.1.2 Beet Sugar Processing 9.10.1.2-1
9.10.2 Salted And Roasted Nuts And Seeds 9.10.2-1
9.10.2.1 Almond Processing 9.10.2.1-1
9.10.2.2 Peanut Processing 9.10.2.2-1
9.11 Fats And Oils 9.11-1
9.11.1 Vegetable Oil Processing 9.11.1-1
9.12 Beverages 9.12-1
9.12.1 Malt Beverages 9.12.1-1
9.12.2 Wines And Brandy . 9.12.2-1
9.12.3 Distilled And Blended Liquors 9.12.3-1
9.13 Miscellaneous Food And Kindred Products 9.13-1
9.13,1 Fish Processing 9.13.1-1
9.13.2 Coffee Roasting 9.13.2-1
9.13.3 Snack Chip Deep Fat Frying 9.13.3-1
9.13.4 Yeast Production 9.13.4-1
VI
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7/1/97 CHAPTER 1 - INTRODUCTION
9.14
9.15
9.16
Tobacco Products
Leather Tanning
Agricultural Wind Erosion
10. WOOD PRODUCTS INDUSTRY
10.1
10.2
10.3
10.4
10.5
10.6
10.6.1
10.6.2
10.6.3
10.7
10.8
11. MINERAL
11.1
11.2
11.3
11,4
11.5
11.6
11.7
11.8
11.9
11.10
11.11
11.12
11.13
11.14
11.15
11.16
11.17
11.18
11.19
11.19.1
11.19.2
11.20
11.21
11.22
11.23
11.24
11.25
Lumber
Chemical Wood Pulping
Pulp Bleaching ;
Papermaking
Plywood
Reconstituted Wood Products
Waferboard And Oriented Strand Board
Particleboard
Medium Density Fiberboard
Charcoal
Wood Preserving
PRODUCTS INDUSTRY
Hot Mix Asphalt Plants
Asphalt Roofing
Bricks And Related Clay Products
Calcium Carbide Manufacturing
Refractory Manufacturing
Portland Cement Manufacturing
Ceramic Clay Manufacturing
Clay And Fly Ash Sintering
Western Surface Coal Mining
Coal Cleaning
Coal Conversion
Concrete Batching
Glass Fiber Manufacturing
Frit Manufacturing
Glass Manufacturing
Gypsum Manufacturing
Lime Manufacturing
Mineral Wool Manufacturing
Construction Aggregate Processing
Sand And Gravel Processing
Crushed Stone Processing ,
Lightweight Aggregate Manufacturing
Phosphate Rock Processing
Diatomite Processing
Taconite Ore Processing
Metallic Minerals Processing
Clay Processing
9.14-1
9.15-1
9.16-1
10.0-1
10.1-1
10.2-1
10.3-1
10.4-1
10.5-1
10.6-1
10.6.1-1
10.6.2-1
10.6.3-1
10.7-1
10.8-1
11.0-1
11.1-1
11.2-1
11.3-1
11.4-1
11.5-1
11.6-1
11.7-1
11.8-1
11.9-1
11.10-1
11.11-1
11.12-1
11.13-1
11.14-1
11.15-1
11.16-1
11.17-1
11.18-1
11.19-1
11.19.1-1
11.19.2-1
11.20-1
11.21-1
11.22-1
11.23-1
11.24-1
11.25-1
1/95 Contents vii
-------
CHAPTER 1 - INTRODUCTION . 7/1/97
11.26 Talc Processing 11.26-1
11.27 Feldspar Processing 11.27-1
11.28 Vermiculite Processing 11.28-1
11.29 Alumina Manufacturing 11.29-1
11.30 Perlite Manufacturing 11.30-1
11.31 Abrasives Manufacturing 11.31-1
12. METALLURGICAL INDUSTRY 12.0-1
12.1 Primary Aluminum Production 12.1-1
12.2 Coke Production 12.2-1
12.3 Primary Copper Smelting 12.3-1
12.4 Ferroalloy Production 12.4-1
12.5 Iron And Steel Production 12.5-1
12.6 Primary Lead Smelting 12.6-1
12.7 Zinc Smelting 12.7-1
12.8 Secondary Aluminum Operations 12.8-1
12.9 Secondary Copper Smelting And Alloying 12.9-1
12.10 Gray Iron Foundries 12.10-1
12.11 Secondary Lead Processing 12.11-1
12.12 Secondary Magnesium Smelting 12.12-1
12.13 Steel Foundries 12.13-1
12.14 Secondary Zinc Processing 12.14-1
12.15 Storage Battery Production 12.15-1
12.16 Lead Oxide And Pigment Production 12.16-1
12.17 Miscellaneous Lead Products 12.17-1
12.18 Leadbearing Ore Crushing And Grinding 12.18-1
12.19 Electric Arc Welding 12.19-1
13. MISCELLANEOUS SOURCES 13.0-1
13.1 Wildfires And Prescribed Burning 13.1-1
13.2 Fugitive Dust Sources 13.2-1
13.2.1 Paved Roads 13.2.1-1
13.2.2 Unpaved Roads 13.2.2-1
13.2.3 Heavy Construction Operations 13.2.3-1
13.2.4 Aggregate Handling And Storage Piles 13.2.4-1
13.2.5 Industrial Wind Erosion 13.2.5-1
13.3 Explosives Detonation 13.3-1
13.4 Wet Cooling Towers 13.4-1
13.5 Industrial Flares 13.5-1
APPENDIX A
Miscellaneous Data And Conversion Factors A-l
APPENDIX B.I
Particle Size Distribution Data And Sized Emission Factors For Selected Sources B.l-1
Vlll
-------
7/1/97 CHAPTER 1 - INTRODUCTION
APPENDIX B.2
Generalized Particle Size Distributions B.2-1
APPENDIX C.I
Procedures For Sampling Surface/Bulk Dust Loading C.l-1
APPENDK C.2
Procedures For Laboratory Analysis Of Surface/Bulk Dust Loading Samples C.2-1
1/95 Contents ix
-------
CHAPTER 1 - INTRODUCTION 7/1/97
This page is intentionally left blank.
-------
7/1/97 CHAPTER 1 - INTRODUCTION
APPENDIX B
CONVERSION FACTORS
FROM AP-42, STH EDITION,
APPENDIX A
Source: EPA. January 1995. Compilation of Air Pollutant Emission Factors, Volume I:
Stationary Point and Area Sources, Fifth Edition and Supplements A-B, AP-42. U.S.
Environmental Protection Agency, Office of Air Quality Planning and Standards. Research
Triangle Park, North Carolina.
EIIP Volume II
-------
CHAPTER 1 - INTRODUCTION 7/1/97
This page is intentionally left blank.
EIIP Volume II
-------
APPENDIX A
MISCELLANEOUS DATA AND CONVERSION FACTORS
9/85 (Reformatted 1/95) Appendix A A-l
-------
A-2 EMISSION FACTORS (Reformatted 1/95) 9/85
-------
SOME USEFUL WEIGHTS AND MEASURES
Unit Of Measure
grain
gram
ounce
kilogram
pound
pound (troy)
ton (short)
ton (long)
ton (metric)
ton (shipping)
centimeter
inch
foot
meter
yard
mile
centimeter2
inch2
foot2
meter2
yard2
mile2
centimeter3
inch3
foot3
foot3
Equivalent
0.002 ounces
0.04 ounces
28.35 grams
2.21 pounds
0.45 kilograms
12 ounces
2000 pounds
2240 pounds
2200 pounds
40 feet3
0.39 inches
2.54 centimeters
30.48 centimeters
1.09 yards
0.91 meters
1.61 kilometers
0.16 inches2
6.45 centimeters2
0.09 meters2
1.2 yards2
0.84 meters2
2.59 kilometers2
0.061 inches3
16.39 centimeters3
283.17 centimeters3
1728 inches3
9/85 (Reformatted 1/95)
Appendix A
A-3
-------
SOME USEFUL WEIGHTS AND MEASURES (cent.)
Unit Of Measure
meter3
yard3
cord
cord
peck
bushel (dry)
bushel
gallon (U. S.)
barrel
hogshead
township
hectare
Equivalent
1.31 yards3
0.77 meters3
128 feet3
4 meters3
8 quarts
4 pecks
2150.4 inches3
231 inches3
31.S gallons
2 barrels
36 miles2
2.5 acres
MISCELLANEOUS DATA
One cubic foot of anthracite coal weighs about 53 pounds.
One cubic foot of bituminous coal weighs from 47 to 50 pounds.
One ton of coal is equivalent to two cords of wood for steam purposes.
A gallon of water (U.S. Standard) weighs 8.33 pounds and contains 231 cubic inches.
There are 9 square feet of heating surface to each square foot of grate surface.
A cubic foot of water contains 7.5 gallons and 1728 cubic inches, and weighs 62.5 Ibs.
Each nominal horsepower of a boiler requires 30 to 35 pounds of water per hour.
A horsepower is equivalent to raising 33,000 pounds one foot per minute, or 550 pounds one foot per
second.
To find the pressure in pounds per square inch of a column of water, multiply the height of the
column in feet by 0.434.
A-4
EMISSION FACTORS
(Reformatted 1/95) 9/85
-------
TYPICAL PARAMETERS OF VARIOUS FUELS"
Type Of Fuel
Solid Fuels
Bituminous Coal
Anthracite Coal
Lignite (@ 35% moisture)
Wood (@ 40% moisture)
Bagasse (@ 50% moisture)
Bark (@ 50% moisture)
Coke, Byproduct
Liquid Fuels
Residual Oil
Distillate Oil
Diesel
Gasoline
Kerosene
Liquid Petroleum Gas
Gaseous Fuels
Natural Gas
Coke Oven Gas
Blast Furnace Gas
Heating Value
kcal
7,200/kg
6,810/kg
3,990/kg
2,880/kg
2,220/kg
2,492/kg
7,380/kg
9.98 x 106/m3
9.30 x lOVm3
9.12x ICWm3
8.62 x 10*/m3
8.32 x 10«/m3
6.25 x IQflm3
9,341/m3
5,249/m3
890/m3
Btu
13,000/lb
12,300/lb
7,200/Ib
5,200/lb
4,000/lb
4,500/lb
13,300/Ib
150,000/gal
140,000/gal
137,000/gal
130,000/gal
135,000/gal
94,000/gal
1,050/SCF
590/SCF
100/SCF
Sulfur
% (by weight)
0.6-5.4
0.5-1.0
0.7
N
N
N
0.5-1.0
0.5-4.0
0.2-1.0
0.4
0:03-0.04
0.02-0.05
N
N
0.5-2.0
N
Ash
% (by weight)
4-20
7.0-16.0
6.2
1-3
1-2
1-3"
0.5-5.0
0.05-0.1
N
N
N
N
N
N
N
N
• N = negligible.
b Ash content may be considerably higher when sand, dirt, etc., are present.
9/85 (Reformatted 1/95)
Appendix A
A-5
-------
THERMAL EQUIVALENTS FOR VARIOUS FUELS
Type Of Fuel
kcal
Btu (gross)
Solid fuels
Bituminous coal
Anthracite coal
Lignite
Wood
Liquid fuels
Residual fuel oil
Distillate fuel oil
Gaseous fuels
Natural gas
Liquefied petroleum
gas
Butane
Propane
(5.8 to 7.8) x
7.03 x lOVMg
4.45 x lOVMg
1.47x lOVm3
10 x Itf/liter
9.35 x lOVliter
9,350/m3
6,480/liter
6,030/1 iter
(21.0 to 28.0) x HP/ton
25.3 x KXVton
16.0 x KXVton
21.Ox K^/cord
6.3 x lO'/bbl
5.9 x lOVbbl
1,050/ft3
97,400/gal
90,500/gal
WEIGHTS OF SELECTED SUBSTANCES
Type Of Substance
Asphalt
Butane, liquid at 60°F
Crude oil
Distillate oil
Gasoline
Propane, liquid at 60 °F
Residual oil
Water
g/liter
1030
579
850
845
739
507
944
1000
Ib/gal
8.57
4.84
7.08
7.05
6.17
4.24
7.88
8.4
A-6
EMISSION FACTORS
(Reformatted 1/95) 9/85
-------
DENSITIES OF SELECTED SUBSTANCES
Substance
Fuels
Crude Oil
Residual Oil
Distillate Oil
Gasoline
Natural Gas
Butane
Propane
Wood (Air dried)
Elm
Fir, Douglas
Fir, Balsam
Hemlock
Hickory
Maple, Sugar
Maple, White
Oak, Red
Oak, White
Pine, Southern
Agricultural Products
Corn
Milo
Oats
Barley
Wheat
Cotton
Mineral Products
Brick
Cement
Cement
Density
874 kg/m3
944 kg/m3
845 kg/m3
739 kg/m3
673 kg/m3
579 kg/m3
507 kg/m3
561 kg/m3
513 kg/m3
400 kg/m3
465 kg/m3
769 kg/m3
689 kg/m3
529 kg/m3
673 kg/m3
769 kg/m3
641 kg/m3
25.4 kg/bu
25.4 kg/bu
14.5 kg/bu
2 1.8 kg/bu
27.2 kg/bu
226 kg/bale
2.95 kg/brick
170 kg/bbl
1483 kg/m3
7.3 Ib/gal
7.88 Ib/gal
7.05 Ib/gal
6. 17 Ib/gal
1 lb/23.8 ft3
4.84 Ib/gal (liquid)
4.24 Ib/gal (liquid)
35 Ib/ft3
32 Ib/ft3
25 Ib/ft3
29 Ib/ft3
48 Ib/ft3
43 Ib/ft3
33 Ib/ft3
42 Ib/ft3
48 Ib/ft3
40 Ib/ft3
56 Ib/bu
56 Ib/bu
32 Ib/bu
48 Ib/bu
60 Ib/bu
500 Ib/bale
6.5 Ib/brick
375 Ib/bbl
2500 lb/yd3
9/85 (Reformatted 1/95)
Appendix A
A-7
-------
DENSITIES OF SELECTED SUBSTANCES (cont.).
Substance
Concrete
Glass, Common
Gravel, Dry Packed
Gravel, Wet
Gypsum, Calcined
Lime, Pebble
Sand, Gravel (Dry, loose)
Density
1600-
880
850-
1440-
2373
2595
1920
2020
-960
1025
1680
kg/m3
kg/m3
kg/m3
kg/m3
kg/m3
kg/m3
kg/m3
100
55
53
90-
4000
162
- 120
126
-60
-64
•105
Ib/yd3
Ib/ft3
Ib/ft3
Ib/ft3
Ib/ft3
Ib/ft3
Ib/ft3
A-8
EMISSION FACTORS
(Refonrattai 1/99) 9/85
-------
CONVERSION FACTORS
The table of conversion factors on the following pages contains factors for converting English
to metric units and metric to English units as well as factors to manipulate units within the same
system. The factors are arranged alphabetically by unit within the following property groups.
- Area
- Density
- Energy
- Force
- Length
- Mass
- Pressure
- Velocity
- Volume
- Volumetric Rate
To convert a number from one unit to another:
1. Locate the unit in which the number is currently expressed in the left-hand column of the
table;
2. Find the desired unit in the center column; and
3. Multiply the number by the corresponding conversion factor in the right-hand column.
9/85 (Reformatted 1/95) Appendix A A-9
-------
CONVERSION FACTORS'
To Convert From
Area
Acres
Acres
Acres
Acres
Acres
Sqfeet
Sqfeet
Sq feet
Sqfeet
Sq feet
Sqfeet
Sq inches
Sq inches
Sq inches
Sq kilometers
Sq kilometers
Sq kilometers
Sq kilometers
Sq kilometers
Sq meters
Sq meters
Sq meters
Sq meters
Sq meters
Sq meters
Sq meters
Sq miles
Sq miles
Sq miles
To
Sq feet
Sq kilometers
Sq meters
Sq miles (statute)
Sq yards
Acres
Sq cm
Sq inches
Sq meters
Sq miles
Sq yards
Sq feet
Sq meters
Sq mm
Acres
Sq feet
Sq meters
Sq miles
Sq yards
Sq cm
Sq feet
Sq inches
Sq kilometers
Sq miles
Sq mm
Sq yards
Acres
Sqfeet
Sq kilometers
Multiply By
4.356 x 104
4.0469 x 10'3
4.0469 x 103
1.5625 x 10'3
4.84 x 103
2.2957 x 103
929.03
144.0
0.092903
3.587 x 10'8
0.111111
6.9444 x 103
6.4516 x 10-»
645.16
247.1
1.0764x 107
1.0x10*
0.386102
1.196x 10*
1.0 x 104
10.764
1.55 x 103
1.0 x 10*
3.861 x 10-7
1.0 x 106
1.196
640.0
2.7878 x 107
2.590
A-10
EMISSION FACTORS
(Refonnatted 1/95) 9/85
-------
CONVERSION FACTORS (cont.).
To Convert From
Sq miles
Sq miles
Sq yards
Sq yards
Sq yards
Sq yards
Sq yards
Sq yards
Density
Dynes/cu cm
Grains/cu foot
Grams/cu cm
Grams/cu cm
Grams/cu cm
Grams/cu cm
Grams/cu cm
Grams/cu cm
Grams/cu cm
Grams/cu cm
Grams/cu cm
Grams/cu meter
Grams/liter
Kilograms/cu meter
Kilograms/cu meter
Kilograms/cu meter
Pounds/cu foot
Pounds/cu foot
Pounds/cu inch
Pounds/cu inch
Pounds/cu inch
To
Sq meters
Sq yards
Acres
Sq cm
Sqft
Sq inches
Sq meters
Sq miles
Grams/cu cm
Grams/cu meter
Dynes/cu cm
Grains/mill iliter
Grams/mill iliter
Pounds/cu inch
Pounds/cu foot
Pounds/cu inch
Pounds/gal (Brit.)
Pounds/gal (U. S., dry)
Pounds/gal (U. S., liq.)
Grains/cu foot
Pounds/gal (U. S.)
Grams/cu cm
Pounds/cu ft
Pounds/cu in ..
Grams/cu cm
kg/cu meter
Grams/cu cm
Grams/liter
kg/cu meter
Multiply By
2.59 x 106
3.0976 x 106
2.0661 x 10^
8.3613 x 103
9.0
1.296x Iff
0.83613
3.2283 x 10-7
1.0197 x 10-3
2.28835
980.665
15.433
1.0
1.162
62.428
0.036127
10.022
9.7111
8.3454
0.4370
8.345 x 103
0.001
0.0624
3.613 x 1Q-5
0.016018
16.018
27.68
27.681
2.768 x 104
9/85 (Reformatted 1/95)
Appendix A
A-ll
-------
CONVERSION FACTORS (cont.).
To Convert From
To
Multiply By
Pounds/gal (U. S., liq.)
Pounds/gal (U. S., liq.)
Energy
Btu
Btu
Btu ,
Btu
Btu
Btu
Btu
Btu/hr
Btu/hr
Btu/hr
Btu/hr
Btu/hr
Btu/hr
Btu/hr
Btu/hr
Btu/Ib
Btu/lb
Btu/lb
Calories, kg (mean)
Calories, kg (mean)
Calories, kg (mean)
Calories, kg (mean)
Calories, kg (mean)
Calories, kg (mean)
Calories, kg (mean)
Ergs
Ergs
Grams/cu cm
Pounds/cu ft
Cal. gm (1ST.)
Ergs
Foot-pounds
Hp-hours
Joules (Int.)
kg-meters
kW-hours (Int.)
Cal. kg/hr
Ergs/sec
Foot-pounds/hr
Horsepower (mechanical)
Horsepower (boiler)
Horsepower (electric)
Horsepower (metric)
Kilowatts
Foot-pounds/lb
Hp-hr/lb
Joules/gram
Btu GST.)
Ergs
Foot-pounds
Hp-hours
Joules
kg-meters
kW-hours (Int.)
Btu
Foot-poundals
0.1198
7.4805
251.83
1.05435 x 10'°
777.65
3.9275 x 104
1054.2
107.51
2.9283 x 10-4
0.252
2.929 x 10*
777.65
3.9275 x 10-4
2.9856 x 10-s
3.926 x IV4
3.982 x 1O4
2.929 x 10-4
777.65
3.9275 x 10"4
2.3244
3.9714
4.190x10'°
3.0904 x 103
1.561 x 10"3
4.190x 103
427.26
1.1637x 10-3
9.4845 x 10-"
2.373 x
A-12
EMISSION FACTORS
(Refoimatted 1/9S) 9/85
-------
CONVERSION FACTORS (cont.).
To Convert From
To
Multiply By
Ergs
Ergs
Ergs
Ergs
Foot-pounds
Foot-pounds
Foot-pounds
Foot-pounds
Foot-pounds
Foot-pounds
Foot-pounds
Foot-pounds
Foot-pounds
Foot-pounds/hr
Foot-pounds/hr
Foot-pounds/hr
Foot-pounds/hr
Foot-pounds/hr
Horsepower (mechanical)
Horsepower (mechanical)
Horsepower (mechanical)
Horsepower (mechanical)
Horsepower (mechanical)
Horsepower (mechanical)
Horsepower (mechanical)
Horsepower (mechanical)
Horsepower (boiler)
Horsepower (boiler)
Horsepower (boiler)
Horsepower (boiler)
Foot-pounds
Joules (Int.)
kW-hours
kg-meters
Btu (1ST.)
Cal. kg (1ST.)
Ergs
Foot-poundals
Hp-hours
Joules
kg-meters
kW-hours (Int.)
Newton-meters
Btu/min
Ergs/min
Horsepower (mechanical)
Horsepower (metric)
Kilowatts
Btu (mean)/hr
Ergs/sec
Foot-pounds/hr
Horsepower (boiler)
Horsepower (electric)
Horsepower (metric)
Joules/sec
Kilowatts (Int.)
Btu (mean)/hr
Ergs/sec
Foot-pounds/min
Horsepower (mechanical)
7.3756 x 10-"
9.99835 x 10"
2.7778 x 1014
1.0197x lO'8
1.2851 x 10-3
3.2384 x 10"4
1.3558x 107
32.174
5.0505 x lO'7
1.3558
0.138255
3.76554 x JO'7
1.3558
2.1432 x 10s
2.2597 x 10s
5.0505 x lO'7
5.121 x 1C'7
3.766 x lO'7
2.5425 x 103
7.457 x 109
1.980x 106
0.07602
0.9996
1.0139
745.70
0.74558
3.3446 x 10*
9.8095 x 1010
4.341 x 10s
13.155
9/85 (Reformatted 1/9S)
Appendix A
A-13
-------
CONVERSION FACTORS (cont.).
To Convert From
To
Multiply By
Horsepower (boiler)
Horsepower (boiler)
Horsepower (boiler)
Horsepower (boiler)
Horsepower (electric)
Horsepower (electric)
Horsepower (electric)
Horsepower (electric)
Horsepower (electric)
Horsepower (electric)
Horsepower (electric)
Horsepower (electric)
Horsepower (metric)
Horsepower (metric)
Horsepower (metric)
Horsepower (metric)
Horsepower (metric)
Horsepower (metric)
Horsepower (metric)
Horsepower (metric)
Horsepower-hours
Horsepower-hours
Horsepower-hours
Horsepower-hours
Horsepower-hours
Joules (Int.)
Joules (Int.)
Joules (Int.)
Joules (Int.)
Joules (Int.)
Horsepower (electric)
Horsepower (metric)
Joules/sec
Kilowatts
Btu (mean)/hr
Cal. kg/hr
Ergs/sec
Foot-pounds/min
Horsepower (boiler)
Horsepower (metric)
Joules/sec
Kilowatts
Btu (mean)/hr
Ergs/sec
Foot-pounds/min
Horsepower (mechanical)
Horsepower (boiler)
Horsepower (electric)
kg-meters/sec
Kilowatts
Btu (mean)
Foot-pounds
Joules
kg-meters
kW-hours
Btu (1ST.)
Ergs
Foot-poundals
Foot-pounds
kW-hours
13.15
13.337
9.8095 x 103
9.8095
2.5435 x 103
641.87
7.46 x 10'
3.3013 x 104
0.07605
1.0143
746.0
0.746
2.5077 x 103
7.355 x 10'
3.255 x 104
0.98632
0.07498
0.9859
75.0
0.7355
2.5425 x 103
1.98x 10*
2.6845 x 10*
2.73745 x 10s
0.7457
9.4799 x 10*
1.0002x 107
12.734
0.73768
2.778 x 10-7
A-14
EMISSION FACTORS
(Reformatted 1/95) 9/85
-------
CONVERSION FACTORS (cont.).
To Convert From
Joules (Int.)/sec
Joules (Int.)/sec
Joules (Int.)/sec
Kilogram-meters
Kilogram-meters
Kilogram-meters
Kilogram-meters
Kilogram-meters
Kilogram-meters
Kilogram-meters
Kilogram-meters
Kilogram-meters/sec
Kilowatts (Int.)
Kilowatts (Int.)
Kilowatts (Int.)
Kilowatts (Int.)
Kilowatts (Int.)
Kilowatts (Int.)
Kilowatts (Int.)
Kilowatts (Int.)
Kilowatts (Int.)
Kilowatts (Int.)
Kilowatts (Int.)
Kilowatt-hours (Int.)
Kilowatt-hours (Int.)
Kilowatt-hours (Int.)
Kilowatt-hours (Int.)
Kilowatt-hours (Int.)
Newton-meters
Newton-meters
To
Btu (mean)/min
Cal. kg/min
Horsepower
Btu (mean)
Cal. kg (mean)
Ergs
Foot-poundals
Foot-pounds
Hp-hours
Joules (Int.)
kW-hours
Watts
Btu (IST.)/hr
Cal. kg (IST.)/hr
Ergs/sec
Foot-poundals/min
Foot-pounds/min
Horsepower (mechanical)
Horsepower (boiler)
Horsepower (electric)
Horsepower (metric)
Joules (Iitt.)/hr
kg-meters/hr
Btu (mean)
Foot-pounds
Hp-hours
Joules (Int.)
kg-meters
Gram-cm
kg-meters
Multiply By
0.05683
0.01434
1.341 x 10'3
9.2878 x 10-3
2.3405 x 10'3
9.80665 x 107
232.715
7.233
3.653 x 10*
9.805
2.724 x 10-6
9.80665
3.413 x 103
860.0
1.0002 x 10'°
1.424x 106
4.4261 x 104
1.341
0.10196
1.3407
1.3599
3.6 x 106
3.6716 x 10s
3.41 x 103
2.6557 x 106
1.341
3.6 x 106
3.6716 x 105
1.01972 x 104
0.101972
9/85 (Reformatted 1/95)
Appendix A
A-15
-------
CONVERSION FACTORS (com.).
To Convert From
Newton-meters
Force
Dynes
Dynes
Dynes
Newtons
Newtons
Poundals
Poundals
Poundals
Pounds (avdp.)
Pounds (avdp.)
Pounds (avdp.)
Length
Feet
Feet
Feet
Feet
Feet
Inches
Inches
Inches
Inches
Kilometers
Kilometers
Kilometers
Kilometers
Meters
Meters
Micrometers
To
Pound-feet
Newtons
Poundals
Pounds
Dynes
Pounds (avdp.)
Dynes
Newtons
Pounds (avdp.)
Dynes
Newtons
Poundals
Centimeters
Inches
Kilometers
Meters
Miles (statute)
Centimeters
Feet
Kilometers
Meters
Feet
Meters
Miles (statute)
Yards
Feet
Inches
Angstrom units
Multiply By
0.73756
l.Ox 10s
7.233 xlO-5
2.248 x 10*
l.OxlO-5
0.22481
1.383x 104
0.1383
0.03108
4.448 x 10s
4.448
32.174
30.48
12
3.048 x 10-4
0.3048
1.894X10-4
2.540
0.08333
2.54 x 10-5
0.0254
3.2808 x 103
1000
0.62137
1.0936x 103
3.2808
39.370
l.Ox 104
A-16
EMISSION FACTORS
(Reformatted 1/95) 9/85
-------
CONVERSION FACTORS (cont.).
To Convert From
Micrometers
Micrometers
Micrometers
Micrometers
Micrometers
Micrometers
Miles (statute)
Miles (statute)
Miles (statute)
Miles (statute)
Millimeters
Millimeters
Millimeters
Millimeters
Millimeters
Millimeters
Nanometers
Nanometers
Nanometers
Nanometers
Nanometers
Yards
Yards
Mass
Grains
Grains
Grains
Grains
Grains
Grams
To
Centimeters
Feet
Inches
Meters
Millimeters
Nanometers
Feet
Kilometers
Meters
Yards
Angstrom units
Centimeters
Inches
Meters
Micrometers
Mils
Angstrom units
Centimeters
Inches
Micrometers
Millimeters
Centimeters
Meters
Grams
Milligrams
Pounds (apoth. or troy)
Pounds (avdp.)
Tons (metric)
Dynes
Multiply By
l.Ox 10-3
3.2808 x 10-6
3.9370 x 10's
l.Ox 10*
0.001
1000
5280
1.6093
1.6093 x 103
1760
l.Ox 107
0.1
0.03937
0.001
1000
39.37
10
l.Ox lO'7
3.937 x 108
0.001
l.Ox 10*
91.44
0.9144
0.064799
64.799
1.7361 x 10"4
1.4286x lO"4
6.4799 x 10-"
980.67
9/85 (Reformatted 1/95)
Appendix A
A-17
-------
CONVERSION FACTORS (cont.).
To Convert From
To
Multiply By
Grams
Grains
Grams
Grams
Grams
Kilograms
Kilograms
Kilograms
Kilograms
Kilograms
Kilograms
Kilograms
Megagrams
Milligrams
Milligrams
Milligrams
Milligrams
Milligrams
Milligrams
Ounces (apoth. or troy)
Ounces (apoth. or troy)
Ounces (apoth. or troy)
Ounces (avdp.)
Ounces (avdp.)
Ounces (avdp.)
Ounces (avdp.)
Ounces (avdp.)
Pounds (avdp.)
Pounds (avdp.)
Pounds (avdp.)
Grains
Kilograms
Micrograms
Pounds (avdp.)
Tons, metric (megagrams)
Grains
Poundals
Pounds (apoth. or troy)
Pounds (avdp.)
Tons (long)
Tons (metric)
Tons (short)
Tons (metric)
Grains
Grams
Ounces (apoth. or troy)
Ounces (avdp.)
Pounds (apoth. or troy)
Pounds (avdp.)
Grains
Grams
Ounces (avdp.)
Grains
Grams
Ounces (apoth. or troy)
Pounds (apoth. or troy)
Pounds (avdp.)
Poundals
Pounds (apoth. or troy)
Tons (long)
15.432
0.001
1 x 106
2.205 x lO*
1 x 10*
1.5432 x 1
-------
CONVERSION FACTORS (cont.).
To Convert From
Pounds (avdp.)
Pounds (avdp.)
Pounds (avdp.)
Pounds (avdp.)
Pounds (avdp.)
Pounds (avdp.)
Tons (long)
Tons (long)
Tons (long)
Tons (long)
Tons (long)
Tons (metric)
Tons (metric)
Tons (metric)
Tons (metric)
Tons (metric)
Tons (metric)
Tons (short)
Tons (short)
Tons (short)
Tons (short)
Tons (short)
Pressure
Atmospheres
Atmospheres
Atmospheres
Atmospheres
Atmospheres
Atmospheres
Inches of Hg (60°F)
To
Tons (metric)
Tons (short)
Grains
Grams
Ounces (apoth. or troy)
Ounces (avdp.)
Kilograms
Pounds (apoth. or troy)
Pounds (avdp.)
Tons (metric)
Tons (short)
Grams
Megagrams
Pounds (apoth. or troy)
Pounds (avdp.)
Tons (long)
Tons (short)
Kilograms
Pounds (apoth. or troy)
Pounds (avdp.)
Tons (long)
Tons (metric)
cm of H2O (4°C)
FtofH2O(39.2°F)
In. ofHg(32°F)
kg/sq cm
mmofHg(0°C)
Pounds/sq inch
Atmospheres
Multiply By
4.5359 x 10-4
5.0 x 10"4
7000
453.59
14.583
16
1.016 x 103
2.722 x 103
2.240 x 103
1.016
1.12
1.0 x 10*
1.0
2.6792 x 103
2.2046 x 103
0.9842
1.1023
907.18
2.4301 x 103
2000
0.8929
0.9072
1.033 x 103
33.8995
29.9213
1.033
760
14.696
0.03333
9/85 (Reformatted 1/95)
Appendix A
A-19
-------
CONVERSION FACTORS (cont.).
To Convert From
Inches of Hg (60°F)
Inches of Hg (60°F)
Inches of Hg (60°F)
Inches of H2O(4°C)
Inches of H2O(4°C)
Inches of H2O (4°C)
Inches of H2O (4°C)
Inches of H2O(4°C)
Kilograms/sq cm
Kilograms/sq cm
Kilograms/sq cm
Kilograms/sq cm
Kilograms/sq cm
Millimeters of Hg (0°C)
Millimeters of Hg (0°C)
Millimeters of Hg (0°C)
Pounds/sq inch
Pounds/sq inch
Pounds/sq inch
Pounds/sq inch
Pounds/sq inch
Pounds/sq inch
Pounds/sq inch
Velocity
Centimeters/sec
Centimeters/sec
Centimeters/sec
Centimeters/sec
Centimeters/sec
To
Grams/sq cm
mmofHg(60°F)
Pounds/sq ft
Atmospheres
In. ofHg(32°F)
kg/sq meter
Pounds/sq ft
Pounds/sq inch
Atmospheres
cmofHg(0°C)
Ft of H2O (39.2°F)
In. of Hg (32°F)
Pounds/sq inch
Atmospheres
Grams/sq cm
Pounds/sq inch
Atmospheres
cm of Hg (0°C)
cm of H2O (4°C)
In. ofHg(32°F)
In. ofH20(39.2°F)
kg/sq cm
mmofHg(0°C)
Feet/min
Feet/sec
Kilometers/hr
Meters/min
Miles/hr
Multiply By
34.434
25.4
70.527
2.458 x lO'3
0.07355
25.399
5.2022
0.036126
0.96784
73.556
32.809
28.959
14.223
1.3158x 10'3
1.3595
0.019337
0.06805
5.1715
70.309
2.036
27.681
0.07031
51.715
1.9685
0.0328
0.036
0.6
0.02237
A-20
EMISSION FACTORS
(Reformatted 1/95) 9/85
-------
CONVERSION FACTORS (cont.).
To Convert From
Feet/minute
Feet/minute
Feet/minute
Feet/minute
Feet/minute
Feet/sec
Feet/sec
Feet/sec
Feet/sec
Kilometers/hr
Kilometers/hr
Kilometers/hr
Kilometers/hr
Kilometers/hr
Meters/min
Meters/min
Meters/min
Meters/min
Miles/hr
Miles/hr
Miles/hr
Miles/hr
Miles/hr
Miles/hr
Volume
Barrels (petroleum, U. S.)
Barrels (petroleum, U. S.)
Barrels (petroleum, U. S.)
Barrels (U. S., liq.)
Barrels (U. S., liq.)
To
cm/sec ';•
KHometersrtir
Meters/min
Meters/sec
Miles/hr ;
cm/sec '?••••'
Kilometers/hr
Meters/min
Miles/hr
cm/sec
Feet/hr
Feet/min
Meters/sec
Miles (statute)/hr
cm/sec
Feet/min
Feet/sec
Kilometers/hr
cm/sec
Feet/hr
Feet/min
Feet/sec
Kilometers/hr
Meters/min
Cu feet
Gallons (U. S.)
Liters
Cu feet
Cu inches
Multiply By
0.508
0.01829
0.3048
5.08 x lO'3
0.01136
30.48
1.0973
18.288
0.6818
27.778
3.2808 x 103
54.681
0.27778
0.62137
1.6667
3.2808
0.05468
0.06
44.704
5280
88
1.4667
1.6093
26.822
5.6146
42
158.98
4.2109
7.2765 x 103
9/85 (Reformatted 1/9S)
Appendix A
A-21
-------
CONVERSION FACTORS (cont.).
To Convert From
Barrels (U. S., liq.)
Barrels (U. S., liq.)
Barrels (U. S., liq.)
Cubic centimeters
Cubic centimeters
Cubic centimeters
Cubic centimeters
Cubic centimeters
Cubic centimeters
Cubic feet
Cubic feet
Cubic feet
Cubic feet
Cubic inches
Cubic inches
Cubic inches
Cubic inches
Cubic inches
Cubic inches
Cubic inches
Cubic meters
Cubic meters
Cubic meters
Cubic meters
Cubic meters
Cubic meters
Cubic meters
Cubic yards
Cubic yards
Cubic yards
To
Cu meters
Gallons (U. S., liq.)
Liters
Cufeet
Cu inches
Cu meters
Cu yards
Gallons (U. S., liq.)
Quarts (U. S., iiq.)
Cu centimeters
Cu meters
Gallons (U. S., liq.)
Liters
Cu cm
Cu feet
Cu meters
Cu yards
Gallons (U. S., liq.)
Liters
Quarts (U. S., liq.)
Barrels (U. S., liq.)
Cu cm
Cufeet
Cu inches
Cu yards
Gallons (U. S., liq.)
Liters
Bushels (Brit.)
Bushels (U. S.)
Cu cm
Multiply By
0.1192
31.5
119.24
3.5315 x 10-5
. 0.06102
1.0 x KT6
1.308 x 10-6
2.642 x Iff4
1.0567 x 10 3
2.8317 x 104
0.028317
7.4805
28.317
16.387
5.787 x 10"4
1.6387 x 10 J
2. 1433 x lO'5
4.329 x 10"3
0.01639
0.01732
8.3864
1.0 x 10*
35.315
6. 1024 x 104
1.308
264.17
1000
21.022
21.696
7.6455 x 10s
A-22
EMISSION FACTORS
(Reformatted 1/95) 9/85
-------
CONVERSION FACTORS (cont.).
To Convert From
Cubic yards
Cubic yards
Cubic yards
Cubic yards
Cubic yards
Cubic yards
Cubic yards
Cubic yards
Cubic yards
Cubic yards
Gallons (U. S., liq.)
Gallons (U. S., liq.)
Gallons (U. S., liq.)
Gallons (U. S., liq.)
Gallons (U. S., liq.)
Gallons (U. S., liq.)
Gallons (U. S., liq.)
Gallons (U. S., liq.)
Gallons (U. S., liq.)
Gallons (U. S., liq.)
Gallons (U. S., liq.)
Gallons (U. S., liq.)
Gallons (U. S., liq.)
Liters
Liters
Liters
Liters
Liters
Liters
To
Cufeet
Cu inches
Cu meters
Gallons
Gallons
Gallons
Liters
Quarts
Quarts
Quarts
Barrels (U. S., liq.)
Barrels (petroleum, U. S.)
Bushels (U. S.)
Cu centimeters
Cu feet
Cu inches
Cu meters
Cu yards
Gallons (wine)
Liters
Ounces (U. S., fluid)
Pints (U. S., liq.)
Quarts (U. S., liq.)
Cu centimeters
Cufeet
Cu inches
Cu meters
Gallons (U. S., liq.)
Ounces (U. S., fluid)
Multiply By
27
4.6656 x 10*
0.76455
168.18
173.57
201.97
764.55
672.71
694.28
807.90
0.03175
0.02381
0.10742
3.7854 x 103
0.13368
231
3.7854 x 10'3
4.951 x 10 3
1.0
3.7854
128.0
8.0
4.0
1000
0.035315
61.024
0.001
0.2642
33.814
9/85 (Reformatted 1/95)
Appendix A
A-23
-------
CONVERSION FACTORS (cont.).
To Convert From
Volumetric Rate
Cu ft/min
Cu ft/min
Cu ft/min
Cu ft/min
Cu meters/min
Cu meters/min
Gallons (U. S.)/hr
Gallons (U. S.)/hr
Gallons (U. S.)/hr
Gallons (U. S.)/hr
Liters/min
Liters/min
To
Cu cm/sec
Cuft/hr
Gal (U. S.)/min
Liters/sec
Gal (U. S.)/min
Liters/min
Cuft/hr
Cu meters/min
Cu yd/min
Liters/hr
Cu ft/min
Gal (U. S., liq.)/min
Multiply By
471.95
60.0
7.4805
0.47193
264.17
999.97
0.13368
6.309 x 10s
8.2519 x lO'5
3.7854
0.0353
0.2642
Where appropriate, the conversion factors appearing in this table have been rounded to four to six
significant figures for ease in use. The accuracy of these numbers is considered suitable for use
with emissions data; if a more accurate number is required, tables containing exact factors should be
consulted.
A-24
EMISSION FACTORS
(Reformatted 1/95) 9/85
-------
CONVERSION FACTORS FOR COMMON AIR POLLUTION MEASUREMENTS
AIRBORNE PARTICULATE MATTER
To Convert From
Milligrams/cu m
Grams/cu ft
Grams/cu m
Micrograms/cu m
Micrograms/cu ft
Pounds/1000 cu ft
To
Grams/cu ft
Grams/cu m
Micrograms/cu m
Micrograms/cu ft
Pounds/ 1000 cu ft
Milligrams/cu m
Grams/cu m
Micrograms/cu m
Micrograms/cu ft
Pounds/ 1000 cu ft
Milligrams/cu m
Grams/cu ft
Micrograms/cu m
Micrograms/cu ft
Pounds/ 1000 cu ft
Milligrams/cu m
Grams/cu ft
Grams/cu m
Micrograms/cu ft
Pounds/ 1000 cu ft
Milligrams/cu m
Grams/cu ft
Grams/cu m
Micrograms/cu m
Pounds/1000 cu ft
Milligrams/cu m
Grams/cu ft
Micrograms/cu m
Grams/cu m
Micrograms/cu ft
Multiply By
283.2 x 10^
0.001
1000.0
28.32
62.43 x lO^5
35.3145 x 103
35.314
35.314 x 106
1.0 x 10*
2.2046
1000.0
0.02832
1.0 xlO6
28.317 x 103
0.06243
0.001
28.317 x lO'9
l.Ox 10-6
0.02832
62.43 x 10'9
35.3 14 x lO'3
l.Ox 10^
35.314 x 10"*
35.314
2.2046 x 10-*
16.018 x 103
0.35314
16.018 x 10*
16.018
353. 14 x 103
9/85 (Reformatted 1/9S)
Appendix A
A-25
-------
CONVERSION FACTORS FOR COMMON AIR POLLUTION MEASUREMENTS (cont.).
SAMPLING PRESSURE
To Convert From
To
Multiply By
Millimeters of mercury (0°C)
Inches of mercury (0°C)
Inches of water (60°F)
Inches of water (60°F)
Inches of water (60 °F)
Millimeters of mercury (0°C)
Inches of mercury (0°C)
0.5358
13.609
1.8663
73.48 x 10-3
A-26
EMISSION FACTORS
(Reformatted 1195) 9/85
-------
CONVERSION FACTORS FOR COMMON AIR POLLUTION MEASUREMENTS (cont.).
ATMOSPHERIC GASES
To Convert From
To
Multiply By
Milligrams/cu m
Micrograms/cu m
Micrograms/liter
ppm by volume (20°C)
ppm by weight
Pounds/cu ft
Micrograms/cu m
Micrograms/liter
ppm by volume (20°C)
ppm by weight
Pounds/cu ft
Milligrams/cu m
Micrograms/liter
ppm by volume (20°C)
ppm by weight
Pounds/cu ft
Milligrams/cu m
Micrograms/cu m
ppm by volume (20 °C)
ppm by weight
Pounds/cu ft
Milligrams/cu m
Micrograms/cu m
Micrograms/liter
ppm by weight
Pounds/cu ft
Milligrams/cu m
Micrograms/cu m
Micrograms/liter
ppm by volume (20°C)
Pounds/cu ft
Milligrams/cu m
Micrograms/cu m
Micrograms/liter
ppm by volume (20°C)
ppm by weight
1000.0
1.0
24.04/M
0.8347
62.43 x 10-9
0.001
0.001
0.02404/M
834.7 x lO"6
62.43 x 10'12
1.0
1000.0
24.04/M
0.8347
62.43 x 109
M/24.04
M/0.02404
M/24.04
M/28.8
M/385.1 x 106
1.198
1.198x 10'3
1.198
28.8/M
7.48 x 10*
16.018 x 106
16.018x 10'
16.018x 106
385.1 x lOVM
133.7 x 103
M = Molecular weight of gas.
9/85 (Reformatted 1/95)
Appendix A
A-27
-------
CONVERSION FACTORS FOR COMMON AIR POLLUTION MEASUREMENTS (cont.).
VELOCITY
To Convert From
Meters/sec
Kilometers/hr
Feet/sec
Miles/hr
To
Kilometers/hr
Feet/sec
Miles/hr
Meters/sec
Feet/sec
Miles/hr
Meters/sec
Kilometers/hr
Miles/hr
Meters/sec
Kilometers/hr
Feet/sec
Multiply By
3.6
3.281
2.237
0.2778
0.9113
0.6214
0.3048
1.09728
0.6818
0.4470
1.6093
1.4667
ATMOSPHERIC PRESSURE
To Convert From
Atmospheres
Millimeters of mercury
Inches of mercury
Millibars
To
Millimeters of mercury
Inches of mercury
Millibars
Atmospheres
Inches of mercury
Millibars
Atmospheres
Millimeters of mercury
Millibars
Atmospheres
Millimeters of mercury
Inches of mercury
VOLUME EMISSIONS
To Convert From
Cubic m/min
Cubic ft/min
To
Cubic ft/min
Cubic m/min
Multiply By
760.0
29.92
1013.2
1.316x lO'3
39.37 x 10-3
1.333
0.03333
25.4005
33.35
0.00987
0.75
0.30
Multiply By
35.314
0.0283
A-28
EMISSION FACTORS
(Reformatted 1/95) 9/85
-------
CONVUSIOM FACTOU
I Megawatt « IO.S x 10* ITU/hr
(8 to 14 i 10* ITU/hr)
t Megawatt - 8 x 10* Ib iMu/hr
Ik luw/hr)
1 NT - 34.5 Ib iteWhr
1 MP • «S < 10s KO/hr
(40 to SO x 10* ITU/hr)
I Ik ateam/hr - 1.4 x 10> ITU/hr
(1.2 to 1.7 x 10* ITU/hr)
MTUi U th* reUtloMhlp*.
H*g*wett !• tlw net electric paver product loo •( • *t**m
electric paver plant.
1KT 1* holler herMpovtr.
Ik atcaa/hr (• the «t*0. S. gallon of water at 16.7*c (62*r) weigh* 3.780 kg. or 8.337 pound* (avoir.)
MASS
Gram*
Ounce* (mir.)...
Pound* (avoir.)*..
Ton* (U. S.)
treat*
1000
28.350
453.59
0.06480
9. 07 2x1 05
0.001
kllocru*
0.001
0.028350
0.45359
6 .480x10-^
907.19
1x10-*
ouitc**
(avoir.)
3.327xlO-J
35.274
16.0
2.286X10'1
3.200x10*
3.527x10-*
pound*
(avoir.)
2.205x10-1
2.2046
0.0625
1 .429x10-*
2000
2 .205x10-*
train*
15.432
13432
437.3
7000
1.4xl07
0.015432
tan*
(U. S.)
1 .102x10-*
1 .102x10"*
3.125x10"*
5.0x10-*
7 .142X10"8
1 .102x10-*
milligram*
1000
1x10*
2.8350x10*
4.5339xlO>
64.799
9.0718x10*
*M**t of 27.692 cubic inch** water neighed U air at 4.0*c, 760 •• mercury preuur*.
9/85 (Reformatted 1/9S)
Appendix A
A-29
-------
u>
o
m
So
00
O
•fl
s
(Ham* bterln.
Uuc Ano«
{•onull
UllMtt «•!»•
1000
I.JMtdO-*
O.IMM
a .inn
l.MIT
0^10067
t.tooi«ia>
UOM
1JMWO-"
l.MI7»IO-*
W1.M
1 45*1x1010
1 .U5tl«lo'
I.OIUI10*
1 .iMIUO
l.«ooo«ioi>
LMOOxlO10
I.MSO
S.*»i5«10*
a Milt
MOO
0.7JTJ*
I4.TU
I.MOOdO*
o .101 t;
10.J3J
I.TJT4ilO>
4.2»TlmlO->
I .470»«10-J
MI.OI
•.MM
3.7J51«19"'
J.TMJriO"'
1.14*0
i.nio.to-'
HIM
1404.)
< .1705»lV
1.1410x10'
I.MMxlOl
». 7771x10-'
1.1)0x10-4
1.7441x10-'
2.7141x10**
1.1144x10-1
1 .17013x10-*
1 .UM
a.777»xlO-»
1.7771x10-*
O.TOO
1.744J.10-*
2.7J41.10-'
741.7
1.17011x10-9
-------
T3
o>
g.
POWER
Kilowatts
Foot pounds per
second
Ergs per second ..
BTU* per minute ..
Crnm Centimeters
per second
Kilogram colories
Horsepower (U. S.)
Joules per second
watts
1000
1.35582
IxlO"7
17.580
9.8067x10-5
69.767
745.7
1.496x10-3
1
0.29299
kw
0.001
1. 3558xlO-3
1x10-1°
0.017580
9.8067x10-8
.069767
0.7457
1.496x10-6
0.001
2.9299x10-"
ft. Ib. /sec
0.73756
737.56
7.3756x10-8
12.9600
7.2330x10-5
51.457
550
1 .0034x10-3
0.73756
0.21610
erg/sec
1x10?
IxlO10
1.3558xl07
1.7580x108
980.665
6.9770xl08
7.457x10'
1.496x10*
1x10?
2.9299x10°
BTU /ml n
0.056884
56.884
0.077124
5.688x10-'
5.5783xlO"6
3.9685
42.4176
8.5096x10-5
0.056884
0.01667
g. cm/sec
. 1.0197x10*
1.0197xl07
1 .3826x10*
1.0197x10-3
1.7926x105
7.1146xl05
7.6042x10^
15.254
1.0197x10*
2.9878x103
kg. cal/min
0.01433
14.3334
0.019433
1.4333x10-'
0.2520
1 .4056xlO-6
10.688
2.1437x10-5
0.01433
4.1997x10-3
HP
1.341x10-3
1.3410
1 .8182x10-3
1.3410xlO-1°
0.023575
1.3151xlO-7
0 .093557
2.0061x10-6
1.341x10-3
3.9291x10-*
Lumens
668
6.68xl05
906.28
6.6845x10-5
11751
0.06S552
46636
498129
668
195.80
Joules/sec
1
1000
1.3558
IxlO-7
17.580
9.8067x10-5
69.769
745.7
1.496x10-3
0.29299
BTU/hr.
3.41304
3413.04
4.6274
3.4130xlO-7
60
3.3470x10-*
238.11
2545.1
5.1069x10-3
3.41304
*Brltlsh Thermal Units (Mean)
-------
CONVERSION FACTORS FOR VARIOUS SUBSTANCES'
Type Of Substance
Conversion Factors
Fuel
Oil
Natural gas
Gaseous Pollutants
O,
NO2
S02
CO
HC (as methane)
Agricultural products
Corn
Milo
Oats
Barley
Wheat
Cotton
Mineral products
Brick
Cement
Cement
Concrete
Mobile sources, fuel efficiency
Motor vehicles
Waterborne vessels
Miscellaneous liquids
Beer
Paint
Varnish
Whiskey
Water
1 bbl = 159 liters (42 gal)
1 therm = 100,000 Btu (approx.25000 kcal)
1 ppm, volume
1 ppm, volume
1 ppm, volume
1 ppm, volume
1 ppm, volume
1 ppm, volume
1960/ig/m3
1880/ig/m3
2610/ig/m3
1390 /tg/m3
1.14 mg/m3
0.654 mg/m3
1 bu = 25.4 kg = 56 Ib
1 bu = 25.4 kg = 56 Ib
1 bu = 14.5 kg = 32 Ib
1 bu = 21.8 kg = 48 Ib
1 bu = 27.2 kg = 60 Ib
1 bale = 226 kg = 500 Ib
1 brick = 2.95 kg = 6.5 Ib
1 bbl = 170 kg = 375 Ib
1 yd3 = 1130kg = 2500 Ib
1 yd3 = 1820 kg = 4000 Ib
1.0 mi/gal = 0.426 km/liter
1.0 gal/naut mi = 2.05 liters/km
1 bbl = 31.5 gal
1 gal = 4.5 to 6.82 kg = 10 to 15 Ib
Igal = 3.18kg = 71b
1 bbl = 190 liters = 50.2 gal
1 gal = 3.81 kg = 8.3 Ib
" Many of the conversion factors in this table represent average values and approximations and some
of the values vary with temperature and pressure. These conversion factors should, however, be
sufficiently accurate for general field use.
A-32
EMISSION FACTORS
(Reformatted 1195) 9/85
-------
7/7/97 CHAPTER 1 - INTRODUCTION
APPENDIX C
CONTACT AND
RESOURCE INFORMATION
EIIP Volume II
-------
CHAPTER 1 - INTRODUCTION 7/1/97
This page is intentionally left blank.
EIIP Volume II
-------
7/7/97 CHAPTER 1 - INTRODUCTION
1. Office of Air Quality Planning and Standards Technology Transfer Network (TTN)
Electronic Bulletin Board (OAQPS TTN)
The OAQPS TTN provides access to the Emission Measurement Technical Information
Center (EMTIC) and Clearinghouse for Inventories and Emission Factors (CHIEF)
bulletin boards.
OAQPS TTN System Operators:
Herschel Rorex, System Manager
Phil Dickerson, Assistant System Manager
Research Triangle Park, NC 27711
(919) 541-5384
TTN Telephone:
(919) 541-5742 (1200, 2400, or 9600 baud)
FTP site:
ttnftp.rtpnc.epa.gov
Internet:
ttnw ww. rtpnc. epa. gov
Telenet:
ttnbbs. rtpnc. epa. go v
Hardware and Software Requirements:
Computer
Communications software package
Modem
Communications software parameters:
8 data bits
1 stop bit
no parity
full duplex
terminal emulation VT100 or VT/ANSI
The OAQPS TTN is down every Monday morning from 8:00 a.m. to 12:00 p.m. EST
for maintenance.
EIIP Volume II l.C-3
-------
CHAPTER 1 - INTRODUCTION 7/1/97
2. Emission Factor Assistance Line (InfoCHIEF) for questions pertaining to
SPECIATE, FIRE, AIRS SCC/SIC file, Air CHIEF CD-ROM, Fax CHIEF,
CHIEF Bulletin Board, TANKS, L&E documents, or AP-42
Address:
Emission Factor and Inventory Group (MD-14)
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711
Contact:
InfoCHIEF Help Line
Telephone:
(919) 541-5285
Fax CHIEF:
(919) 541-0548
(919) 541-5626
3. New SCC Assignments
Address:
Emission Factor and Inventory Group (MD-14)
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711
Contact:
Ron Ryan
Telephone:
(919)541-4330
4. Air Pollution Training Institute
Address:
Environmental Research Center
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711
l.C-4
EIIP Volume II
-------
7/7/97 CHAPTER 1 - INTRODUCTION
Contact:
J. Nunn, Training Coordinator
Telephone:
(919) 541-3724
5. Information on CHEMDAT& and WATERS
Address: , :
Emission Standards Division
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711
Contact: ;.>,. j •
Elaine Manning
Telephone:
(919)541-5499
6. Information on LAEEM
Address:
Air Pollution Prevention and Control Division
Office of Research and. Development
U.S. Environmental Protection Agency
Research Triangle Park, ;NC 27711
Contact: •, ;
Susan Thorneloe
Telephone:
(919) 541-2709
7. U.S. Environmental Protection Agency Library
Single copies of some EPA documents and personal computer tools are available free to
government and non-profit organizations from the EPA library. For-profit
organizations should order from the Government Printing Office (GPO) or from the
National Technical Information Service (NTIS).
EIIP Volume II l.C-5
-------
CHAPTER 1 - INTRODUCTION 7/7/97
Address:
U.S. Environmental Protection Agency Library
MD-35
Research Triangle Park, NC 27711
Telephone:
(919) 541-2777
8. Government Printing Office (GPO)
Address:
Government Printing Office
Superintendent of Documents
P.O. Box 371954
Pittsburgh, PA 15250-795420402
Telephone:
(202) 512-1800
(202) 512-2250 (Fax)
9. National Technical Information Service (NTIS)
Address:
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
Ordering and Catalog Information:
(703)487-4650
(703) 321-8547 (fax)
(800) 553-6847 (rush orders only)
Telecommunications Devices for the Deaf (TDD):
(703) 487-4639
NTIS documents are generally available on paper or microfiche.
l-C-6 EIIP Volume II
-------
7/1/97 CHAPTER 1 - INTRODUCTION
10. Pollution Prevention Information Clearinghouse
Telephone:
(202) 260-1023
Pollution Prevention Information Exchange System (PIES)
(access via computer)
(703) 506-1025
Hardware and Software Requirements
Computer
Communications software package
Modem
Communications software parameters:
8 data bits
1 stop bit
no parity
11. Control Technology Center
Address:
U.S. Environmental Protection Agency
ORD/APPCD (MD-91) or
OAQPS/ITPID (MD-12)
Air Pollution Prevention and Control Division
MD-91
Research Triangle Park, NC 27711
Telephone:
(919) 541-0800
12. Emergency Planning and Community Right-to-Know Act Hotline
(703) 412-9810
(800) 424-9346
Telecommunications Devices for the Deaf (TDD): (800) 553-7672
EIIP Volume II l.C-7
-------
CHAPTER 1 - INTRODUCTION 7/7/97
13. EIIP Point Sources Committee
Co-chairs
Dennis Beauregard
Emission Factor and Inventory Group (MD-14) ,
Environmental Protection Agency
Research Triangle Park, NC 27711
E-Mail: beauregard.dennis@epamail.epa.gov
Phone: (919)541-5512
Fax: (919) 541-0684
Bill Gill
Emissions Inventory Section
Texas Natural Resource Conservation Commission
12100 Park 35 Circle
Post Office Box 13087
Austin, TX 78711-3087
(Federal Express ZIP Code 78753)
E-Mail: wgill@smtpgate.tnrcc. state. tx .us
Phone: (512)239-5750
Fax: (512) 239-1515
Members
Denise Alston-Guiden
Galson Consulting
6601 Kirkville Road
Syracuse, NY 13057
E-Mail: dralstong@aol.com
Phone: (800) 724-0669 or (315) 432-0506 (ext. 119)
Fax: (315)437-0509
Bob Betterton
South Carolina Department of Health and Environmental Control
Bureau of Air Quality
2600 Bull Street
Columbia, SC 29201
E-Mail: betterrj@columb31.dhec.state.sc.us
Phone: (803)734-4549
Fax: (803)734-4556
l.C-8
EIIP Volume II
-------
7/1/97 CHAPTER 1 - INTRODUCTION
Paul Brochi
Emissions Inventory Section
Texas Natural Resource Conservation Commission
12100 Park 35 Circle
Post Office Box 13087
Austin, TX 78711-3087
(Federal Express Zip Code 78753)
E-Mail: pbrochi@smtpgate. tnrcc. state. tx. us
Phone: (512)239-1942
Fax: (512)239-1515
Alice Fredlund
Louisiana Department of Environmental Quality
Air Quality/Technical Services
Post Office Box 82135
Baton Rouge, LA 70884-2135
E-Mail: alice_f@deq.state.la.us
Phone: (504)763-3955
Fax: (504)765-0222
Gary Helm
Air Quality Management, Inc.
Post Office Box 8
Macungie, PA 18062
E-Mail: helm@enter.net
Phone: (610)967-1688
Fax: (610)967-0308
Paul Kim
Air Quality Division
Compliance Determination Unit
Minnesota Pollution Control Agency
520 Lafayette Road
St. Paul, MN 55155
E-Mail: paul.yw.kim@pca.state.mn.us
Phone: (612)296-7320
Fax: (612)297-7709
EIIP Volume II l.C-9
-------
CHAPTER 1 - INTRODUCTION 7/7/97
Toch Mangat
Bay Area Air Quality Management District
Planning Department
939 Ellis Street
San Francisco, CA 94109
E-Mail: tmangat@baaqmd.gov
Phone: (415)749-4651
Fax: (415)749-4741
Ralph Patterson
Wisconsin Department of Natural Resources
101 South Webster Street
7th Floor
Post Office Box 7921
Madison, WI 53707
E-Mail: patter@dnr.state.wi.us
Phone: (608)267-7546
Fax: (608)267-0560
Jim Southerland
North Carolina Department of Environment,
Health and Natural Resources
Air Quality Division
Post Office Box 29580
Raleigh, NC 27626-0580
Federal Express Address:
2728 Capital Boulevard
Parker Lincoln Building
Raleigh, NC 27604
E-Mail: jim_southerland@aq.ehnr.state.nc.us
Phone: (919)715-7566
Fax: (919)715-7476
Eitan Tsabari
City of Omaha
Air Quality Control Division
5600 South 10th Street
Omaha, NE 68107
E-Mail: etsabari@ci.omaha.ne.us
Phone: (402)444-6015
Fax: (402)444-6016
l.C-10 EIIP Volume II
-------
7/1/97 CHAPTER 1 - INTRODUCTION
Robert Woolen
North Carolina Department of Environment,
Health and Natural Resources
Air Quality Section
Post Office Box 29580
Raleigh, NC 27626-0580
E-Mail: bob_wooten@aq. ehnr. state. nc. us
Federal Express Address:
2728 Capital Blvd.
Parker Lincoln Building
Raleigh, NC 27604
Phone: (919)733-1815
Fax: (919)715-7476
EIIP Volume II l.C-11
-------
CHAPTER 1 - INTRODUCTION 7/1/97
This page is intentionally left blank.
l.C-12 EIIP Volume II
-------
7/1/97
CHAPTER 1 - INTRODUCTION
APPENDIX D
CHECKLIST FOR STATIOMAI
POINT SOURCES
El IP Volume II
-------
CHAPTER 1 - INTRODUCTION 7/1/97
This page is intentionally left blank.
El IP Volume II
-------
7/1/97
CHAPTER 1 - INTRODUCTION
ANNUAL EMISSIONS INVENTORY CHECKLIST FOR STATIONARY POINT SOURCES
Completeness Checks - Point Sources
Have all VOC point sources with actual
emissions ^ 10 tpy been included in the
inventory?
Have process, point, and segment level data
been provided for all VOC point sources with
actual emissions ^ 10 tpy?
Have all VOC sources in the 25-mile zone
outside of the nonattainment area with
emissions > 100 tpy been addressed in the
inventory?
Have all NOX and CO sources in the
nonattainment area and 25-mile zone outside of
the nonattainment area with emissions
> 100 tpy been addressed in the inventory?
Have all process, point, and segment level
documentation data required for the 100-ton
NOX and CO sources been provided?
Does the inventory include point sources for
VOCs in the 10 - 25 tpy (actual) range?
Are the following VOC point source categories
represented among the 10 - 25 tpy plant
listings?
Note: Provide documentation if any are "no. "
• Graphic Arts
• Commercial/Institutional Boilers
• Industrial Boilers
• Gasoline Bulk Plants
Yes
No
Comments
•
EIIP Volume II
l.D-1
-------
CHAPTER 1 - INTRODUCTION
7/1/97
ANNUAL EMISSIONS INVENTORY CHECKLIST FOR STATIONARY POINT SOURCES
(CONTINUED)
Completeness Checks - Point Sources
• Degreasing Operations
• Waste Disposal/Treatment
Are the following broad source categories
represented among the > 25 tpy VOC plant
listing?
• Storage, transportation and marketing of
petroleum products and volatile organic
liquids
• Industrial Processes
• Industrial Surface Coating
Are the following CO and NOX source
categories represented among the plant listings?
• Utility Boilers
• Industrial Boilers
• Commercial/Institutional External Fuel
Combustion
• Waste Disposal/Combustion
Is the annual emission inventory signed by the
proper authority who will take legal
responsibility for the accuracy of the
information verified in the report to the state?
Is the following information provided in the
report (to the state) and is it accurate: source
addresses, contact information, and SIC
code(s)?
Yes
No
Comments
l.D-2
EIIP Volume II
-------
7/7/97
CHAPTER 1 - INTRODUCTION
ANNUAL EMISSIONS INVENTORY CHECKLIST FOR STATIONARY POINT SOURCES
(CONTINUED)
Procedures Checks(Continued)
Have you made a copy of the inventory and
report you are mailing to the state agency?
Does the inventory documentation describe the
methodology used (i.e., survey, plant
inspections, continuous emissions monitoring
data, fuel analysis data, air quality modeling
data, material balance, AFS, and permit files)
to develop the point source inventory listing?
Does the point source inventory reflect a base
year of 1990?
Note: If another inventory was used as a
starting point, documentation should be
provided to show what adjustments were
made to reflect the 1990 base year.
Were emissions estimates adjusted to reflect the
O3 season and rule effectiveness?
Does the inventory documentation describe the
methodology used to define months of the O3
season?
Indicate which of the following basic options
were used to submit data for point sources:
• EIIP data transfer format
• AFS batch transaction format
• Interactive direct entry to AFS
Was a computer model used to estimate
emissions from waste treatment/disposal
sources? If yes, which model?
Yes
No
Comments
EIIP Volume II
l.D-3
-------
CHAPTER 1 - INTRODUCTION
7/1/97
ANNUAL EMISSIONS INVENTORY CHECKLIST FOR STATIONARY POINT SOURCES
(CONTINUED)
Procedures Checks (Continued)
Was a rule effectiveness factor of 80 percent
used for all categories?
Does the point source inventory documentation
include the contact person(s) for referring
questions?
Was rule effectiveness applied to emission
estimates for the following point source
categories?
• Surface Coating of Cans
• Surface Coating of Metal Coils
• Surface Coating of Fabric and Vinyl
• Surface Coating of Paper Products
• Coating of Automobiles and Light-duty
Trucks in Assembly Plants
• Surface Coating of Metal Furniture
• Surface Coating of Magnetic Wire
• Tank Truck Gasoline Loading Terminals
• Bulk Gasoline Plants
Yes
No
Comments
l.D-4
EIIP Volume II
-------
7/7/97
CHAPTER 1 - INTRODUCTION
ANNUAL EMISSIONS INVENTORY CHECKLIST FOR STATIONARY POINT SOURCES
(CONTINUED)
Procedures Checks (Continued)
Select a subset that represents at least
10 percent of the listed point sources (in the
> 25 tpy range) and determine if the following
data are compiled and presented for each
source.
Note: Identify in the comment column the
record number of those plants that were
checked.
• Plant name and location (including
latitude, longitude, and zip code)
• AFS point ID
SIC code(s)
• Operating schedule
• Applicable regulations
• Current environmental permits
UTM zone
• FIP State, city, and county codes
• Plot plan of the facility
• Pollutant code or CAS code
• Inventory of vents and stacks (for point
pollutant data)
• Stack parameter data
• Emission limitations (only if subject to
SIP regulation)
Yes
No
Comments
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ANNUAL EMISSIONS INVENTORY CHECKLIST FOR STATIONARY POINT SOURCES
(CONTINUED)
Reasonableness Checks
• Compliance year (only if subject to SIP
Regulation)
• SCC for process unit
• Daily process rate and units
• Listing and description of processes and
support activities
• Listing of cooling units and air
conditioners using CFCs
• Type and volume of CFC used
• Control equipment type
• Control efficiency
• Date of equipment installation and latest
modification
• Emissions estimation method
• Emission factors
• List, description, and volume of wastes
generated
• Chemical and fuel storage tank data
• Current emission source testing results
• Material safety data sheets for
production and maintenance-related raw
materials
• Rule effectiveness
• Seasonal adjustment factor
Yes
No
Comments
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ANNUAL EMISSIONS INVENTORY CHECKLIST FOR STATIONARY POINT SOURCES
(CONTINUED)
Reasonableness Checks (Continued)
• O3 season daily emissions
Does the sum of emission estimates from small
VOC point sources represent at least 5 percent
of the total point source VOC contribution?
If point source VOC emissions are attributed to
the synthetic organic chemical manufacturing
industry (SOCMI), are fugitive leaks also
quantified?
Note: Fugitive equipment leak emissions
should be 1 to 10 times larger than
emissions from vents, reactors, etc.
Are unadjusted annual emissions estimates for
VOC, CO, and NOX from point sources within
25 percent of the values reported in AFS?
Are the following data elements within the
ranges listed below for general point sources
data?
• Hours per day ^24
• Days per week <7
• Hours per year < 8,760
• Seasonal throughputs 0-100
• Boiler capacity 80 - 120 percent of
hourly maximum rate x fuel heat content
• Is percent space heat for winter greater
than summer
Yes
No
Comments
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ANNUAL EMISSIONS INVENTORY CHECKLIST FOR STATIONARY POINT SOURCES
(CONTINUED)
Reasonableness Checks (Continued)
Are the following data elements within the
ranges listed below for point pollutant data?
Stack height > 50 Feet
• Stack diameter 0.5 and 30 Feet
• Plume height > 200 Feet
• Temperature of exit gases between 60 °F
and 2,000°F
• Temperature of exit gases with wet
scrubber <250°F
• Temperature of exit gases without wet
scrubber >250°F
• Exhaust gas flow rate and velocity
within expected range?
Are the following data elements within the
ranges listed below for general segment data?
• For control devices, is the control
efficiency between 0-100 percent?
• Are emission estimates within the
ranges expected?
Yes
No
Comments
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APPENDIX E
TEST METHODS
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This appendix describes available pollutant monitoring and fuel analysis methodologies.
Table l.E-1 contains a listing of the published and approved methodologies available for
determining pollutant emissions using stack test data. Continuous emission monitoring
(CEM), manual monitoring, and fuel analysis are included. A description of each method
listed in Table l.E-1 is discussed below. Section E.I summarizes EPA methods and section
E.2 addresses other (i.e., non-EPA methods).
E.1 EPA METHODS
E.1.1 EPA METHOD 2 (STACK SAMPLING)
This method is applicable for measurement of the average velocity of a gas stream and for
quantifying gas flow rate. The average gas velocity is determined from the gas density and
from measurement of the average velocity head with a Type S (Stausscheibe or reverse type)
pitot tube. Gas velocity is then multiplied by the cross-sectional area of the stack or duct to
determine volumetric gas flow rate. This method cannot be used for direct measurement in
cyclonic or swirling gas streams.
E.1.2 EPA METHOD 3 (STACK SAMPLING)
This method is used to determine oxygen (O2) and carbon dioxide (CO2) concentrations in flue
gas from fossil-fuel-fired combustion processes. A gas sample is extracted from the stack
either from a single point or by multipoint integrated sampling. The sample is passed through
an Orsat analyzer containing a solution of 45-percent potassium hydroxide (KOH) in one
impinger and a solution of pyrogallol in the second impinger. The CO2 is absorbed by KOH,
and the O2 is absorbed by pyrogallol. The decrease in sample volume due to this absorption is
directly proportional to the concentration in the sample.
E.1.3 EPA METHOD 3A (CEM)
This method may be used to determine O2 and CO2 concentrations when CEM systems are in
place. A gas sample is extracted continuously from the stack and conveyed to the O 2 and CO2
analyzers. The sample can be wet or dry depending on the type of analyzer used.
CO2 can only be measured using infrared analyzers such as nondispersive infrared (NDIR)
systems or gas filter correlation (GFC) analyzers.
NDIR analyzers consist of sample and reference optical cells through which a beam of infrared
light passes. This beam of light is modulated so that the infrared light passing through the
optical cell pulses. The modulated infrared light then enters a two-chambered detector that is
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TABLE 1.E-1
SUMMARY OF AVAILABLE MONITORING AND FUEL ANALYSIS METHODS
Parameter
S02
S03
NOX
O2/CO2
CO
voc
THC
Speciated organics
Heavy metals
PM
PM10
Sulfuric acid mist
Flow rate
Monitoring Methods
Stack Sampling
EPA Method 6
EPA Method 8
EPA Method 7
EPA Method 3
EPA Method 10B
EPA Method 25
EPA Method 25
EPA Method 0030
EPA Method 29
EPA Method 5
EPA Method
201/202
EPA Method 8
EPA Method 2
CEM
EPA Method 6C
NA
EPA Method 7E
EPA Method 3A
EPA Method 10
NA
EPA Method
25A
NA
NA
NA
NA
NA
EPA Method 19,
CFRMC
Fuel Analysis
Method
ASTM D-1552-83/
D4507-8P
SW 846 Methods
3040/7090"
Sources: EPA, 1986; Test Methods for Evaluating Solid Waste, SW-846, Third
Edition; ASTM, 1992; Title 40 CFR, Appendices A and B,
September 1992. Title 40 CFR Part 60, Appendix A and Part 61,
Appendix B.
a For liquid fuels. ASTM D3177-75/D4239-85 is used for coal.
b For liquid fuels.
c Continuous flow rate monitoring.
NA = Not applicable; no CEM method exists.
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filled with the same gas that is being analyzed. The gas in the detector chambers absorbs the
infrared light and heats up, causing it to expand. Separating the two chambers is a thin
diaphragm which flexes as the pressure between the two chambers varies. Since the sample
has absorbed some of the infrared light, the detector chamber associated with the sample cell
does not heat up as much as the reference side. This causes a pressure differential between the
two chambers, deflecting the diaphragm. Because the infrared light is modulated, the
diaphragm pulses. This degree of deflection in conjunction with the pulsing is converted into
an electrical signal proportional to gas concentration.
O2 analyzers generally use electrochemical cells. Porous platinum electrodes are attached to
the inside and outside of the cell to provide the instrument voltage response. Zirconium oxide
contained in the cell conducts electrons when it is hot due to the mobility of O2 ions in its
crystal structure. A difference in O2 concentration between the sample side of the cell and the
reference (outside) side of the cell produces a voltage. This response is proportional to the
logarithm of the O2 concentration ratio. The reference gas is ambient air at 20.9 percent O2
by volume.
E.1.4 EPA METHOD 5 OR 17 (STACK SAMPLING)
EPA Method 5 or 17 may be used to monitor emissions of paniculate matter (PM) from
boilers. In Method 5, PM is withdrawn isokinetically from the source and collected externally
on a heated glass fiber filter maintained at 248°F ± 25 °F. Method 17 employs an in-stack
filter and particulate matter is collected at source temperature and pressure. The particulate
mass is determined gravimetrically.
E.1.5 EPA METHOD 6 (STACK SAMPLING)
Method 6 is used to measure SO2 emissions. A gas sample is extracted from the sampling
point in the stack. The sample passes through a filter to remove PM and the sulfuric acid
(including sulfur trioxide) and sulfur dioxide (SO2) are separated hi a series of impingers
containing 80 percent isopropanol and 3 percent hydrogen peroxide. The SO2 is then
measured by barium-thorin titration.
E.1.6 EPA METHOD 6C(CEM)
Method 6 is used to measure SO2 emissions when CEM systems are in place. A gas sample is
continuously extracted from a stack, and a portion of the sample is conveyed to a continuous
analyzer for determination of SO2 gas concentration using an NDIR, ultraviolet (UV), or
fluorescence analyzer.
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NDIR analyzers were discussed in section E.I.3.
UV analyzers work very similarly to NDIR instruments. A beam of UV light passes through
the gas sample, which absorbs some of the light. The remaining light passes through the
sample cell and is measured by the detector.
Fluorescence analyzers are typically used in ambient monitoring. The analyzer works by
exposing the sample to a pulse of ultraviolet light. SO2 molecules absorb this light, which
"excites" the molecule into a higher energy state. The molecule loses some of this excess
energy by fluorescing (detected by a photomultiplier tube), which in turn provides an SO2
concentration value.
E.1.7 EPA METHOD 7 (STACK SAMPLING)
Method 7 is used to measure NOX emissions. A grab sample is collected in an evacuated flask
containing a dilute sulfuric acid-hydrogen peroxide absorbing solution, and the NOX, except
nitrous oxide (N20), are measured colorimetrically using phenoldisulfonic acid (PDS).
E.1.8 EPA METHOD 7E (CEM)
When CEM systems are in place, Method 7E is used. A gas sample is continuously extracted
from the stack and a portion of the sample is conveyed to an instrumental chemiluminescent
analyzer for determination of NOX concentration. This measurement technique uses a chemical
reaction (ozone combining with nitric oxide [NO]) to cause light to be emitted. This light is
measured with a photomultiplier tube, similar to the SO2 fluorescence analyzer.
E.1.9 EPA METHOD 8 (STACK SAMPLING)
This method is applicable for the determination of sulfuric acid mist (including SO3) and SO2
emissions from stationary sources. A gas sample is extracted isokinetically from the stack.
The sulfuric acid mist and SO2 are separated, and both fractions are measured separately by
the barium-thorium titration method.
E.1.10 EPA METHOD 10 (CEM)
When CEM systems are in place, Method 10 may be used to measure CO concentration. A
gas sample is continuously extracted from the stack and a portion of the sample is conveyed to
an instrumental NDIR analyzer for determination of CO concentration. The principle of
operation is similar to the NDIR SO2 analyzer.
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E.1.11 EPA METHOD 10B (STACK SAMPLING)
An integrated bag sample is extracted from the sampling point and analyzed for CO. The
sample is passed through a conditioning system to remove interferences and collected in a
Tedlar® bag. The CO is separated from the sample by a gas chromatograph (GC) and
catalytically reduced to methane (CH4) prior to analysis by flame ionization detection (FID).
E.1.12 EPA METHOD 19
This method is applicable for:
• Determining PM, S02, and NOX emission rates;
• Determining sulfur removal efficiencies of fuel pretreatment and SO2 control
devices;
• Determining overall reduction of potential SO2 emissions; and
• Determining SO2 rates based on fuel sampling and analysis procedures.
Pollutant emission rates and SO2 control device efficiencies are determined from
concentrations of PM, SO2, or NOX, and O2 or CO2, along with F factors (ratios of combustion
gas volumes to heat inputs).
E.1.13 EPA METHOD 25 (STACK SAMPLING)
This method is applicable for the determination of total gaseous nonmethane organic
(TGNMO) emissions as carbon. A gas sample is extracted from the stack at a constant rate
through a heated filter and a chilled condensate trap by means of an evacuated sample tank.
After sampling is completed, the TGNMO emissions are determined by independent analysis
of the condensate trap and the sample tank fractions and combining the analytical results. The
organic content of the condensate trap fraction is determined by oxidizing the nonmethane
organics to CO2 and quantitatively collecting the effluent in an evacuated vessel; then, a
portion of the CO2 is reduced to CH4 and measured by FID. The organic content of the
sample tank fraction is measured by injecting a portion of the sample into a GC equipped with
a capillary column capable of separating the nonmethane organic emissions from CO, CO2 and
CH4.
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E.1.14 EPA METHOD 25A(CEM)
This method applies to the measurement of total gaseous organic concentrations of vapors
consisting primarily of alkanes, alkenes, and aromatic hydrocarbons. A gas sample is
extracted continuously from the source through a heated sample line and directed to the total
hydrocarbon analyzer that uses FID. The sample gas enters the detector and is combusted in a
hydrogen flame. The ions and electrons formed in the flame enter an electrode gap, decrease
the gas resistance, and allow a current to flow in an external circuit. The resulting current is
proportional to the instantaneous concentration of total hydrocarbons. The concentration is
expressed in terms of methane or propane.
E.1.15 EPA METHOD 29 (STACK SAMPLING)
This method is applicable for the determination of chromium, cadmium, arsenic, nickel,
manganese, beryllium, copper, lead, selenium, silver, antimony, and mercury emissions from
stationary sources. The stack gas sample is withdrawn isokinetically. Paniculate emissions
are collected in the probe and on a heated filter while gaseous emissions are collected in
solutions of acidic hydrogen peroxide and acidic potassium permanganate. The recovered
samples are digested and the appropriate fractions are analyzed by atomic absorption
spectrophotometry.
E.1.16 EPA METHOD 0030 (STACK SAMPLING)
Method 0030 is a manual method for collecting VOCs which are defined for purposes of this
method as those organics with boiling points less than 100°C. The gas sample is collected
from the sampling point and cooled to 20 °C by passing through a water-cooled condenser and
the volatile organics are collected on a pair of sorbent resin traps. The resin traps are then
analyzed in the laboratory using a gas chromatograph equipped with an electron capture
detector (ECD), flame ionization detector (FID), or mass spectrometer to determine speciated
organics.
E.1.17 EPA METHODS 201 AND 202 (STACK SAMPLING)
In this method, a gas sample is isokinetically extracted from the source. An in-stack cyclone
is used to separate PM with a diameter greater than 10 micrometers, and an in-stack glass fiber
filter is used to collect the PM10. The particulate mass is determined gravimetrically after
removal of uncombined water. Method 202 is used to determine the condensable PM. The
condensable PM is determined gravimetrically by analysis of the impinger fractions.
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E.2 OTHER METHODS
E.2.1 CONTINUOUS FLOW RATE MONITORS
A new monitoring requirement under Acid Rain regulations (Title IV of the CAAA) is the
measurement of exhaust gas velocities. There are three velocity monitoring techniques
applicable to utility stacks or exhaust ducts. These are: (1) ultrasonic flow monitors,
(2) thermal flow monitors, and (3) differential pressure monitors.
Ultrasonic monitors operate by passing a pulse of ultrasonic sound diagonally through the
moving stack gas. The frequency of the ultrasonic pulse is changed in proportion to the
velocity of the stack gas. This frequency shift is measured and gas velocity is then calculated.
Thermal flow monitors operate by inserting a heated element into the exhaust stream. As gas
moves over the probe, the heated element is cooled thus requiring additional power to be
supplied to the heater in order to maintain a constant temperature. This additional power is
proportional to the gas velocity being measured.
Differential pressure monitors measure the difference between the velocity head and static
pressure. This difference is proportional to the velocity of the gas stream. The gas flow rate
is then calculated using this pressure difference.
E.2.2 FUEL ANALYSIS (ASTM D1552-83/D4507-81)
SO2 emissions from combustion sources can also be estimated by fuel analysis. The fuel is
analyzed for sulfur content and emissions are calculated based on the assumption that all of the
sulfur is converted to SO2. Depending on the characteristics of the fuel ash, a portion of the
SO2 may be absorbed onto the ash (generally less than 5 percent). The remainder is emitted.
E.2.3 FUEL ANALYSIS (SW 846 METHODS 3040/7090)
Metal emissions from combustion sources can also be estimated by fuel analysis. The fuel is
analyzed for the metals of interest and emissions are calculated assuming all of the metals are
emitted. Because most of the metals are associated with either boiler ash or PM (which may
be collected by an air pollution control system), this approach will provide a conservative
emission estimate.
E.2.4 FLUX CHAMBER MEASUREMENT
Flux chamber measurement is a direct measurement technique used to estimate emissions from
area sources of fugitive emissions such as contaminated soil, landfills, and lagoons. The
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approach employs an emission isolation flux chamber to obtain an estimate of the amount of
pollutant, or pollutants, being emitted from a given surface area per unit time. A variety of
flux chamber equipment designs and operating procedures have been employed. EPA has
issued guidance identifying flux chamber measurement as a recommended method of
estimating baseline air emissions from Superfund sites (EPA, 1990).
E.2.5 OPTICAL REMOTE MEASUREMENT
Another method used to estimate emissions from open areas or otherwise inaccessible sources
(e.g., plumes from smoke stacks, hazardous waste landfills) is the use of optical remote
sensing (ORS). ORS is an open-path method of determining pollutant concentration using
optical absorption spectroscopy. Pollutant concentration data combined with on-site
meteorological data may then be used to estimate emissions. ORS techniques include Fourier
transform spectroscopy, differential optical absorption spectroscopy, laser long-path
absorption, differential absorption lidar, and gas cell correlation spectroscopy.
E.3 REFERENCE
EPA. 1986. Test Methods for Evaluating Solid Waste, SW-846, Third Edition, U.S.
Environmental Protection Agency, Office of Solid Waste and Emergency Response.
Washington, D.C.
EPA. 1990. Procedures for Conducting Air Pathway Analyses for Superfund Activities,
Interim Final Documents: Volume 2 - Estimation of Baseline Air Emissions at Superfund
Sites. EPA-450/l-89-002a (NTIS PB90-270588), August.
ASTM. Annual Book ofASTM Standards, Volumes 06.01 and 15.05. September 1992.
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APPENDIX F
EMISSION ESTIMATION TOOLS
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This appendix describes emission factor databases, models, and other data tools that may be
useful or required for inventory preparation. Specific emissions measurement are generally the
best and most accurate method to quantify emissions; however, source data are not always
available. As an alternative, emission factors and models can be used as tools to estimate air
pollutant emissions for inventory purposes.
An emission factor relates a quantity of air pollutant to a process parameter, so that if the process
parameter is known, an estimate of emissions can be made. For example, an emission factor in
the form of pounds of volatile organic compound (VOC) per ton of product can be used to
estimate VOC emissions from a source, if the weight of product is known or can be determined.
A more complex model is used to estimate emissions when emissions are not directly related to
any one parameter. Models may use computers so that a large number of equations and
interactions can be easily calculated. The data requirements for such models vary but in most
cases, at least one physical parameter is needed from the source for which the model will be used
to estimate emissions. The reader should refer to Appendix C for contact information or to
request the most current version available for each of the tools discussed below.
F.1 LOCATING AND ESTIMATING EMISSIONS OF ... DOCUMENTS
In addition to AP-42, EPA has published about 40 reports, each with the title, Locating and
Estimating Air (Toxic) Emissions From (or of) Source Category (or Substance). These reports
(also known as L&Es) identify the source categories for which emissions of a substance have
been characterized. The reports include general process descriptions of the emitting processes
identifying potential release points and emission factors. Table l.F-1 lists the available L&E
documents, which are available by contacting the EPA's Emission Factors and Inventory Group
(EFIG), downloading from the EPA Clearinghouse for Inventories and Emission Factors Bulletin
Boards System (CHIEF BBS), or ordering through the National Technical Information Service
(NTIS).
F.2 EMISSION FACTOR DATABASE SYSTEMS
F.2.1 DATABASES AND SYSTEMS
The most comprehensive compilation of emission factors for hazardous air pollutants (HAPs) is
available in the Factor Information Retrieval (FIRE) System, which is available from EPA on
one 5.25 inch high density diskette [via request from the Info CHIEF helpline (see Appendix C)]
or by downloading from the CHIEF BBS. FIRE contains emission factors for 106 toxic and
criteria pollutants from various source categories (EPA, 1995).
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TABLE 1.F-1
LOCATING AND ESTIMATING DOCUMENT SERIES
Substance or Source Category
1,3-Butadiene (revised)
Acrylonitrile
Arsenic
Benzene (under revision)
Cadmium
Carbon Tetrachloride (under revision)
Chlorobenzenes
Chloroform (under revision)
Chromium
Chromium, supplement
Coal and Oil Combustion Sources
Cyanide Compounds
Dioxins/Furans
Epichlorohydrin
Ethylene Oxide
Ethylene Bichloride
Formaldehyde (under revision)
Lead
Manganese
Medical Waste Incinerators
Mercury and Mercury Compounds (under revision)
Methyl Chloroform
Methyl Ethyl Ketone
Methylene Chloride
Municipal Waste Combustors
Nickel
Organic Liquid Storage Tanks
Perchloroethylene and Trichloroethylene (under revision)
Phosgene
Polychlorinated Biphenyls (PCBs) (under revision)
Polycyclic Organic Matter (POM) (under revision)
Sewage Sludge Incinerators
Styrene
Toluene
Vinylidene Chloride
Xylenes
EPA Publication Number
EPA-454/R-96-008
EPA-450/4-84-007a
In Production- 1997
EPA-450/4-84-007q
EPA-454/R-93-040
EPA-450/4-84-007b
EPA-454/R-93-044
EPA-450/4-84-007c
EPA-450/4-84-007g
EPA-450/2-89-002
EPA-450/2-89-001
EPA-454/R-93-041
In Production- 1997
EPA-450/4-84-007J
EPA-450/4-84-0071
EPA-450/4-84-007d
EPA-450/2-91-012
In Production- 1997
EPA-450/4-84-007h
EPA-454/R-93-053
EPA-453/R-93-023
EPA-454/R-93-045
EPA-454/R-93-046
EPA-454/R-93-006
EPA-450/2-89-006
EPA-450/4-84-007f
EPA-450/4-88-004
EPA-450/2-89-013
EPA-450/4-84-007i
EPA-450/4-84-007n
EPA-450/4-84-007p
EPA-450/2-90-009
EPA-454/4-93-011
EPA-454/R-93-047
EPA-450/4-84-007k
EPA-454/R-93-048
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Factor Information Retrieval System
The EPA's Factor Information Retrieval System (FIRE) is a user friendly, menu driven system.
FIRE is a consolidation of emission factors for criteria pollutants and HAPs found in older EPA
databases such as Crosswalk/Air Toxic Emission Factor (XATEF), and Aerometric Information
Retrieval System (AIRS) Facility Subsystem Emission Factors (AFSEF), as well as emission
factors from EPA documents such as AP-42 and the L&Es. FIRE also contains emission factors
for some sources based on single source tests or literature-reported values, where no AP-42 or
L&E data are available. These factors are primarily for HAPs.
Additional and updated emission factors from AP-42 supplements and new L&Es are entered
into FIRE annually. Each emission factor in FIRE also includes information about the pollutant
(Chemical Abstract Services [CAS] numbers and chemical synonyms) and about the Source
Classification Codes [SCCs] and descriptions). Each emission factor entry includes supporting
data such as process parameters, source test methods, control devices, emission factor ranges
and/or source conditions, as well as the references where the data were obtained. The emission
factor also includes a factor quality rating.
The FIRE database has been designed to be very "user friendly." Data can be searched in many
different ways and can be downloaded to print standard reports, or can be printed in a report
format that is designed by the user. The FIRE database can be accessed on the EPA's CHIEF
electronic bulletin board system.
SPEC I ATE
The VOC/PM Speciation Database Management System (SPECIATE, Version 1.5) is a
clearinghouse for speciation profiles (not emission factors) for both VOCs and PM used
primarily for photochemical modeling and source-receptor modeling (EPA, 1993). Each profile
lists the elements or compounds identified as being emitted by a source category or process
according to the weight percent of each compound as a function of total organic compounds or
PM emissions. The SPECIATE PM profiles include three particle size range distributions and
total measured PM data for each species. SPECIATE is designed to search for profiles based on
a user-provided SCC, pollutant name, or a source category description. Because this system
represents a compilation from available literature for use in EPA's photochemical modeling
efforts, it will not address toxic compounds with any degree of completeness or accuracy.
The SPECIATE database is updated annually, and is accompanied by a user's manual. The
SPECIATE database is available for downloading from the CHIEF BBS or website. All user
related questions should be directed to the InfoCHIEF help line.
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F.3 CLEARINGHOUSE FOR INVENTORIES AND EMISSION FACTORS
BULLETIN BOARD
CHIEF is maintained by the EPA's Emission Factor and Inventory Group in Research Triangle
Park, North Carolina. As a clearinghouse, CHIEF is the repository of the most up-to-date
information on inventories and emission estimation tools, such as emission factors.
The CHIEF bulletin board contains all of the AP-42 stationary source volumes and draft
revisions, the SPECIATE database, the MOBILE5a model, the AFS database, e-mail from other
users of CHIEF. Other information may be available in the future. CHIEF may be accessed on
the internet at the following address: ttnwww.rtpnc.epa.gov.
F.4 AEROMETRIC INFORMATION RETRIEVAL SYSTEM BULLETIN BOARD
The AIRS bulletin board is an electronic bulletin board maintained by the EPA that holds
information useful to AIRS users. The AIRS bulletin board can be accessed through a telephone
line modem and provides information on utility information, file transfers, communications, and
public communications.
F.4.1 ACCESSING THE SYSTEMS
Most of the EPA materials described in this section are available through the CHIEF BBS or on
Air CHIEF CD-ROM. Any user accessing the CHIEF BBS can download AP-42 chapters,
Locating and Estimating Emissions of... documents, FIRE, SPECIATE, TANKS, Surface
Impoundment Modeling System (SIMS), the AIRS Facility Subsystem Emission Factors
(AFSEF) database, and many more tools for estimating emissions. The CHIEF BBS is a subpart
of the EPA's Office of Air Quality Planning and Standards (OAQPS) Technology Transfer
Network (TTN).
The Air CHIEF CD-ROM for accessing many of EPA's documents and databases is available for
purchase from the Government Printing Office (GPO) for about $20 or from InfoCHIEF (see
Appendix C). Users need an IBM™ - compatible personal computer (PC) with a VGA monitor,
MS-DOS version 3.0 or later, 8 megabytes (MB) random access memory (RAM), a CD-ROM
drive, an interface card, and MS-DOS CD-ROM extensions. Version 4.0 of Air CHIEF
CD-ROM includes Volume I of AP-42, 5th Edition (criteria pollutant emission factors for point
and area sources, not including mobile sources), FIRE, SPECIATE, and 32 documents in the
Locating and Estimating Emissions of... series. The Air CHIEF CD-ROM is updated annually.
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F.5 GEOGRAPHIC MODELING SYSTEMS SUPPORT
Computerized modeling systems can be used in many facets of the emissions inventory to locate
emissions sources and track the progress of a control strategy. The most common of these
systems are the Geographic Information System and the Global Positioning System.
F.5.1 GEOGRAPHIC INFORMATION SYSTEM
The Geographical Information System uses modem computer technology to store, retrieve,
analyze, update, and display spatially arranged data (maps). Because the characterization of
emissions is enhanced by knowledge of the location and spatial arrangement of all identified
sources, the Geographical Information System can be a useful tool for emissions inventories.
Locating each point source, defining the boundaries around each area source, and mapping all
road networks can provide valuable information for formulating, evaluating, and implementing
emissions reduction strategies. Mapping point and area sources is also important in defining, and
subsequently modifying, nonattainment area boundaries. Map features are available in digital
formats from transportation departments, tax offices, planning/zoning offices, and emergency
response agencies.
Further information about the potential applications of the Geographical Information System
technologies in emissions inventory preparation can be obtained from the EPA's OAQPS, and
Office of Research and Development (ORD), Research Triangle Park, North Carolina; local
colleges or universities with geography, civil engineering, or natural sciences departments; state
and local land/resource management or environmental protection agencies; and private
organizations that provide mapping services.
F.5.2 GLOBAL POSITIONING SYSTEM
The Global Positioning System performs map feature registration using banks of geosynchronous
Earth-orbiting satellites that act as known reference points in triangulation calculations. The
coordinates of the unknown Earth surface location can be calculated from the known coordinates
of orbiting satellites. This can serve as a valuable quality assurance/quality control (QA/QC)
check for locating point source data. Geographical positioning units offer a cost-effective
alternative for locating emissions sources, assuming that a registration accuracy of plus or minus
three meters will provide adequate mapping resolution within a nonattainment area that covers
tens or hundreds of square miles. It is anticipated that as Global Positioning Systems become
cheaper and more common, they will be the standard method of determining coordinate
locations, if the required accuracy goal can be achieved. Other methods, such as map reading,
address matching, and zip code centroids may then decrease in popularity.
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The EPA locational data policy (LDP), which became effective in 1995, prescribes that latitude/
longitude coordinates be maintained for all EPA facility data (i.e., all media, not just air). The
coordinates are to have an accuracy goal of ±1 second.
F.6 WATER AND WASTEWATER AIR EMISSIONS MODELS
F.6.1 CHEMDAT8
CHEMDAT8 is a Lotus 1-2-3® spreadsheet prepared by the EPA's Emission Standards Division
that includes analytical models for estimating VOCs from treatment, storage, and disposal
facility (TSDF) processes. The original models include disposal impoundments, closed landfills,
land treatment facilities, and aeration and nonaeration impoundment processes. Predicted
emissions can be viewed on the screen or printed. A graphical presentation of the relationships
between emission prediction and vapor pressure and between emission prediction and the
partition coefficient is also available. The resulting scatter diagrams can be printed via
PrintGraph®, another Lotus® program.
The models in CHEMDAT8 can be applied to other types of TSDF processes besides those
contained in the original design. The nonaerated impoundment model in CHEMDAT8 can
estimate emissions from storage surface impoundments and open-top wastewater treatment
tanks. The CHEMDAT8 aerated impoundment model may be used for predicting emissions
from surface treatment impoundments and aerated wastewater treatment tanks. The land
treatment model in CHEMDAT8 can estimate emissions from land treatment soil, open landfills,
and wastepiles. Emissions from an oil film surface in a land treatment facility or an oil film on
surface impoundments can be predicted via the oil film model in CHEMDAT8. When a
CHEMDAT8 model is not available to predict emissions, the equations shown in the reports that
provide the background to the model can be used to perform hand calculations of emissions.
This eighth version of the CHEMDAT spreadsheet contains several major operational
modifications. In CHEMDAT8, the user can select a subset of target compounds for
investigation. The user can also specify which TSDF processes are to be considered during a
session. These two selections improve the efficiency of CHEMDAT8 relative to some of the
earlier versions by minimizing storage requirements as well as actual loading and execution time.
Default input parameters in the CHEMDAT8 diskette demonstrate example calculations.
However, the input parameters can be changed to reflect different TSDF characteristics and then
recalculate emissions under these modified conditions. The list of 60 compounds currently in
CHEMDAT8 can be augmented by an additional 700 chemicals. Procedures for introducing data
for additional compounds into CHEMDAT8 are described in the supporting documentation
report.
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F.6.2 WATERS
WATERS is a menu-driven computer program that is intended for estimating emissions from
wastewater treatment systems only. WATERS uses some of the same models found in
CHEMDAT8, but has data for a total of 800 compounds. The WATERS program also has
graphic enhancements to aid the user in visualizing the system being modeled.
F.7 LANDFILL AIR EMISSIONS ESTIMATION MODEL
The Landfill Air Emissions Estimation Model (LAEEM) is a computer program specifically
designed for use by state and local regulatory agencies to monitor the emissions of HAPs from
landfills. The system allows the user to enter specific information regarding the characteristics
and capacity of an individual landfill and to project the emissions of methane, CO, nonmethane
organic compounds, and individual HAPs over time using the Scholl Canyon decay model for
landfill gas production estimation. The Scholl Canyon Model is a first-order decay equation that
uses site-specific characteristics for estimating the gas generation rate. In the absence of site-
specific data, the program provides conservative default values. The user also may tailor decay
rate characteristics on an individual basis. An integrated decay rate constant calculator is
provided for landfills that may be operating a gas recovery system to allow more accurate
assessments of decay attributes. Outputs may be reviewed in either tabular or graphical forms.
A help system is also provided with information on the model operation as well as details on
assumptions and defaults used by the system.
The model is IBM™-PC compatible, requires at least 512 kb of memory, and can be used with a
monochrome or color graphics adaptor. It is recommended that the user's guide be thoroughly
read before using the model.
F.8 TANKS
The TANKS program is designed to estimate emissions of organic chemicals from storage tanks.
After the user provides specific information concerning the storage tank and its contents, the
TANKS program estimates the annual or seasonal emissions and produces a report. The
emissions can be separated into standing storage and working losses.
The TANKS program has a chemical database of over 100 organic liquids and meteorology data
from over 250 cities in the U.S. The user may add new chemicals and cities to their version of
the database. The tank types addressed in the program include vertical and horizontal fixed roof
tanks, and internal and external floating roof tanks. The tank contents can consist of single-
component liquid or a multicomponent mixture.
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The disadvantage of using the TANKS program orAP-42 equations is that more resources are
required to gather the input data and use the equations or program than are needed to use other
approximation techniques. If storage tank emissions are expected to be small relative to
emissions from other sources in the inventory, the extra effort may not be warranted. A
compromise is to develop region-specific default emission factors using the AP-42 equations or
TANKS program that reflect average temperature, tank conditions, and chemical contents for the
inventory region.
TANKS version 3.0 is currently available. The program is written in FoxPro™, a dBase-
compatible language, and is distributed by the EPA through the CHIEF BBS or through the mail
on diskette.
F.9 TRADE ASSOCIATIONS
Trade associations are another information resource regarding emission estimation tools and
software for a specific industry. The larger trade associations (e.g., the Aluminum Association or
the American Iron and Steel Institute) often serve as liaisons between government and industry.
As such, they sometimes support environmental research and negotiations with EPA and other
federal agencies. Trade associations may be able to provide emission factor information, test
data, control system performance data, and other useful information to industry personnel. Many
relevant associations are listed in the National Trade and Professional Associations of the United
States directory (Russell 1992).
F.10 REFERENCES
EPA. 1993. VOC/PM Speciation Data System Documentation and User's Guide, Version 1.5.
EPA-450/4-92-027. U.S. Environmental Protection Agency, Office of Air Quality Planning and
Standards. Research Triangle Park, North Carolina.
EPA. 1995. Factor Information Retrieval System (FIRE), Version 4.0. U.S. Environmental
Protection Agency, Office of Air Quality Planning and Standards. Research Triangle Park,
North Carolina.
Russell, John J., Managing Editor. 1992. National Trade and Professional Associations of the
United States. 27th Annual Edition. Columbia Books, Inc., Washington, DC.
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VOLUME II: CHAPTER 2
PREFERRED AND ALTERNATIVE
METHODS FOR ESTIMATING AIR
EMISSIONS FROM BOILERS
June 1996
Prepared by:
Radian Corporation
Prepared for:
Point Sources Committee
Emission Inventory Improvement Program
-------
DISCLAIMER
This document was furnished to the Emission Inventory Improvement Program and the
U.S. Environmental Protection Agency by Radian Corporation, Research Triangle Park,
North Carolina. This report is intended to be a final document and has been reviewed
and approved for publication. The opinions, findings, and conclusions expressed
represent a consensus of the members of the Emission Inventory Improvement Program.
-------
ACKOWLEDGEMENT
This document was prepared by Radian Corporation, Research Triangle Park, North
Carolina, for the Point Sources Committee, Emission Inventory Improvement Program
and for Dennis Beauregard of the Emission Factor and Inventory Group, U.S.
Environmental Protection Agency. Members of the Point Sources Committee
contributing to the preparation of this document are:
Bill Gill, Co-Chair, Texas Natural Resource Conservation Commission
Jim Southerland, Co-Chair, Emission Factor and Inventory Group, U.S. Environmental Protection Agency
Denise Alston-Guiden, Galsen Corporation
Evette Alvarado, Texas Natural Resource Conservation Commission
Dennis Beauregard, Emission Factor and Inventory Group, U.S. Environmental Protection Agency
Bob Betterton, South Carolina Department of Health and Environmental Control
Alice Fredlund, Louisana Department of Environmental Quality
Karla Smith Hardison, Texas Natural Resource Conservation Commission
Gary Helm, Air Quality Management, Inc.
Paul Kim, Minnesota Pollution Control Agency
Toch Mangat, Bay Area Air Quality Management District
Ralph Patterson, Wisconsin Department of Natural Resources
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iv EHP Volume II
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CONTENTS
Section Page
1 Introduction 2.1-1
2 General Source Category Description 2.2-1
2.1 Source Category Description 2.2-1
2.1.1 Coal-Fired Boilers 2.2-1
2.1.2 Oil-Fired Boilers 2.2-3
2.1.3 Natural Gas-Fired Boilers 2.2-3
2.1.4 Boilers Using Other Types of Fuel 2.2-4
2.1.5 Cogeneration Units 2.2-4
2.1.6 Auxiliary Sources 2.2-5
2.2 Emission Sources 2.2-5
2.2.1 Material Handling (Fugitive Emissions) 2.2-5
2.2.2 Storage Tanks 2.2-6
2.2.3 Process Emissions 2.2-6
2.3 Factors and Design Considerations Influencing Emissions 2.2-7
2.3.1 Process Operating Factors 2.2-7
2.3.2 Control Techniques 2.2-8
3 Overview of Available Methods for Estimating Emissions 2.3-1
3.1 Emission Estimation Methodologies 2.3-1
3.1.1 CEMS 2.3-1
3.1.2 PEM 2.3-1
3.1.3 Stack Sampling 2.3-2
3.1.4 Fuel Analysis 2.3-2
3.1.5 Emission Factors 2.3-2
3.2 Comparison of Available Emission Estimation Methodologies 2.3-2
3.2.1 Continuous Emission Monitoring System (CEMS) 2.3-5
3.2.2 Predictive Emission Monitoring (PEM) 2.3-6
3.2.3 Stack Sampling 2.3-6
3.2.4 Fuel Analysis 2.3.6
3.2.5 Emission Factors 2.3-7
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CONTENTS (CONTINUED)
Section Page
4 Preferred Methods for Estimating Emissions 2.4-1
4.1 Emission Calculations Using CEMS Data 2.4-1
4.1.1 Calculating Hourly Emissions from Concentration
Measurements . 2.4-4
4.1.2 Calculating Stack Gas Flow Rate 2.4-4
4.1.3 Calculating Emission Factors from Heat Input 2.4-5
4.1.4 Calculating Actual Annual Emissions 2.4-6
4.2 PEM 2.4-9
4.3 Emission Calculations Using Stack Sampling Data 2.4-9
4.4 Emission Calculations Using Fuel Analysis Data 2.4-13
5 Alternative Methods for Estimating Emissions 2.5-1
5.1 Emission Factor Calculations 2.5-1
5.2 Emission Calculations Using Rule Effectiveness 2.5-2
6 Quality Assurance/Quality Control 2.6-1
6.1 General Factors Involved in Emission Estimation Techniques 2.6-1
6.1.1 Stack Test and CEMS . 2.6-1
6.1.2 Emission Factors 2.6-2
6.2 Data Attribute Rating System (DARS) Scores 2.6-2
7 Data Coding Procedures 2.7-1
7.1 Process Emissions 2.7-1
7.2 Storage Tanks 2.7-1
7.3 Fugitive Emissions 2.7-1
7.4 Control Devices 2.7-2
8 References 2.8-1
Appendix A: Example Data Collection Form and Instructions - Boiler
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TABLES
Page
2.2-1 Boiler Controls 2.2-9
2.3-1 Summary of Preferred and Alternative Emission Estimation
Methods for Boilers 2.3-3
2.4-1 List of Variables and Symbols 2.4-2
2.4-2 Example CEMS Output for a Boiler Burning No. 6 Fuel Oil 2.4-3
2.4-3 Fd Factors for Various Fuels 2.4-6
2.4-4 Predictive Emission Monitoring Analysis 2.4-10
2.4-5 Sample Test Results - Method 201 2.4-12
2.6-1 DARS Scores: CEM/PEM Data 2.6-3
2.6-2 DARS Scores: Stack Sample Data 2.6-4
2.6-3 DARS Scores: Source-Specific Emission Factor 2.6-5
2.6-4 DARS Scores: AP-42 Emission Factor 2.6-6
2.7-1 Source Classification Codes for Utility Boilers (SIC Code 4911) 2.7-3
2.7-2 AIRS Control Device Codes 2.7-11
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1
INTRODUCTION
The purposes of the preferred methods guidelines are to describe emission estimation
techniques for stationary point sources in a clear and unambiguous manner and to
provide concise example calculations to aid in the preparation of emission inventories.
This chapter describes the procedures and recommended approaches for estimating
emissions from external combustion sources (i.e., boilers).
Section 2 of this chapter contains a general description of the boiler source category, a
listing of emission sources commonly associated with boilers, and an overview of the
available control technologies for various boiler types. Section 3 of this chapter provides
an overview of available emission estimation methods. It should be noted that the use of
site-specific emission data is often preferred over the use of industry-averaged data such
as AP-42 emission factors. However, depending upon available resources, site-specific
data may not be cost effective to obtain. Section 4 presents the preferred emission
estimation methods for boilers by pollutant, and Section 5 presents the alternative
emission estimation techniques. Quality assurance (QA) and quality control (QC)
procedures are described in Section 6, and data coding procedures are discussed in
Section 7. Section 8 lists references. Appendix A provides an example data collection
form for boilers to assist in information gathering prior to emissions calculations. Refer
to Chapter 1 of this volume, Introduction to Stationary Point Source Emission Inventory
Development, for general concepts and technical approaches.
This chapter does not specifically discuss State Implementation Plans (SIPs) or base year,
periodic, and planning inventories. However, the reader should be aware that the U.S.
Environmental Protection Agency (EPA) procedures manuals pertaining to the
preparation of emission inventories for carbon monoxide and precursors of ozone are
available (EPA, May 1991).
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GENERAL SOURCE CATEGORY
DESCRIPTION
2.1 SOURCE CATEGORY DESCRIPTION
This section provides a brief overview discussion of boilers. The reader is referred to
the Air Pollution Engineering Manual (sometimes referred to as AP-40) and AP-42 for a
more detailed discussion on boilers, boiler designs, boiler operations and their influences
on emissions (Buonicore and Davis, 1992; EPA, January 1995).
The boiler source category comprises sources that combust fuels to produce hot water
and/or steam. Utility boilers utilize steam to generate electricity. Industrial boilers
often generate steam for electrical power as well as process steam. Space heaters use
the hot water for heating commercial and residential building space. Fuels typically used
in boilers include coal, oil, and natural gas. In addition, liquified petroleum gas (LPG),
process and waste gases, and wood wastes may be used. In general, boilers are
categorized as follows:
Types of Boilers
Utility
Industrial
Commercial
Residential
Size
> 100 MMBtu/hr
10 - 250 MMBtu/hr
< 10 MMBtu/hr
« 10 MMBtu/hr
2.1.1 COAL-FIRED BOILERS
Coal is broadly classified into one of four types (anthracite, bituminous, subbituminous,
or lignite) based on differences in heating values and amounts of fixed carbon, volatile
matter, ash, sulfur, and moisture. The following sections discuss the four main types of
coal boilers (pulverized coal, cyclone, spreader stoker, and fluidized bed) and the
processes that occur at all four types of coal-fired boilers. Pulverized coal and cyclone
boilers employ a technique known as suspension firing; they are sometimes categorized
by this technique.
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Pulverized Coal Furnaces
Pulverized coal furnaces are used primarily in utility and large industrial boilers
(Buonicore and Davis, 1992; EPA, January 1995). In a pulverized coal system, the coal
is pulverized in a mill to the consistency of talcum powder. The pulverized coal is then
entrained in primary air before being fed through the burners to the combustion
chamber, where it burns in suspension. Pulverized coal furnaces are classified as either
dry or wet bottom, depending on the ash removal technique. Dry-bottom furnaces may
either be tangential- or nontangential-fired units. Some examples of nontangential-fired
pulverized coal furnaces are wall-fired, turbo, cell-fired, vertical, and arch. Dry-bottom
furnaces fire coal with high ash fusion temperatures, whereas wet-bottom furnaces fire
coal with low ash fusion temperatures. Wet-bottom furnace designs have higher nitrogen
oxides (NOX) emission rates and are no longer being built, though many remain in
service.
Cyclone Furnaces
Cyclone furnaces are used mostly in utility and large industrial applications (Buonicore
and Davis, 1992). Cyclone furnaces burn coal that has a low ash fusion temperature and
has been crushed to a four-mesh size (larger than pulverized coal). Coal in a cyclone
furnace is fed tangentially with primary air to a horizontal cylindrical combustion
chamber. In this chamber, small coal particles are burned in suspension, while the larger
particles are forced against the outer wall. Because of the high temperatures developed
in the relatively small combustion chamber and because of the low fusion temperature of
the coal ash, much of the ash forms a liquid slag that is drained from the bottom of the
furnace through a slag tap opening (EPA, January 1995).
Spreader Stokers
In spreader stokers, a rotating flipping mechanism throws the coal into the furnace and
onto a moving fuel bed. Combustion occurs partly in suspension and partly on the grate.
Because of significant amounts of carbon in the particulate, fly ash reinjection from
mechanical collectors is commonly employed to improve boiler efficiency. Ash residue
in the fuel bed is deposited in a receiving pit at the end of the grate (EPA, January
1995). Anthracite coal is not used in spreader stokers because of its low volatile matter
content and relatively high ignition temperature.
Fluidized Bed Combustors
In a fluidized bed combustor (FBC), coal is introduced to a bed of either sorbent
(limestone or dolomite) or inert material (usually sand) that is fluidized by an upward
flow of air. Combustion takes place in the bed at lower temperatures than other boiler
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types. Key benefits to this relatively new process are fuel flexibility and reduced
emissions. FBCs are typically used for industrial-sized boilers and may be emerging as a
competitive design for electric power generation (Stultz and Kitto, 1992).
2.1.2 OIL-FIRED BOILERS
There is little variation between the design of oil-fired units and the design of coal-fired
units; almost all are either tangential-fired or wall-fired. Fuel oils are broadly classified
into two major types: distillate and residual. Distillate oils (fuel oil grade Nos. 1 and 2)
are used mainly in domestic and small commercial applications in which easy fuel
burning is required. Distillates are more volatile and less viscous than residual oils.
Being more refined, they have negligible ash content, and usually contain less than
0.3 weight percent sulfur. Residual oils (grade Nos. 4, 5, and 6) are used mainly in
utility, industrial, and large commercial applications with sophisticated combustion
equipment. Residual No. 4 oil is sometimes classified as a distillate, and No. 6 is
sometimes referred to as Bunker C. The heavier residual oils (grade Nos. 5 and 6) are
more viscous and less volatile than distillate oils and, therefore, must be heated to
facilitate handling and proper atomization. Because residual oils are produced from the
crude oil residue after lighter fractions (gasoline, kerosene, and distillate oils) have been
removed, these oils contain significant quantities of ash, nitrogen, and sulfur (EPA,
January 1995). However, low-sulfur residual oil is becoming more commonplace.
2.1.3 NATURAL GAS-FIRED BOILERS
Natural gas is used for power generation, industrial process steam and production
activities, and domestic and commercial space heating. The primary component of
natural gas is methane, although small amounts of ethane, nitrogen, helium, and carbon
dioxide (CO2) can also be present (EPA, January 1995).
Natural gas boilers are considered clean relative to coal- or oil-fired boilers, but
improper operating conditions (such as poor air-fuel mixing) may still result in smoke
(unburned carbon) in the exhaust, as well as carbon monoxide (CO) and perhaps small
amounts of unburned hydrocarbons. NOX emissions are usually the major pollutants of
concern in a well-operated natural gas boiler. NOX emissions are primarily a function of
the combustion chamber temperature.
Several modifications can be made to natural gas boilers to reduce NOX emissions.
Staged combustion can reduce NOX emissions by 5 to 20 percent (EPA, January 1995);
low excess air levels and flue gas recirculation also often lower NOX emissions.
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2.1.4 BOILERS USING OTHER TYPES OF FUEL
Other fuels such as LPG, process gas, wood and/or bark, and solid/liquid waste may be
used in boilers.
LPG is either butane, propane, or a mixture of the two. This gas is often called bottled
gas. Grade A LPG is mostly butane and Grade F is mostly propane, with Grades B
through E consisting of varying mixtures of butane and propane. Although LPG is
considered a clean fuel, gaseous pollutants such as CO, organic compounds (including
volatile organic compounds or VOCs), and NOX are emitted as are small amounts of
sulfur dioxide (SO2).
Process gases that are used for fuel include petroleum refinery gas, blast furnace gas,
coke oven gas, landfill gas, and any other process gases with sufficient and economically
recoverable heating values.
The burning of wood and/or bark in boilers is mostly confined to situations where steady
supplies of wood or bark are available as a byproduct or in close proximity to the boiler.
In most cases, the wood is waste that would otherwise present a solid waste disposal
problem. The common types of boilers used to burn wood/bark are Dutch ovens, fuel
cell ovens, spreader stokers, vibrating grate stokers, and cyclone (tangential-fired) boilers
(EPA, January 1995).
Solid or liquid waste may consist of general waste solids or liquids, refuse-derived fuel,
or waste oil. Waste oil, or used oil, refers to spent lubrication and other industrial oils
that would otherwise present a liquid waste disposal problem. The most common type of
waste oil is used vehicle crankcase oil. Other oils include metalworking lubricants,
animal and vegetable oils and fats, and transformer and other heat transfer fluids.
Waste oils may have higher emissions of SO2 and particulates than refined fuel oils, but
will have similar levels of emissions for NOX, CO, and organic compounds (EPA, January
1995). Heavy metal emissions may be greater from crankcase oil combustion.
2.1.5 COGENERATION UNITS
Cogeneration is the production of more than one useful form of energy (such as process
heat and electric power) from the same energy source. Cogeneration plants produce
electric power and also meet the process heat requirements of industrial processes
(Cengel and Boles, 1989). A steam turbine, gas-cycle turbine, or combined-cycle turbine
can be used to produce power in a Cogeneration plant.
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In a typical cogeneration plant, energy is transferred to water by burning coal, oil,
natural gas, or other (nonfossil) fuels in a boiler. The high-pressure, high-temperature
steam leaving the boiler is expanded in a turbine that drives a generator to produce
electric power. The low-pressure, low-temperature steam leaving the turbine is used as
process heat. Industries likely to use cogenerated process heat are the chemical, pulp
and paper, oil production and refining, steel making, food processing, and textile
industries. Besides the steam-turbine cycle described above, a gas-cycle or a combined-
cycle turbine can be used to produce power in a cogeneration plant (Cengel and Boles,
1989). Combustion turbines are also commonly used for cogeneration.
2.1.6 AUXILIARY SOURCES
Auxiliary sources associated with boilers include fuel storage piles, fuel storage tanks,
materials handling, and other sources of fugitive emissions. These sources are often
overlooked and not reported as a part of the emission inventory. However, it is essential
that these sources be considered in the emission inventory to develop a complete record
of the emissions coming from the facility.
Coal storage piles are used to store coal at the boiler site. Material handling involves
the receipt of coal, movement of coal to the preparation (crushing) facility, and
movement of coal to the boilers, which may result in the release of particulate
matter (PM) emissions. A coal-fired boiler may also use fuel oil or gas for the initial
light-off of the boilers. In this case, as well as for oil-fired boilers, VOC losses from fuel
oil storage tanks should be considered (EPA, January 1995).
Because coal crushing operations can generate a significant amount of fine PM, they
should be included in the inventory. Because of the potential for explosion from this
fine particulate, crushing operations are typically well controlled (EPA, January 1995).
2.2 EMISSION SOURCES
Air pollutant emissions associated with boilers can occur at the following
points/processes. Section 7 lists the source classification codes (SCCs) for these emission
points.
2.2.1 MATERIAL HANDLING (FUGITIVE EMISSIONS)
Material handling includes the receipt, movement, and processing of fuel and materials
to be used at the boiler facility. Coal, limestone, wood, bark, and solid waste may all be
included, and their handling may result in particulate emissions. Organic compound
emissions can also result from the transfer of liquid and gaseous fuels. This source
category includes storage bins and open stockpiles, as well as the processes used to
transfer these materials (e.g., unloading, loading, and conveying).
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2.2.2 STORAGE TANKS
Storage tanks are used to store fuel oils at boiler facilities, and should be inventoried as
a source of organic compound emissions. Storage tanks at boiler facilities are usually
one of two types: fixed roof or floating roof. Emissions at fixed-roof tanks are typically
divided into two categories: working losses and breathing losses. Working losses refer
to the combined loss from filling and emptying the tank. Filling losses occur when the
organic compounds and VOCs contained in the saturated air are displaced from a
fixed-roof vessel during loading. Emptying losses occur when air drawn into the tank
becomes saturated and expands, exceeding the capacity of the vapor space. Breathing
losses are the expulsion of vapor from a tank through vapor expansion caused by changes
in temperature and pressure.
Emissions at floating roof tanks are reported in two categories: standing losses and
withdrawal losses. Withdrawal loss is the vaporization of liquid that clings to the tank
wall and that is exposed to the atmosphere when a floating roof is lowered by withdrawal
of liquid. Standing losses result from wind-induced mechanisms and occur at rim seals,
deck fittings, and deck seams (EPA, January 1995).
The TANKS program is commonly used to quantify emissions from oil-fired boilers. Its
use at boiler installations should be carefully evaluated because it is a complicated
program with a great number of input parameters. It is commonly used at large
oil-burning facilities where VOC emissions may be significant. Check with your local or
state authority as to whether TANKS is required for your facility. The use of the
TANKS program for calculating emissions from storage tanks is discussed in Chapter 1
of Volume II, Introduction to Stationary Point Source Emissions Inventory Development.
2.2.3 PROCESS EMISSIONS
For boilers, emissions resulting from the process (combustion of fuel to generate hot
water and steam) are typically vented to the atmosphere via a stack or vent. The major
pollutants of concern from boiler stacks are PM, sulfur oxides (SO2 and sulfur trioxide
[SO3]), and NOX. CO and unburned combustibles, including numerous organic
compounds (e.g., benzene) can also be emitted under certain boiler operating conditions.
Most of the carbon in fossil fuels is emitted as CO2 during combustion, and may be
inventoried due to its role as a greenhouse gas. Trace metals, such as arsenic and
cadmium, may also be emitted as a result of combustion of coal and oil. Additionally,
organic pollutants such as formaldehyde and polycyclic organic matter (POM) may be
formed during combustion and emitted (EPA, April 1989).
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2.3 FACTORS AND DESIGN CONSIDERATIONS INFLUENCING
EMISSIONS
2.3.1 PROCESS OPERATING FACTORS
The combustion process is defined as the rapid oxidation of substances (fuels) with the
evolution of heat. Boilers utilize the heat generated by combustion to produce hot
water, steam, or both. The fuel types discussed in this chapter include coal, oil, natural
gas, and other fuels such as wood, LPG, and process gases. When these burn, they are
converted into CO2 and water, referred to as the combustion products. The
noncombustible portion of a fuel remains as a solid residue or ash. The coarser, heavier
portion remains within the combustion chamber and is called "bottom ash." The finer
portion, referred to as "fly ash," exits the furnace with the flue gas.
Combustion products from boiler operation can also include partially oxidized
hydrocarbons, CO, SO2, SO3, NOX, acids such as hydrochloric acid, and organohalides
such as dioxins and furans. The generation of undesirable combustion products is
strongly influenced by fuel type, furnace type, firing configuration, and boiler operating
conditions. Although a detailed discussion of boiler operations cannot be presented
here, some general observations are included to assist in understanding the relative
impact of various boilers and fuel types on air emissions.
The discussion on coal-fired boilers introduced the four primary classifications of coal:
lignite, anthracite, bituminous, and subbituminous. Fuel is ranked based on American
Society for Testing and Materials (ASTM) standard methods referred to as "proximate"
and "ultimate" analyses. Proximate analyses report fuel composition in broad categories
such as moisture content and ash content. Ultimate analyses provide an estimate of the
carbon, hydrogen, sulfur, oxygen, nitrogen, and water content of the fuel. An ultimate
analysis is used to compute combustion air requirements and can also be used to
calculate fuel factors (Fd) for determining exhaust gas flow rates (see Equation 2.4-4).
Sections 3 and 4 discuss how fuel analysis can be used to estimate emissions of sulfur
oxides and metals from fuel combustion. Generally, boiler size, firing configuration, and
operation have little effect on the percent conversion of fuel sulfur to sulfur oxides, so
fuel analysis is typically a valid means of predicting emissions of sulfur oxides.
By contrast, NOX formation is highly dependent on boiler conditions, especially
temperature and air/fuel ratios near the burner. NOX is produced by two mechanisms:
conversion of fuel-bound nitrogen in fuel and oxidation of molecular nitrogen from
combustion air (referred to as thermal NOX formation). Thermal NOX formation is
highly temperature dependent and becomes rapid as temperatures exceed 3,000°F
(Buonicore and Davis, 1992). Lower operating temperatures result in decreased thermal
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NOX production. Shorter residence time also lowers thermal NOX generation. Fuel NOX
will generally account for over 50 percent of the total NOX generated by oil- and coal-
fired boilers. NOX emissions from tangential-fired oil boilers are typically lower than
those from horizontally opposed units. Many boilers employ combustion modifications
to reduce NOX emissions. These include staged combustion, off-stoichiometric firing, flue
gas recirculation, and low-NOx burners with overfire air (OFA). These control strategies
can reduce NOX emissions by 5 to 50 percent (Buonicore and Davis, 1992).
The utility sector is dominated by pulverized dry-bottom, coal-fired units. Stoker boilers,
currently accounting for a small percentage of total national capacity, are less common.
Coal-fired pulverized wet-bottom and cyclone boilers are no longer sold due to their
inability to meet NOX standards, although many are still in use.
In the industrial sector, more natural gas is used relative to coal and oil. The
commercial/institutional sector consumes a greater proportion of oil and natural gas
relative to coal consumption than the other two sectors.
2.3.2 CONTROL TECHNIQUES
Table 2.2-1, "Boiler Controls," lists the control technologies associated with boiler
operations, along with their typical efficiencies. Control efficiency for a specific piece of
equipment will vary depending on the age of the equipment and quality of the
maintenance/repair program at a particular facility.
Paniculate Control
In addition to PM and PM with an aerodynamic diameter of less than 10 pm (PM10)
emissions, particulate control also serves to remove trace metals, as well as metals (such
as mercury) that are vaporized in the combustion chamber and condensed onto fly ash in
the exhaust. However, the PM control efficiencies listed in Table 2.2-1 may not
correspond to actual removal efficiencies of specific hazardous air pollutants (HAPs) or
metals, due to the phenomena of fine particle enrichment. This phenomena may be
especially important for metals with relatively high vapor pressures such as mercury
(EPA, April 1989).
Electrostatic Precipitators (ESPs). ESPs are widely used to control emissions from
coal-fired boilers and account for 95 percent of all utility particulate controls in the
United States (Buonicore and Davis, 1992). ESPs are PM control devices that employ
electrical forces to remove particles from the flue gas onto collecting plates (EPA,
June 1991). The accumulated particles are then knocked or washed off the plates and
into collecting hoppers.
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CHAPTER 2 - BOILERS
TABLE 2.2-1
BOILER CONTROLS
Fuel
Coal
Oil
Pollutant
NOX
SO2
PM and PM10
NOX
SO2
PM and PM10
Device/Technique
SCR
SNCR
LEA
LNB and OFA
Spray drying
Wet scrubber
Low-sulfur coal
Coal washing
ESP
Fabric filter (in conjunction
with dry scrubber)
Multiple cyclones
Venturi scrubbers
SCR
SNCR
LNB and OFA
LEA
Spray drying
Wet scrubber
Low-sulfur oil
Good combustion
Typical Efficiency (%)
80
50
5-25
5-25
70-90
80-95
50
30
99
99
90
97
40-90
50
20-50
0-28
70-90
80-98
80
—
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TABLE 2.2-1
(CONTINUED)
Fuel
Natural Gas
Wood Waste
Pollutant
NOX
PM
Device/Technique
SCR
SNCR
LNB
Wet scrubber
ESP
Fabric filter
Typical Efficiency (%)
80
50
50
—
—
—
Source: EPA, January 1995; Cooper and Alley, 1994.
ESP = Electrostatic precipitator.
LEA = Low excess air.
LNB = Law NOX burner.
OFA = Overfire air.
SCR = Selective catalytic reduction.
SNCR = Selective noncatalytic reduction.
Means data not available.
2.2-10
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Fabric Filters. Fabric filter systems (also called baghouses) filter particles through fabric
filtering elements (bags). Particles are caught on the surface of the bags, while the
cleaned flue gas passes through. To minimize pressure drop, the bags must be cleaned
periodically as the dust layer builds up. Fabric filters can achieve the highest particulate
collection efficiency of all particulate control devices. A trend toward using more fabric
filters in the electric utility industry is expected because of increasing restrictions on
emissions of PM10 and the growing use of dry SO2 control technologies, such as dry
injection and spray drying (Buonicore and Davis, 1992).
Multiple Cyclones. The cyclone (also known as a "mechanical collector") is a
particulate control device that uses gravity, inertia, and impaction to remove particles
from the flue gas. A multiple cyclone consists of numerous small-diameter cyclones
operating in parallel. Multiple cyclones are less expensive to install and operate than
ESPs and fabric filters, but are not as effective at removing particulates. They are often
used as precleaners to remove the bulk of heavier particles from the flue gas before it
enters the main control device. They are often used on wood-fired boilers in series with
scrubbers, ESPs, or fabric filters (Buonicore and Davis, 1992).
Venturi Scrubbers. Venturi scrubbers (sometimes referred to as high-energy wet
scrubbers) are used to remove coarse and fine PM. Flue gas passes through a venturi
tube while low-pressure water is added at the throat. The turbulence in the venturi tube
promotes intimate contact between the particles and the water. The wetted particles and
droplets are collected in a cyclone spray separator (sometimes called a cyclonic
demister). Venturi scrubbers are often used on wood-fired boilers. Venturi scrubbers
have a relatively high pressure drop, often ranging from 25 to 50 inches of water.
Sulfur Dioxide Control
Dry Scrubbers. Dry scrubbing is sometimes referred to as spray drying or spray
absorption. It involves spraying a highly atomized slurry of an alkaline reagent (slaked
lime) into the hot flue gas to absorb the SO2. Unlike wet scrubbers, the dry scrubber is
positioned before the dust collector. Dry scrubbers are often applied on smaller
industrial boilers, waste-to-energy plants, and units burning low-sulfur fuels (Stultz and
Kitto, 1992).
Wet Scrubbers. In wet scrubbers, an alkaline liquid solution is introduced into the flue
gas. Wet scrubbing results in the generation of wet waste, which typically must be
treated and disposed of in accordance with landfill and wastewater regulations.
Limestone scrubbing is widely used on coal-fired utility boilers. Less common are
regenerable systems that treat the absorber product to recover reagents, sometimes
producing salable gypsum, elemental sulfur, or sulfuric acid.
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Low-Sulfur Fuel. This approach to reducing SO2 emissions reduces the sulfur fed to the
combustor by burning low-sulfur coals or oils. Fuel blending is the process of mixing
high-sulfur-content fuels with low-sulfur-content fuels. The goal of effective fuel
blending is to meet the blend specification, including sulfur content, heating value,
moisture content, and (for coal) grindability. This practice is highly effective since most
studies estimate that over 95 percent of the fuel sulfur is converted to SO2 during
combustion. The minor amount of sulfur not converted is typically bound in the ash.
High-alkali coal tends to bind more SO2 in the ash.
Nitrogen Oxides Control
Selective Catalytic Reduction. SCR is an add-on control technology that catalytically
promotes the reaction between ammonia and NOX to form nitrogen (N2) and water.
SCR is currently used primarily with natural gas- and oil-fired boilers. In addition,
several SCR systems have recently been installed on coal-fired boilers. If sulfur is
present in the fuel, ammonium sulfate and bisulfate can form at around 500°F and can
deposit on and foul the catalyst. If chlorine is present, ammonium chloride can form at
around 250°F and result in a visible plume.
Selective Noncatalytic Reduction. SNCR technologies inject a reducing agent into
NOx-laden flue gas to reduce the NOX to N2 and water (H2O). Two basic processes are
currently available, one based on ammonia injection (Thermal DeNOx®), and one based
on urea injection (sponsored by the Electric Power Research Institute [EPRI]). Both
systems require careful attention to the problem of unreacted ammonia, which can form
corrosive ammonia salts that damage downstream equipment.
Low NOX Burners and Overfire Air. LNB and OFA have been demonstrated to be
effective means of lowering NOX production at utility boilers. These are combustion
control methods that reduce peak temperatures in the combustion zone, reduce the gas
residence time in the high-temperature zone, and provide a rich fuel/air ratio in the
primary flame zone. This is considered a design change although it results in a reduction
of emissions.
Low Excess Air. LEA is another combustion modification designed to lower NOX
emissions by inhibiting the creation of thermal NOX. This is accomplished by limiting the
amount of free nitrogen in the combustion zone. Excess air must be present to ensure
good fuel use and to prevent smoke formation.
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VOC Control
Boilers do not have controls for organics or VOCs since the combustion process destroys
most organic pollutants. Boilers do have residual amounts of organics and HAPs in their
exhaust streams, which may be reduced by some add-on controls such as scrubbers used
to control other pollutants.
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2.2-14 EHP Volume II
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OVERVIEW OF AVAILABLE METHODS
FOR ESTIMATING EMISSIONS
3.1 EMISSION ESTIMATION METHODOLOGIES
Several methodologies are available for calculating emissions from boilers. The method
used is dependent upon available data, available resources, and the degree of accuracy
required in the estimate. In general, site-specific data that are representative of normal
operation at that site are preferred over industry-averaged data such as AP-42 emission
factors. For purposes of calculating peak season daily emissions for SIP inventories,
refer to the EPA Procedures manual (EPA, May 1991)
This section discusses the methods available for calculating emissions from boilers and
identifies the preferred method of calculation on a pollutant basis. This discussion
focuses on estimating emissions from fuel combustion. Emission estimation approaches
for auxiliary processes, such as using EPA's TANKS program to calculate storage tank
emissions, are briefly discussed in Chapter 1 of this volume.
3.1.1 CONTINUOUS EMISSION MONITORING SYSTEM (CEMS)
A CEMS provides a continuous record of emissions over an extended and uninterrupted
period of time. Various principles are employed to measure the concentration of
pollutants in the gas stream; they are usually based on photometric measurements. Once
the pollutant concentration is known, emission rates are obtained by multiplying the
pollutant concentration by the volumetric stack gas flow rate. The accuracy of this
method may be problematic at low pollutant concentrations.
3.1.2 PREDICTIVE EMISSION MONITORING (PEM)
PEM is based on developing a correlation between pollutant emission rates and process
parameters and could be considered a hybrid of continuous monitoring, emission factors,
and stack tests. A correlation test must first be performed to develop this relationship.
Emissions at a later time can then be estimated or predicted using process parameters to
predict emission rates based on the results of the initial source test. For example,
emissions from a boiler controlled by an SO2 scrubber could be predicted, based on the
correlation of the scrubbing solution to the pH and flow rate.
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3.1.3 STACK SAMPLING
Stack sampling provides a "snapshot" of emissions during the period of the test. Samples
are collected using probes inserted into the stack, and pollutants are collected in or on
various media and sent to a laboratory for analysis or analyzed on-site by continuous
analysis. Pollutant concentrations are obtained by dividing the amount of pollutant
collected during the test by the volume of the sample. Emission rates are then
determined by multiplying the pollutant concentration by the volumetric stack flow rate.
Only experienced stack testers should perform the stack tests. The accuracy of this
method may be problematic at low pollutant concentrations.
3.1.4 FUEL ANALYSIS
Fuel analysis data can be used to predict emissions by applying mass conservation laws.
For example, if the concentration of a pollutant, or pollutant precursor, in a fuel is
known, emissions of that pollutant can be calculated by assuming that all of the pollutant
is emitted. This approach is appropriate for pollutants such as metals, SO2, and CO2. It
should be noted, however, that some of the pollutant may end up in physical or chemical
states (ash, unburned hydrocarbons, etc.) not emitted to the atmosphere.
3.1.5 EMISSION FACTORS
Emission factors are available for many source categories and are based on the results of
source tests performed at one or more facilities within an industry. Basically, an
emission factor is the pollutant emission rate relative to the level of source activity.
Chapter 1 of this volume contains a detailed discussion of the reliability, or quality, of
available emission factors. EPA provides compiled emission factors for criteria and
HAPs inAP-42, the locating and estimating (L&E) series of documents, and the Factor
Information Retrieval (FIRE) System.
3.2 COMPARISON OF AVAILABLE EMISSION ESTIMATION
METHODOLOGIES
Table 2.3-1 identifies the preferred and alternative emission estimation approach for
selected pollutants. For many of the pollutants emitted from boilers, several of the
previously defined emission estimation methodologies can be used.
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CHAPTER 2 - BOILERS
TABLE 2.3-1
SUMMARY OF PREFERRED AND ALTERNATIVE EMISSION
ESTIMATION METHODS FOR BOILERS
Parameter
S02
NOX
CO
CO2
VOC
THC
PM
PM10
Preferred Emission
Estimation Approach
Fuel analysis6
CEMS/PEM data
CEMS/PEM data
CEMS/PEM data
Stack sampling data
CEMS/PEM data
Stack sampling data
Stack sampling data
Alternative Emission
Estimation Approach"
1. CEMS/PEM
2. Stack sampling data
3. EPA/state published
emission factors
1. Stack sampling data
2. EPA/state published
emission factors
1. Stack sampling data
2. EPA/state published
emission factors
1. Stack sampling data
2. Fuel analysis
3. EPA/state published
emission factors
EPA/state published
emission factors
1. Stack sampling data
2. EPA/state published
emission factors
EPA/state published
emission factors
EPA/state published
emissions factors
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TABLE 2.3-1
(CONTINUED)
Parameter
Heavy metals
Speciated organics
Sulfuric acid mist
Flow rate
Preferred Emission
Estimation Approach
Fuel analysis'*
Stack sampling data
Stack sampling data
CFRMe data/stack
sampling data
Alternative Emission
Estimation Approach*
1. Stack sampling data
2. EPA/state published
emission factors
EPA/state published
emission factors
EPA/state published
emission factors
1. Stack sampling data
2. EPA/state published
emission factors
a In most cases, there are several alternative emission estimation approaches.
Use when no control device is present; otherwise use CEMS.
c THC = Total hydrocarbons.
d Use when no control device is present; otherwise use stack sampling data.
e CFRM = Continuous flow rate monitor.
2.3-4
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The preferred method for estimating boiler emissions is to use some form of direct or
indirect measurement. This includes stack samples using a standard EPA reference
method or other method of known quality, CEMS, or PEM. None of these approaches
is inherently better than the other. The preferred method is determined by the time
specificity of the emission estimate (i.e., is an average acceptable or is the value on a
given day needed?) and the data quality; the quality of the data will depend on a variety
of factors including the number of data points generated, the representativeness of those
data points, and the proper operation and maintenance of the equipment being used to
record the measurements.
The main use of CEMS/PEM is to show compliance on an hourly or daily (or other
short-term) basis. Therefore, average estimates of emissions are not acceptable for this
purpose. If the objective is to estimate annual emissions or average daily emissions,
CEMS/PEM do not necessarily produce better results than stack sampling data.
Although CEM data are expected to provide a continuous record of emissions,
malfunctions in the CEMS or the data recording may provide an incomplete record. If
the data capture does not cover a representative set of operating conditions of the boiler,
using the CEMS data to estimate annual emissions may give poor results.
In general, stack samples using an EPA reference method will give the highest quality
(most accurate) data for any given point in time. The performance of CEMS and PEM
is measured with respect to the EPA reference method using an index known as relative
accuracy (RA). The RA for CEMS or PEM is generally expressed as a percentage, and
should have been quantified for any CEMS/PEM installed for regulatory compliance
purposes. Also, the stack sampling data used to establish RA should be available; if the
standard error of the sample data is greater than the RA, and if the CEMS is known to
be adequately maintained, the CEMS data should be used to calculate emissions for any
averaging period. Otherwise, the most recent stack sampling data may give results that
are as good as the CEMS data. The same discussion applies to PEM. For more
discussion of statistical measures of uncertainty and data quality, refer to the Quality
Assurance Source Document (Chapter 3, Section 7, and Chapter 4).
3.2.1 CEMS
The use of site-specific CEMS data is preferred for estimating NOX, CO, CO2, and total
hydrocarbon (THC) emissions because it provides a detailed record of emissions over
time. SO2 is the only pollutant that can be measured using CEMS where a CEMS may
not be the preferred method. This is due to the fact that if the amount of sulfur in the
fuel is monitored, SO2 emissions may be calculated using the results of fuel analysis.
Other alternative methods available to estimate emissions of these pollutants provide
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only short-term emissions data (in the case of stack sampling) or industry averages (in
the case of emission factors) that may not be accurate or representative for a specific
source.
Instrument calibration drift can be problematic for CEMS and uncaptured data can
create long-term incomplete data sets. However, it is misleading to assert that a
snapshot (stack sampling) can better predict long-term emission characteristics. It is the
responsibility of the source owner to properly operate, calibrate, and validate the
monitoring equipment and the corresponding emission data.
The preferred approach for obtaining stack gas flow rate is through the use of
continuous monitoring. While flow rate can be measured using short-term stack
sampling measurements, continuous monitoring provides more accurate long-term data.
3.2.2 PEM
PEM is a predictive emission estimation methodology whereby emissions are correlated
to process parameters based on demonstrated correlations between emissions and
process parameters. For example, testing may be performed on a boiler stack while the
boiler is operated at various loads. Parameters such as fuel usage, steam production,
and furnace temperature are monitored during the tests. These data are then used to
produce emission curves. Periodic stack sampling may be required to verify that the
emission curves are still accurate or to develop new curves based on the test results.
3.2.3 STACK SAMPLING
Stack sampling is the preferred emission estimation methodology for PM, PM10,
speciated organics, and sulfuric acid mist. There are currently no CEMS methods for
measuring these pollutants so the use of short-term, site-specific information is preferred
over using emission factors that provide averaged emission data for a particular industry.
3.2.4 FUEL ANALYSIS
Site-specific fuel analysis is the preferred emission estimation methodology for SO2 and
metals when air pollution control equipment (e.g., scrubber, ESP) are not installed. In
cases where control equipment is installed, fuel analysis may be preferred if accurate
data are available on pollutant-specific collection efficiencies and the amount of
pollutant present in bottom ash and fly ash are known. Once the concentrations of
sulfur and metals in a fuel are known, their emissions can be calculated based on mass
conservation laws. While emission factors are available for SO2 and most metals, the use
of site-specific fuel analysis data provides a more accurate emission estimate. Fuel
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analysis may also be used to calculate CO2 emissions by assuming complete conversion of
the carbon in the fuel to CO2.
3.2.5 EMISSION FACTORS
Due to their availability and acceptance in the industry, emission factors are commonly
used to prepare emission inventories. However, the emission estimate obtained from
using emission factors is based upon emission testing performed at similar facilities and
may not accurately reflect emissions at a single source. Thus, the user should recognize
that, in most cases, emission factors are averages of available industry-wide data with
varying degrees of quality and may not be representative for an individual facility within
that industry.
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2.3-8 EIIP Volume II
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PREFERRED METHODS FOR
ESTIMATING EMISSIONS
The preferred method for estimating emissions of most pollutants emitted from boilers is
usually the use of site-specific information (either CEMS data, PEM data, or recent stack
tests). This section provides an outline for calculating emissions from boilers based on
raw data collected by the CEMS and stack tests. The CEMS is usually used to measure
SO2, NO^ THC, CO, flow rate, and a diluent, which can be either oxygen (O2) or CO2.
While CEMS data may be used to estimate SO2 emissions, the preferred emission
estimation method for SO2 is the use of fuel analysis data for the reasons stated in
Section 3. Fuel analysis is also the preferred method for estimating emissions of metals.
For PM, sulfuric acid mist, and speciated organic emissions, the preferred emission
estimation method is the use of stack sampling test data. Table 2.4-1 lists the variables
and symbols used in the following discussion.
4.1 EMISSION CALCULATIONS USING CEMS DATA
To monitor SO2, NOX, THC, and CO emissions using a CEMS, a facility uses a pollutant
concentration monitor, which measures concentration in parts per million by volume dry
air (ppmvd). Flow rates are measured using a volumetric flow rate monitor or they can
be estimated based on heat input using fuel factors.
Table 2.4-2 presents an example output from a boiler using a CEMS consisting of SO2,
NO^ CO, O2, and flow rate monitors. The output usually includes pollutant
concentration in parts per million (ppm) and emission rates in pounds per hour (Ib/hr).
The measurements presented in Table 2.4-2 represent a "snapshot" of a boiler's
operation; in this case, over a time period of 1 hour and 45 minutes. From these data, it
is possible to determine that between 11:00 a.m. and noon, emissions of SO2 totaled
6,525 Ib. Assuming the CEMS operates properly all year long, an accurate emission
estimate can be made by summing the hourly emission estimates.
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TABLE 2.4-1
LIST OF VARIABLES AND SYMBOLS
Variable
Concentration
Molecular weight
Molar volume
Flow rate
Hourly emissions
Heat input rate
Annual heat input
rate
Annual emissions
Higher heating value
Fuel factor (dry)
Filter catch
Metered volume
Fuel flow
Annual fuel use
Emission factor
Annual Op hours
Symbol
C
MW
V
Q
Ex
Hin
TT
nin,ann
^tpy,x
HHV
Fd
cf
vm
Or
Qf,ann
EFX
OpHrs
Units
parts per million by volume dry air (ppmvd)
Ib/lb-mole
cubic feet (ft3)/lb-mole
dry standard cubic feet per minute (dscfm)
or actual cubic feet per minute (acfm)
typically Ib/hr of pollutant x
million British thermal units (Btu) per hour
(MMBtu/hr)a
MMBtu/yr
tons per year (tpy) of pollutant x
Btu/lb
dscf/MMBtu at 0% O2
g
ft3
typically, Ib/hr
Ib/yr
typically Ib/MMBtu, lb/ft3, or Ib/gal of
pollutant x
annual operating hours (hr/yr)
8 MMBtu = 106 Btu.
2.4-2
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<6
TABLE 2.4-2
EXAMPLE GEMS OUTPUT FOR A BOILER BURNING No. 6 FUEL OIL
§
o>
Period
11:00
11:15
11:30
11:45
12:00
12:15
12:30
12:45
«2
(%V)
2.1
2.0
2.1
1.9
1.9
1.8
2.0
2.0
S02(C)
(ppmvd)
1,004.0
1,100.0
1,050.0
1,070.0
1,070.0
1,050.0
1,100.0
1,078.0
NO,
(Q
(ppmvd)
216.2
200.6
216.7
220.5
213.8
214.0
209.1
210.8
CO(C)
(ppmvd)
31.5
25.5
25.1
20.8
19.4
19.4
21.5
50.3
Fuel
Rate
&
(10%/hr)
46.0
46.5
46.0
46.2
46.8
46.3
46.3
46.5
Stack Gas
Flow Rate
(Q)
(dscfm)
155,087
155,943
155,087
154,122
156,123
153,647
155,273
155,943
Emissions
S02m
(Ib/MMBtu)
1.9
2.0
2.0
2.0
2.0
1.9
2.0
2.0
NO/
(Ib/MMBtu)
0.4
0.4
0.4
0.4
0.4
0.4
0.4
0.4
S02
(Ib/hr)
1,551
1,709
1,622
1,643
1,664
1,607
1,701
1,675
NOX
(Ib/hr)
334
312
335
338
332
328
323
327
Based on a fuel heating value of 18,000 Btu/lb.
to
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CHAPTER 2 - BOILERS 6/14/96
4.1.1 CALCULATING HOURLY EMISSIONS FROM CONCENTRATION MEASUREMENTS
Although CEMS can report real-time hourly emissions automatically, it may be necessary
to manually estimate predicted annual emissions from hourly concentration data. This
section describes how to calculate emissions from raw CEMS concentration data.
Hourly emissions can be based on concentration measurements as shown in
Equation 2.4-1.
E = (C * MW * Q * 60) (241)
(V * 106)
where:
60 = 60 min/hr
Ex = Hourly emissions in Ib/hr of pollutant x
C = Pollutant concentration in ppmvd
MW = Molecular weight of the pollutant (Ib/lb-mole)
Q = Stack gas volumetric flow rate in dscfrn
V = Volume occupied by 1 mole of ideal gas at standard
temperature and pressure (385.5 ft3/lb-mole @ 68°F and 1 atm)
4.1.2 CALCULATING STACK GAS FLOW RATE
When direct measurements of stack gas flow rates are not available, Q can be calculated
using fuel factors (F factors) according to EPA Method 19 as shown below.
r\ n 20.9 Hjn /-, A <,\
Q = FH * * —_ (2-4-2)
d (20.9 - %02) 60
where:
Fd = Fuel factor, dry basis (from EPA Method 19)
%O2 = Measured oxygen concentration, dry basis expressed as a percentage
Hin = Heat input rate in MMBtu/hr
The F factor is the ratio of the gas volume of the products of combustion to the heat
content of the fuel. Fd includes all components of combustion less water. Fd can be
calculated from fuel analysis results using the following equation:
2.4-4 EIIP Volume II
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6/14/96 CHAPTER 2 - BOILERS
_ 106 [3.64(%H)+1.53(%C) +0.57(%S) ->-0.14(%N) -0.46(%O)] (2.4-3)
"
d HHV
where:
H, C, S, N, and O = Concentrations of hydrogen, carbon, sulfur, nitrogen,
and oxygen in the fuel expressed as a percentage as
determined by a fuel analysis
HHV = Higher heating value of the fuel in Btu/lb
Fuel heating values are available in publications such as Steam, Its Generation and Use
(Stultz and Kitto, 1992). The average Fd factors are provided in EPA Reference
Method 19 for different fuels and are shown in Table 2.4-3.
4.1.3 CALCULATING EMISSION FACTORS FROM HEAT INPUT
Sometimes it is desirable to calculate emissions in terms of pounds of pollutant per unit
of heat combusted. For regulatory purposes, heat input is calculated based on the HHV
of the fuel as measured by analysis. The heat input in terms of MMBtu/hr is calculated
using:
Hio . (,4-4)
where:
Hin = Heat input rate in MMBtu/hr
Qf = Mass fuel flow rate in Ib/hr
HHV = Higher heating value in Btu/lb
An emission factor relating emissions to the heat input rate for the boiler is expressed
as:
EFX = Ex/Hjn (2.4-5)
where:
EFX = Emission factor in Ib/MMBtu of pollutant x
Ex = Emissions of pollutant x in Ib/hr
EIIP Volume II 2.4-5
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CHAPTER 2 - BOILERS
6/14/96
TABLE 2.4-3
FH FACTORS FOR VARIOUS FUELS*
Fuel Type
Coal
Anthracite0
Bituminous0
Lignite
Oild
Gas
Natural
Propane
Butane
Wood
Wood Bark
Fd
dscm/Jb
2.71 * lO'7
2.62 * ID'7
2.65 * 10'7
2.65 * lO'7
2.34 • lO"7
2.34 * lO'7
2.34 * lO'7
2.48 * lO'7
2.58 * 10'7
dscf/MMBtu
10,100
9,780
9,860
9,190
8,710
8,710
8,710
9,240
9,600
a Deterained at standard conditions: 20°C (68°F) and 760 mm Hg (29.92 in. Hg).
dscm/J = Dry standard cubic meters per joule.
c As classified according to ASTM Method D 388-77.
d Crude, residual, or distillate.
4.1.4 CALCULATING ACTUAL ANNUAL EMISSIONS
Emissions in tons per year can be calculated either by multiplying the average hourly
emission rate by the number of annual operating hours (Equation 2.4-6) or by
multiplying the average emission factor in Ib/MMBtu by the annual heat input
(Equation 2.4-8). Equation 2.4-7 shows how to calculate the annual heat input.
Example 2.4-1 depicts the use of these equations.
2.4-6
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CHAPTER 2 - BOILERS
where:
J'py.*
OpHrs/2,000
E^ = Actual annual emissions in ton/yr of pollutant x
Ex = Emissions of pollutant x in Ib/hr
OpHrs = Operating hours per year
2,000 = Ib/ton
Annual heat input may be calculated from annual fuel use using:
(2.4-6)
where:
TT
r^i
Qf,ann
HHV
H
(Q,
f,ann
HHV)
in.ann
106
Annual heat input rate in MMBtu/yr
Annual fuel flow rate in Ib/yr
Higher heating value in Btu/lb
(2.4-7)
tpy,x x in.ann
(2.4-8)
where:
E,
E
Actual annual emissions of pollutant x in ton/yr
Emission factor in Ib/MMBtu of pollutant x
EIIP Volume II
2.4-7
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CHAPTER 2 - BOILERS 6/14/96
Example 2.4-1
This example shows how SO2 emissions can be calculated based on the raw CEMS
data for 11:00 shown in Table 2.4-2. Hourly emissions are calculated using
Equation 2.4-1:
ES02 = (C * MW * Q « 60)/(V * 106)
1,004 * 64 * 155,087 * 60/(385.5 * 106)
1,551 Ib/hr
Heat input is calculated using Equation 2.4-4:
Hin = (Qf'HHV)/106
= 46,000 * 18,000/106
= 828 MMBtu/hr
An emission factor, in terms of Ib/MMBtu, is calculated using Equation 2.4-5:
EFSO2 = ESO2/Hin
1,551/828
1.9 Ib/MMBtu
Emissions in tpy (based on a 5,840 hr/yr operating schedule) can then be calculated
using Equation 2.4-6:
Etpy,so2 = ES02 * OpHrs/2,000
1,551 * (5,840/2,000)
4,529 tpy
Emissions in tpy (based on 2.69 * 108 Ib annual fuel use) can then be calculated by
first using Equation 2.4-7 to calculate annual heat input:
Hin,ann = (Qf>ann • HHV)/106
(2.69 * 108 « 18,000)/106
4.84 * 106 MMBtu/yr
(Continued)
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6/14/96 CHAPTER 2 • BOILERS
Example 2.4-1 (Continued)
Emissions in tpy (based on 4.84 * 106 MMBtu/yr) can then be calculated using
Equation 2.4-8:
E,py,so2 = EFS02 * HiMnn/2,000
1.9 * 4.84 * 106/2,000
4,598 tpy
Note that the last two calculations in Example 2.4-1 show an actual annual emission
estimate based on a single 1-hour test point and are provided as an example only.
Average values of Ex should be used to obtain a representative annual emissions
estimate.
4.2 PEM
This section outlines an example of SO2 emission monitoring that could be used to
develop a PEM protocol for a boiler equipped with a wet scrubber. Boiler and scrubber
parameters that affect emissions and that are most likely to be included in the testing
algorithm are scrubber water pH and flow rate, and fuel combustion rate.
To develop this algorithm, correlation testing of the stack gas, scrubber, and boiler
process variables could be conducted over a range of potential operating conditions using
EPA Method 6A or Method 6C to measure SO2 emissions. Potential testing conditions
are shown in Table 2.4-4. Based on the test data, a mathematical correlation can be
developed that predicts SO2 emissions using these parameters.
4.3 EMISSION CALCULATIONS USING STACK SAMPLING DATA
Stack sampling test reports often provide emissions in terms of Ib/hr or Ib/MMBtu.
Annual emissions may be calculated from these data using Equations 2.4-6 or 2.4-8 as
shown in Example 2.4-1. Stack tests performed under a proposed permit condition or a
maximum emissions rate may not accurately reflect the emissions that would result under
normal operating conditions. Therefore, when using stack sampling test data to estimate
emissions, tests should be conducted under "normal" operating conditions.
EIIP Volume II 2.4-9
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CHAPTER 2 - BOILERS
6/14/96
TABLE 2.4-4
PREDICTIVE EMISSION MONITORING ANALYSIS'
Test Number
1
2
3
4
5
6
7
8
9
Scrubber Water
Flow Rate
B
B
B
B
B
B
B
B
B
Scrubber Water pH
H
H
H
M
M
M
L
L
L
Fuel Firing Rate
H
M
L
H
M
L
H
M
L
a H = High.
M = Medium.
L = Low.
B = Baseline.
This section shows how to calculate emissions in Ib/hr based on raw stack sampling data.
Calculations involved in determining SO2 and PM10 emissions from raw EPA Method 201
data are presented in Examples 2.4-2 and 2.4-3, respectively. Because PM10 emissions
cannot be measured continuously, the best method available for measuring PM10
emissions is Method 201.
An example summary of a Method 201 test is shown in Table 2.4-5. The table shows the
results of three different sampling runs conducted during one test event. The source
parameters measured as part of a Method 201 run include gas velocity and moisture
content, which are used to determine exhaust gas flow rates in dscfm. The filter weight
gain is determined gravimetrically and divided by the volume of gas sampled as shown in
Equation 2.4-11 to determine the PM concentration in Ib/dscf. Pollutant concentration
is then multiplied by the volumetric flow rate to determine the emission rate in pounds
per hour, as shown in Equation 2.4-1.
2.4-10
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6/14/96 CHAPTER 2 - BOILERS
Example 2.4-2
This example shows how to calculate SO2 emissions when the stack gas flow rate, Q,
is not available.
The F factor for No. 6 fuel oil, based on Table 2.4-3, is 9,190 dscf/MMBtu. The
oxygen content is 2.1 percent. From Example 2.4-1, Hin is 828 MMBtu/hr. The stack
gas flow rate is calculated using Equation 2.4-9:
0 = Fd ' (20.9)/(20.9 - %02) * (Hin/60) (2.4-9)
Q = 9,190 * (20.9)/(20.9 - 2.1) * (828/60)
Q = 140,988 dscfm
Using the CEMS data from Table 2.4-2 (for 11:00) and the calculated flow rate,
hourly emissions can now be calculated using Equation 2.4-1:
Eso2 = (C * MW * Q * 60)/(V * 106) (2.4-1)
ES02 = (1,004 * 64 * 140,988 * 60)/(385.5 * 106)
lb/hr
To express the emissions in terms of pounds per unit of heat combusted, use
Equation 2.4-10:
EFS02 = Eso2/Hin (2.4-10)
EFS02 = 1,410/828
EFS02 = 1.71b/MMBtu
Note that ES02 and EFS02 calculated using F factors is slightly different than the
emissions calculated using flow rate measurements. This difference is due to different
estimation approaches; depending on the use of the data, either approach may be
acceptable.
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CHAPTER 2 - BOILERS
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TABLE 2.4-5
SAMPLE TEST RESULTS - METHOD 201
Parameter
Total sampling time (minutes)
Corrected barometric pressure (in. Hg)
Absolute stack pressure, Ps (in. Hg)
Stack static pressure (in. H2O)
Average stack temperature (°F)
Stack area (ft2)
Metered volume of sample, Vm (ft3)
Average meter pressure (in. H2O)
Average meter temperature (°F)
Moisture collected (g)
Carbon dioxide concentration (%V)
Oxygen concentration (%V)
Nitrogen concentration (%V)
Dry gas meter factor
Pilot constant
PM10 filter catch (g)
Average sampling rate (dscfm)
Standard metered volume, Vm (std) (dscf)
Standard volume water vapor, Vw (scf)
Stack moisture (%V)
Mole fraction dry stack gas
Dry molecular weight (g)
Wet molecular weight (g)
Stack gas velocity, Vs (ft/min)
Volumetric flow rate (acfm)
Volumetric flow rate (dscfm)
Percent isokinetic
Concentration of paniculate (g/dscf)
PM10 emission rate (Ib/hr)
Run 1
180.00
30.56
30.49
-0.89
328.00
113.09
116.51
0.81
69.28
258.50
15.50
2.30
82.20
1.01080
0.84
0.003
0.67
120.23
12.19
9.20
0.908
29.37
28.32
3000.00
339270
206404
96.48
0.00002
0.68
Run 2
180.00
30.56
30.49
-0.89
330.00
113.09
110.20
0.81
71.00
265.00
15.40
2.30
82.30
1.01080
0.84
0.004
0.67
121.30
13.00
9.50
0.908
29.37
28.32
2950.00
333616
201791
97.00
0.00003
0.90
Run 3
180.00
30.56
30.49
-0.89
335.00
113.09
115.30
0.81
70.20
261.00
15.30
2.30
82.40
1.01080
0.84
0.003
0.67
118.50
12.50
9.60
0.908
29.37
28.32
2965.00
335312
201319
98.00
0.00003
0.69
2.4-12
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Ex = (Q/VJ * Q * 60/453.6 (2.4-11)
where:
Ex = Emissions of pollutant x in Ib/hr
Cf = Filter catch (g)
Vm = Metered volume of sample (ft3)
Q = Stack gas volumetric flow rate (dscfm)
60 = 60 min/hr
453.6 = 453.6 g/lb
Example 2.4-3
This example shows how PM10 emissions may be calculated using Equation 2.4-11
and the stack sampling data for Run 1 (presented in Table 2.4-5).
E = (Cyvj • Q • 60/453.6
(0.003/120.23) ' 206,404 * 60/453.6
0.68 Ib/hr
4.4 EMISSION CALCULATIONS USING FUEL ANALYSIS DATA
Fuel analysis can be used to predict emissions based on application of conservation laws.
The presence of certain elements in fuels may be used to predict their presence in
emission streams. This includes toxic elements such as metals found in coal as well as
other elements such as sulfur that may be converted to other compounds during the
combustion process.
The basic equation used in fuel analysis emission calculations is:
MW
E = Q * Pollutant concentration in fuel .*
p
MWf
(2.4-12)
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CHAPTER 2 - BOILERS 6/14/96
where:
Qf = Fuel flow rate (Ib/hr)
MWp = Molecular weight of pollutant emitted (Ib/lb-mole)
MWf = Molecular weight of pollutant in fuel (Ib/lb-mole)
For example, SO2 emissions from oil combustion can be calculated based on the
concentration of sulfur in the oil. This approach assumes complete conversion of sulfur
to SO2. Therefore, for every pound of sulfur (MW = 32 g) burned, 2 Ib of SO2
(MW = 64 g) are emitted. The application of this emission estimation technique is
shown in Example 2.4-4.
Example 2.4-4
This example shows how SO2 emissions can be calculated from oil combustion based
on fuel analysis results and the fuel flow information provided in Table 2.4-2.
ESQJ may be calculated using Equation 2.4-12.
Qf = 46,000 Ib/hr
Percent sulfur (%S) in fuel = 1.17
Eso2 = Of * Pollutant concentration in fuel * (MW /MWf)
(46,000) * (1.17/100) * (64/32)
1,076 Ib/hr
2.4-14 EIIP Volume II
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ALTERNATIVE METHODS FOR
ESTIMATING EMISSIONS
5.1 EMISSION FACTOR CALCULATIONS
Emission factors are commonly used to calculate emissions when site-specific stack
monitoring data are unavailable. The EPA maintains a compilation of emission factors
in AP-42 (EPA, January 1995) for criteria pollutants and HAPs. The most
comprehensive source for toxic air pollutant emission factors is the FIRE data system
(EPA, June 1995). FIRE also contains emission factors for criteria pollutants.
Much work has been done recently on developing emission factors for HAPs and recent
AP-42 revisions have included these factors. In addition, many states have developed
their own HAP emission factors for certain source categories and may require their use
in any inventories including HAPs. Refer to Chapter 1 of Volume II for a complete
discussion of available information sources for locating, developing, and using emission
factors as an estimation technique.
Emission factors developed from measurements for a specific boiler may sometimes be
used to estimate emissions at other sites. For example, a company may have several
boilers of a similar model and size; if emissions were measured from one boiler, a factor
can be developed and applied to the other boilers. It is advisable to have the factor
approved by state/local agencies or by the EPA.
The basic equation used in emission factor emissions calculations is:
Ex = EFX * Activity Rate (2.5-1)
where:
Ex = Emissions of pollutant x
EFV = Emission factor
X
In cases where more than one fuel type is used, annual emissions should be calculated
using appropriate emission factors and proportioned based on the amount of each type
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CHAPTER 2 - BOILERS 6/14/96
In cases where more than one fuel type is used, annual emissions should be calculated
using appropriate emission factors and proportioned based on the amount of each type
of fuel used. Examples 2.5-1 and 2.5-2 show the use of Equations 2.5-1.
Example 2.5-1
This example shows how CO emissions may be calculated for No. 6 oil combustion
based on the boiler fuel rate information provided in Table 2.4-2 and a CO
emission factor from AP-42, Table 1.3-2, for No. 6 fuel oil.
Ex = EFX « Activity Rate (Qf)
EFCO = Slb/H^gal
Qf = (46.0 * 103 Ib/hr) * 1 gal/8 Ib
5,750 gal/hr
5/105 * 5,750
5.2 EMISSION CALCULATIONS USING RULE EFFECTIVENESS
Some emission inventories, such as SIP Base Year inventories, may require incorporation
of the concept of rule effectiveness (RE). RE is an adjustment to estimated emission
data to account for emission underestimates due to compliance failures. The RE
adjustment accounts for known underestimates due to noncompliance with existing rules,
control equipment downtime, operating problems, and/or process upsets. The concepts
and philosophy behind RE are discussed in Chapter 1, Section 6, of this volume,
Introduction to Stationary Point Source Emission Inventory Development. Additional
information on the application of RE can be found in Guidelines for Estimating and
Applying Rule Effectiveness for Ozone/CO State Implementation Plan Base Year Inventories
(EPA, November 1992). Example 2.5-3 presents an application of RE to boiler emission
estimates.
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CHAPTER 2 - BOILERS
Example 2.5-2
This example shows how chromium emissions may be calculated for No. 6 oil
combustion based on a heat input rate of 828 MMBtu/hr and a chromium
emission factor from FIRE for SCC 1-01-004-01.
EF(chromium)
Chromium emissions
6.31 .* 10-6 Ib/MMBtu
EF(chromium) * Hin
(6.31 * 10-6) * 828
5.22 * 10'3 Ib/hr
Example 2.5-3
This example shows how the application of RE can affect the emission estimate.
This example is based on a pulverized coal-fired, dry-bottom, wall-fired boiler.
The firing rate is 6.9 ton/hr, and the SO2 emission factor is from AP-42,
Table 1.1-1. The boiler is subject to a regulation that requires that it be equipped
with a sodium carbonate wet scrubber with a control efficiency (CE) of 90 percent.
RE is set equal to 80 percent, the default value.
EF(SOx)
S
Firing rate
Uncontrolled SOX
emissions
Controlled SO,
Controlled SOX
including RE
38 (S) Ib/ton, where S = weight percent sulfur
0.70 percent
6.9 ton/hr
(EFSOx)(Activity rate)
(38)(0.7)(6.9)
183.5 Ib/hr
(EFsoJCActivity rate)(l - [CE])
(38)(0.7)(6.9)(1 - [0.9])
18 Ib/hr
(EFsox)(Activity rate)(l - [CE][RE])
(38)(0.7)(6.9)(1 - [0.9][0.8])
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2.5-4 EHP Volume II
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QUALITY ASSURANCE/QUALITY
CONTROL
The consistent use of standardized methods and procedures is essential in the
compilation of reliable emission inventories. QA and QC of an inventory is
accomplished through a set of procedures that ensure the quality and reliability of data
collection and analysis. These procedures include the use of appropriate emission
estimation techniques, applicable and reasonable assumptions, accuracy/logic checks of
computer models, checks of calculations, and data reliability checks. Chapter 3 of
Volume VI of this series describes additional QA/QC methods and tools for performing
these procedures.
Chapter 1, Introduction to Stationary Point Source Emission Inventory Development, of this
volume presents recommended standard procedures to follow that ensure the reported
inventory of this volume data are complete and accurate. Chapter 1, Section 9, should
be consulted for current EIIP guidance for QA/QC checks for general procedures,
recommended components of a QA plan, and recommended components for point
source inventories. The QA plan discussion includes recommendations for data
collection, analysis, handling, and reporting. The recommended QC procedures include
checks for completeness, consistency, accuracy, and the use of approved standardized
methods for emission calculations, where applicable. Chapter 1, Section 9, also describes
guidelines to follow in order to assure the quality and validity of the data from manual
and continuous emission monitoring methodologies used to estimate emissions.
6.1 GENERAL FACTORS INVOLVED IN EMISSION ESTIMATION
TECHNIQUES
6.1.1 STACK TESTS AND CEMS
Data collected via CEMS, PEM, or stack tests must meet quality objectives. Stack test
data must be reviewed to ensure that the test was conducted under normal operating
conditions and that data were generated according to an acceptable method for each
pollutant of interest. Calculation and interpretation of accuracy for stack testing
methods and CEMS are described in detail in Quality Assurance Handbook for Air
Pollution Measurements Systems: Volume III. Stationary Source Specific Methods (Interim
Edition) (EPA, April 1994).
The acceptance criteria, limits, and values for each control parameter associated with
EIIP Volume II 2.6-1
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CHAPTER 2 - BOILERS 6/14/96
The acceptance criteria, limits, and values for each control parameter associated with
manual sampling methods, such as dry gas meter calibration and leak rates, are
summarized in of Chapter 1 of this volume. Continuous monitoring for NO,, CO, CO2,
and THCs using various instruments is discussed in Section 3 of this chapter. QC
procedures for all instruments used to continuously collect emissions data are similar.
The primary control check for precision of the continuous monitors is daily analysis of
control standards. The CEMS acceptance criteria and control limits are also listed in
Chapter 1.
6.1.2 EMISSION FACTORS
The use of emission factors is straightforward when the relationship between process
data and emissions is direct and relatively uncomplicated. When using emission factors,
the user should be aware of the quality indicator associated with the value. Emission
factors published within EPA documents and electronic tools have a quality rating
applied to them. The lower the quality indicator, the more likely that a given emission
factor may not be representative of the source type. When an emission factor for a
specific source or category may not provide a reasonably adequate emission estimate, it
is always better to rely on actual stack test or CEMS data, where available. The
reliability and uncertainty of using emission factors as an emission estimation technique
are discussed in detail in Chapter 1 of this volume.
6.2 DATA ATTRIBUTE RATING SYSTEM (DARS) SCORES
One measure of emission inventory data quality is the DARS score (Beck et al. 1994).
Four examples are given here to illustrate DARS scoring using the preferred and
alternative methods. The DARS provides a numerical ranking on a scale of 1 to 10 for
individual attributes of the emission factor and the activity data. Each score is based on
what is known about the factor and the activity data, such as the specificity to the source
category and the measurement technique employed. The composite attribute score for
the emissions estimate can be viewed as a statement about the confidence that can be
placed in the data. For a complete discussion of DARS and other rating systems, see the
QA Source Document (Volume VI, Chapter 4) and Volume II, Chapter 1, Introduction to
Stationary Point Source Emission Inventory Development.
Each of the examples below is hypothetical. A range is given where appropriate to cover
different situations. The scores are assumed to apply to annual emissions from a boiler.
Table 2.6-1 gives a set of scores for an estimate based on CEMS/PEM data. A perfect
score of 1.0 is achievable using this method if data quality is very good. Note that
maximum scores of 1.0 are automatic for the source definition and spatial congruity
attributes. Likewise, the temporal congruity attribute receives a 1.0 if data capture is
greater than 90 percent; this assumes that data are sampled adequately throughout the
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CHAPTER 2 - BOILERS
year. The measurement attribute score of 1.0 assumes that the pollutants of interest
were measured directly. A lower score is given if the emissions are speciated using a
profile, or if the emissions are used as a surrogate for another pollutant. Also, the
measurement/method score can be less than 1.0 if the relative accuracy is poor
(e.g., > 10 percent), if the data are biased, or if data capture is closer to 90 percent than
to 100 percent.
TABLE 2.6-1
DARS SCORES: CEMS/PEM DATA"
Attribute
Measurement/method
Source definition
Spatial congruity
Temporal congruity
Weighted Score
Emission
Factor Score
0.9- 1
1.0
1.0
1.0
0.98 - 1
Activity
Data Score
0.9- 1
1.0
1.0
1.0
0.98 - 1
Composite Scores
Range
0.81 - 1
1.0
1.0
1.0
0.95 - 1
Midpoint
0.905
1.0
1.0
1.0
0.98
Comment
Lower scores given
if relative accuracy
poor (e.g.,
> 10 percent) or
data capture closer
to 90 percent.
8 Assumes data capture is 90 percent or better, and representative of entire year; monitors, sensors, and
other equipment properly maintained.
The use of stack sample data can give DARS scores as high as those for CEMS/PEM
data. However, the sample size is usually too low to be considered completely
representative of the range of possible emissions making a score of 1.0 for
measurement/method unlikely. A typical DARS score is generally closer to the low end
of the range shown in Table 2.6-2.
Two examples are given for emissions calculated using emission factors. For both of
these examples, the activity data are assumed to be measured directly or indirectly.
Table 2.6-3 applies to an emission factor developed from CEMS/PEM data from one
boiler and then applied to a different boiler of similar design and age. Table 2.6-4 gives
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TABLE 2.6-2
DARS SCORES: STACK SAMPLE DATA3
Attribute
Measurement/method
Source definition
Spatial congruity
Temporal congruity
Weighted Score
Emission
Factor Score
0.7- 1
1- 1
1 - 1
0.7- 1
0.85 - 1
Activity
Data Score
0.7- 1
1- 1
1 - 1
0.7- 1
0.85 - 1
Composite Scores
Range
0.49 - 1
1-1
1 - 1
0.49 - 1
0.75 - 1
Midpoint
0.745
1
1
0.745
0.87
Comment
Lower scores given
if emissions vary
temporally and
sample does not
cover range.
Assumes use of an EPA reference method, high quality data.
an example for an estimate made with an AP-42 emission factor. AP-42 factors are
defined for classes of boilers (based on size and fuel type); for some pollutants, the
variability in emissions among this population may be high. The AP-42 factor is a mean
and could overestimate or underestimate emissions for any single boiler in the
population. Also, the data on which some of these factors are based are often limited in
numbers and may be 10-20 years old. Thus, the confidence that can be placed in
emissions estimated for a specific boiler with a general AP-42 factor is lower than
emissions based on source-specific data.
The example in Table 2.6-3 shows that emission factors based on high-quality data from
a similar unit will typically give better results than a general factor. The main criterion
affecting the score is how similar the boiler used to generate the factor is to the target
boiler.
If sufficient data are available, the uncertainty in the estimate should be quantified. QA
methods are described in the (Volume VI, Chapter 4).
2.6-4
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6/14/96
CHAPTER 2 - BOILERS
TABLE 2.6-3
DARS SCORES: SOURCE-SPECIFIC EMISSION FACTOR"
Attribute
Measurement/method
Source definition
Spatial congruity
Temporal congruity
Weighted Score
Emission
Factor Score
0.9- 1
0.5 - 0.9
1- 1
1 - 1
0.85 - 0.98
Activity
Data Score
0.8- 1
0.8 - 0.9
1 - 1
0.5 - 0.9
0.78 - 0.95
Composite Scores
Range
0.72 - 1
0.4 - 0.81
1- 1
0.5 - 0.9
0.66 - 0.93
Midpoint
0.86
0.61
1
0.7
0.79
Comment
Factor score for
this attribute
depends entirely
on data quality.
Factor score
lowest if unit
differs much from
original source of
data.
Assumes factor developed from PEM or CEMS data from an identical emission unit (same manufacturer,
model).
EIIP Volume II
2.6-5
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CHAPTER 2 - BOILERS
6/14/96
TABLE 2.6-4
DARS SCORES: AP-42 EMISSION FACTOR"
Attribute
Measurement/method
Source definition
Spatial congruity
Temporal congruity
Weighted Score
Emission
Factor Score
0.6 - 0.8
0.5 - 0.9
0.6 - 0.8
0.5 - 0.9
0.55 - 0.85
Activity
Data Score
0.8-1
0.8 - 0.9
1 - 1
0.5 - 0.9
0.78 - 0.95
Composite Scores
Range
0.48 - 0.7
0.4 - 0.81
0.6 - 0.8
0.25 - 0.81
0.43 - 0.78
Midpoint
0.59
0.605
0.7
0.53
0.61
Comment
Score depends on
quality and
quantity of data
points used to
develop factor.
Emission factor
score will be low if
variability in
source population
is high.
Factor score lower
if geographic
location has
significant effect
on emissions.
Lower scores given
if emissions vary
temporally and
sample does not
cover range.
Assumes activity data (e.g., fuel use) or surrogate is measured directly in some manner.
2.6-6
EIIP Volume II
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DATA CODING PROCEDURES
This section describes the methods and codes available for characterizing emission
sources at boiler facilities using SCC and Aerometric Information Retrieval System
(AIRS) control device codes. Consistent categorization and coding will result in greater
uniformity among inventories. The SCCs are the building blocks on which point source
emissions data are structured. Each SCC represents a unique process or function within
a source category that is logically associated with an emission point. Without an
appropriate SCC, a process cannot be accurately identified for retrieval purposes. In
addition, the procedures described here will assist the reader preparing data for input to
a database management system. For example, the use of the SCCs provided in
Table 2.7-1 are recommended for describing boiler operations. Refer to the
Clearinghouse for Inventories and Emission Factors (CHIEF) bulletin board for a
complete listing of SCCs for boilers. While the codes presented here are currently in
use, they may change based on further refinement by the emission inventory user
community. As part of the Emission Inventory Improvement Program (EIIP), a common
emissions data exchange format is being developed to facilitate data transfer between
industry, states, and EPA.
7.1 PROCESS EMISSIONS
Use of the codes in Table 2.7-1 are recommended for describing boilers that burn
anthracite, bituminous, subbituminous, or lignite coal; oil- or natural gas-fired electric
utility boilers; peaking plants; cogeneration units; and electric utility boilers that burn
other types of fuel. More than one code may be necessary for each boiler if auxiliary
fuel is used. Auxiliary fuels such as oil are used during start-up of utility boilers, or to
sustain combustion (such as coal, oil, or natural gas used at utility boilers that
predominantly burn wood/bark or waste).
7,2 STORAGE TANKS
The codes in Table 2.7-1 are recommended to describe emissions related to fuel storage.
7.3 FUGITIVE EMISSIONS
Fugitive emissions at boiler facilities may result from coal, wood/bark, and solid/liquid
waste handling and storage. Limestone handling and storage emissions may also occur if
the facility uses limestone in control devices such as scrubbers. There are undoubtedly
sources of fugitive emissions within the facility or sources that have not been specifically
EIIP Volume II 2.7-1
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CHAPTER 2 - BOILERS 6/14/96
sources of fugitive emissions within the facility or sources that have not been specifically
discussed thus far; these should be included. Conditions vary from plant to plant, so
each specific case cannot be discussed within the context of this document.
Codes that may be used to describe fugitive emissions at boiler facilities are also
presented in Table 2.7-1. It may be necessary to use a miscellaneous fugitive emission
code for sources without a unique code. Many database systems used for inventory
management contain a comment field that may be used to describe the fugitive
emissions.
7.4 CONTROL DEVICES
The codes found in Table 2.7-2 are recommended for describing control devices used at
electric utilities and may also be applicable to control devices used at commercial and
institutional boilers. The "099" control code may be used to handle miscellaneous
control devices that do not have a unique control equipment identification code. For a
complete listing, the reader may consult the AIRS User's Guide Volume XI: AFS Data
Dictionary (AFS is AIRS Facility Subsystem) (EPA, January 1992).
2.7-2 EHP Volume It
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6/14/96
CHAPTER 2 - BOILERS
TABLE 2.7-1
SOURCE CLASSIFICATION CODES FOR BOILERS'*
Source
Description
Process Description
sec
Units
Process Emissions
Anthracite Coal
Bituminous Coal
Pulverized Coal
Pulverized Coal
Traveling Grate (Overfeed) Stoker
Traveling Grate (Overfeed) Stoker
Hand-fired
Pulverized Coal: Wet Bottom
Pulverized Coal: Wet Bottom
Pulverized Coal: Dry
Bottom/Nontangential
Pulverized Coal: Dry
Bottom/Nontangential
Pulverized Coal: Dry
Bottom/Tangential
Pulverized Coal: Dry
Bottom/Tangential
Atmospheric Fluidized Bed
Combustion: Bubbling Bed
Cyclone Furnace
Cyclone Furnace
Spreader Stoker
Spreader Stoker
Overfeed Stoker
Traveling Grate (Overfeed) Stoker
Overfeed Stoker
Underfeed Stoker
Hand-fired
Atmospheric Fluidized Bed Combustion
1-01-001-01
1-03-001-01
1-01-001-02
1-03-001-02
1-03-001-03
1-01-002-01
1-03-002-05
1-01-002-02
1-03-002-06
1-01-002-12
1-03-002-16
1-03-002-17
1-01-002-03
1-03-002-03
1-01-002-04
1-03-002-09
1-03-002-11
1-01-002-05
1-03-002-07
1-03-002-08
1-03-002-14
1-01-002-17
Tons Burned
Tons Burned
Tons Burned
Tons Burned
Tons Burned
Tons Burned
Tons Burned
Tons Burned
Tons Burned
Tons Burned
Tons Burned
Tons Burned
Tons Burned
Tons Burned
Tons Burned
Tons Burned
Tons Burned
Tons Burned
Tons Burned
Tons Burned
Tons Burned
Tons Burned
EIIP Volume II
2.7-3
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CHAPTER 2 - BOILERS
6/14/96
TABLE 2.7-1
(CONTINUED)
Source
Description
Process Description
sec
Units
Process Emission (Continued)
Bituminous Coal
(Continued)
Subbituminous Coal
Lignite Coal
Atmospheric Fluidized Bed
Combustion: Circulating Bed
Pulverized Coal: Wet Bottom
Pulverized Coal: Wet Bottom
Pulverized Coal: Dry
Bottom/Nontangential
Pulverized Coal: Dry
Bottom/Nontangential
Pulverized Coal: Dry
Bottom/Tangential
Pulverized Coal: Dry
Bottom/Tangential
Cyclone Furnace
Cyclone Furnace
Spreader Stoker
Spreader Stoker
Traveling Grate (Overfeed) Stoker
Traveling Grate (Overfeed) Stoker
Pulverized Coal: Nontangential Firing
Pulverized Coal: Nontangential
Firing
Pulverized Coal: Tangential Firing
Pulverized Coal: Tangential Firing
Cyclone Furnance
Traveling Grate (Overfeed) Stoker
Traveling Grate (Overfeed) Stoker
Spreader Stoker
Spreader Stoker
1-03-002-18
1-01-002-21
1-03-002-21
1-01-002-22
1-03-002-22
1-01-002-26
1-03-002-26
1-01-002-23
1-03-002-23
1-01-002-24
1-03-002-24
1-01-002-25
1-03-002-25
1-01-003-01
1-03-003-05
1-01-003-02
1-03-003-06
1-01-003-03
1-01-003-04
1-03-003-07
1-01-003-06
1-03-003-09
Tons Burned
Tons Burned
Tons Burned
Tons Burned
Tons Burned
Tons Burned
Tons Burned
Tons Burned
Tons Burned
Tons Burned
Tons Burned
Tons Burned
Tons Burned
Tons Burned
Tons Burned
Tons Burned
Tons Burned
Tons Burned
Tons Burned
Tons Burned
Tons Burned
Tons Burned
2.7-4
EIIP Volume II
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6/14/96
CHAPTER 2 - BOILERS
TABLE 2.7-1
(CONTINUED)
Source
Description
Process Emission \
Residual Oil
Distillate Oil
Natural Gas
Coke
Process Description
sec
Units
Continued)
Grade No. 6 Oil: Normal Firing
Grade No. 6 Oil
10-100 Million Btu/hr
< 10 Million Btu/hr
Grade No. 6 Oil: Tangential Firing
Grade No. 5 Oil: Normal Firing
Grade No. 5 Oil
Grade No. 5 Oil: Tangential Firing
Grades Nos. 1 and 2 Oil
Grades Nos. 1 and 2 Oil
10-100 Million Btu/hr
< 10 Million Btu/hr
Grade No. 4 Oil: Normal Firing
Grade No. 4 Oil
Grade No. 4 Oil: Tangential Firing
Boilers > 100 Million Btu/hr
(Nontangential)
Boilers > 100 Million Btu/hr
10-100 Million Btu/hr
Boilers < 100 Million Btu/hr
(Nontangential)
Boilers < 100 Million Btu/hr
Boiler - Tangential
All Boiler Sizes
1-01-004-01
1-03-004-01
1-03-004-02
1-03-004-03
1-01-004-04
1-01-004-05
1-03-004-04
1-01-004-06
1-01-005-01
1-03-005-01
1-03-005-02
1-03-005-03
1-01-005-04
1-03-005-04
1-01-005-05
1-01-006-01
1-03-006-01
1-03-006-02
1-01-006-02
1-03-006-03
1-01-006-04
1-01-008-01
1000 Gallons Burned
1000 Gallons Burned
1000 Gallons Burned
1000 Gallons Burned
1000 Gallons Burned
1000 Gallons Burned
1000 Gallons Burned
1000 Gallons Burned
1000 Gallons Burned
1000 Gallons Burned
1000 Gallons Burned
1000 Gallons Burned
1000 Gallons Burned
1000 Gallons Burned
1000 Gallons Burned
Million ft3 Burned
Million ft3 Burned
Million ft3 Burned
Million ft3 Burned
Million ft3 Burned
Million ft3 Burned
Tons Burned
EHP Volume II
2.7-5
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CHAPTER 2 - BOILERS
6/14/96
TABLE 2.7-1
(CONTINUED)
Source
Description
Process Description
sec
Units
Process Emission (Continued)
Liquefied Petroleum
Gas
Process Gas
Landfill Gas
Wood/Bark
Solid/Liquid Waste
Butane
Butane
Propane
Propane
Butane/Propane Mixture: Specify
Percent Butane in Comments
Butane/Propane Mixture: Specify
Percent Butane in Comments
Boilers > 100 Million Btu/hr
POTW6 Digester Gas-fired Boiler
Boilers < 100 Million Btu/hr
Other Not Classified
Landfill Gas
Bark Only
Bark-fired Boiler
Wood/Bark
Wood/Bark-fired Boiler
Wood-fired Boiler
Wood Only
Solid Waste/Specify in Comments
Specify Waste Material in Comments
Refuse-derived Fuel
Refuse-derived Fuel
Liquid Waste/Specify in Comments
1-01-010-01
1-03-010-01
1-01-010-02
1-03-010-02
1-01-010-03
1-03-010-03
1-01-007-01
1-03-007-01
1-01-007-02
1-03-007-99
1-03-008-11
1-01-009-01
1-03-009-01
1-01-009-02
1-03-009-02
1-03-009-03
1-01-009-01
1-01-012-01
1-03-012-01
1-01-012-02
1-03-012-02
1-01-013-01
1000 Gallons Burned
1000 Gallons Burned
1000 Gallons Burned
1000 Gallons Burned
1000 Gallons Burned
1000 Gallons Burned
Million ft3 Burned
Million ft3 Burned
Million ft3 Burned
Million ft3 Burned
Million ft3 Burned
Tons Burned
Tons Burned
Tons Burned
Tons Burned
Tons Burned
Tons Burned
Tons Burned
Tons Burned
Tons Burned
Tons Burned
1000 Gallons Burned
2.7-6
EIIP Volume II
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6/14/96
CHAPTER 2 - BOILERS
TABLE 2.7-1
(CONTINUED)
Source
Description
Process Description
sec
Units
Process Emission (Continued)
Solid/Liquid Waste
(Continued)
Cogeneration Units
Specify Waste Material in Comments
Waste Oil
Waste Oil
Sewage Grease Skimmings
Bituminous Coal
Subbituminous Coal
Lignite
Residual Oil
Distillate Oil
Natural Gas
Process Gas
Coke
Wood
1-03-013-01
1-01-013-02
1-03-013-02
1-03-013-03
To Be Added
To Be Added
To Be Added
To Be Added
To Be Added
To Be Added
To Be Added
To Be Added
To Be Added
1000 Gallons Burned
1000 Gallons Burned
1000 Gallons Burned
1000 Gallons Burned
Tons Burned
Tons Burned
Tons Burned
1000 Gallons Burned
1000 Gallons Burned
Million ft Burned
Million ft Burned
Tons Burned
Tons Burned
Storage Tanks
Fixed-Roof 67,000-
Barrel Fuel Tanks:
Breathing Loss
Fixed-Roof Tanks (67,000 bbl): Grade
No. 6 Oilc
Fixed-Roof Tanks (67,000 bbl): Grade
No. 5 Oil
Fixed-Roof Tanks (67,000 bbl): Grade
No. 4 Oil
Fixed-Roof Tanks (67,000 bbl): Grade
No. 2 Oil
Fixed-Roof Tanks (67,000 bbl): Grade
No. 1 Oil
4-03-010-25
4-03-010-26
4-03-010-27
4-03-010-28
4-03-010-29
1000 Gallons Storage
Capacity
1000 Gallons Storage
Capacity
1000 Gallons Storage
Capacity
1000 Gallons Storage
Capacity
1000 Gallons Storage
Capacity
EIIP Volume II
2.7-7
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CHAPTER 2 - BOILERS
6/14/96
TABLE 2.7-1
(CONTINUED)
Source
Description
Process Description
sex:
Units
Storage Tanks (Continued)
Fixed-Roof 250,000-
Barrel Fuel Tanks:
Breathing Loss
Fixed-Roof Fuel
Tanks: Working Loss
Floating-Roof 67,000-
Barrel Fuel Tanks:
Standing Loss
Fixed-Roof Tanks (250,000 bbl): Grade
No. 6 Oil
Fixed-Roof Tanks (250,000 bbl): Grade
No. 5 Oil
Fixed-Roof Tanks (250,000 bbl): Grade
No. 4 Oil
Fixed-Roof Tanks (250,000 bbl): Grade
No. 2 Oil
Fixed-Roof Tanks (250,000 bbl): Grade
No. 1 Oil
Fixed-Roof Tanks: Grade No. 6 Oil
Fixed-Roof Tanks: Grade No. 5 Oil
Fixed-Roof Tanks: Grade No. 4 Oil
Fixed-Roof Tanks: Grade No. 2 Oil
Fixed-Roof Tanks: Grade No. 1 Oil
Floating-Roof Tanks (67,000 bbl):
Grade No. 6 Oil
Floating-Roof Tanks (67,000 bbl):
Grade No. 5 Oil
Floating-Roof Tanks (67,000 bbl):
Grade No. 4 Oil
Floating-Roof Tanks (67,000 bbl):
Grade No. 2 Oil
4-03-010-65
4-03-010-66
4-03-010-67
4-03-010-68
4-03-010-69
4-03-010-75
4-03-010-76
4-03-010-77
4-03-010-78
4-03-010-79
4-03-011-25
4-03-011-25
4-03-011-67
4-03-011-68
1000 Gallons Storage
Capacity
1000 Gallons Storage
Capacity
1000 Gallons Storage
Capacity
1000 Gallons Storage
Capacity
1000 Gallons Storage
Capacity
1000 Gallons
Throughput
1000 Gallons
Throughput
1000 Gallons
Throughput
1000 Gallons
Throughput
1000 Gallons
Throughput
1000 Gallons Storage
Capacity
1000 Gallons Storage
Capacity
1000 Gallons Storage
Capacity
1000 Gallons Storage
Capacity
2.7-8
EIIP Volume II
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6/14/96
CHAPTER 2 - BOILERS
TABLE 2.7-1
(CONTINUED)
Source
Description
Process Description
sec
Units
Storage Tanks (Continued)
Floating-Roof 67,000-
Barrel Fuel Tanks:
Standing Loss
(Continued)
Floating-Roof Fuel
Tanks: Withdrawal
Loss
Floating-Roof Tanks (67,000 bbl):
Grade No. 1 Oil
Floating-Roof Tanks: Grade No. 6 Oil
Floating-Roof Tanks: Grade No. 5 Oil
Floating-Roof Tanks: Grade No. 4 Oil
Floating-Roof Tanks: Grade No. 2 Oil
Floating-Roof Tanks: Grade No. 1 Oil
4-03-011-69
4-03-011-75
4-03-011-76
4-03-011-77
4-03-011-78
4-03-011-79
1000 Gallons Storage
Capacity
1000 Gallons
Throughput
1000 Gallons
Throughput
1000 Gallons
Throughput
1000 Gallons
Throughput
1000 Gallons
Throughput
Fugitive Emissions
Coal
Limestone
Wood/Bark
Storage Bins - Coal
Open Stockpiles - Coal
Unloading - Coal
Loading - Coal
Conveyors
Storage Bins - Limestone
Open Stockpiles - Limestone
Unloading - Limestone
Loading - Limestone
Conveyors - Limestone
Storage Bins - Wood/Bark
3-05-102-03
3-05-103-03
3-05-104-03
3-05-105-03
3-05-101-03
3-05-102-05
3-05-103-05
3-05-104-05
3-05-105-05
3-05-101-05
3-07-040-01
Tons Processed
Tons Processed
Tons Processed
Tons Processed
Tons Processed
Tons Processed
Tons Processed
Tons Processed
Tons Processed
Tons Processed
Tons Processed
EIIP Volume II
2.7-9
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CHAPTER 2 - BOILERS
6/14/96
TABLE 2.7-1
(CONTINUED)
Source
Description
Process Description
sex;
Units
Fugitive Emissions (Continued)
Wood/Bark
(Continued)
Solid and Liquid
Waste
Miscellaneous
Stockpiles - Wood/Bark
Unloading - Wood/Bark
Loading - Wood/Bark
Conveyors - Wood/Bark
Storage Bins - Solid Waste
Storage Bins - Liquid Waste
Stockpile - Solid Waste
Loading - Solid Waste
Transfer - Liquid Waste
Unloading - Solid Waste *
Miscellaneous Fugitive Emissions
3-07-040-02
3-07-040-03
3-07-040-04
3-07-040-05
5-04-003-20
5-04-003-50
5-04-003-01
5-04-003-03
5-04-003-51
5-04-003-02
3-05-888-01
to 05
Tons Processed
Tons Processed
Tons Processed
Tons Processed
Tons Processed
Tons Processed
Tons Processed
Tons Processed
Tons Processed
Tons Processed
Tons Burned
a To determine which SCC is most appropriate, more detailed information can be found on the CHIEF
bulletin board.
b POTW = Publicly owned treatment works.
c bbl = Barrel.
2.7-10
EIIP Volume II
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6/14/96
CHAPTER 2 - BOILERS
TABLE 2.7-2
AIRS CONTROL DEVICE CODES"
Control Device
Wet Scrubber - High-Efficiency
Wet Scrubber - Medium-Efficiency
Wet Scrubber - Low-Efficiency
Gravity Collector - High-Efficiency
Gravity Collector - Medium-Efficiency
Gravity Collector - Low-Efficiency
Centrifugal Collector - High-Efficiency
Centrifugal Collector - Medium-Efficiency
Centrifugal Collector - Low-Efficiency
Electrostatic Precipitator - High-Efficiency
Electrostatic Precipitator - Medium-Efficiency
Electrostatic Precipitator - Low-Efficiency
Fabric Filter - High-Efficiency
Fabric Filter - Medium-Efficiency
Fabric Filter - Low-Efficiency
Mist Eliminator - High- Velocity
Mist Eliminator - Low- Velocity
Modified Furnace or Burner Design
Staged Combustion
Flue Gas Recirculation
Reduced Combustion-Air Preheating
Steam or Water Injection
Low-Excess Air Firing
Code
001
002
003
004
005
006
007
008
009
010
Oil
012
016
017
018
014
015
024
025
026
027
028
029
EIIP Volume II
2.7-11
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CHAPTER 2 - BOILERS
6/14/96
TABLE 2.7-2
(CONTINUED)
Control Device
Use of Fuel with Low Nitrogen Content
Catalytic Reduction
Selective Noncatalytic Reduction for NOX
Catalytic Oxidation - Flue Gas
Desulfurization
Dry Limestone Injection
Wet Limestone Injection
Venturi Scrubber
Wet Lime Slurry Scrubbing
Alkaline Fly Ash Scrubbing
Sodium Carbonate Scrubbing
Miscellaneous Control Device
Code
030
065
107
039
041
042
053
067
068
069
099
a Source: EPA, January 1992. Control device efficiency ranges are defined for individual pollutants in
AP-42 (EPA, January 1995).
2.7-12
EIIP Volume II
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8
REFERENCES
Beck, L.L., R.L. Peer, L.A. Bravo, Y. Van. November 3, 1994. A Data Attribute Rating
System. Presented at the Air and Waste Management Association Specialty Conference
on Emissions Inventory Issues. Raleigh, North Carolina.
Buonicore, Anthony J., and Wayne T. Davis, Editors. 1992. Chapter 1: Air Pollution
Control Engineering. Air Pollution Engineering Manual. Van Nostrand Reinhold, New
York, New York.
Cengel, Y.A., and M.A. Boles. 1989. Thermodynamics. McGraw Hill Book Company,
New York, New York.
Cooper, C.D. and F.C. Alley. 1994. Air Pollution Control, A Design Approach, 2nd Ed.
Wareland Press, Inc. Prospect Heights, Illinois.
EPA. April 1989. Estimating Air Toxic Emissions from Coal and Oil Combustion Sources.
EPA-450/2-89-001. U.S. Environmental Protection Agency, Office of Air Quality
Planning and Standards, Research Triangle Park, North Carolina.
EPA. May 1991. Procedures for the Preparation of Emission Inventories for Carbon
Monoxide and Precursors of Ozone. Volume I: General Guidance for Stationary Sources.
U.S. Environmental Protection Agency, Office of Air Quality Planning and Standards,
Research Triangle Park, North Carolina.
EPA. June 1991. Handbook: Control Technologies for Hazardous Air Pollutants.
EPA/625/6-91/014. U.S. Environmental Protection Agency, Office of Research and
Development, Washington, D.C.
EPA. January 1992. AIRS User's Guide Volume XI: AFS Data Dictionary. U.S.
Environmental Protection Agency, Research Triangle Park, North Carolina.
EPA. November 1992. Guidelines for Estimating and Applying Rule Effectiveness for
Ozone/CO State Implementation Plan Base Year Inventories. EPA-452/R-92-010.
U.S. Environmental Protection Agency, Research Triangle Park, North Carolina.
EIIP Volume II 2.8-1
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CHAPTER 2 - BOILERS 6/14/96
EPA. April 1994. Quality Assurance Handbook for Air Pollution Measurement Systems:
Volume III. Stationary Source-Specific Methods (Interim Edition). EPA-600/R-94/038c.
U.S. Environmental Protection Agency, Atmospheric Research and Exposure Assessment
Laboratory, Research Triangle Park, North Carolina.
EPA. January 1995. Compilation of Air Pollutant Emission Factors. Volume I:
Stationary Point and Area Sources, Fifth Edition, AP-42. U.S. Environmental Protection
Agency, Office of Air Quality Planning and Standards, Research Triangle Park, North
Carolina.
EPA. June 1995. Factor Information and Retrieval (FIRE) System, Version 4.0. Updated
Annually. U.S. Environmental Protection Agency. Office of Air Quality Planning and
Standards, Research Triangle Park, North Carolina.
Stultz, Steven G, and John B. Kitto, Editors. 1992. Steam, Its Generation and Use. The
Babcock & Wilcox Company, New York, New York.
2.8-2 EIIP Volume tt
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6/14/96 CHAPTER 2 - BOILERS
APPENDIX A
EXAMPLE DATA COLLECTION FORM
AND INSTRUCTIONS - BOILER
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6/14/96 CHAPTER 2 - BOILERS
EXAMPLE DATA COLLECTION FORM INSTRUCTIONS - BOILER
1. This form may be used as a work sheet to aid the plant engineer in
collecting the information necessary to calculate emissions from boilers.
The information requested on the form relates to the methods (described
in Sections 3 and 4) for quantifying emissions. This form may also be used
by the regulatory agency to assist in area-wide inventory preparation.
2. The completed forms should be maintained in a reference file by the plant
engineer with other supporting documentation.
3. The information identified on these forms is needed to generate a
complete emissions inventory. If the information requested does not apply
to a particular boiler, write "NA" in the blank.
4. If you want to modify the form to better serve your needs, an electronic
copy of the form may be obtained through the EIIP on the CHIEF bulletin
board system (BBS).
5. If rated capacity is not documented in MMBtu/hr, please enter the
capacity in Ib/hr steam produced, or other appropriate units of measure.
6. If hourly or monthly fuel use information is not available, enter the
information in another unit (quarterly or yearly). Be sure to indicate on
the form what the unit of measure is.
7. Use the comments field on the form to record all useful information that
will allow your work to be reviewed and reconstructed.
EIIP Volume II 2.A-1
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CHAPTER 2 - BOILERS 6/14/96
EXAMPLE DATA COLLECTION FORM - BOILER
GENERAL INFORMATION
Facility/Plant Name:
SIC Code:
SCC
SCC Description:
Utility
Commercial
Industrial :
Location:
County:
City:
State:
Plant Geographical Coordinates:
Latitude:
Longitude:
UTM Zone:
UTM Easting:
UTM Northing:
Contact Name:
Title:
Telephone Number:
Unit ID Number:
Permit Number:
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6/14/96 CHAPTER 2 - BOILERS
SOURCE INFORMATION COMMENTS
Unit ID:
Manufacturer:
Date Installed:
I
ated Capacity (units):
laximum Heat Input (units):
jel Type:
Qperating Schedule:
Hours/Day:
Days/Week:
Weeks/Year:
USE":
ar:
I
aximum Hourly Fuel Use (units):
onthly Fuel Use (units):
January:
February:
March:
April:
May:
June:
July:
August:
September:
October:
November:
December:
•tal Annual Fuel Use (units):
This form should be completed for each fuel type used.
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CHAPTER 2 • BOILERS 6/14/96
FIRING CONFIGURATION (Check the appropriate type)
Tangential Fired D Horizontally Fired D Vertically Fired D Pulverized Coal Fired D
Dry Bottom D Wet Bottom D
Cyclone Furnace D
Spreader Stoker D Uncontrolled D Controlled D
Overfeed Stoker D Uncontrolled D Controlled D
Underfeed Stoker D Uncontrolled D Controlled D
Hand-fired Units D
POLLUTION CONTROL EQUIPMENT (Enter control efficiency and source of information)
ESP:
Baghouse:
Wet Scrubber:
Dry Scrubber:
Spray Dryer:
Cyclone:
Other:
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6/14/96 CHAPTER 2 - BOILERS
el
:
FUEL ANALYSIS COMMENTS
lulfur Content (S):
ih Content:
el
;
itrogen Content (N):
ad Content (Pb):
i
ercury (Hg):
thers:
1
Igher Heating Value (HHV in Btu/lb):
eference (Attach Analysis if Available):
fACK INFORMATION:
Stack ID:
•nit ID:
Stack (Release) Height (feet):
ack Diameter (inch):
t
tack Gas Temperature (°F):
ack Gas Velocity (ft/sec):
I
ack Gas Flow Rate (ascf/min):
o Other Sources Share This Stack (Y/N)?:
«f yes, include Unit IDs for each).
te-specific Stack Sampling Report Available (Y/N)?:
Reference (Include Full Citation of Test Reports Used):
EIIP Volume II 2.A-5
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o\
EMISSION ESTIMATION RESULTS
i
s
Unit ID:
Fuel Type:
Pollutant
VOC
NOX
CO
S02
PM10
Total Paniculate
Hazardous Air
Pollutants (list
individually)
Emission
Estimation
Method"
Emissions
Emissions
Units
Emission
Factorb
Emission
Factor
Units
Comments
i
a Use the following codes to indicate which emission estimation method is used for each pollutant:
CEMS/PEM = CEMS/PEM
Stack Test Data = ST
Fuel Analysis = FA
Emission Factor = EF
Other (indicate) = O
Where applicable, enter the emission factor and provide the full citation of the reference or source of information from where the emission
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VOLUME II: CHAPTERS
PREFERRED AND ALTERNATIVE
METHODS FOR ESTIMATING AIR
EMISSIONS FROM HOT-MIX
ASPHALT PLANTS
July 1996
Prepared by:
Eastern Research Group, Inc.
Prepared for:
Point Sources Committee
Emission Inventory Improvement Program
-------
DISCLAIMER
This document was furnished to the Emission Inventory Improvement Program and the
U.S. Environmental Protection Agency by Eastern Research Group, Inc., Morrisville,
North Carolina. This report is intended to be a final document and has been reviewed
and approved for publication. The opinions, findings, and conclusions expressed
represent a consensus of the members of the Emission Inventory Improvement Program.
-------
ACKNOWLEDGEMENT
This document was prepared by Eastern Research Group, Inc. for the Point Sources
Committee of the Emission Inventory Improvement Program and for Dennis Beauregard
of the Emission Factor and Inventory Group, U.S. Environmental Protection Agency.
Members of the Point Sources Committee contributing to the preparation of this
document are:
Dennis Beauregard, Co-Chair, Emission Factor and Inventory Group, U.S. Environmental Protection Agency
Bill Gill, Co-Chair, Texas Natural Resource Conservation Commission
Jim Southerland, North Carolina Department of Environment, Health and Natural Resources
Denise Alston-Gulden, Galsen Corporation
Bob Betterton, South Carolina Department of Health and Environmental Control
Alice Fredlund, Louisiana Department of Environmental Quality
Karla Smith Hardison, Texas Natural Resource Conservation Commission
Gary Helm, Air Quality Management, Inc.
Paul Kim, Minnesota Pollution Control Agency
Toch Mangat, Bay Area Air Quality Management District
Ralph Patterson, Wisconsin Department of Natural Resources
EIIP Volume II 111
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IV EIIP Volume II
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CONTENTS
Section Page
1 Introduction 3.1-1
2 General Source Category Description 3.2-1
2.1 Process Description 3.2-1
2.1.1 Batch Mixing Process 3.2-2
2.1.2 Parallel Flow Drum Mixing Process 3.2-2
2.1.3 Counterflow Drum Mixing Process 3.2-3
2.2 Emission Sources 3.2-3
2.2.1 Material Handling (Fugitive Emissions) 3.2-3
2.2.2 Generators 3.2-4
2.2.3 Storage Tanks 3.2-4
2.2.4 Process Emissions 3.2-4
2.3 Process Design and Operating Factors Influencing Emissions 3.2-6
2.4 Control Techniques 3.2-8
2.4.1 Process and Process Fugitive Particulate Control
(Including Metals) 3.2-8
2.4.2 Fugitive Particulate Emissions Control 3.2-11
2.4.3 VOC (Including HAP) Control 3.2-11
2.4.4 Sulfur Oxides Control 3.2-12
2.4.5 Nitrogen Oxides Control 3.2-12
3 Overview of Available Methods 3.3-1
3.1 Description of Emission Estimation Methodologies 3.3-1
3.1.1 Stack Sampling 3.3-1
3.1.2 Emission Factors 3.3-2
3.1.3 Fuel Analysis 3.3-2
3.1.4 Continuous Emission Monitoring System (CEMS) and
Predictive Emission Monitoring (PEM) 3.3-2
3.2 Comparison of Available Emission Estimation Methodologies 3.3-3
3.2.1 Stack Sampling 3.3-3
3.2.2 Emission Factors 3.3-3
3.2.3 Fuel Analysis 3.3-3
3.2.4 CEMS and PEM 3.3-6
EIIP Volume II V
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CONTENTS (CONTINUED)
Section Page
4 Preferred Methods for Estimating Emissions 3.4-1
4.1 Emission Calculations Using Stack Sampling Data 3.4-1
4.2 Emission Factor Calculations 3.4-5
4.3 Emission Calculations Using Fuel Analysis Data 3.4-6
5 Alternative Methods for Estimating Emissions 3.5-1
5.1 Emission Calculations Using CEMS Data . 3.5-1
5.2 Predictive Emission Monitoring 3.5-4
6 Quality Assurance/Quality Control 3.6-1
6.1 Considerations for Using Stack Test and CEMS Data 3.6-1
6.2 Considerations for Using Emission Factors 3.6-4
6.3 Data Attribute Rating System (DARS) Scores 3.6-4
7 Data Coding Procedures 3.7-1
8 References 3.8-1
Appendix A: Example Data Collection Form and Instructions for Hot-Mix Asphalt
Plants
vi EIIP Volume II
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FIGURE AND TABLES
Figure Page
3.6-1 Example Emission Inventory Development Checklist for Asphalt Plants .... 6-2
Tables Page
3.2-1 Typical Hot-Mix Asphalt Plant Emission Control Techniques 3.2-9
3.3-1 Summary of Preferred Emission Estimation
Methods for Hot-Mix Asphalt Plants 3.3-4
3.4-1 List of Variables and Symbols 3.4-2
3.4-2 Test Results - Method 5 3.4-4
3.5-1 Example CEM Output for a Parallel Flow Drum Mixer
Firing Waste Fuel Oil 3.5-2
3.5-2 Predictive Emission Monitoring Analysis 3.5-6
3.6-1 DARS Scores: CEMS/PEM Data 3.6-6
3.6-2 DARS Scores: Stack Sample Data 3.6-7
o
3.6-3 DARS Scores: Source-specific Emission Factor 3.6-8
3.6-4 DARS Scores: AP-42 Emission Factor 3.6-9
3.7-1 Source Classification Codes for Asphalt Concrete Production 3.7-3
3.7-2 AIRS Control Device Codes 3.7-4
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viii EIIP Volume II
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1
INTRODUCTION
The purposes of the preferred methods guidelines are to describe emission estimation
techniques for stationary point sources in a clear and unambiguous manner and to
provide concise example calculations to aid in the preparation of emission inventories.
While emissions estimates are not provided, this information may be used to select an
emission estimation technique best suited to a particular application. This chapter
describes the procedures and recommends approaches for estimating emissions from
hot-mix asphalt (HMA) plants.
Section 2 of this chapter contains a general description of the HMA plant source
category, common emission sources, and an overview of the available control
technologies used at HMA plants. Section 3 of this chapter provides an overview of
available emission estimation methods.
Section 4 presents the preferred methods for estimating emissions from HMA plants,
while Section 5 presents the alternative emission estimation techniques. It should be
noted that the use of site-specific emission data is preferred over the use of
industry-averaged data such as AP-42 emission factors (EPA, 1995a). Depending upon
available resources, site-specific data may not be cost effective to obtain. However, this
site-specific data may be a requirement of the state implementation plan (SIP) and may
preclude the use of other data. Quality assurance and control procedures are described
in Section 6. Coding procedures used for data input and storage are discussed in
Section 7. Some states use their own unique identification codes, so individual state
agencies should be contacted to determine the appropriate coding scheme to use.
References are cited in Section 8. Appendix A provides an example data collection
form to assist in information gathering prior to emissions calculations.
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3.1-2 EHP Volume II
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GENERAL SOURCE CATEGORY
DESCRIPTION
This section provides a brief overview of HMA plants. The reader is referred to the Air
Pollution Engineering Manual (referred to as AP-40) and AP-42, 5th Edition,
January 1995, for a more detailed discussion on these facilities (AWMA, 1992; EPA,
1995a).
2.1 PROCESS DESCRIPTION
HMA paving materials are a mixture of well graded, high quality aggregate (which can
include reclaimed or recycled asphalt pavement [RAP]) and liquid asphalt cement,
which is heated and mixed in measured quantities to produce HMA. Aggregate and
RAP (if used) constitute over 92 percent by weight of the total HMA mixture. Aside
from the relative amounts and types of aggregate and RAP used, mix characteristics are
determined by the amount and grade of asphalt cement used. Additionally, the asphalt
cement may be blended with petroleum distillates or emulsifiers to produce "cold mix"
asphalt, sometimes referred to as cutback or emulsified asphalt, respectively (EPA,
1995a; Gunkel, 1992; TNRCC, 1994).
The process of producing HMA involves drying and heating the aggregate to prepare
them for the asphalt cement coating. In the drying process, the aggregate are dried in a
rotating, slightly inclined, direct-fired drum dryer. The aggregate is introduced into the
higher end of the dryer. The interior of the dryer is equipped with flights that veil the
aggregate through the hot exhaust as the dryer rotates. After drying, the aggregate is
typically heated to temperatures ranging from 275 to 325°F and then coated with asphalt
cement in one of two ways. In most drum mix plants, the asphalt is introduced directly
into the dryer chamber to coat the aggregate. In batch mix plants, the mixing of
aggregate and asphalt takes place in a separate mixing chamber called a pug mill.
The variations in the HMA manufacturing process are primarily defined by the
following types of plants:
• Batch mix plants;
• Parallel flow drum mix plants; and
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CHAPTER 3 - HOT-MIX ASPHAL T PLANTS 7/26/96
• Counterflow drum mix plants.
(Continuous mix plants, which represent a very small fraction of the plants presently
operating, are not discussed here [EPA, 1995a]. The estimation techniques described
for the batch mixing process should be followed when estimating emissions from
continuous mix plant operations.).
2.1.1 BATCH MIXING PROCESS
In the batch mixing process, the aggregate is transported from storage piles and is
placed in the appropriate hoppers of a cold feed unit. The material is metered from the
hoppers onto a conveyor belt and is transported into a rotary dryer (typically gas- or
oil-fired) (Gunkel, 1992; NAPA, 1995).
As hot aggregate leave the dryer, it drops into a bucket elevator and is transferred to a
set of vibrating screens, that drop the aggregate into individual "hot" bins according to
size. To control aggregate size distribution in the final batch mix, the operator opens
various hot bins over a weigh hopper until the desired mix and weight for individual
components are obtained. RAP may also be added at this point. Concurrent with the
aggregate being weighed, liquid asphalt cement is pumped from a heated storage tank to
an asphalt bucket, where it is weighed to achieve the desired mix.
Aggregate from the weigh hopper is dropped into the mixer (pug mill) and dry-mixed
for 6 to 10 seconds. The liquid asphalt is then dropped into the pug mill where it is
wet-mixed until homogeneous. The hot-mix is conveyed to a hot storage silo or dropped
directly into a truck and hauled to a job site.
2.1.2 PARALLEL FLOW DRUM MIXING PROCESS
The parallel flow drum mixing process is a continuous mixing type process that uses
proportioning cold feed controls for the process materials. The major difference
between this process and the batch process is that the dryer is used not only to dry
aggregate but also to mix the heated and dried aggregate with the liquid asphalt cement.
Aggregate, which has been proportioned by size gradations, is introduced to the drum at
the burner end. As the drum rotates, the aggregate, as well as the combustion products,
move toward the other end of the drum in parallel (EPA, 1995). The asphalt cement is
introduced into approximately the lower third of the drum. The aggregate are is coated
with asphalt cement as it veils to the end of the drum. The RAP is introduced at some
point along the length of the drum, as far away from the combustion zone as possible
(about the midpoint of the drum), but with enough drum length remaining to dry and
heat the material adequately before it reaches the coating zone (Gunkel, 1992). The
flow of liquid asphalt cement is controlled by a variable flow pump electronically linked
to the aggregate and RAP weigh scales (EPA, 1995a).
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2.1.3 COUNTERFLOW DRUM MIXING PROCESS
In the counterflow drum mixing process, the aggregate is proportioned through a cold
feed system prior to introduction to the drying process. As opposed to the parallel flow
drum mixing process though, the aggregate moves opposite to the flow of the exhaust
gases. After drying and heating take place, the aggregate is transferred to a part of the
drum that is not exposed to the exhaust gas and coated with asphalt cement. This
process prevents stripping of the asphalt cement by the hot exhaust gas. If RAP is used,
it is usually introduced into the coating chamber.
2.2 EMISSION SOURCES
Emissions from HMA plants derive from both controlled (i.e., ducted) and uncontrolled
sources. Section 7 lists the source classification codes (SCCs) for these emission points.
2.2.1 MATERIAL HANDLING (FUGITIVE EMISSIONS)
Material handling includes the receipt, movement, and processing of fuel and materials
used at the HMA facility. Fugitive paniculate matter (PM) emissions from aggregate
storage piles are typically caused by front-end loader operations that transport the
aggregate to the cold feed unit hoppers. The amount of fugitive PM emissions from
aggregate piles will be greater in strong winds (Gunkel, 1992). Piles of RAP, because
RAP is coated with asphalt cement, are not likely to cause significant fugitive dust
problems. Other pre-dryer fugitive emission sources include the transfer of aggregate
from the cold feed unit hoppers to the dryer feed conveyor and, subsequently, to the
dryer entrance. Aggregate moisture content prior to entry into the dryer is typically
3 percent to 7 percent. This moisture content, along with aggregate size classification,
tend to minimize emissions from these sources, which contribute little to total facility
PM emissions. PM less than or equal to 10 pm in diameter (PM10) emissions from
these sources are reported to account for about 19 percent of their total PM emissions
(NAPA, 1995).
If crushing, breaking, or grinding operations occur at the plant, these may result in
fugitive PM emissions (TNRCC, 1994). Also, fine paniculate collected from the
baghouses can be a source of fugitive emissions as the overflow PM is transported by
truck (enclosed or tarped) for on-site disposal. At all HMA plants there may be PM
and slight process fugitive volatile organic compound (VOC) emissions from the
transport and handling of the hot-mix from the mixer to the storage silo and also from
the load-out operations to the delivery trucks (EPA, 1994a). Small amounts of VOC
emissions can also result from the transfer of liquid and gaseous fuels, although natural
gas is normally transported in a pipeline (Gunkel, 1992, Wiese, 1995).
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CHAPTER 3 - HOT-MIXASPHALT PLANTS 7/26/96
2.2.2 GENERATORS
Diesel generators may be used at portable HMA plants to provide electricity.
Maximum electricity generation during process operations is typically less than
500 kilowatts per hour (kW/hr) with rates of 20-50 kW/hr at other times (Fore, 1995).
(Note that 1 kW equals 1.34 horsepower.) Emissions from these generators are likely
uncontrolled and are correlated with fuel usage, as determined by engine size, load
factor, and hours of operation. Emissions primarily include criteria
pollutants-particularly NOX and CO (EPA, 1995b).
2.2.3 STORAGE TANKS
Storage tanks are used to store fuel oils, heated liquid asphalts, and asphalt cement at
HMA plants, and may be a source of VOC emissions. Storage tanks at HMA plants are
usually fixed roof (closed or enclosed) due to the smaller size of the tanks, usually less
than 30,000 gallons (Fore, 1995; Patterson, 1995). Emissions from fixed-roof tanks
(closed or enclosed) are typically divided into two categories: working losses and
breathing losses. Working losses refer to the combined loss from filling and emptying
the tank. Filling losses occur when the VOC contained in the saturated air are
displaced from a fixed-roof vessel during loading. Emptying losses occur when air
drawn into the tank becomes saturated and expands, exceeding the capacity of the vapor
space. Breathing losses are the expulsion of vapor from a tank through vapor expansion
caused by changes in temperature and pressure. Because of the small tank sizes and
fuel usage, total VOC emissions would typically be less than 1 ton per year. Emissions
from tanks used for No. 5 or 6 oils or for asphalt cement may be increased when they
are heated to control oil viscosity. Emissions from asphalt cement tanks are particularly
low, due to its low vapor pressure.
The TANKS computer program, available from the EPA, is commonly used to quantify
emissions; however, its use should be carefully evaluated since it is a complicated
program with a great number of input parameters. Check with your local or state
authority as to whether TANKS is required for your facility. The use of the TANKS
program for calculating emissions from storage tanks is discussed in Chapter 1 of this
volume, Introduction to Stationary Point Source Emissions Inventory Development.
2.2A PROCESS EMISSIONS
The most significant source of emissions from HMA plants is the dryer (EPA, 1995a;
Gunkel, 1992; NAPA, 1995). Dryer burners capacities are usually less than 100 million
British thermal units per hour (100 MMBtu/hr), but may be as large as 200 MMBtu/hr
(NAPA, 1995; Wiese, 1995). Combustion emissions from the dryer include products of
complete combustion and products of incomplete combustion. Products of complete
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combustion include carbon dioxide (CO2), water, oxides of nitrogen (NOX), and, if sulfur
is present in the fuel, oxides of sulfur (SOX), for example sulfur dioxide (SO2). Products
of incomplete combustion include carbon monoxide (CO), VOC, including smaller
quantities of hazardous air pollutants (HAP) (e.g., benzene, toluene, and xylene), and
other organic particulate matter. These incomplete combustion emissions result from
improper air and fuel mixtures (e.g., poor mixing of fuel and air), inadequate fuel air
residence time and temperature, and quenching of the burner flame. Depending on the
fuel, small amounts of ash may also be emitted. In addition to combustion emissions,
emissions from a dryer include water and PM from the aggregate. Non-combustion
emissions from rotary drum dryers may include small amounts of VOC, polynuclear
aromatic hydrocarbons (PAH), aldehydes, and HAP from the volatile fraction of the
asphalt cement and organic residues that are commonly found in recycled asphalt
(i.e., gasoline and engine oils) (EPA, 1995a; Gunkel, 1992; TNRCC, 1994; EPA, 1991a;
NAPA, 1995).
For drum mix processes, the dryer contributes most of the facility's total PM emissions
(NAPA, 1995). At these plants, PM emissions from post-dryer processes are minimal
due to the mixing with asphalt cement.
In batch mix plants, post-dryer PM emission sources include hot aggregate screens, hot
bins, weigh hoppers, and pug mill mixers (NAPA, 1995, TNRCC, 1994). Uncontrolled
PM emissions from these sources will be greater than emissions from pre-dryer sources
primarily due to the lower aggregate moisture content in addition to the greater number
of transfer points (NAPA, 1995). Post-dryer emission sources at batch plants are usually
controlled by venting to the primary dust collector (along with the dryer gas) or
sometimes to a separate dust collection system. Captured emissions are mostly
aggregate dust, but they may also contain gaseous VOC and a fine aerosol of condensed
liquid particles. This liquid aerosol is created by the condensation of gas into particles
during the cooling of organic vapors volatilized from the asphalt cement and RAP in the
pug mill. The aerosol emissions are primarily dependent upon the temperatures of the
materials entering the mixing process. This problem appears to be more acute when the
RAP has not been preheated prior to entering the pug mill or boot of the hot elevator.
This results in a sudden, rapid release of steam resulting from evaporation of the
moisture in the RAP upon mixing it into the superheated (often above 400°F) aggregate
(EPA, 1995a; Gunkel, 1992).
Recycled tires, which are sometimes used in the production of asphalt concrete, may be
a source of VOC and PM emissions. When heated, ground up tire pieces (referred to
as crumb rubber) have been shown to emit VOC. These emissions are a function of the
quantity of crumb rubber used in the liquid asphalt and the temperature of the mix
(TNRCC, 1994).
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CHAPTER 3 - HOT-MIX ASPHALT PLANTS 7/26/96
If cutback or emulsions are used to make cold mix asphalt concrete, VOC emissions can
be significant. These emissions can occur as stack emissions from mixing of asphalt
batches and as fugitives from handling areas. Emission levels depend on the type and
quantity of the cold mix produced. VOC emissions associated with cutback asphalt
production may include naphtha, kerosene, or diesel vapors.
In some states (e.g., Wisconsin) asphalt drum dryers are used for soil remediation. In
this practice, the contaminated soil may be run through the dryer as an aggregate, cut
with virgin aggregate at ratios ranging from 1:1 to 1:10 (contaminated soil to virgin
aggregate) depending on the clay content of the material. The dried material is coated
with asphalt and "RAP" is produced. The manufactured RAP can then be fed into the
hot mix asphalt process normally, as any RAP would be, and incorporated into the final
mix. This practice can result in HAP emissions, which are a function of the HAP
content and quantity of the soil as well as the dryer temperature and residence time.
There is significant control of VOC/HAPs in the dryer drum. Based on testing
performed by the asphalt industry, a control on the average of 75 percent with numbers
ranging from 45 to 98 percent control depending on the plant type (parallel flow versus
counterflow drum designs) have been recorded. (Wiese, 1995).
2.3 PROCESS DESIGN AND OPERATING FACTORS INFLUENCING
EMISSIONS
There are two methods of introducing combustion air to the dryer burners and two types
of combustion chambers, with the combination resulting in four types of burner systems
that can be found at HMA plants. The type of burner system employed has a direct
effect on gaseous combustion emissions, including VOC, HAP, CO, and NOX. The two
types of burners related to the introduction of combustion air include the induced draft
burner and the forced draft burner. Forced draft burners are usually more fuel efficient
under proper operating and maintenance conditions and, consequently, have lower
emissions (Gunkel, 1992). The two types of burners related to the use of combustion
chambers include those with refractory-lined combustion chambers and those without
combustion chambers. While most older burners had combustion chambers, today's
burners generally do not (Gunkel, 1992).
Incomplete combustion in the dryer burner increases emissions of CO and organics
(e.g., VOC). This may be caused by: (1) improper air and fuel mixtures (e.g., poor
mixing prior to combustion); (2) inadequate residence time (i.e., too short) and
temperature (i.e., too low); and (3) flame quenching. The primary cause of CO and
organic emissions in chamberless burners is quenching of the flame caused by improper
flighting. This occurs when the flame temperature is reduced by contact with cold
surfaces or cold material dropping through the flame (NAPA, 1995). In addition, the
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7/26/96 CHAPTER 3 - HOT-MIXASPHALT PLANTS
moisture content of the aggregate in the dryer may contribute to the formation of CO
and unburned fuel emissions by reducing the temperature (Gunkel, 1992). A secondary
cause of these gaseous pollutants may be excess air entering the combustion process,
particularly in the case of an induced draft burner. The use of a precombustion
chamber to promote better fuel air mixing may reduce VOC and CO emissions.
NOX is primarily formed from nitrogen in the combustion air, thermal NOX, and from
nitrogen in the fuel, fuel NOX. Thermal NOX is negligible below 1300°C and increases
with combustion temperature (Nevers, 1995). Fuel NOX, which is likely lower than
thermal NOX from dryer burners, is formed by conversion of some of the nitrogen in the
burner fuel. While No. 4, 5 and 6 fuel oils may contain significant amounts of nitrogen,
No. 1 and 2 oils and natural gas contain very little (Nevers, 1995).
Dryer burners can be designed to operate on almost any type of fuel; natural gas,
liquefied petroleum gas (LPG), light fuel oils, heavy fuel oils, and waste fuel oils
(Gunkel, 1992). The type of fuel and its sulfur content will affect SOX, VOC, and HAP
emissions and, to a lesser extent, NOX and CO emissions. Sulfur in the burner fuel will
convert to SOX during combustion; burner operation will have little effect on the percent
of this conversion (TNRCC, 1994; EIIP, 1995). VOC emissions from natural gas
combustion are less than emissions from LPG or fuel oil combustion, which are lower
than emissions from waste-blended fuel combustion (TNRCC, 1994). Ash levels and
concentrations of most of the trace elements in waste oils are normally much higher
than those in virgin oils, producing higher emission levels of PM and trace metals.
Chlorine in waste oils also typically exceeds the levels in virgin oils. High levels of
halogenated solvents are often found in waste oil as a result of the additions of
contaminant solvents to the waste oils.
When cold mix asphalt cement is heated, organic fumes (i.e., VOC) may be released as
visible emissions if the asphalt is cut with lighter ends or other additives needed for a
specification; however, these emissions are not normally seen when heating asphalt
cement, as the boiling point of asphalt cement is much higher (Patterson, 1995). In
drum mix plants, hydrocarbon (e.g, aldehydes) and PAH emissions may result from the
heating and mixing of liquid asphalt inside the drum as hot exhaust gas in the drum
strips light ends from the asphalt. The magnitude of these emissions is a function of the
process temperatures and constituents of the asphalt being used. The mking zone
temperature in parallel flow drums is largely a function of drum length and flighting.
The processing of RAP materials, particularly in parallel flow plants, may also increase
VOC emissions, because of an increase in mixing zone temperature during processing.
In counterflow drum mix plants, the liquid asphalt cement, aggregate, and sometimes
RAP, are mixed in a zone not in contact with the hot exhaust gas stream. Consequently,
counterflow drum mix plants will likely have lower VOC emissions than parallel flow
drum mix plants. In batch mix plants, the amount of hydrocarbons (i.e., liquid aerosol)
produced depends to a large extent on the temperature of the asphalt cement and
aggregate entering the pug mill (EPA, 1995a; Gunkel, 1992).
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Particulate emissions from parallel flow drum mix plants are reduced because the
aggregate and asphalt cement mix for a longer time. The amount of PM generated
within the dryer in this process is usually lower than that generated within batch dryers,
but because the asphalt is heated to higher temperatures for a longer period of time,
organic emissions (gaseous and liquid aerosol) are typically greater than in conventional
batch plants (EPA, 1991a).
2.4 CONTROL TECHNIQUES
Control techniques and devices typically used at HMA facilities are described below and
presented in Table 3.2-1. Control efficiency for a specific piece of equipment will vary
depending not only on the type of equipment and quality of the maintenance/repair
program at a particular facility, but also the velocity of the air through the dryer.
2.4.1 PROCESS AND PROCESS FUGITIVE PARTICULATE CONTROL (INCLUDING
METALS)
Process and process fugitive particulates at HMA plants are typically controlled using
primary and secondary collection devices. Primary devices typically include cyclone and
settling chambers to remove larger PM. Smaller PM is typically collected by secondary
devices, including fabric filters and venturi scrubbers. PM from the dry control devices
is usually collected and mixed back into the process near the entry point of the asphalt
cement in drum-mix plants. In addition to PM and PM10 emissions, particulate control
also serves to remove trace metals emitted as particulate. These controls are primarily
used to reduce PM emissions from the dryer; however at batch mix plants, these
controls are also used for post-dryer sources, where fugitive emissions may be scavenged
at an efficiency of 98 percent (NAPA, 1995).
Cyclones
The cyclone (also known as a "mechanical collector") is a particulate control device that
uses gravity, inertia, and impaction to remove particles from a ducted stream. Large
diameter cyclones are often used as primary precleaners to remove the bulk of heavier
particles from the flue gas before it enters a secondary or final collection system. A
secondary collection device, which is more effective at removing particulates than a
primary collector, is used to capture remaining PM from the primary collector effluent.
In batch plants, cyclones are often used to return collected material to the hot elevator
and to combine it with the drier virgin aggregate (EPA, 1995a; Gunkel, 1992;
Khan, 1977: NAPA, 1995.
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TABLE 3.2-1
TYPICAL HOT-MIX ASPHALT PLANT EMISSION CONTROL TECHNIQUES
Emission Source
Process
Fugitive dust
Pollutant
PMand
PM10
voc
sox
PMand
PM10
Control Technique
Cyclones
Multiple cyclones
Settling chamber
Baghouse
Venturi scrubber
Dryer and combustion
process modifications
Limestone
Low sulfur fuel
Paving and maintenance
Wetting and crusting
agents
Crushed RAP material,
asphalt shingles
Typical Efficiency
(%)
50 - 75a'b
90°
<50b
99 - 99.97a'd
90 - 99.5d'e
37 - 86f-g
50b-e
80°
60 - 99g
70b - 80*
70h
a Control efficiency dependent on particle size ratio and size of equipment.
b Source: Patterson, 1995c.
c Source: EHP, 1995.
d Typical efficiencies at a hot-mix asphalt plant.
e Source: TNRCC, 1995.
f Source: Gunkel, 1992.
g Source: TNRCC, 1994.
h Source: Patterson, 1995a.
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Multiple Cyclones
A multiple cyclone consists of numerous small-diameter cyclones operating in parallel.
Multiple cyclones are less expensive to install and operate than fabric filters, but are not
as effective at removing smaller particulates. They are often used as precleaners to
remove the bulk of heavier particles from the flue gas before it enters the main control
device (EPA, 1995a; Gunkel, 1992; Khan, 1977).
Settling Chambers
Settling chambers, also referred to as knock-out boxes, are used at HMA plants as
primary dust collection equipment. To capture remaining PM, the primary collector
effluent is ducted to a secondary collection device such as a baghouse, which is more
effective at removing particulates (EPA, 1995a, Khan, 1977).
Baghouses
Baghouses, or fabric filter systems, filter particles through fabric filtering elements
(bags). Particles are caught on the surface of the bags, while the cleaned flue gas passes
through. To minimize pressure drop, the bags must be cleaned periodically as the dust
layer builds up. Fabric filters can achieve the highest paniculate collection efficiency of
all particulate control devices. Most HMA plants with baghouses use them for process
and process fugitive emissions control. The captured dust from these devices is usually
returned to the production process (EPA, 1995a; Gunkel, 1992).
Venturi Scrubbers
Venturi scrubbers (sometimes referred to as high energy wet scrubbers) are used to
remove coarse and fine particulate matter. Flue gas passes through a venturi tube while
low pressure water is added at the throat. The turbulence in the venturi promotes
intimate contact between the particles and the water. The wetted particles and droplets
are collected in a cyclone spray separator (sometimes called a cyclonic demister).
Venturi scrubbers are often used in similar applications to baghouses (EPA, 1995a;
Gunkel, 1992).
In addition to controlling particulate emissions, the venturi scrubber is likely to remove
some of the process organic emissions from the exhaust gas (Gunkel, 1992). While the
high-pressure venturi scrubber is reliable at controlling PM, it requires considerable
attention and daily maintenance to maintain a high degree of PM removal efficiency
(Gunkel, 1992).
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2.4.2 FUGITIVE PARTICULATE EMISSIONS CONTROL
Driving Surfaces
Unpaved driving surfaces are commonly maintained by utilizing wet-down techniques
using water, or other agents. In some areas unpaved roadways may alternatively be
covered with crushed recycled material (e.g., tires, asphalt shingles) with equal success.
In recent years, there has been a trend toward paving the driving surfaces to eliminate
fugitive particulates. Facilities with paved surfaces may additionally employ sweeping or
vacuuming as maintenance measures to reduce PM emissions (EPA, 1995a; Gunkel,
1992; TRNCC, 1994).
Aggregate Stockpiles
Watering of the stockpiles is not typically used because of the burden it puts on the
heating and drying process (Gunkel, 1992). Occasionally, crusting agents may be
applied to aggregate piles. These crusting agents have served fairly well to mitigate
fugitive dust emissions in these instances (TNRCC, 1994). There are many variables
that affect the fugitive dust emissions from stockpiles including moisture content of the
material, amount of fines (< 200 mesh), and age of pile (i.e., older piles tend to loose
their surface fines). Pre-washed aggregate, from which fines have been removed, may
be used for additional PM control (Patterson, 1995a).
2.4.3 VOC (INCLUDING HAP) CONTROL
VOCs are the total organic compounds emitted by the process minus the methane
constituent. Once the exhaust stream cools after discharge from the process stack, some
VOCs condense to form a fine liquid aerosol or "blue smoke" plume. A number of
process modifications or restrictions have been introduced to reduce blue smoke,
including installation of flame shields, rearrangement of flights inside the drum,
adjustments of the asphalt injection point, and other design changes (EPA, 1995a;
Gunkel, 1992). Periodic burner tune-ups may reduce VOC emissions by about
38 percent (Patterson, 1995a). Burner combustion air can be optimized to reduce
emissions by monitoring the pressure drop across induced draft burners with a
photohelic device tied to an automatic damper that adjusts the exhaust fan
(Patterson, 1995a).
Organic vapors from heated asphalt cement storage tanks can be reduced by condensing
the vapors with air-cooled vent pipes. In some cases, tank emissions may be routed
back to combustion units. Organic emissions from heated asphalt storage tanks may
also be controlled with carbon canisters on the vents or by other measures such as
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condensing precipitation or stainless steel shaving condensers (Wiese, 1995). Although
not common, organic emissions from truck-loading of asphaltic concrete can be
controlled by venting into the dryer (EPA, 1995a). This is usually practiced in
non-attainment areas.
2.4.4 SULFUR OXIDES CONTROL
Low Sulfur Fuel
This approach to reducing SOX emissions reduces the sulfur fed to the combustor by
burning low sulfur fuels. Fuel blending is the process of mixing higher sulfur content
fuels with lower sulfur fuels (e.g., low sulfur oil). The goal of effective fuel blending is
to provide a fuel supply with reasonably uniform properties that meet the blend
specification, typically including sulfur content, heating value, and moisture content
(EIIP, 1995).
Aggregate Adsorption
Alkaline aggregate (i.e., limestone) may adsorb sulfur compounds from the exhaust gas.
In exhaust streams controlled by baghouses, SOX may be reduced by limestone dust that
coats the baghouse filters (Patterson, 1995). Consequently, limestone aggregate may
maximize the removal of sulfur compounds (Gunkel, 1992). Sulfur compounds from the
exhaust gas may also be adsorbed by a venturi scrubber with recirculated water
containing limestone (Wiese, 1995).
2.4.5 NITROGEN OXIDES CONTROL
Low Nitrogen Fuels
Fuels lower in nitrogen content may reduce some NOX emissions (NAPA, 1995). At
temperatures above 1300°C, however, conversion from high-nitrogen fuels to low-
nitrogen fuels may not substantially reduce NOX emissions, as thermal NOX contributions
will be more significant (Nevers, 1995). Consequently, NOX emissions are generally
inversely related to CO emissions (NAPA, 1995).
Staged combustion systems such as low NOX burners that are used to reduce NOX
emissions in other industries, are not typically employed in the HMA industry due to
economic and engineering considerations (NAPA, 1995). Recirculation of the exhaust
gas may be precluded by the relatively high moisture content (e.g., 30 percent) of the
gas stream. Exhaust recirculation in these instances may cause some flame quenching
around the edges and could contribute to higher VOC and CO emissions when sealed
burners are not used (Patterson, 1995a).
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OVERVIEW OF AVAILABLE METHODS
3.1 DESCRIPTION OF EMISSION ESTIMATION METHODOLOGIES
There are several methodologies available for calculating emissions from HMA plants.
The method used is dependent upon available data, available resources, and the degree
of accuracy required in the estimate. In general, site-specific data is preferred over
industry averaged data such as AP-42 emission factors for more accurate emissions
estimates (EPA, 1995a). (Each state may have a different preference or requirement
and so it is suggested that the reader contact the nearest state or local air pollution
agency before deciding on which emission estimation methodology to use.) This
document evaluates emission estimation methodologies with respect to accuracy and
does not mandate any emission estimation method. For purposes of calculating peak
season daily emissions for State Implementation Plan inventories, refer to the EPA
Procedures manual (EPA, May 1991).
This section discusses the methods available for calculating emissions from HMA plants
and identifies the preferred method of calculation on a pollutant basis. These emission
estimation methodologies are listed in no particular order and the reader should not
infer a preference based on the order they are listed in this section. A discussion of the
sampling and analytical methods available for monitoring each pollutant is provided in
Chapter 1, Introduction to Stationary Point Source Emissions Inventory Development.
Emission estimation techniques for auxiliary processes, such as using EPA's TANKS
program to calculate storage tank emissions, are also discussed in Chapter 1.
3.1.1 STACK SAMPLING
Stack sampling provides a "snapshot" of emissions during the period of the stack test.
Stack tests are typically performed during either representative (i.e., normal) or worst
case conditions, depending upon the requirements of the state. Samples are collected
from the stack using probes inserted through a port in the stack wall, and pollutants are
collected in or on various media and sent to a laboratory for analysis. Pollutant
concentrations are obtained by dividing the amount of pollutant collected during the test
by the volume of the sample. Emission rates are then determined by multiplying the
pollutant concentration by the volumetric stack gas flow rate. Because there are many
steps in the stack sampling procedures where errors can occur, only experienced stack
testers should perform such tests.
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3.1.2 EMISSION FACTORS
Emission factors are available for many source categories and are based on the results
of source tests performed at an individual plant or at one or more facilities within an
industry. Basically, an emission factor is the pollutant emission rate relative to the level
of source activity. Chapter 1 of this volume of documents contains a detailed discussion
of the reliability, or quality, of available emission factors. EPA-developed emission
factors for criteria and hazardous air pollutants are available in AP-42, the Locating and
Estimating Series of documents, and the Factor Information Retrieval (FIRE) System.
3.1.3 FUEL ANALYSIS
Fuel analysis data can sometimes be used to predict emissions by applying mass
conservation laws. For example, if the concentration of a pollutant, or pollutant
precursor, in a fuel is known, emissions of that pollutant can be calculated by assuming
that all of the pollutant is emitted or by adjusting the calculated emissions by the
control efficiency. This approach is appropriate for SO2.
3.1.4 CONTINUOUS EMISSION MONITORING SYSTEM (CEMS) AND PREDICTIVE
EMISSION MONITORING (PEM)
A CEMS provides a continuous record of emissions over time. Various principles are
employed to measure the concentration of pollutants in the gas stream and are usually
based on photometric measurements. Once the pollutant concentration is known,
emission rates are obtained by multiplying the pollutant concentration by the volumetric
gas flow rate. Stack gas flow rate can also be measured by continuous monitoring
instruments; but it is more typically determined using manual methods (e.g., pilot tube
traverse). At low pollutant concentrations, the accuracy of this method may decrease.
Instrument drift can be problematic for CEMS and uncaptured data can create long-
term, incomplete data sets.
PEM is based on developing a correlation between pollutant emission rates and process
parameters. A PEM may be considered a specialized usage of an emission factor.
Correlation tests must first be performed to develop this relationship. At a later time
emissions can then be calculated using process parameters to predict emission rates
based on the results of the initial source test.
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3.2 COMPARISON OF AVAILABLE EMISSION ESTIMATION
METHODOLOGIES
Table 3.3-1 identifies the preferred and alternative emission estimation approach(s) for
selected pollutants. Table 3.3-1 is ordered according to the accuracy of the emission
estimation approach. The reader and the local air pollution agency must decide which
emission estimation approach is applicable based on costs and air pollution control
requirements in their area. The preferred method chosen should also recognize the
time specificity of the emission estimate and the data quality. The quality of the data
will depend on a variety of factors including the number of data points generated, the
representativeness of those data points, and the proper operation and maintenance of
the equipment being used to record the measurements.
3.2.1 STACK SAMPLING
Without considering cost, stack sampling is the preferred emission estimation
methodology for process NOX, CO, VOC, THC, PM, PM10, metals and speciated
organics. EPA reference methods and other methods of known quality can be used to
obtain accurate estimates of emissions at a given time for a particular facility.
3.2.2 EMISSION FACTORS
Due to their availability and acceptance in the industry, emission factors are commonly
used to prepare emission inventories. However, the emission estimate obtained from
using emission factors is based upon emissions testing performed at similar facilities and
may not accurately reflect emissions at a single source. Thus, the user should recognize
that, in most cases, emission factors are averages of available industry-wide data with
varying degrees of quality and may not be representative of averages for an individual
facility within that industry. Emission factors are the preferred technique for estimating
fugitive dust emissions for aggregate stockpiles and driving surfaces, as well as process
fugitives.
3.2.3 FUEL ANALYSIS
Fuel analysis can be used as an approximation if no emission factors or site specific
stack test data are available. Once the concentration of sulfur in a fuel is known, SO2
emissions can be calculated based on mass conservation laws, assuming negligible
adsorption by alkaline aggregates.
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TABLE 3.3-1
SUMMARY OF PREFERRED EMISSION
ESTIMATION METHODS FOR HOT-MIX ASPHALT PLANTS
Parameter
S02
NOX
CO
VOC
THC
PM
PM10
Heavy metals
Preferred Emission Estimation
Approach Ordered by Accuracy"
1. Stack sampling data
2. CEMS/PEM
3. Fuel analysis
4. EPA/state published emission factors'*
1. Stack sampling data
2. CEMS/PEM data
3. EPA/state published emission factors'*
1. Stack sampling data
2. CEMS/PEM data
3. EPA/state published emission factors'*
1. Stack sampling data
2. EPA/state published emission factors
1. Stack sampling data
2. CEMS/PEM data
3. EPA/state published emission factors5
1. Stack sampling datad
2. EPA/state published emission factors'
1. Stack sampling datad
2. EPA/state published emission factors'
1. Stack sampling data
2. EPA/state published emission factors5
3.3-4
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TABLE 3.3-1
(CONTINUED)
Parameter
Speciated organics
Preferred Emission Estimation
Approach Ordered by Accuracy"
1. Stack sampling data
2. EPA/state published emission factors5
a Preferred emission estimation approaches do not include considerations such as cost. The costs,
benefits, and relative accuracy should be considered prior to method selection. Readers are advised
to check with local air pollution control agency before choosing a preferred emission estimation
approach.
b Assumes emission factors are not based on site-specific fuel analysis.
c THC = total hydrocarbons.
Preferred method for process and process fugitive emissions.
e Preferred method for fugitive dust.
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3.2.4 CEMS AND PEM
HMA plants would not likely estimate emissions using CEMS and PEM. HMA plants
have conditions unfavorable to generating accurate CEM data including, high vibrations,
high moisture content of the stack gas, and dust. Nightly shutdown of CEMS would also
adversely affect their performance. In some instances, however, CEMS may be used to
estimate emissions of NOX, CO, and THC. This method may be used, for example,
when detailed records of emissions are needed over time. Similarly, stack gas flow rate
may be monitored using a continuous flow rate monitor, including pitot tubes,
ultrasonic, and thermal monitors (Patterson, 1995a).
PEM is a predictive emission estimation methodology whereby emissions are correlated
to process parameters based on an initial series of stack tests at a facility. For example,
VOC emissions may occur from asphalt mixtures produced at various temperatures with
different combustion fuels and varying quantities of asphalt cement, aggregates, RAP,
and crumb rubber. Similarly, sulfur dioxide emissions may be controlled by scrubbers
that operate at variable pressure drops, alkalinity, and recirculation rates. These
parameters may be monitored during the tests and correlated to the pollutant emission
rates. Following the correlation development, parameters would be monitored to
periodically predict emission rates. Periodic stack sampling may be required to verify
that the predictive emission correlations are still accurate; if not, new correlations are
developed.
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PREFERRED METHODS FOR
ESTIMATING EMISSIONS
Without consideration of cost, the preferred method for estimating emissions of most
pollutants emitted from HMA plants is the use of site-specific recent stack tests. Each
state may have a different preference or requirement and so it is suggested that the
reader contact the nearest state or local air pollution agency before deciding on which
emission estimation methodology to use. This section provides an outline for calculating
emissions from HMA plants based on raw data collected by stack tests.
Table 3.4-1 lists the variables and symbols used in the following discussions.
4.1 EMISSION CALCULATIONS USING STACK SAMPLING DATA
Stack sampling test reports often provide emissions data in terms of Ib/hr or grain/dscf.
Annual emissions may be calculated from these data using Equations 3.4-1 or 3.4-2.
Stack tests performed under a proposed permit condition or a maximum emissions rate
are likely to be higher than the emissions which would result under normal operating
conditions. The emission testing should only be completed after the purpose of the
testing is known. For example, emission testing for particulate emissions may be
different than emission testing for New Source Performance Standards (NSPS) because
the back-half catch portion is not considered.
This section shows how to calculate emissions in Ib/hr based on stack sampling data.
Calculations involved in determining particulate emissions from Method 5 data are used
as an example. Because continuous PM monitors have not been demonstrated for this
industry, the only available methods for measuring PM emissions are EPA Methods 5
or 17 and EPA Method 201A for PM10. EPA Method 5 is used for NSPS testing. If
condensible PM is needed in the emissions estimate, the test method selected must be
configured accordingly.
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TABLE 3.4-1
LIST OF VARIABLES AND SYMBOLS
Variable
Concentration
Molecular weight
Molar volume
Flow rate
Flow rate
Emissions
Annual emissions
Filter catch
Fuel use
PM concentration
Metered volume at
standard temperature
and pressure
Moisture
Temperature
Asphalt production
Annual operating hours
Symbol
C
MW
V
Qa
Qd
Ex
Etpy,x
cf
Qf
CPM
*m,STP
R
T
A
OpHrs
Units
parts per million volume dry (ppmvd)
Ib/lb-mole
385.5 ft3/lb-mole @ 68°F and 1
atmosphere
actual cubic feet per minute (acfm)
dry standard cubic feet per minute (dscfm)
typically Ib/hr of pollutant x
ton/year of pollutant x
grams (g)
typically, Ib/hr
grain/dscf
dscf
percent
degrees fahrenheit
ton/hr
hr/yr
3.4-2
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An example summary of a Method 5 test is shown in Table 3.4-2. The table shows the
results of three different sampling runs conducted during one test event. The source
parameters measured as part of a Method 5 run include gas velocity and moisture
content, which are used to determine exhaust gas flow rates in dscfm. The filter weight
gain is determined gravimetrically and divided by the volume of gas sampled (as shown
in Equation 3.4-1) to determine the PM concentration in grains per dscf. Note that this
example does not present the condensible PM emissions.
Pollutant concentration is then multiplied by the volumetric flow rate to determine the
emission rate in pounds per hour, as shown in Equation 3.4-2 and Example 3.4-1.
CPM = Cf/Vmyrp * 15.43 (3.4-1)
where:
CPM = concentration of PM or grain loading (grain/dscf)
Cf = filter catch (g)
Vm,srp = metered volume of sample at STP (dscf)
15.43 = 15.43 grains per gram
EPM = CpM * Qd * 60/7000 (3.4-2)
where:
EPM = hourly emissions in Ib/hr of PM
Qd = stack gas volumetric flow rate (dscfm)
60 = 60min/hr
7000 = 7000 grains per pound
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TABLE 3.4-2
TEST RESULTS - METHOD 5
Parameter
Total sampling time
(minutes)
Moisture collected
(grams)
Filter catch (grams)
Average sampling
rate (dscfm)
Standard metered
volume, (dscf)
Volumetric flow
rate (acfm or
dscfm)
Concentration of
particulate
(grains/dscf)
Particulate emission
rate (Ib/hr)
Symbol
min
g
Q
dscfm
v
vm,STP
Qa or Qd
CpM
EPM
Run 1
120
395.6
0.0851
0.34
41.83
17,972
0.00204
4.84
Run 2
120
372.6
0.0449
0.34
40.68
17,867
0.00110
2.61
Run 3
120
341.4
0.0625
0.34
40.78
17,914
0.00153
3.63
3.4-4
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Example 3.4-1
PM emissions calculated using Equations 3.4-1 and 3.4-2 and the stack sampling
data for Run 1 (presented in Table 3.4-2 are shown below).
CPM = Cf/Vm>OT * 15.43
(0.085/41.83) * 15.43
0.03 grain/dscf
EPM = CPM ' Qd * 60/7000
0.03 * 17,972 * (60 min/hr) * (1 lb/7000 grains)
4.84 Ib/hr
The information from some stack tests may be reported in pounds of particulate per
pounds of exhaust gas (wet). Use Equation 3.4-3 to calculate the dry particulate
emissions in Ib/hr.
EPM = Qa/1000 * 60 * 0.075 (1 - R) * (528/460 + T) (3.4-3)
where:
EPM = hourly emissions in Ib/hr PM
Qa = actual cubic feet of exhaust gas per minute (acfm)
1000 = 1000 Ib exhaust gas per Ib of PM
60 = 60 min/hr
0.075 = 0.075 lb/ft3
R = moisture percent (%)
528 = 528°F
460 = 460°F
T = stack gas temperature in °F
4.2 EMISSION FACTOR CALCULATIONS
Emission factors are commonly used to calculate emissions for fugitive dust sources and
when site-specific monitoring data are unavailable. EPA maintains a compilation of
emission factors in AP-42 for criteria pollutants and HAPs (EPA, 1995a). A
supplementary source for toxic air pollutant emission factors is the Factor Information
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and Retrieval (FIRE) data system (EPA, 1994). FIRE also contains emission factors for
criteria pollutants.
Much work has been done recently on developing emission factors for HAPs and recent
AP-42 revisions have included these factors (EPA, 1995a,b). In addition, many states
have developed their own HAP emission factors for certain source categories and
require their use in any inventories including HAPs. Refer to Chapter 1 of Volume III
for a complete discussion of available information sources for locating, developing, and
using emission factors as an estimation technique.
Emission factors developed from measurements for a specific mixer or dryer may
sometimes be used to estimate emissions at other sites. For example, a company may
have several units of similar model and size; if emissions were measured from one dryer
or mixer, an emission factor could be developed and applied other similar units. It is
advisable to have the emission factor reviewed and approved by state/local agencies or
the EPA prior to its use.
The basic equation for using an emission factor to calculate emissions is the following:
Ex = EFX * Activity or Production Rate (3-4'4)
where:
Ex = emissions of pollutant x
EFX = emission factor of pollutant x
Calculations using emission factors are presented in Examples 3.4-2 and 3.4-3.
4.3 EMISSION CALCULATIONS USING FUEL ANALYSIS DATA
Fuel analysis can be used to predict SO2 and other emissions based on application of
conservation laws, if fuel rate (Qf) is measured. The presence of certain elements in
fuels may be used to predict their presence in emission streams. This includes elements
such as sulfur which may be converted to other compounds during the combustion
process.
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Example 3.4-2
Example 3.4-2 shows how potential hourly VOC combustion emissions may be
calculated for a parallel flow drum mixer using a total organic compound
(TOC) emission factor fromAP-42, Table 11.1-8, for an oil-fired dryer. The
asphalt plant is assumed to operate 1,200 hours per year.
EE
TOC
Maximum asphalt production rate
TOC emissions
0.069 Ib/ton asphalt produced
350 ton/hr
EFTOC * asphalt production rate
0.069 * 350
24.15 Ib/hr * 1 ton/2000 Ib * 1200 hr/yr
14.5 ton/yr
Example 3.4-3
Example 3.4-3 shows how potential hourly xylene emissions may be calculated
for a batch mix HMA plant with a natural gas-fired dryer based on a xylene
emission factor fromAP-42, Table 11.1-9. The HMA plant is assumed to
operate 1,200 hours per year.
EFxylene
Xylene emissions
0.0043 Ib/ton asphalt produced
EFxy)ene * maximum asphalt production rate
(0.0043 Ib/ton) * 350 ton/hr
1.5 Ib/hr * 1 ton/2000 Ib * 1200 hr/yr
0.9 ton/yr
The basic equation used in fuel analysis emission calculations is the following:
Ex =
* Pollutant concentration in fuel *
MW_
MW,
(3.4-4)
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CHAPTER 3 - HOT-MIX ASPHAL T PLANTS 7/26/96
where:
E = emissions of pollutant x
Qf = fuel use (Ib/hr)
MW = Molecular weight of pollutant emitted (Ib/lb-mole)
MWJ. = Molecular weight of pollutant in fuel (Ib/lb-mole)
For instance, SO2 emissions from oil combustion can be calculated based on the
concentration of sulfur in the oil. This approach assumes complete conversion of sulfur
to SO2. Therefore, for every pound of sulfur (MW = 32 g) burned, two pounds of SO2
(MW = 64 g) are emitted. The application of this emission estimation technique is
shown in Example 3.4-4.
Example 3.4-4
This example shows how SO2 emissions can be calculated from oil combustion
based on fuel analysis results and the fuel flow information, if available. The
asphalt plant is assumed to operate 1,200 hours per year.
ESO2 may be calculated using Equation 3.4-4.
Assume a given Qf = 5,000 Ib/hr
Given percent weight sulfur (% S) in fuel = 1.17
= Qf * pollutant concentration in fuel * (MW /MWf)
(5,000) * (1.17/100) * (64/32)
117 Ib/hr * ton/2000 Ib * 1,200 hr/yr
70.2 ton/yr
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ALTERNATIVE METHODS FOR
ESTIMATING EMISSIONS
5.1 EMISSION CALCULATIONS USING OEMS DATA
To monitor SO2, NOX, THC, and CO emissions using a CEMS, a facility uses a pollutant
concentration monitor, which measures concentration in parts per million by volume dry
air (ppmvd). Note that a CEMS would not likely be used to monitor emissions for an
extended period due to the unfavorable conditions at an HMA plant. Flow rates should
be measured using a volumetric flow rate monitor. Flow rates estimated based on heat
input using fuel factors may be inaccurate because these systems typically run with high
excess air to remove the moisture out of the drum (Patterson, 1995). Emission rates
(Ib/hr) are then calculated by multiplying the stack gas concentrations by the stack gas
flow rates.
Table 3.5-1 presents example CEMS data output averaged for three periods for a
parallel flow drum mixer. The output includes pollutant concentrations in parts per
million dry basis (ppmvd), diluent (O2 or CO2) concentrations in percent by volume dry
basis (%v,d), and emission rates in pounds per hour (Ib/hr). These data represent a
"snapshot" of a drum mixer operation. While it is possible to determine total emissions
of an individual pollutant over a given time period from these data assuming the CEM
operates properly all year long, an accurate emission estimate can be made by summing
the hourly emission estimates if the CEMS data are representative of typical operating
conditions.
Although CEMS can report real-time hourly emissions automatically, it may be
necessary to manually estimate annual emissions from hourly concentration data. This
section describes how to calculate emissions from CEMS concentration data. The
selected CEMS data should be representative of operating conditions. When possible,
data collected over longer periods should be used. It is important to note that prior to
using CEMS to estimate emissions, a protocol should be developed for collecting and
averaging the data.
EIIP Volume II 3.5-1
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S)
TABLE 3.5-1
EXAMPLE CEM OUTPUT AVERAGED FOR A PARALLEL FLOW DRUM MIXER FIRING WASTE FUEL OIL
Period
0830-1039
1355-1606
1236-1503
Oz
(%V)
10.3
10.1
11.8
Concentration (C)
(ppmvd)
S02
150.9
144.0
123.0
NO,
142.9
145.7
112.7
CO
42.9
41.8
128.4
THC
554.2
582.9
515.1
Stack
Gas
Flow
Rate
(Q)
(dscfm)
18,061
17,975
18,760
Emission Rate (E)
(Ib/hr)
SO2
27.15
25.78
22.99
NO,
25.71
26.09
21.06
CO
3.38
3.27
10.50
THC
24.93
26.09
24.06
Asphalt
Production
Rate (A)
(ton/hr)
287
290
267
i
•o
a
CO
I
§
I
§
Source: EPA, 1991b.
I
S
s
Oi
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7/26/96 CHAPTER 3 - HOT-MIX ASPHALT PLANTS
Hourly emissions can be based on concentration measurements as shown in
Equation 3.5-1 and Example 3.5-1.
E = (C * MW * Q * 60) (3 5_1}
(V * 106)
where:
Ex = hourly emissions in Ib/hr of pollutant x
C = pollutant concentration in ppmvd
MW = molecular weight of the pollutant (Ib/lb-mole)
Q = stack gas volumetric flow rate in dscfm
60 = 60 min/hr
V = volume occupied by one mole of ideal gas at standard
temperature and pressure (385.5 ft3/lb-mole @ 68°F and 1 atm)
Actual emissions in tons per year can be calculated by multiplying the emission rate in
Ib/hr by the number of actual annual operating hours (OpHrs) as shown in
Equation 3.5-2 and Example 3.5-1.
Etpy>x = Ex * OpHrs/2000 (3.5-2)
where:
= annual emissions in ton/yr of pollutant x
= hourly emissions in Ib/hr of pollutant x
OpHrs = annual operating hours in hr/yr
Emissions in pounds of pollutant per ton of asphalt produced can be calculated by
dividing the emission rate in Ib/hr by the asphalt production in rate (ton/hr) during the
same period (Equation 3.5-3) as shown below. It should be noted that the emission
factor calculated below assumes that the selected period (i.e., hour) is representative of
annual operating conditions and longer time periods should be used when available.
Use of the calculation is shown in Example 3.5-1.
Etpy,x=Ex/A (3.5-3)
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CHAPTER 3 - HOT-MIX ASPHALT PLANTS 7/26/96
where:
= emissions of pollutant x (Ib/ton) per ton of asphalt produced
Ex = hourly emissions in Ib/hr of pollutant x
= asphalt production (ton/hr)
Example 3.5-1
This example shows how SO2 emissions can be calculated using Equation 3.5-1
based on the average CEMS data for 8:30-10:39 shown in Table 3.5-1.
ES02 = (C * MW * Q * 60)/(V * 106)
150.9 * 64 * 18,061 * 60/(385.5 * 106)
27.15 Ib/hr
Emissions in ton/yr (based on a 1,200 hr/yr operating schedule) can then be
calculated using Equation 3.5-2; however, based on the above period this
estimate should be calculated from the average CEMS data for year using
Equation 3.5-1:
EtPy,so2 = ES02 * OpHrs/2,000
27.15 * (1,200/2,000)
16.29 ton/yr
Emissions, in terms of Ib/ton asphalt produced, are calculated using
Equation 3.5-3:
9.46 * 10'2 Ib SO2/ton asphalt produced
5.2 PREDICTIVE EMISSION MONITORING
Emissions from the HMA process depend upon several variables, which are discussed in
Section 3 of this chapter. For example, VOC process emissions for a given plant may
vary with several parameters, including: the type of fuel burned; the relative quantities
of asphalt constituents (e.g., RAP, crumb rubber, and emulsifiers); aggregate type and
moisture content; the temperature of the asphalt constituents; the mixing zone
temperature; and, fuel combustion rate. An example emissions monitoring that could be
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CHAPTER 3 • HOT-MIX ASPHALT PLANTS
used to develop a PEM protocol would need to account for the variability in these
parameters and, consequently, may require a complex testing algorithm.
To develop this algorithm, correlation testing of the process variables could be
conducted over a range of potential operating conditions using EPA Method 25 or
Method 25A to measure THC emissions and EPA Method 6A or Method 6C to
measure SO2 emissions. Potential testing conditions covering several parameters are
shown in Table 3.5-2. Based on the test data, a mathematical correlation can be
developed which predicts emissions using these parameters. This method may be cost
prohibitive for a single source.
TABLE 3.5-2
PREDICTIVE EMISSION MONITORING ANALYSIS3
Test Number
1
2
3
4
5
6
7
8
9
Temperature of
Asphalt Constituents
B
B
B
B
B
B
B
B
B
Mixing Zone
Temperature
H
H
H
M
M
M
L
L
L
Fuel Firing Rate
H
M
L
H
M
L
H
M
L
aH
M
L
B
= high.
= medium.
= low.
= baseline.
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This page is intentionally left blank.
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QUALITY ASSURANCE/QUALITY
CONTROL
The consistent use of standardized methods and procedures is essential in the
compilation of reliable emission inventories. QA and QC of an inventory is
accomplished through a set of procedures that ensure the quality and reliability of data
collection and analysis. These procedures include the use of appropriate emission
estimation techniques, applicable and reasonable assumptions, accuracy/logic checks of
computer models, checks of calculations, and data reliability checks. Figure 3.6-1
provides an example checklist that could aid the inventory preparer at a HMA plant.
Volume VI, QA Procedures of this series describes additional QA/QC methods and tools
for performing these procedures.
Volume II, Chapter 1, Introduction to Stationary Point Source Emission Inventory
Development, presents recommended standard procedures to follow that ensure the
reported inventory data are complete and accurate. The QA/QC section of Chapter 1
should be consulted for current EIIP guidance for QA/QC checks for general
procedures, recommended components of a QA plan, and recommended components
for point source inventories. The QA plan discussion includes recommendations for
data collection, analysis, handling, and reporting. The recommended QC procedures
include checks for completeness, consistency, accuracy, and the use of approved
standardized methods for emission calculations, where applicable. Chapter 1 also
describes guidelines to follow in order to ensure the quality and validity of the data
from manual and continuous emission monitoring methodologies used to estimate
emissions.
6.1 CONSIDERATIONS FOR USING STACK TEST AND CEMS DATA
Data collected via CEMS, PEM, or stack tests must meet quality objectives. Stack test
data must be reviewed to ensure that the test was conducted under normal operating
conditions, or under maximum operating conditions in some states, and that it was
generated according to an acceptable method for each pollutant of interest. Calculation
and interpretation of accuracy for stack testing methods and CEMS are described in
detail in Quality Assurance Handbook for Air Pollution Measurements Systems:
Volume III. Stationary Source Specific Methods (Interim Edition).
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7/26/96
Item
Y/N
Corrective Action
(complete if "N";
describe, sign, and date)
Have the toxic emissions been calculated and
reported using approved stack test methods or using
the emission factors provided from AP-42, FIRE,
and/or NAPA (National Asphalt Pavement
Association)? Have asphalt production rates been
included? Each facility should request from their
state agency guidance on which test methods or
emission factors should be used.
2. Fugitive emissions are required for the inventory, but
will not count towards a Title V determination unless
the facility is NSPS affected. Presently, in the case of
the asphalt plants, only particulate emissions for the
process as defined in 40 CFR 60.90 are NSPS
affected. Have fugitive emissions been calculated?
3. If emission factors are used to calculate fuel usage
emissions, have fuel usage rates been determined for
the dryer and for the asphalt heater separately? If
the AP-42 dryer emission factors are used, they
already contain emissions from fuel combustion in the
dryer.
4. Again, request guidance from the state regulatory
agency on whether or not to calculate toxic emissions
from fuel usage. Most toxic emission factors usually
are inclusive of the asphalt and the fuel. Has the
state agency been contacted for guidance?
5. Have stack parameters been provided for each stack
or vent which emits criteria or toxic pollutants? This
includes the fabric filter or scrubber installed on the
asphalt dryer/mixer, the asphalt cement heaters, and
any storage silos other than asphalt concrete storage.
FIGURE 3.6-1. EXAMPLE EMISSION INVENTORY DEVELOPMENT
CHECKLIST FOR ASPHALT PLANTS
3.6-2
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CHAPTER 3 - HOT-MIX ASPHALT PLANTS
Item
6. Check with the state regulatory agency to determine
whether emissions should be calculated using AP-42
emission factors:
Dryer/Mix Type:
Rotary Dryer (Batch Mix): Conventional Plant
(3-05-002-01)
Drum (Mix) Dryer: Hot Asphalt Plant (3-05-002-05)
Diesel Generators: Industrial diesel reciprocating
(2-02-001-02)
Asphalt Heaters:
"In Process Fuel Use Factors" (Residual, 3-05-002-07;
Distillate, 3-05-002-08; Natural Gas, 3-05-002-06; LPG,
3-05-002-09).
7. Have you considered storage piles (3-05-002-03)(includes
handling of piles) from both Batch and Drum Plants?
8. If required by the state, has a site diagram been included
with the emission inventory? This should be a detailed
plant drawing showing the location of sources/stacks with
ID numbers for all processes, control equipment, and
exhaust points.
9. Have examples of all calculations been included?
10. Have all conversions and units been reviewed
and checked for accuracy?
Y/N
Corrective Action
(complete if "N";
describe, sign,
and date)
FIGURE 3.6-1. (CONTINUED)
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CHAPTER 3 • HOT-MIX ASPHALT PLANTS 7/26/96
The acceptance criteria, limits, and values for each control parameter associated with
manual sampling methods, such as dry gas meter calibration and leak rates, are
summarized within the tabular format of the QA/QC section of Chapter 1. QC
procedures for all instruments used to continuously collect emissions data are similar.
The primary control check for precision of the continuous monitors is daily analysis of
control standards. The CEMS acceptance criteria and control limits are listed within
the tabular format of the QA/QC section of Chapter 1.
Quality assurance should be delineated in a Quality Assurance Plan (QAP) by the team
conducting the test prior to each specific test. The main objective of any QA/QC effort
for any program is to independently assess and document the precision, accuracy, and
adequacy of emission data generated during sampling and analysis. It is essential that
the emissions measurement program be performed by qualified personnel using proper
test equipment. Also, valid test results require the use of appropriate and properly
functioning test equipment and use of appropriate reference methods.
The QAP should be developed to assure that all testing and analytical data generated
are scientifically valid, defensible, comparable, and of known and acceptable precision
and accuracy. EPA guidance, is available for assistance in preparing any QAP (EPA,
October, 1989).
6.2 CONSIDERATIONS FOR USING EMISSION FACTORS
The use of emission factors is straightforward when the relationship between process
data and emissions is direct and relatively uncomplicated. When using emission factors,
the user should be aware of the quality indicator associated with the value. Emission
factors published within EPA documents and electronic tools have a quality rating
applied to them. The lower the quality indicator, the more likely that a given emission
factor may not be representative of the source type. When an emission factor for a
specific source or category may not provide a reasonably adequate emission estimate, it
is always better to rely on actual stack test or CEMS data, where available. The
reliability and uncertainty of using emission factors as an emission estimation technique
are discussed in detail in the QA/QC Section of Chapter 1.
a
6.3 DATA ATTRIBUTE RATING SYSTEM (DARS) SCORES
One measure of emission inventory data quality is the DARS score. Four examples are
given here to illustrate DARS scoring using the preferred and alternative methods. The
DARS provides a numerical ranking on a scale of 1 to 10 for individual attributes of the
emission factor and the activity data. Each score is based on what is known about the
factor and the activity data, such as the specificity to the source category and the
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measurement technique employed. The composite attribute score for the emissions
estimate can be viewed as a statement of the confidence that can be placed in the data.
For a complete discussion of DARS and other rating systems, see the QA Source
Document (Volume VI, Chapter 4) and the QA/QC Section within Volume II
Chapter 1, Introduction to Stationary Point Sources Emission Inventory Development.
Each of the examples below is hypothetical. A range is given where appropriate to
cover different situations. The scores are assumed to apply to annual emissions from an
HMA plant. Table 3.6-1 gives a set of scores for an estimate based on CEMS/PEM
data. A perfect score of 1.0 is achievable using this method if data quality is very good.
Note that maximum scores of 1.0 are automatic for the source definition and spatial
congruity attributes. Likewise, the temporal congruity attribute receives a 1.0 if data
capture is greater than 90 percent; this assumes that data are sampled adequately
throughout the year. The measurement attribute score of 1.0 assumes that the
pollutants of interest were measured directly. A lower score is given if the emissions
are speciated using a profile, or if the emissions are used as a surrogate for another
pollutant. Also, the measurement/method score can be less than 1.0 if the relative
accuracy is poor (e.g., > 10 percent), if the data are biased, or if data capture is closer to
90 percent than to 100 percent.
The use of stack sample data can give DARS scores as high as those for CEMS/PEM
data. However, the sample size is usually too low to be considered completely
representative of the range of possible emissions making a score of 1.0 for
measurement/method unlikely. A typical DARS score for stack sample data is generally
closer to the low end of the range shown in Table 3.6-2.
Two examples are given for emissions calculated using emission factors. For both of
these examples, the activity data is assumed to be measured directly or indirectly.
Table 3.6-3 applies to an emission factor developed from CEMS/PEM data from one
dryer or mixer and then applied to a different dryer or mixer of similar design and age.
Table 3.6-4 gives an example for an estimate made with an AP-42 emission factor. The
AP-42 factor is a mean and could overestimate or underestimate emissions for any
single unit in the population. Thus, the confidence that can be placed in emissions
estimated for a specific unit with a general AP-42 factor is lower than emissions based
on source-specific data. This assumes that the source-specific data were developed
while the HMA plant was operating under normal conditions. If it was not operated
under normal conditions then the AP-42 emission factor may be a better
characterization of the emissions from the HMA plant.
The example in Table 3.6-3 shows that emission factors based on high-quality data from
a similar unit will typically give better results than a general factor. The main criterion
affecting the score is how similar the unit used to generate the factor is to the target
dryer or mixer.
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7/26/96
TABLE 3.6-1
DARS SCORES: CEMS/PEM DATA8
Attribute
Measurement/
method
Source
definition
Spatial
congruity
Temporal
congruity
Weighted Score
Emission
Factor
Score
0.9 - 1.0
1.0
1.0
1.0
0.98 - 1.0
Activity
Data
Score
0.9 - 1.0
1.0
1.0
1.0
0.98 - 1.0
Composite Scores
Range
0.81 - 1.0
1.0 - 1.0
1.0 - 1.0
1.0 - 1.0
0.95 - 1.0
Midpoint
0.91
1.0
1.0
1.0
0.98
Comment
Lower scores given
if relative accuracy
poor (e.g.,
> 10 percent) or data
capture closer to
90 percent.
a Assumes data capture is 90 percent or better, representative of entire year, monitors sensors, and
other equipment is properly maintained.
3.6-6
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CHAPTER 3 • HOT-MIX ASPHALT PLANTS
TABLE 3.6-2
DARS SCORES: STACK SAMPLE DATA3
Attribute
Measurement/
method
Source
definition
Spatial
congruity
Temporal
congruity
Weighted Score
Emission
Factor
Score
0.7 - 1.0
1.0 - 1.0
1.0 - 1.0
0.7 - 1.0
0.85 - 1.0
Activity
Data Score
0.7 - 1.0
1.0 - 1.0
1.0 - 1.0
0.7 - 1.0
0.85 - 1.0
Composite Scores
Range
0.49 - 1.0
1.0 - 1.0
1.0 - 1.0
0.49 - 1.0
0.75 - 1.0
Midpoint
0.745
1.0
1.0
0.745
0.878
Comment
Lower scores
given if emissions
vary temporally
and sample does
not cover range.
Assumes use of EPA Reference Method, high quality data.
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7/26/96
TABLE 3.6-3
DARS SCORES: SOURCE-SPECIFIC EMISSION FACTOR8
Attribute
Measurement/method
Source definition
Spatial congruity
Temporal congruity
Weighted Score
Emission
Factor Score
0.9 - 1.0
0.5 - 0.9
1.0 - 1.0
1.0 - 1.0
0.85 - 0.98
Activity
Data Score
0.8 - 1.0
0.8 - 0.9
1.0 - 1.0
0.5 - 0.9
0.78 - 0.95
Composite Scores
Range
0.72 - 1.0
0.4 - 0.81
1.0 - 1.0
0.5 - 0.9
0.66 - 0.93
Midpoint
0.86
0.61
1.0
0.7
0.79
Comment
Factor score
for this
attribute
depends
entirely on
data quality.
Factor score
lowest if unit
differs much
from original
source of
data.
a Assumes factor developed from PEM or CEMS data from an identical emission unit (same
manufacturer, model).
3.6-8
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CHAPTER 3 - HOT-MIX ASPHALT PLANTS
TABLE 3.6-4
DARS SCORES: AP-42 EMISSION FACTOR3
Attribute
Measurement/method
Source definition
Spatial congruity
Temporal congruity
Weighted Score
Emission
Factor Score
0.6 - 0.8
0.5 - 0.9
0.6 - 0.8
0.5 - 0.9
0.55 - 0.85
Activity
Data Score
0.8 - 1.0
0.8 - 0.9
1.0 - 1.0
0.5 - 0.9
0.78 - 0.95
Composite Scores
Range
0.48 - 0.7
0.4 - 0.81
0.6 - 0.8
0.25 - 0.81
0.43 - 0.78
Midpoint
0.59
0.605
0.7
0.53
0.61
Comment
Score
depends on
quality and
quantity of
data points
used to
develop
factor.
Emission
factor score
will be low if
variability in
source
population is
high.
Factor score
lower if
geographic
location has
significant
effect on
emissions.
Lower scores
given if
emissions
vary
temporally
and sample
does not
cover range.
' Assumes activity data (e.g., fuel use) or surrogate is measured directly in some manner.
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CHAPTER 3 - HOT-MIX ASPHAL T PLANTS 7/26/96
If sufficient data are available, the uncertainty in the estimate should be quantified. If
sufficient data are not available, a qualitative analysis of uncertainty is still
recommended. Some methods and examples are described in QA Procedures
(Volume VI, Chapter 3).
The reader should note that the presentation of the DARS scores here is shown as a
hypothetical example, only. Although the highest DARS score results from the use of
CEMS, this estimation technique will not practically be applied or used by the majority
of facilities operating. Due to technical feasibility issues and costs incurred by applying
CEMS to a HMA plant, stack testing or emission factors may provide the best choice
when selecting an appropriate method for estimating emissions (even though stack
testing or emission factors did not receive the highest DARS score). The reader should
always contact their state regulatory agency for approval of selected methodologies or
techniques. Also, it should be noted that this hypothetical application of DARS does
not mandate any emission estimation method, but only offers the reader a means for
selecting any one method over another.
3.6-10 EIIP Volume II
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DATA CODING PROCEDURES
This section describes the methods and codes available for characterizing emission
sources at HMA facilities. Consistent categorization and coding will result in greater
uniformity among inventories. The SCCs are the building blocks on which point source
emissions data are structured. Each SCC represents a unique process or function within
a source category that is logically associated with an emission point. Without an
appropriate SCC, a process cannot be accurately identified for retrieval purposes. In
addition, the procedures described here will assist the reader preparing data for input to
the Aerometric Information Retrieval System (AIRS) or a similar database management
system. For example, the use of the SCCs provided in Table 3.7-1 are recommended for
describing HMA operations. Refer to the CHIEF bulletin board for a complete listing
of SCCs for HMA plants. While the codes presented here are currently in use, they
may change based on further refinement by the emission inventory user community. As
part of the EIIP, a common emissions data exchange format is being developed to
facilitate data transfer between industry, states, and EPA. Details on SCCs for specific
emission sources are as follows:
• Process Emissions: For asphaltic concrete production processes, be careful to use
only one SCC for each process. Use the codes for either the batch or continuous
process or for the drum mix process, depending on which process is used. The
process-specific codes should be used as often as possible; however, "Entire Unit"
and "General" codes are available. If the "Entire Unit" code is used, do not use
the chemical-specific or process-specific codes as this would double-count
emissions. AP-42 emission factors for dryer emissions include all stack emissions
(including products of combustion from the dryer burner).
• In-Process Fuel: In-process fuel includes SCCs for asphalt cement heaters.
These emissions are separate and apart from dryer emissions.
• Generators: Diesel generators may be used at portable HMA plants to generate
electricity. These emissions are not included in emission factors for process
emissions.
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• Storage Tanks: Storage tanks may be used in the asphaltic concrete production
process to store fuel such as oih Potential emissions from storage tanks will likely
be insignificant. The codes in Table 3.7-1 are recommended to describe fuel
storage emissions.
• Fugitive Emissions: Fugitive emissions from asphaltic concrete production result
primarily from the storage and handling of raw materials and finished product.
The miscellaneous codes may be used for fugitive emission sources without a
unique code. Remember to use the comment section to describe the emissions.
Control device codes applicable to asphaltic concrete production are presented in
Table 3.7-2. These should be used to enter the type of applicable emissions control
device into the AIRS Facility Subsystem (AFS). The "099" control code may be used for
miscellaneous control devices that do not have a unique identification code.
If there are significant sources of fugitive emissions within the facility, or sources that
have not been specifically discussed thus far, they should be included in the emissions
estimates if required by the state. Conditions vary from plant to plant, thus, each
specific case cannot be discussed within the context of this document.
3.7-2
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7/26/96
CHAPTER 3 - HOT-MIX ASPHALT PLANTS
TABLE 3.7-1
SOURCE CLASSIFICATION CODES FOR ASPHALTIC CONCRETE
PRODUCTION (SIC CODE 2951)
Source Description
Process Description
sec
Units
Process Emissions
Batch or continuous
mix process
Drum mix process
General process
Rotary dryer
Hot elevators, screens, bins, and
mixer
Drum mixer: hot asphalt plants
General process/specify in
comments
In-place recycling - propane
3-05-002-01
3-05-002-02
3-05-002-05
3-05-002-99
3-05-002-15
Tons HMA produced
Tons aggregate
processed
Tons HMA produced
Tons produced
Tons produced
In-Process Fuel
Asphalt heater fuel
use
Residual oil
Distillate oil
Natural gas
Waste oil
Liquid petroleum gas
3-05-002-07
3-05-002-08
3-05-002-06
3-05-002-10
3-05-002-09
1000 gallons burned
1000 gallons burned
Million ft3 burned
1000 gallons burned
1000 gallons burned
Generators
Diesel
Reciprocating
2-02-001-02
Horsepower hours
Fugitive Emissions
Fugitive emissions
Raw material storage piles
Cold aggregate handling
Storage silo
Truck load-out
Miscellaneous fugitive emissions
Haul roads - general
3-05-002-03
3-05-002-04
3-05-002-13
3-05-002-14
3-05-888-01 to 05
3-05-002-90
Tons aggregate
processed
Tons aggregate
processed
Tons HMA produced
Tons HMA loaded
Vehicle miles
travelled
Tons product
EIIP Volume II
3.7-3
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CHAPTER 3 - HOT-MIX ASPHALT PLANTS
7/26/96
TABLE 3.7-2
AIRS CONTROL DEVICE CODES
Control Device
Settling chamber: high-efficiency
Settling chamber: medium-efficiency
Settling chamber: low-efficiency
Single cyclone
Multiple cyclone
Centrifugal collector: high-efficiency
Centrifugal collector: medium-efficiency
Centrifugal collector: low-efficiency
Fabric filter: high temperature
Fabric filter: medium temperature
Fabric filter: low temperature
Wet fan
Spray tower
Venturi scrubber
Baffle spray tower
Miscellaneous control device
Code
004
005
006
075
076
007
008
009
016
017
018
085
052
053
052
099
Source: EPA, January 1992.
3.7-4
EIIP Volume II
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8
REFERENCES
Code of Federal Regulations. July 1, 1987. Title 40, Part 60, Appendix A. Office of
the Federal Register, Washington, DC.
EIIP. March 1995. Preferred and Alternative Methods for Estimating Air Emissions from
Boilers, Review Draft. Emission Inventory Improvement Program, Point Sources
Committee. Prepared under EPA Contract No. 68-D2-0160, Work Assignment No. 41.
U.S. Environmental Protection Agency, Office of Air Quality Planning and Standards,
Research Triangle Park, North Carolina.
EPA. 1986. Test Methods for Evaluating Solid Waste, Report No. SW-846, Third Edition.
U.S. Environmental Protection Agency, Office of Solid Waste and Emergency Response,
Washington, DC.
EPA. April 1989. Estimating Air Toxic Emissions from Coal and Oil Combustion
Sources. EPA-450/2-89-001. U.S. Environmental Protection Agency, Office of Air
Quality Planning and Standards, Research Triangle Park, North Carolina.
EPA. October 1989. Preparing Perfect Project Plans. EPA-600/9-89/087.
U.S. Environmental Protection Agency, Risk Reduction Laboratory, Cincinnati, Ohio.
EPA. September 199la. Emission Testing for Asphalt Concrete Industry. Site Specific
Test Plan and Quality Assurance Project Plan. Mathy Construction Company Plant 6.
U.S. Environmental Protection Agency, Office of Air Quality Planning and Standards,
Research Triangle Park, North Carolina.
EPA. September 1991b. Asphalt Emission Test Report. Mathy Construction Company,
LaCrosse, Wisconsin. U.S. Environmental Protection Agency, Office of Air Quality
Planning and Standards, Research Triangle Park, North Carolina.
EPA. May 1991. Procedures for the Preparation of Emission Inventories for Carbon
Monoxide and Precursors of Ozone. Volume I: .General Guidance for Stationary
Sources. U.S. Environmental Protection Agency, Office of Air Quality Planning and
Standards, Research Triangle Park, North Carolina.
EIIP Volume II 3.8-1
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CHAPTER 3 - HOT-MIX ASPHALT PLANTS 7/26/96
EPA. January 1992. AIRS User's Guide, Volume XI: AFS Data Dictionary. U.S.
Environmental Protection Agency, Office of Air Quality Planning and Standards,
Research Triangle Park, North Carolina.
EPA. 1994. Factor Information and Retrieval (FIRE) Data System, Version 4.0.
Updated Annually. U.S. Environmental Protection Agency, Office of Air Quality
Planning and Standards, Research Triangle Park, North Carolina.
EPA. January 1995a. Compilation of Air Pollutant Emission Factors. Volume I:
Stationary Point and Area Sources, Fifth Edition, AP-42. Section 11.1, Hot-Mix Asphalt
Plants. U.S. Environmental Protection Agency, Office of Air Quality Planning and
Standards, Research Triangle Park, North Carolina.
EPA. January 1995b. Compilation of Air Pollutant Emission Factors. Volume I.
Stationary Point and Area Sources, Fifth Edition, AP-42. Section 3.3-1, Stationary Internal
Combustion Sources. U.S. Environmental Protection Agency, Office of Air Quality
Planning and Standards, Research Triangle Park, North Carolina.
EPA. January 1995c. Compilation of Air Pollutant Emission Factors. Volume I.
Stationary Point and Area Sources, Fifth Edition, AP-42. Section 1.11, Waste Oil
Combustion. U.S. Environmental Protection Agency, Office of Air Quality Planning and
Standards, Research Triangle Park, North Carolina.
Fore, Gary, of National Asphalt Pavement Association, Lanham, Maryland.
Telecommunication with Robert Harrison, Radian Corporation. August 18, 1995.
Gunkel, Kathryn O'C. 1992. Hot-Mix Asphalt Mixing Facilities. Buonicore, Anthony J.,
and Wayne T. Davis, Editors. Air Pollution Engineering Manual. Van Nostrand
Reinhold, New York, New York.
Khan, Z.S., and T.W. Hughes. November 1977. Source Assessment: Asphalt Hot-Mix.
EPA-600/2-77-107n. U.S. Environmental Protection Agency, Industrial Environmental
Research Laboratory, Cincinnati, Ohio.
National Asphalt Pavement Association (NAPA). February 1995. Dealing with Title V
Operating Permits: the Synthetic Minor Alternative. Special Report 175. Lanham,
Maryland.
•
Nevers, Noel. 1995. Air Pollution Control Engineering. McGraw-Hill, Incorporated.
3.8-2 EIIP Volume II
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7/26/96 CHAPTER 3 - HOT-MIX ASPHAL T PLANTS
Patterson, Ralph, of Wisconsin Department of Natural Resources. May 2, 1995a.
Memorandum to Theresa Kemmer Moody, Radian Corporation, Comments on Preferred
and Alternative Methods for Estimating Air Emissions from Hot-Mix Asphalt Plants.
Patterson, Ralph, of Wisconsin Department of Natural Resources. June 16, 1995b.
Telecommunication with Robert Harrison, Radian Corporation.
Patterson, Ralph, of Wisconsin Department of Natural Resources. October 26, 1995c.
Memorandum to Theresa Kemmer Moody, Radian Corporation, Comments on Preferred
and Alternative Methods for Estimating Air Emissions from Hot-Mix Asphalt Plants.
Stultz, Steven C, and John B. Kitto, Editors. 1992. Steam, Its Generation and Use. The
Babcock and Wilcox Company.
Texas Natural Resource Conservation Commission, Office of Air Quality. January 1994.
Asphalt Concrete Plants: Emissions Calculations Instructions. Compiled by TNRCC
Mechanical Section Engineers, Austin, Texas.
Wiese, Lynda, of Wisconsin Department of Natural Resources. June 15, 1995.
Memorandum to Theresa Kemmer Moody, Radian Corporation. Comments on Preferred
and Alternative Methods for Estimating Air Emissions from Hot-Mix Asphalt Plants.
EIIP Volume II 3.8-3
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3.8-4 EIIP Volume II
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7/26/96 CHAPTER 3 - HOT-MIXASPHALT PLANTS
APPENDIX A
EXAMPLE DATA COLLECTION FORM
AND INSTRUCTIONS FOR HOT-MIX
ASPHALT PLANTS
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7/26/96 CHAPTER 3 - HOT-MIX ASPHALT PLANTS
EXAMPLE DATA COLLECTION FORM
INSTRUCTIONS
1. This form may be used as a work sheet to aid the plant engineer in collecting the
information necessary to calculate emissions from HMA plants. The information
requested on the form relates to the methods (described in Sections 3 through 5)
for quantifying emissions. This form may also be used by the regulatory agency
to assist in area wide inventory preparation.
2. The completed forms should be maintained in a reference file by the plant
engineer with other supporting documentation.
3. The information requested on these forms is needed to complete emission
calculations. If the information requested does not apply to a particular dryer,
mixer, or unit, write "NA" in the blank.
4. If you want to modify the form to better serve your needs, an electronic copy of
the form may be obtained through the EIIP on the CHIEF bulletin board system
(BBS).
5. If hourly or monthly fuel use information is not available, enter the information
in another unit (quarterly or yearly). Be sure to indicate on the form what the
unit of measure is.
6. Use the comments field on the form to record all useful information that will
allow your work to be reviewed and reconstructed.
EIIP Volume II 3.A-1
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CHAPTER 3 - HOT-MIX ASPHAL T PLANTS 7/26/96
EXAMPLE DATA COLLECTION FORM - HOT-MIX ASPHALT PLANTS
GENERAL INFORMATION
Facility/Plant Name:
SIC Code:
SCC:
SCC Description:
Location:
County:
City:
State:
Parent Company Address:
Plant Geographical Coordinates (if portable, state so):
Latitude:
Longitude:
UTM Zone:
UTM Easting:
UTM Northing:
Contact Name:
Title:
Telephone Number:
Source ID Number: AIRS or FID?
Type of Plant (i.e., batch, drum):
Permit Number:
Permitted Hours of Operation (per year):
Actual Hours of Operation (per year):
Hours/Day:
Days/Weeks:
Weeks/Year:
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7/26/96
CHAPTER 3 - HOT-MIX ASPHALT PLANTS
EXAMPLE DATA COLLECTION FORM - HOT-MIX ASPHALT PLANTS
COMBUSTION OPERATIONS
ASPHALT CEMENT HEATERS:
Unit ID No.:
Fuel A
FuelB
FuelC
Comments
fuel Type:
Year:
laximum Hourly Fuel Use (units):
fotal Annual Fuel Use (units):
laximum Capacity of Heater(s) (Million Btu/hr):
pte: Complete this form for each type of fuel used and for each unit.
EIIP Volume II
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CHAPTER 3 - HOT-MIX ASPHALT PLANTS
7/26/96
EXAMPLE DATA COLLECTION FORM - HOT-MIX ASPHALT PLANTS
COMBUSTION OPERATIONS ,
DRYERS:
Unit ID No.:
Fuel Type:
Year:
Composition (% sulfur)
Composition (metals)
Maximum Hourly Fuel Use (units):
Monthly Fuel Use (units):
January:
February:
March:
April:
May:
June:
July:
August:
September:
October:
November:
December:
Total Annual Fuel Use (units):
Fuel A
FuelB
FuelC
-
Comments
-
3.A-4
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7/26/96
CHAPTER 3 - HOT-MIX ASPHALT PLANTS
EXAMPLE DATA COLLECTION FORM - HOT-MIX ASPHALT PLANTS
GENERATORS:
: Horsepower or kilowatts:
Unit ID:
Kiel Type:
tar:
iximum Hourly Fuel Use (units):
»tal Annual Fuel Use (units):
STACK/VENT INFORMATION
Fuel A
FuelB
Fuel C Comments
fease fill out the following information for each stack/vent. Attach additional sheets as needed.
STACK
PARAMETER
Source(s) Vented:
•rtitude/Longitude:
UTM Zone:
WM Easting:
^fTM Northing:
ftight (feet):
fjameter (feet):
Temperature (°F):
feocity (FPS):
Flow Rate (ACFM):
Sck/Vent Direction:
rt./horiz./fugitive)
fc. Capped (yes/no):
STACK ID NUMBER
(circle one)
VHP
STACK ID NUMBER
(circle one)
VHP
STACK ID NUMBER
(circle one)
VHP
EIIP Volume II
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CHAPTER 3 - HOT-MIX ASPHALT PLANTS
7/26/96
EXAMPLE DATA COLLECTION FORM - HOT-MIX ASPHALT PLANTS
PRODUCTION OPERATIONS
COMMENTS
Year:
Asphalt Produced (tons):
Maximum Design Capacity of Plants (tons/hr) (This
should be standardized at 5% moisture):
Liquid Asphaltic Cement Used (tons):
Tons of RAP Processed:
Tons of Mineral Filler Used from Silos:
AIR POLLUTION CONTROL EQUIPMENT
Please fill out the following information for each control device. Attach additional sheets as need'
&m
Control Type
Location
Efficiency (%)
How calculated?
EXAMPLE: Fabric Filter
Dryer Exhaust
99
Vendor's specs
3.A-6
EIIP Volume II
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Ni
EMISSION ESTIMATION RESULTS
Unit ID No.
§
Pollutant
VOC
NOX
CO
SO2
PM10
Total Paniculate
Hazardous Air
Pollutants (list
individually)
Emission
Estimation
Method3
Emission
Factor
Throughput
Emission
Factor*
Emissions
Factor
Units
Annual
Emissions
Emission
Units
Comments
a Use the following codes to indicate which emission estimation method is used for each pollutant:
CEMS/PEM = CEM/PEM Emission Factor = EF
Stack Test Data = ST Other (indicate) = O
Fuel Analysis = FA
Where applicable, enter the emission factor and provide the full citation of the reference or source of information from where the
emission factor came. Include edition, version, table, and page numbers if AP-42 is used.
1
t)
Co
1
r-
a
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3.A-8 EIIP Volume II
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VOLUME II: CHAPTER 4
PREFERRED AND ALTERNATIVE
METHODS FOR ESTIMATING
FUGITIVE EMISSIONS FROM
EQUIPMENT LEAKS
November 1996
Prepared by:
Eastern Research Group
Prepared for:
Point Sources Committee
Emission Inventory Improvement Program
-------
DISCLAIMER
This document was furnished to the Emission Inventory Improvement Program and the
U.S. Environmental Protection Agency by Eastern Research Group, Inc., Morrisville,
North Carolina. This report is intended to be a final document and has been reviewed
and approved for publication. The opinions, findings, and conclusions expressed
represent a consensus of the members of the Emission Inventory Improvement Program.
Any mention of company or product names does not constitute an endorsement of the
company or product; rather the names are used as examples.
-------
ACKNOWLEDGEMENT
This document was prepared by Eastern Research Group, Inc., Wiley Barbour of the
Office of Policy, Planning and Evaluation, U.S. Environmental Protection Agency, and
Radian International, LLC, for the Point Sources Committee, Emission Inventory
Improvement Program and for Dennis Beauregard of the Emission Factor and Inventory
Group, U.S. Environmental Protection Agency. Members of the Point Sources
Committee contributing to the preparation of this document are:
Demise Alston-Gulden, Galsen Corporation
Paul Brochi, Texas Natural Resource Conservation Commission
Bob Betterton, South Carolina Department of Health and Environmental Control
Alice Fredlund, Louisana Department of Environmental Quality
Bill Gill, Co-Chair, Texas Natural Resource Conservation Commission
Karla Smith Hardison, Texas Natural Resource Conservation Commission
Gary Helm, Air Quality Management, Inc.
Paul Kim, Minnesota Pollution Control Agency
Toch Mangat, Bay Area Air Quality Management District
Ralph Patterson, Wisconsin Department of Natural Resources
Jim Southerland, North Carolina Department of Environment, Health and Natural Resources
Eitan Tsabari, Omaha Air Quality Control Division
Robert Wooten, North Carolina Department of Environment, Health and Natural Resources
EIIP Volume II 111
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CHAPTER 4 - EQUIPMENT LEAKS 11/29/96
This page is intentionally left blank.
iv EIIP Volume II
-------
CONTENTS
Section Page
1 Introduction 4.1-1
2 General Source Category Description 4.2-1
2.1 Source Category Description 4.2-1
2.1.1 Pumps 4.2-1
2.1.2 Valves 4.2-2
2.1.3 Compressors . '. . . . . 4.2-2
2.1.4 Pressure Relief Devices 4.2-2
2.1.5 Connectors and Flanges 4.2-2
2.1.6 Agitators 4.2-3
2.1.7 Open-Ended Lines 4.2-3
2.1.8 Sampling Connections 4.2-4
2.2 Pollutant Coverage 4.2-4
2.2.1 Total Organic Compounds 4.2-4
2.2.2 Speciated Organics/Hazardous and Toxic Air Pollutants 4.2-4
2.2.3 Inorganic Compounds 4.2-4
2.3 Estimation of Control Efficiencies for Equipment Leak Control
Techniques 4.2-5
2.3.1 Replacement/Modification of Existing Equipment 4.2-5
2.3.2 Leak Detection and Repair (LDAR) Programs 4.2-8
3 Overview of Available Methods ; 4.3-1
3.1 Emission Estimation Approaches 4.3-1
3.2 Speciating Emissions 4.3-6
3.3 Organic Compound Emission Estimates From Equipment
Containing Non-VOCs 4.3-6
3.4 Inorganic Compound Emission Estimates 4.3-7
EIIP Volume II
-------
CONTENTS (CONTINUED)
Section Page
3.5 Description of Available Procedures for Collecting Equipment Leaks
Data 4.3-8
3.5.1 Source Screening 4.3-8
3.5.2 Mass Emissions Sampling (Bagging) 4.3-12
3.6 Comparison of Available Emission Estimation
Methodologies/Approaches 4.3-17
4 Preferred Method for Estimating Emissions 4.4-1
5 Alternative Methods for Estimating Emissions 4.5-1
5.1 Emission Calculations Using the Average Emission Factor
Approach 4.5-1
5.2 Emission Calculations Using the Screening Ranges Approach 4.5-6
5.3 Emission Calculations Using Unit-Specific Correlation Approach 4.5-7
6 Quality Assurance/Quality Control Procedures 4.6-1
6.1 Screening and Bagging Data Collection 4.6-1
6.2 Other QA/QC Issues 4.6-5
6.3 Data Attribute Rating System (DARS) Scores 4.6-5
7 Data Coding Procedures 4.7-1
8 References 4.8-1
Appendix A: Estimating Leak Detection and Repair (LDAR) Control Effectiveness
Appendix B: Source Screening - Response Factors
Appendix C: Mass Emission Sampling - Methods and Calculation Procedures
Appendix D: Example Data Collection Form
VI EIIP Volume II
-------
FIGURES AND TABLES
Figures Page
4.3-1 Overview of Data Collection and Analysis Approaches for Developing
Equipment Leak Emissions Inventory 4.3-4
4.3-2 HW-101 Portable Organic Compound Detection
Instrument (HNU Systems, Inc.) 4.3-14
4.3-3 OVA-108 Portable Organic Compound Detection
Instrument (Foxboro) 4.3-15
4.3-4 TVA-1000 Portable Organic/Inorganic Compound Detection
Instrument (Foxboro) 4.3-16
4.6-1 Example Field Sheet for Equipment Screening Data 4.6-2
4.6-2 Example Data Collection Form for Fugitive Emissions Bagging Test
(Vacuum Method) 4.6-3
4.6-3 Example Data Collection Form for Fugitive Emissions Bagging Test
(Blow-Through Method) 4.6-4
Tables Page
4.2-1 Summary of Equipment Modifications 4.2-6
4.2-2 Control Effectiveness for an LDAR Program at a SOCMI Process Unit 4.2-10
4.2-3 Control Effectiveness for LDAR Component Monitoring Frequencies for
Petroleum Refineries 4.2-11
4.3-1 List of Variables and Symbols 4.3-2
4.3-2 Equipment Leak Emission Sources 4.3-9
4.3-3 EPA Reference Method 21 Performance Criteria for
Portable Organic Compound Detectors 4.3-11
EIIP Volume II vii
-------
FIGURES AND TABLES (CONTINUED)
Tables Page
4.3-4 Portable Organic Compound Detection Instruments 4.3-13
4,3-5 Summary of the Advantages and Disadvantages of Preferred and
Alternative Emission Estimation Approaches for Equipment Leaks 4.3-18
4.4-1 Sample Data for Example Calculations 4.4-2
4.4-2 EPA Correlation Equation Method 4.4-3
4.4-3 Correlation Equations, Default Zero Emission Rates, and Pegged
Emission Rates for Estimating SOCMI TOC Emission Rates 4.4-5
4.4-4 Correlation Equations, Default Zero Emission Rates, and Pegged
Emission Rates for Estimating Petroleum Industry TOC
Emission Rates 4.4-6
4.5-1 SOCMI Average Emission Factors 4.5-2
4.5-2 Refinery Average Emission Factors 4.5-3
4.5-3 Average Emission Factor Method 4.5-5
4.5-4 Screening Value Ranges Method 4.5-8
4.6-1 DARS Scores: EPA Correlation Approach . 4.6-6
4.6-2 DARS Scores: Average Emission Factor Approach 4.6-6
4.6-3 DARS Scores: Unit-Specific Correlation Approach 4.6-7
4.7-1 Source Classification Codes and Descriptions for Fugitive Emissions
from Equipment Leaks 4.7-2
Vlll EIIP Volume II
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1
INTRODUCTION
The purposes of this document are to present general information on methodologies and/or
approaches for estimating air emissions from equipment leaks in a clear and concise manner
and to provide specific example calculations to aid in the preparation and review of emission
inventories.
Because documents describing procedures for estimating emissions from equipment leaks are
readily available, duplication of detailed information will be avoided in this document. The
reader is referred to the following reports that were used to develop this document:
• Environmental Protection Agency (EPA). November 1995. Protocol for
Equipment Leak Emission Estimates. EPA-453/R-95-017; U.S. Environmental
Protection Agency, Office of Air and Radiation, Office of Air Quality Planning
and Standards, Research Triangle Park, North Carolina;
• Chemical Manufacturers Association (CMA). 1989. Improving Air Quality:
Guidance for Estimating Fugitive Emissions. Second Edition. Washington,
DC; and,
During the development of this guideline document, results of recent studies developed by the
EPA for the petroleum industry were incorporated (Epperson, January, 1995). This
information is available on the Office of Air Quality Planning and Standards (OAQPS)
Technology Transfer Network (TTN) bulletin board (under the Clearinghouse for Inventories
and Emission Factors [CHIEF]).
Section 2 of this chapter contains a general description of the equipment leak sources, such as
valves, pumps, and compressors and also includes information on equipment leak control
techniques and efficiencies. Section 3 of this chapter provides an overview of available
approaches for estimating emissions from equipment leaks. Four main approaches are
discussed and compared in Section 3: (1) average emission factor; (2) screening ranges; (3)
EPA correlation equation; and (4) unit-specific correlation equations. Also included in this
section are descriptions of available procedures for collecting equipment leaks data and a
comparison of available emission estimation approaches. Section 4 presents the preferred
method for estimating emissions, while Section 5 presents alternative emission estimation
methods. Quality assurance and control procedures are described in Section 6 and data coding
procedures are discussed in Section 7. References are listed in Section 8.
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CHAPTER 4 - EQUIPMENT LEAKS 11/29/96
Appendix A presents information on how to estimate the control effectiveness of leak
detection and repair (LDAR) programs. Appendix B presents additional information on
response factors (RFs) and some guidelines on how to evaluate whether an RF correction to a
screening value should be made. Appendix C of this chapter presents general information on
methods and calculation procedures for mass emissions sampling (bagging). Appendix D
presents an example data collection form that can be used for gathering information to
estimate fugitive emissions from equipment leaks.
4.1-2 EIIP Volume II
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GENERAL SOURCE CATEGORY
DESCRIPTION
2.1 SOURCE CATEGORY DESCRIPTION
Emissions occur from process equipment whenever components in the liquid or gas stream
leak. These emissions generally occur randomly and are difficult to predict. In addition,
these emissions may be intermittent and vary in intensity over time. Therefore, measurements
of equipment leak emissions actually represent a "snapshot" of the leaking process. There are
several potential sources of equipment leak emissions. Components such as pumps, valves,
pressure relief valves, flanges, agitators, and compressors are potential sources that can leak
due to seal failure. Other sources, such as open-ended lines, and sampling connections may
leak to the atmosphere for reasons other than faulty seals. The majority of data collected for
estimating equipment leak emissions has been for total organic compounds and non-methane
organic compounds. Equipment leak emission data have been collected from the following
industry segments:
• Synthetic Organic Chemical Manufacturing Industry (SOCMI);
• Petroleum Refineries;
• Petroleum Marketing Terminals; and
• Oil and Gas Production Facilities.
Each of these emission sources is briefly described in this section. A more detailed discussion
of these sources can be found in the Protocol for Equipment Leak Emission Estimates (EPA,
November 1995) and the Equipment Leaks Enabling Document (EPA, July 1992).
2.1.1 PUMPS
Pumps are used extensively in the petroleum and chemical industries for the movement of
liquids. The centrifugal pump is the most widely used pump type in the chemical industry;
however, other types, such as the positive displacement (reciprocating) pump, are also used.
Chemicals transferred by pump can leak at the point of contact between the moving shaft and
the stationary casing. Consequently, all pumps except the sealless type, such as canned-motor,
magnetic drive, and diaphragm pumps, require a seal at the point where the shaft penetrates
the housing in order to isolate the pumped fluid from the environment.
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CHAPTER 4 - EQUIPMENT LEAKS 11/29/96
Two generic types of seals, packed and mechanical, are used on pumps. Packed seals can be
used on both reciprocating and centrifugal pumps. A packed seal consists of a cavity
("stuffing box") in the pump casing filled with packing gland to form a seal around the shaft.
Mechanical seals are limited in application to pumps with rotating shafts. There are single
and dual mechanical seals, with many variations to their basic design and arrangement, but all
have a lapped seal face between a stationary element and a rotating seal ring.
2.1.2 VALVES
Except for connectors, valves are the most common and numerous process equipment type
found in the petroleum and chemical industries. Valves are available in many designs, and
most contain a valve stem that operates to restrict or allow fluid flow. Typically, the stem is
sealed by a packing gland or 0-ring to prevent leakage of process fluid to the atmosphere.
Emissions from valves occur at the stem or gland area of the valve body when the packing or
O-ring in the valve fails.
2.1.3 COMPRESSORS
Compressors provide motive force for transporting gases through a process unit in much the
same way that pumps transport liquids. Compressors are typically driven with rotating or
reciprocating shafts. Thus, the sealing mechanisms for compressors are similar to those for
pumps (i.e., packed and mechanical seals).
2.1.4 PRESSURE RELIEF DEVICES
Pressure relief devices are safety devices commonly used in petroleum and chemical facilities
to prevent operating pressures from exceeding the maximum allowable working pressures of
the process equipment. Note that it is not considered an equipment leak-type emission when a
pressure relief device functions as designed during an over pressure incident allowing pressure
to be reduced. Equipment leaks from pressure relief devices occur when material escapes
from the pressure relief device during normal operation. The most common pressure relief
valve (PRV) is spring-loaded. The PRV is designed to open when the operating pressure
exceeds a set pressure and to reseat after the operating pressure has decreased to below the set
pressure. Another pressure relief device is a rupture disk (RD) which does not result in
equipment leak emissions. The disks are designed to remain whole and intact, and burst at a
set pressure.
2.1.5 CONNECTORS AND FLANGES
Connectors and flanges are used to join sections of piping and equipment. They are used
wherever pipes or other equipment (such as vessels, pumps, valves, and heat exchangers)
require isolation or removal. Flanges are bolted, gasket-sealed connectors and are normally
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used for pipes with diameters of 2.0 inches or greater. The primary causes of flange leakage
are poor installation, aging and deterioration of the sealant, and thermal stress. Flanges can
also leak if improper gasket material is chosen.
Threaded fittings (connectors) are made by cutting threads into the outside end of one piece
(male) and the inside end of another piece (female). These male and female parts are then
screwed together like a nut and bolt. Threaded fittings are normally used to connect piping
and equipment having diameters of 2.0 inches or less. Seals for threaded fittings are made by
coating the male threads with a sealant before joining it to the female piece. The sealant may
be a polymeric tape, brush-on paste, or other spreadable material that acts like glue in the
joint. These sealants typically need to be replaced each time the joint is broken. Emissions
can occur as the sealant ages and eventually cracks. Leakage can also occur as the result of
poor assembly or sealant application, or from thermal stress on the piping and fittings.
In the 1993 petroleum industry studies, flanges were analyzed separately from connectors.
Non-flanged connectors (or just connectors) were defined as plugs, screwed or threaded
connectors, and union connectors that ranged in diameter from 0.5 to 8.0 inches, but were
typically less than 3.0 inches in diameter. Flanged connectors (flanges) were larger, with
diameters in some cases of 22.0 inches or more.
2.1.6 AGITATORS
Agitators are used in the chemical industry to stir or blend chemicals. Four seal arrangements
are commonly used with agitators: packed seals, mechanical seals, hydraulic seals, and lip
seals. Packed and mechanical seals for agitators are similar in design and application to
packed and mechanical seals for pumps. In a hydraulic seal, an annular cup attached to the
process vessel contains a liquid that contracts an inverted cup attached to the rotating agitator
shaft. Although the simplest agitator shaft seal, the hydraulic seal, is limited to low
temperature/low pressure applications, and can handle only very small pressure changes. A
lip seal consists of a spring-loaded, nonlubricated elastomer element, and is limited in
application to low-pressure, top-entering agitators.
2.1.7 OPEN-ENDED LINES
Some valves are installed in a system so that they function with the downstream line open to
the atmosphere. A faulty valve seat or incompletely closed valve on such an open-ended line
would result in a leakage through the open end.
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2.1.8 SAMPLING CONNECTIONS
Sampling connections are used to obtain samples from within the process. Emissions occur as
a result of purging the sampling line to obtain a representative sample of the process fluid.
2.2 POLLUTANT COVERAGE
2.2.1 TOTAL ORGANIC COMPOUNDS
The majority of data collected for estimating equipment leaks within the petroleum and gas
industries and the SOCMI has been for total organic compounds and non-methane organic
compounds. Therefore, the emission factors and correlations developed for emission
estimation approaches are intended to be used for estimating total organic compound (TOC)
emissions.
2.2.2 SPECIATED ORGANICS/HAZARDOUS AND Toxic AIR POLLUTANTS
Because material in equipment within a process unit is often a mixture of several chemicals,
equipment leak emission estimates for specific volatile organic compounds (VOCs), hazardous
air pollutants (HAPs), and/or pollutants under Section 112(r) of the Clean Air Act, as
amended can be obtained by multiplying the TOC emissions from a particular equipment
times the ratio of the concentration of the specific VOC/pollutant to the TOC concentration,
both in weight percent. An assumption in the above estimation is that the weight percent of
the chemicals in the mixture contained in the equipment will equal the weight percent of the
chemicals in the leaking material. In general, this assumption should be accurate for single-
phase streams containing any gas/vapor material or liquid mixtures containing constituents of
similar volatilities. Engineering judgement should be used to estimate emissions of individual
chemical species, in cases when:
• The material in the equipment piece is a liquid mixture of constituents with
varying volatilities; or
• It is suspected that the leaking vapor will have different concentrations than the
liquid.
2.2.3 INORGANIC COMPOUNDS
The emission estimation approaches developed for estimating TOC emissions may be used to
estimate emissions of inorganic compounds—particularly for volatile compounds or those
present as a gas/vapor. Also, in the event that there is no approach available to estimate the
concentration of the inorganic compound at the leak interface, the average emission factors
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developed for organic compounds can be used; however, the accuracy of the emission
estimate will be unknown.
2.3 ESTIMATION OF CONTROL EFFICIENCIES FOR EQUIPMENT LEAK
CONTROL TECHNIQUES
Two primary techniques are used to reduce equipment leak emissions: (1) modifying or
replacing existing equipment, and (2) implementing an LDAR program. Equipment
modifications are applicable for each of the leaking equipment described in this section. An
LDAR program is a structured program to detect and repair equipment that are identified as
leaking; however, it is more effective on some equipment than others.
The use of equipment modifications and equipment included in an LDAR program are
predicated by state and federal regulations that facilities/process units are required to meet. In
most equipment leak regulations, a combination of equipment modifications and LDAR
requirements are used. Table 4.A-1 in Appendix A of this chapter summarizes requirements
in several federal equipment leak control regulations.
2.3.1 REPLACEMENT/MODIFICATION OF EXISTING EQUIPMENT
Controlling emissions by modifying existing equipment is achieved by either installing
additional equipment that eliminates or reduces emissions, or replacing existing equipment
with sealless types. Equipment modifications that can be used for each type of equipment
described in this section, and their corresponding emission control efficiencies are presented in
Table 4.2-1. A closed-vent system is a typical modification for pumps, compressors, and
pressure relief devices. A closed-vent system captures leaking vapors and routes them to a
control device. The control efficiency of a closed-vent system depends on the efficiency of
the vapor transport system and the efficiency of the control device. A closed-vent system can
be installed on a single piece of equipment or on a group of equipment pieces. A description
of the controls by equipment type are briefly presented below.
Pumps
Equipment modifications that are control options for pumps include: (1) routing leaking
vapors to a closed-vent system, (2) installing a dual mechanical seal containing a barrier fluid,
or (3) replacing the existing pump with a sealless type. Dual mechanical seals and sealless
pumps are discussed in detail in Chapter 5 of the Equipment Leaks Enabling Document (EPA,
July 1992). The control efficiency of sealless pumps and a dual mechanical seal with a
barrier fluid at a higher pressure than the pumped fluid is essentially 100 percent, assuming
both the inner and outer seal do not fail simultaneously.
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TABLE 4.2-1
SUMMARY OF EQUIPMENT MODIFICATIONS
Equipment Type
Pumps
Valves
Compressors
Pressure relief
devices
Connectors
Open-ended lines
Sampling
connections
Modification
Sealless design
Closed-vent system
Dual mechanical seal with barrier fluid
maintained at a higher pressure than the
pumped fluid
Sealless design
Closed-vent system
Dual mechanical seal with barrier fluid
maintained at a higher pressure than the
compressed gas
Closed-vent system
Rupture disk assembly
Weld together
Blind, cap, plug, or second valve
Closed-loop sampling
Approximate
Control
Efficiency
(%)
100a
90b
100
100a
90b
100
c
100
100
100
100
a Sealless equipment can be a large source of emissions in the event of equipment failure.
b Actual efficiency of a closed-vent system depends on percentage of vapors collected and the efficiency
of the control device to which the vapors are routed.
c Control efficiency of closed vent-systems installed on a pressure relief device may be lower than other
closed-vent systems because they must be designed to handle both potentially large and small volumes
of vapor.
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Valves
Emissions from process valves can be eliminated if the valve stem can be isolated from the
process fluid, (i.e., using sealless valves). Two types of sealless valves, diaphragm valves and
sealed bellows, are available. The control efficiency of both diaphragm and sealed bellowed
valves is essentially 100 percent.
Compressors
Emissions from compressors may be reduced by collecting and controlling the emissions from
the seal using a closed-vent system or by improving seal performance by using a dual
mechanical seal system similar to pumps. The dual mechanical seal system has an emissions
control efficiency of 100 percent, assuming both the inner and outer seal do not fail
simultaneously.
Pressure Relief Valves
Equipment leaks from pressure relief valves (PRVs) occur as a result of improper reseating of
the valve after a release, or if the process is operating too close to the set pressure of the PRV
and the PRV does not maintain the seal. There are two primary equipment modifications that
can be used for controlling equipment leaks from pressure relief devices: (1) a closed-vent
system, or (2) use of a rupture disk in conjunction with the PRV.
The equipment leak control efficiency for a closed-vent system installed on a PRV may not be
as high as what can be achieved for other pieces of equipment because emissions from PRVs
can have variable flow during an overpressure situation and it may be difficult to design a
control device to efficiently handle both high and low flow emissions. Rupture disks can be
installed upstream of a PRV to prevent fugitive emissions through the PRV seat. The control
efficiency of a rupture disk/PRV combination is essentially 100 percent when operated and
maintained properly.
Connectors and Flanges
In cases where connectors are not required for safety, maintenance, process modification, or
periodic equipment removal, emissions can be eliminated by welding the connectors together.
Open-Ended Lines
Emissions from open-ended lines can be controlled by properly installing a cap, plug, or
second valve to the open end. The control efficiency of these measures is essentially
100 percent.
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Sampling Connections
Emissions from sampling connections can be reduced by using a closed-loop sampling system
or by collecting the purged process fluid and transferring it to a control device or back to the
process. The efficiency of a closed-loop system is 100 percent.
2.3.2 LEAK DETECTION AND REPAIR (LDAR) PROGRAMS
An LDAR program is a structured program to detect and repair equipment that is identified as
leaking. A portable screening device is used to identify (monitor) pieces of equipment that
are emitting sufficient amounts of material to warrant reduction of the emissions through
simple repair techniques. These programs are best applied to equipment types that can be
repaired on-line, resulting in immediate emissions reduction.
An LDAR program may include most types of equipment leaks; however, it is best-suited to
valves and pumps and can also be implemented for connectors. For other equipment types, an
LDAR program is not as applicable. Compressors are repaired in a manner similar to pumps;
however, because compressors ordinarily do not have a spare for bypass, a process unit
shutdown may be required for repair. Open-ended lines are most easily controlled by
equipment modifications. Emissions from sampling connections can only be reduced by
changing the method of collecting the sample, and cannot be reduced by an LDAR program.
Safety considerations may preclude the use on an LDAR program on pressure relief valves.
The control efficiency of an LDAR program is dependent on three factors: (1) how a leak is
defined, (2) the monitoring frequency of the LDAR program, and (3) the final leak frequency
after the LDAR program is implemented. The leak definition is the screening value measured
by a portable screening device at which a leak is indicated if a piece of equipment screens
equal to or greater than that value. Screening values are measured as concentrations in parts
per million by volume (ppmv). The leak definition is a given part of an LDAR program and
can either be defined by the facility implementing the program or by an equipment standard
to which the facility must comply. Table 4.A-1 in Appendix A of this document provides
equipment leak screening values for several equipment leak control programs. The
monitoring frequency is the number of times a year (daily, weekly, monthly, quarterly, yearly)
that equipment are monitored with a portable screening device. The monitoring frequency
may be estimated from the initial leak frequency before the LDAR program is implemented,
and the final leak frequency after the LDAR program is implemented. The leak frequency is
the fraction of equipment with screening values equal to or greater than the leak definition.
The LDAR program control efficiency approach is based on the relationship between the
percentage of equipment pieces that are leaking and the corresponding average leak rate for
all of the equipment.
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Most federal equipment leak control programs have quarterly or monthly monitoring
requirements. However, the LDAR monitoring frequency and leak definitions at some state
equipment leak control programs may be different from federal programs. During the
planning of a LDAR program, it is recommended to contact the local environmental agency to
find out about their LDAR program guidelines and/or requirements.
The EPA has developed control efficiencies for equipment monitored at specified leak
definitions and frequencies. Tables 4.2-2 and 4.2-3 summarize the control efficiencies for
equipment that are monitored quarterly and monthly at a leak definition of 10,000 ppmv,
and equipment meeting the LDAR requirements of the National Emission Standard for
Hazardous Air Pollutants (NESHAP) for hazardous organics known as the Hazardous Organic
NESHAP (HON). Although it was developed for the SOOvfl, it is the basis for most new
equipment leak regulations for other industries. Appendix A presents information on how to
develop process/facility-specific control efficiencies.
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to
1
H^
o
TABLE 4.2-2
CONTROL EFFECTIVENESS FOR AN LDAR PROGRAM AT A SOCMI PROCESS UNIT
Equipment Type and Service
Valves - gas
Valves - light liquid
Pumps - light liquid
Compressors - gas
Connectors - gas and light liquid
Pressure relief devices - gas
Control Effectiveness (%)
Monthly
Monitoring
10,000 ppmv Leak
Definition
87
84
69
b
b
b
Quarterly Monitoring
10,000 ppmv Leak
Definition
67
61
45
b
33
44
HONa
92
88
75
93
b
b
" Control effectiveness attributed to the requirements of the HON equipment leak regulation is estimated based on equipment-specific leak
definitions and performance levels.
b Data are not available to estimate control effectiveness.
i
s
g
1
-H
r—
CD
CO
Oj
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TABLE 4.2-3
I
CD
CONTROL EFFECTIVENESS FOR LDAR COMPONENT MONITORING FREQUENCIES FOR
PETROLEUM REFINERIES
(o
05
Equipment Type and Service
Valves - gas
Valves - light liquid
Pumps - light liquid
Compressors - gas
Connectors - gas and light liquid
Pressure relief devices - gas
Control Effectiveness (%)
Monthly
Monitoring
10,000 ppmv Leak
Definition2
88
76
68
d
f
d
Quarterly Monitoring
10,000 ppmv Leak
Definition3'''
70
61
45
33
r
44
HON^1
96
95
88
e
81
e
1
"0
a
c;
I
-H
i—
2!
• Source: EPA, July 1992.
b Source: EPA, April 1982.
c Control effectiveness attributed to the requirements of the HON equipment leak regulation is estimated based on equipment-specific leak
definitions and performance levels.
d Monthly monitoring of component is not required in any control program.
c Rule requires equipment modifications instead of LDAR.
f Information not available.
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OVERVIEW OF AVAILABLE METHODS
This section contains general information on the four basic approaches for estimating
equipment leak emissions. The approach used is dependent upon available data, available
resources to develop additional data, and the degree of accuracy needed in the estimate.
Regulatory considerations should also be taken into account in selecting an emission
estimation approach. These considerations may include air toxic evaluations, nonattainment
emission inventory reporting requirements, permit reporting requirements, and employee
exposure concerns.
Each approach is briefly described including its corresponding data requirements. Since data
collection procedures will impact the accuracy of the emission estimate, this section also
includes a general description of the two variable procedures for collecting equipment leaks
data, screening and bagging procedures, and available monitoring methods. Finally, a general
description for estimating control efficiencies for equipment leak control techniques is
presented. Table 4.3-1 lists the variables and symbols used in the following discussions on
emissions estimates.
3.1 EMISSION ESTIMATION APPROACHES
There are four basic approaches for estimating emissions from equipment leaks in a specific
processing unit. The approaches, in order of increasing refinement, are:
• Average emission factor approach;
• Screening ranges approach;
• EPA correlation approach; and
• Unit-specific correlation approach.
The approaches increase in complexity and in the amount of data collection and analysis
required. All the approaches require some data collection, data analysis and/or statistical
evaluation.
These approaches range from simply applying accurate equipment counts to average emission
factors to the more complex project of developing unit-specific correlations of mass emission
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TABLE 4.3-1
LIST OF VARIABLES AND SYMBOLS
Variable
TOC mass emissions
VOC mass emissions
Mass emissions of organic chemical x
Concentration of TOCs
VOC concentration
Concentration of organic chemical x
Average emission factor
Emission factor for screening value >1 0,000
ppmv
Emission factor for screening value <1 0,000
ppmv
Concentration from screening value
Symbol
ETOC
EVOC
Ex
WPTOC
WPvoc
WPX
FA
FG
FL
SV
Units
kg/hr of TOC
kg/hrofVOC
kg/hr of organic chemical x
weight percent of TOCs
weight percent of VOCs
weight percent of organic
chemical x
typically, kg/hr per source
kg/hr per source
kg/hr per source
ppmv
4.3-2
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rates and screening values. In general, the more refined approaches require more data and
provide more accurate emission estimates for a process unit. Also, the more refined
approaches, especially the unit-specific correlation approach which requires bagging data,
require a larger budget to implement the program and develop the correlation equations.
Figure 4.3-1 shows an overview of the data collection and analysis required to apply each of
the above approaches. All of the approaches require an accurate count of equipment
components by the type of equipment (e.g., valves, pumps, connectors), and for some of the
equipment types, the count must be further described by service (e.g., heavy liquid, light
liquid, and gas).
The chemical industry has developed alternative methods for estimating equipment component
count (CMA, 1989). One of the methods calls for an accurate count of the number of pumps
in the process and the service of the pumps. Equipment components in the entire process are
then estimated through use of the number of pumps. Another method calls for an accurate
count of valves directly associated with a specific piece of equipment using process flow
sheets; and then based on the number of valves, the number of flanges and fittings are
estimated using ratios (e.g., flanges/valves) A careful selection/development of the
methodology used to quantify the equipment component count should be made to accurately
reflect the equipment leak emission estimates for any facilities and/or process units.
Except for the average emission factor approach, all of the approaches require screening data.
Screening data are collected by using a portable monitoring instrument to sample air from
potential leak interfaces on individual pieces of equipment. A screening value is a measure of
the concentration of leaking compounds in the ambient air that provides an indication of the
leak rate from an equipment piece, and is measured in units of parts per million by volume
(ppmv). See "Source Screening" in this section for details about screening procedures.
In addition to equipment counts and screening data, the unit-specific correlation approach
requires bagging data. Bagging data consist of screening values and their associated measured
leak rates. A leak rate is measured by enclosing an equipment piece in a bag to determine the
actual mass emission rate of the leak. The screening values and measured leak rates from
several pieces of equipment are used to develop a unit-specific correlation. The resulting leak
rate/screening value correlation predicts the mass emission rate as a function of the screening
value. See "Mass Emissions Sampling (Bagging)" in this section for details about bagging
procedures.
These approaches are applicable to any chemical- and petroleum-handling facility. However,
more than one set of emission factors or correlations have been developed by the EPA and
other regulatory agencies, depending upon the type of process unit being considered.
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Count Equipment Components
(by type and service)
Conduct Complete
Screening Survey
Bag Components for Each
Equipment Type and Service
Develop Unit-Specific
Correlations
Apply Average Emission Factors
and Composite Total Emissions
Apply,1 10.000/
< IQ.OOOppmv Emission Factors
and Composite Total Emissions
Apply EPA Correlations and
Composite Total Emissions
Apply New Correlations
and Composite Total Emissions
Inventory
Inventory
Inventory
Inventory
Figure 4.3-1. Overview of Data Collection and Analysis Approaches
For Developing Equipment Leak Emissions Inventory
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EPA data collection on emissions from equipment leaks in SOCMI facilities, refineries, oil
and gas production operations, and marketing terminals has yielded emission factors and
correlations for these source categories. Emission factors and correlations for oil and gas
production facilities, including well heads, have also been developed by regulatory agencies
and the American Petroleum Institute (CARB, August 1989; API, 1993).
For process units in source categories for which emission factors and/or correlations have not
been developed, the factors and/or correlations already developed can be utilized. However,
appropriate evidence should indicate that the existing emission factors and correlations are
applicable to the source category in question. Criteria for determining the appropriateness of
applying existing emission factors and correlations to another source category may include
one or more of the following: (1) process design; (2) process operation parameters
(i.e., pressure and temperature); (3) types of equipment used; and, (4) types of material
handled. For example, in most cases, SOCMI emission factors and correlations are applicable
for estimating equipment leak emissions from the polymer and resin manufacturing industry.
This is because, in general, these two industries have comparable process design and
comparable process operations; they use the same types of equipment and they tend to use
similar feedstock with similar operations, molecular weight, density, and viscosity. Therefore,
response factors should also be similar for screening values.
In estimating emissions for a given process unit, all equipment components must be screened
for each class of components. However, in some cases, equipment is difficult or unsafe to
screen or it is not possible to screen every equipment piece due to cost considerations. The
latter is particularly true for connectors. The Protocol for Equipment Leak Emission
Estimates (EPA, November 1995) provides criteria for determining how may connectors must
be screened to constitute a large enough sample size to identify the screening value
distribution for connectors. However, if the process unit to be screened is subject to a
standard which requires the screening of connectors, then all connectors must be screened. If
the criteria presented in the Protocol document are met, the average emission rate for
connectors that were connected can be applied to connectors that were not screened. For
equipment types other than connectors, including difficult or unsafe-to-screen equipment, that
are not monitored, the average emission factor approach or the average emission rate for the
equipment components that were screened can be used to estimate emissions.
Also, screening data collected at several different times can be used for estimating emissions,
as long as the elapsed time between values obtained is known. For example, if quarterly
monitoring is performed on a valve, four screening values will be obtained from the valve in
an annual period. The annual emissions from the valve should be calculated by determining
the emissions for each quarter based on the operational hours for the quarter, and summing
the quarterly emission together to get entire year emissions.
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3.2 SPECIATING EMISSIONS
In some cases, it may be necessary to estimate emissions of a specific VOC in a mixture of
several chemicals. The equations developed for each one of the approaches (see Sections 4
and 5) are used to estimate total VOC emissions; the following equation is used to speciate
emissions from a single equipment piece:
Ex = ETOC x WPX/WPTOC (4.3-1)
where:
Ex = The mass emissions of organic chemical "x" from the equipment
(kg/hr);
ETOC = The TOC mass emissions from the equipment (kg/hr) calculated
from either the Average Emission Factor, Screening Ranges,
EPA Correlation, or Unit-Specific Correlation approaches;
WPX = The concentration of organic chemical x in the equipment in
weight percent; and
WPTOC = The TOC concentration in the equipment in weight percent.
An assumption in the above equation is that the weight percent of the chemicals in the
mixture contained in the equipment will equal the weight percent of the chemicals in the
leaking material. In general, this assumption should be accurate for single-phase streams
containing any gas/vapor material or liquid mixtures containing constituents of similar
volatilities.
Engineering judgement should be used to estimate emissions of individual chemical species
from liquid mixtures of constituents with varying volatilities or in cases where it is suspected
that the leaking vapor has different concentrations than the liquid.
3.3 ORGANIC COMPOUND EMISSION ESTIMATES FROM EQUIPMENT
CONTAINING NoN-VOCs
A very similar approach to the one used to speciate emissions can be used to estimate organic
compound emissions from equipment containing organic compounds not classified as VOCs.
Because the concentrations of these compounds (such as methane or ethane) are included with
VOC concentrations in the screening value, the emissions associated with the screening value
will include emissions of the "non-VOCs."
Once TOC emissions have been estimated, the organic compound emissions from a group of
equipment containing similar composition can be calculated using the equation:
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EVOC = ETOC X WPVOC/WPTOC (4.3-2)
where:
Evoc = The VOC mass emissions from the equipment (kg/hr);
ETOC = The TOC mass emissions from the equipment (kg/hr) calculated
from either the Average Emission Factor, Screening Ranges,
EPA Correlation, or Unit-Specific Correlation approaches;
WPVOC = The concentration of VOC in the equipment in weight percent;
and
WPTOC = The TOC concentration in the equipment in weight percent.
3.4 INORGANIC COMPOUND EMISSION ESTIMATES
The emission factors and correlations presented in this document are intended to be applied to
estimate emissions of total organic compounds. However, in some cases, it may be necessary
to estimate equipment leak emissions of inorganic compounds, particularly for those existing
as gas/vapor or for volatile compounds.
Equipment leak emission estimates of inorganic compounds can be obtained by the following
methods:
• Develop unit-specific correlations;
• Use a portable monitoring instrument to obtain actual concentrations of the
inorganic compounds and then enter the screening values obtained into the
applicable correlations developed by the EPA;
• Use the screening values obtained above and apply the emission factors
corresponding to that screening range; or
• Multiply the average emission factor by the component count to estimate the
leak rate.
Also, surrogate measurements can be used to estimate emissions of inorganic compounds. For
example, potassium iodide (KI) or a similar salt solution is an indicator for equipment leaks
from acid (hydrochloric acid [HC1], hydrofluoric acid [HF]) process lines.
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3.5 DESCRIPTION OF AVAILABLE PROCEDURES FOR COLLECTING
EQUIPMENT LEAKS DATA
The Protocol document (EPA, November 1995) provides a consistent approach for collecting
equipment leaks data, which will ensure the development of acceptable emission factors
and/or correlation equations for emission estimation purposes. Recognizing the importance of
the above statement, general information on the two available procedures for collecting
equipment leaks data, screening and bagging, is presented in this section.
3.5.1 SOURCE SCREENING
This part of the section provides general information for conducting a screening program
on-site and provides a short description of the type of portable analyzers that can be used
when conducting screening surveys.
Source screening is performed with a portable organic compound analyzer (screening device).
The Protocol document (EPA, November 1995) requires that the portable analyzer probe
opening be placed at the leak interface of the equipment component to obtain a "screening"
value. The screening value is an indication of the concentration level of any leaking material
at the leak interface.
Some state and local agencies may require different screening procedures with respect to the
distance between the probe and the leak interface. The reader should contact their state or
local agency to determine the appropriate screening guidelines. However, use of the leak rate
correlations require screening values gathered as closely as practicable to the leak interface.
The main objective of a screening program is to measure organic compound concentration at
any potential leak point associated with a process unit. A list of equipment types that are
potential sources of equipment leak emissions is provided in Table 4.3-2.
The first step is to define the process unit boundaries and obtain a component count of the
equipment that could release fugitive emissions. A process unit can be defined as the smallest
set of process equipment that can operate independently and includes all operations necessary
to achieve its process objective. The use of a simplified flow diagram of the process is
recommended to note the process streams. The actual screening data collection can be done
efficiently by systematically following each stream.
The procedures outlined in EPA Reference Method 21 — Determination of Volatile Organic
Compound Leaks (40 CFR 60, Appendix A) should be followed to screen each equipment
type that has been identified. The Protocol document (EPA, November 1995) describes the
location on each type of equipment where screening efforts should be concentrated. For
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TABLE 4.3-2
EQUIPMENT LEAK EMISSION SOURCES
Equipment Types
Pump seals
Compressor seals
Valves
Pressure relief devices
Flanges
Connectors
Open-ended lines
Agitator seals
Other3
Services
Gas/vapor
Light liquid
Heavy liquid
Includes instruments, loading arms, stuffing boxes, vents, dump lever
arms, diaphragms, drains, hatches, meters, polished rods, and vents.
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CHAPTER 4 - EQUIPMENT LEAKS 11/29/96
equipment with no moving parts at the leak interface, the probe should be placed directly on
the leak interface (perpendicular, not tangential, to the leak potential interface). On the other
hand, for equipment with moving parts, the probe should be placed approximately 1
centimeter off from the leak interface (EPA, November 1995). The Chemical Manufacturers
Association has also made some suggestions to maintain good screening practices (CMA,
1989). Recent ongoing efforts by the American Petroleum Institute have also been focused on
increasing the accuracy of screening readings.
Various portable organic compound detection devices can be used to measure concentration
levels at the equipment leak interface. Any analyzer can be used provided it meets the
specifications and performance criteria set forth in EPA Reference Method 21.
Reference Method 21 requires that the analyzer meet the following specifications:
• The VOC detector should respond to those organic compounds being processed
(determined by the response factor [RF]);
• Both the linear response range and the measurable range of the instrument for
the VOC to be measured and the calibration gas must encompass the leak
definition concentration specified in the regulation;
• The scale of the analyzer meter must be readable to ±2.5 percent of the
specified leak definition concentration;
• The analyzer must be equipped with an electrically driven pump so that a
continuous sample is provided at a nominal flow rate of between 0.1 and
3.0 liters per minute;
• The analyzer must be intrinsically safe for operation in explosive atmospheres;
and
• The analyzer must be equipped with a probe or probe extension for sampling
not to exceed 0.25 inch in outside diameter, with a single end opening for
admission of sample.
Note that the suction flow rate span allowed by Reference Method 21 is intended to
accommodate a wide variety of instruments, and manufacturers guidelines for appropriate
suction flow rate should be followed.
In addition to the specifications for analyzers, each analyzer must meet instrument
performance criteria, including instrument response factor, instrument response time, and
calibration precision. Table 4.3-3 presents the performance criteria requirements that portable
organic compound detectors must meet to be accepted for use in a screening program.
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CHAPTER 4 - EQUIPMENT LEAKS
TABLE 4.3-3
EPA REFERENCE METHOD 21 PERFORMANCE CRITERIA FOR PORTABLE ORGANIC
COMPOUND DETECTORS"
Criteria
Instrument
response factor*5
Instrument
response time0
Calibration
precision*1
Requirement
Must be <10 unless
correction curve is used
Must be <30 seconds
Must be <10 percent of
calibration gas value
Time Interval
One time, before detector is put in
service.
One time, before detector is put in
service. If modification to sample
pumping or flow configuration is
made, a new test is required.
Before detector is put in service and
at 3 -month intervals or next use,
whichever is later.
Source: 40 CFR Part 60, Appendix A, EPA Reference Method 21. These performance criteria must be
met in order to use the portable analyzer in question for screening.
The response factor is the ratio of the known concentration of a VOC to the observed meter reading
when measured using an instrument calibrated with the reference compound specified in the applicable
regulation.
The response time is the time interval from a step change in VOC concentration at the input of .the
sampling system to the time at which 90 percent of the corresponding final value is reached as displayed
on the instrument readout meter.
The precision is the degree of agreement between measurements of the same known value, expressed as
the relative percentage of the average difference between the meter readings and the known
concentration to the known concentration; i.e., between two meter readings of a sample of known
concentration.
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CHAPTER 4 - EQUIPMENT LEAKS 11/29/96
Table 4.3-4 lists several portable organic compound detection instruments, their
manufacturers, model number, pollutants detected, principle of operation, and range.
Figure 4.3-2 shows the HW-101 (HNU Systems, Inc.) instrument, Figure 4.3-3 shows the
Foxboro OVA-108, and Figure 4.3-4 shows the Foxboro TVA-1000. When a monitoring
device does not meet all of the EPA Reference Method 21 requirements, it can still be used
for the purpose of estimating emissions if its reliability is documented. For information on
operating principles and limitations of portable organic compound detection devices, as well
as specifications and performance criteria, please refer to the Protocol for Equipment Leak
Emission Estimates document (EPA, November 1995).
Data loggers are available for use with portable organic compound detection devices to aid in
the collection of screening data and in downloading the data to a computer. Database
management programs are also available to aid in screening data inventory management and
compiling emissions. Contact the American Petroleum Institute or state and local agencies for
more information about data loggers and database management programs.
As mentioned earlier, screening values are obtained by using a portable monitoring instrument
to detect TOCs at an equipment leak interface. However, portable monitoring instruments
used to detect TOC concentrations do not respond to different organic compounds equally.
To correct screening values to compensate for variations in a monitor's response to different
compounds, response factors (RFs) have been developed. An RF relates measured
concentrations to actual concentrations for specific compounds using specific instruments.
Appendix B of this chapter presents additional information on response factors and includes
some guidelines on how to evaluate whether an RF correction to a screening value should be
made.
3.5.2 MASS EMISSIONS SAMPLING (BAGGING)
An equipment component is bagged by enclosing the component to collect leaking vapors. A
bag (or tent) made of material that is impermeable to the compound(s) of interest is
constructed around the leak interface of the piece of the equipment.
A known rate of carrier gas is introduced into the bag. A sample of the gas from the bag is
collected and analyzed to determine the concentration (in parts per million by volume [ppmv])
of leaking material. The concentration is measured using laboratory instrumentation and
procedures. The use of analytical instrumentation in a laboratory is critical to accurately
estimate mass emissions. A gas chromatograph (GC) equipped with a flame ionization
detector or electron capture detector is commonly used to identify individual constituents of a
sample (EPA, November 1995).
4.3-12 EIIP Volume II
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TABLE 4.3-4
PORTABLE ORGANIC COMPOUND DETECTION INSTRUMENTS
o>
Manufacturer
Bacharach Instrument Co., Santa
Clara, California
Foxboro
S. Norwalk, Connecticut
Health Consultants
HNU Systems, Inc.
Newton Upper Falls,
Massachusetts
Mine Safety Appliances Co.,
Pittsburgh, Pennsylvania
Survey and Analysis, Inc.,
Northboro, Massachusetts
Rae Systems
Sunnyvale, California
Model
Number
L
TLV Sniffer
OVA- 128
OVA- 108
Miran ffiX
TVA-1000
Detecto- PAK
III
HW-101
40
On Mark
Model 5
MiniRAE
PGM-75K
Pollutant(s)
Detected
Combustible gases
Combustible gases
Most organic compounds
Most organic compounds
Compounds that absorb
infrared radiation
Most organic and inorganic
compounds
Most organic compounds
Chlorinated hydrocarbons,
aromatics, aldehydes,
ketones, any substance that
ultraviolet light ionizes
Combustible gases
Combustible gases
Chlorinated hydrocarbons,
aromatics, aldehydes,
ketones, any substance that
ultraviolet light ionizes
Detection
Technique
Catalytic
combustion
Catalytic
combustion
FID/GCb
FID/GC
NDIRC
Photoionization
and FID/GC
FID/GC
Photoionization
Catalytic
combustion
Thermal
conductivity
Photoionization
Range
0 - 100% LEL"
0 - 1,000 and
0 - 10,000 ppm
0 - 1,000 ppm
0 - 10,000 ppm
Compound specific
0.5-2,000 ppm
(photoionization)
1-50,000 ppm (FID/GC)
0 - 10,000 ppm
0 - 20, 0 - 200 and
0 - 2,000 ppm
0 - 10% and
0 - 100% LEL
0 - 5% and
0 - 100% LEL
0 - 1,999 ppm
U)
i
u>
a LEL = Lower explosive limit.
b FID/GC = Flame ionization detection/gas chromatography.
c NDIR = Nondispersive infrared analysis.
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CHAPTER 4 - EQUIPMENT LEAKS
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O
*
CM
O
m
a>
FIGURE 4.3-2. HW-101 PORTABLE ORGANIC COMPOUND DETECTION INSTRUMENT
(HNU SYSTEM, INC.)
4.3-14
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CHAPTER 4 - EQUIPMENT LEAKS
FIGURE 4.3-3. OVA-108 PORTABLE ORGANIC COMPOUND DETECTION INSTRUMENT
(FOXBORO)
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CHAPTER 4 - EQUIPMENT LEAKS
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FIGURE 4.3-4. TVA-1000 PORTABLE ORGANIC/INORGANIC COMPOUND DETECTION
INSTRUMENT (FOXBORO)
4.3-16
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/ 1/29/96 CHAPTER 4 - EQUIPMENT LEAKS
Appendix C of this chapter presents general information on the methods generally employed
in sampling source enclosures (vacuum and blow-through methods) and presents the
calculation procedures for leak rates when using both methods.
The Protocol for Equipment Leak Emission Estimates document provides detailed information
on sampling methods for bagging equipment, considerations for bagging each equipment type
and analytical techniques (EPA, November 1995).
3.6 COMPARISON OF AVAILABLE EMISSION ESTIMATION
METHODOLOGIES/APPROACHES
Table 4.3-5 identifies the preferred and alternative emission estimation approaches for
equipment leaks, and presents their advantages and disadvantages. All four emission
estimation approaches presented are more appropriately applied to the estimation of emissions
from equipment population rather than individual equipment pieces.
The preferred approach for estimating fugitive emissions from equipment leaks is to use the
EPA correlation equations that relate screening values to mass emission rates. The selection
of the preferred method for emission estimation purposes is based on the degree of accuracy
obtained and the amount of resources and cost associated with the method.
Because the equipment leak emissions may occur randomly, intermittently, and vary in
intensity over time, the "snapshot" of emissions from a given leak indicated by screening
and/or bagging results, which are used either to develop or apply all of the approaches, may
or may not be representative of the individual leak. However, by taking measurements from
several pieces of a given equipment type, the snapshots of individual deviations from the
actual leaks offset one another such that the ensemble of leaks should be representative. All
of these approaches are imperfect tools for estimating fugitive emissions from equipment
leaks; however, they are the best tools available. The best of these tools, the preferred
method, can be expected to account for approximately 50 to 70 percent of the variability of
the snapshot ensemble of equipment leak emissions.
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CHAPTER 4 - EQUIPMENT LEAKS
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TABLE 4.3-5
SUMMARY OF THE ADVANTAGES AND DISADVANTAGES OF PREFERRED AND
ALTERNATIVE EMISSION ESTIMATION APPROACHES FOR EQUIPMENT LEAKS
Preferred
Emission
Estimation
Approach
Alternative
Emission
Estimation
Approach
Advantages
Disadvantages
EPA
Correlation
Equations
Provides a refined emission
estimate when actual screening
values are available.
Provides a continuous function over
the entire range of screening values
instead of discrete intervals.
Screening value measurements used
with these correlations should have the
same format as the one followed to
develop the correlations
(OVAa/methane).
The development of an instrument
response curve may be needed to relate
screening values to actual
concentration.
Average
Emission
Factors
In the absence of screening data,
offers good indication of equipment
leak emission rates from equipment
in a process unit.
They are not necessarily an accurate
indication of the mass emission rate
from an individual piece of equipment.
Average emission factors do not reflect
different site-specific conditions among
process units within a source category.
May present the largest potential error
(among the other approaches) when
applied to estimate emissions from
equipment populations.
Screening
Ranges
Offers some refinement over the
Average Emission Factor approach.
Allows some adjustment for
individual unit conditions and
operation.
Available data indicate that measured
mass emission rates can vary
considerably from the rates predicted
by the use of these emission factors.
Process-
Unit
Specific
Correlation
The correlations are developed on a
process unit basis to minimize the
error associated with different leak
rate characteristics between units.
High cost.
' Organic vapor analyzer.
4.3-18
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PREFERRED METHOD FOR
ESTIMATING EMISSIONS
The EPA correlation equation approach is the preferred method when actual screening values
are available. This approach involves entering the screening value into the correlation
equation, which predicts the mass emission rate based on the screening value. For new
sources, when no actual screening values are available, average emission factors can be used
temporarily to determine fugitive emissions from equipment leaks until specific and/or better
data are available. However, it is recommended that the local environmental agency be
contacted to discuss the best approach and assumptions when data are not available.
This approach offers a good refinement to estimating emissions from equipment leaks by
providing an equation to predict mass emission rate as a function of screening value for a
particular equipment type. This approach is most valid for estimating emissions from a
population of equipment and is not intended for estimating emissions from an individual
equipment piece over a short time period (i.e., 1 hour). EPA correlation equations relating
screening values to mass emission rates have been developed by the EPA for SOCMI process
units and for the petroleum industry (EPA, November 1995).
Correlations for SOCMI are available for: (1) gas valves; (2) light liquid valves;
(3) connectors; (4) single equation for light liquid pump seals. Correlation equations, for the
petroleum industry that apply to refineries, marketing terminals, and oil and gas production
operations data are available for: (1) valves; (2) connectors; (3) flanges; and (4) pump seals;
(5) open-ended lines; and (6) other. The petroleum industry correlations apply to all services
for a given equipment type.
An example of the EPA correlation equation approach is demonstrated for Streams A and B
described in Table 4.4-1. This example is for a hypothetical chemical processing facility and
is shown for the sole purpose of demonstrating the emission estimating techniques described
in this chapter. As mentioned before, the correlation approach involves entering screening
values into a correlation equation to generate an emission rate for each equipment piece. In
Table 4.4-2, example screening values and the resulting emissions for each individual
equipment piece are presented. Emissions from the pump that was not screened are
estimated using the corresponding average emission factor.
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CHAPTER 4 - EQUIPMENT LEAKS
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TABLE 4.4-1
SAMPLE DATA FOR EXAMPLE CALCULATIONS*
Stream
ID
A
B
C
Equipment
Type/Service
Pumps/light
liquid
Pumps/light
liquid
Valves/gas
Equipment
Count
15
12
40
Hours of
Operation5
(hr/yr)
8,760
4,380
8,760
Stream Composition
Constituent
Ethyl acrylate
Water
Ethyl acrylate
Styrene
Ethyl acrylate
Ethane
Water vapor
Weight
Fraction
0.80
0.20
0.10
0.90
0.65
0.25
0.10
" Source: EPA, November 1995, Table A-l.
b Hours of operation include all of the time in which material is contained in the equipment.
4.4-2
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CHAPTER 4 - EQUIPMENT LEAKS
TABLE 4.4-2
EPA CORRELATION EQUATION METHOD3
Equipment IDb
A-l
A-2
A-3
A-4
A-5
A-6
A-7
A-8
A-9
A-10
A-ll
A-12
A-13
A-14
A-15
Screening Value
(ppmv)
0
0
0
0
0
20
50
50
100
100
200
400
1,000
2,000
5,000
VOC Mass Emissions'
(kg/yr)
0.066
0.066
0.066
0.066
0.066
2.0
4.2
4.2
7.4
7.4
13
23
49
87
190
Total Stream A Emissions: 390
B-l
B-2
B-3
B-4
B-5
B-6
B-7
B-8
B-9
B-10
B-ll
B-12 (100% VOC)d
0
0
0
10
30
250
500
2,000
5,000
8,000
25,000
Not screened
0.033
0.033
0.033
0.55
1.4
7.9
14
44
93
140
350
87
Total Stream B Emissions: 740
Total Emissions 1,130
8 Source: EPA, November, 1995, Table A-4.
b Equipment type: Light liquid pumps.
Correlation equation: Leak rate (kg/hr) = 1.90 x 10"5 x (Screening Value)0824; Default-zero mass emission
rate: 7.49 x W6 kg/hr.
Hours of operation: Stream A = 8,760; Stream B = 4,380.
c VOC Emissions = (correlation equation or default-zero emission rate) x (WPVOC/WPTOC) x (hours of
operation).
d VOC Emissions = (average emission factor) x (wt. fraction of TOC) x (WPVOC/WPTOC) x (hours of operation).
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CHAPTER 4 - EQUIPMENT LEAKS 11/29/96
VOC emission estimates using the EPA correlation equation approach are 1,130 kg/yr. On
the other hand, VOC emission estimates using the average emission factor approach and
screening value range for the same Streams A and B included in Table 4.4-1 are 3,138 and
1,480 kg/yr, respectively (see Section 5, Tables 4.5-3 and 4.5-4).
The leak rate/screening value correlations, default zero emission rates, and pegged emission
rates are presented in Table 4.4-3 for SOCMI and in Table 4.4-4 for the petroleum industry.
Example calculations utilizing the information presented in Tables 4.4-2 through 4.4-3 are
demonstrated in Example 4.4-1.
The EPA correlation equations can be used to estimate emissions when the adjusted screening
value (adjusted for the background concentration) is not a "pegged" screening value (the
screening value that represents the upper detection limit of the monitoring device) or a "zero"
screening value (the screening value that represents the minimum detection limit of the
monitoring device). All non-zero and non-pegged screening values can be entered directly
into the EPA correlation equation to predict the mass emissions (kg/hr) associated with the
adjusted screening value (ppmv) measured by the monitoring device.
The correlation equations mathematically predict zero emissions for zero screening values
(note that any screening value that is less than or equal to ambient [background]
concentration is considered a screening value of zero). However, data collected by EPA
show this prediction to be incorrect. Mass emissions have been measured from equipment
having a screening value of zero. This is because the lower detection limit of the monitoring
devices used is larger than zero and because of the difficulty in taking precise measurements
close to zero. The default-zero emission rates are applicable only when the minimum
detection limit of the portable monitoring device is 1 ppmv or less above background. In
cases where a monitoring device has a minimum detection limit greater than 1 ppmv, the
available default-zero emission leak rates presented in Tables 4.4-3 and 4.4-4 of this section
are not applicable. For these cases, an alternative approach for determining a default-zero
leak rate is to (1) determine one-half the
minimum screening value of the monitoring device, and (2) enter this screening value into
the applicable correlation to determine the associated default-zero leak rate.
In instances of pegged screening values, the true screening value is unknown and use of the
correlation equation is not appropriate. Pegged emission rates have been developed using
mass emissions data associated with known screening values of 10,000 ppmv or greater and
for known screening values of 100,000 ppmv or greater. When the monitoring device is
pegged at either of these levels, the appropriate pegged emission rate should be used to
estimate the mass emissions of the component.
4.4-4 EIIP Volume II
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TABLE 4.4-3
KS
(B
CORRELATION EQUATIONS, DEFAULT ZERO EMISSION RATES, AND PEGGED EMISSION RATES FOR
ESTIMATING SOCMI TOC EMISSION RATES3
CO
05
Equipment Type
Gas valves
Light liquid valves
Light liquid pumps0
Connectors
Default Zero
Emission Rate
(kg/hr per source)
6.6E-07
4.9E-07
7.5E-06
6.1E-07
Pegged Emission Rates
(kg/hr per source)
10,000 ppmv
0.024
0.036
0.14
0.044
100,000 ppmv
0.11
0.15
0.62
0.22
Correlation Equation
(kg/hr per source)1*
Leak Rate = 1.87E-06 x (SV)0'873
Leak Rate = 6.41E-06 x (SV)0797
Leak Rate = 1.90E-05 x (SV)0824
Leak Rate = 3.05E-06 x (SV)0885
8 Source: EPA, November 1995, Tables 2-9, 2-11, and 2-13. To estimate emissions: Use the default zero emission rates only when the
screening value (adjusted for background) equals 0.0 ppmv; otherwise use the correlation equations. If the monitoring device registers a
pegged value, use the appropriate pegged emission rate.
b SV is the screening value (ppmv) measured by the monitoring device.
c The emission estimates for light liquid pump seals can be applied to compressor seals, pressure relief valves, agitator seals, and heavy
liquid pumps.
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TABLE 4.4-4
CORRELATION EQUATIONS, DEFAULT ZERO EMISSION RATES, AND PEGGED EMISSION RATES FOR
ESTIMATING PETROLEUM INDUSTRY TOC EMISSION RATES"
Equipment Type/Service
Connector/ All
Flange/All
Open-Ended Line/All
Pump/All
Valve/All
OtherVAll
Default Zero
Emission Rate
(kg/hr per source)11
7.5E-06
3.1E-07
2.0E-06
2.4E-05
7.8E-06
4.0E-06
Pegged Emission Rates
(kg/hr per source)'
10,000
ppmv
0.028
0.085
0.030
0.074
0.064
0.073
100,000 ppmv
0.030
0.084
0.079
0.1 60e
0.140
0.110
Correlation Equation
(kg/hr per source)d
Leak Rate = 1.51E-06 x (SV)0735
Leak Rate = 4.44E-06 x (SV)0703
Leak Rate = 2.16E-06 x (SV)0704
Leak Rate = 4.82E-05 x (SV)0610
Leak Rate = 2.28E-06 x (SV)0746
Leak Rate = 1.32E-05 x (SV)0589
Source: EPA, November 1995, Tables 2-10, 2-12, and 2-14. Developed from the combined 1993 refinery, marketing terminal, and
oil and gas production operations data. To estimate emissions: use the default zero emission rates only when the screening value
(adjusted for background) equals 0.0 ppmv; otherwise use the correlation equations. If the monitoring device registers a pegged
value, use the appropriate pegged emission rate.
Default zero emission rates were based on the combined 1993 refinery and marketing terminal data only (default zero data were not
collected from oil and gas production facilities).
The 10,000 ppmv pegged emission rate was based on components screened at greater than 10,000 ppmv; however, in some cases,
most of the data could have come from components screened at greater than 100,000 ppmv, thereby resulting in similar pegged
emission rates for both the 10,000 and 100,000 ppmv pegged levels (e.g., connector and flanges).
SV is the screening value (ppmv) measured by the monitoring device.
Only two data points were available for the pump 100,000 ppmv pegged emission rate; therefore, the ratio of the pump 10,000 ppmv
pegged emission rate to the overall 10,000 ppmv pegged emission rate was multiplied by the overall 100,000 ppmv pegged emission
rate to approximate the pump 100,000 ppmv pegged emission rate.
The other equipment type includes instruments, loading arms, pressure relief valves, stuffing boxes, vents, compressors, and dump
lever arms.
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1 1/29/96 CHAPTER 4 - EQUIPMENT LEAKS
Example 4.4-1:
• Stream A, Equipment IDs: A-l, A-2, A-3, A-4, and A-5
Equipment Type: Light-liquid Pumps
Hours of Operation: 8,760 hours
SV (Screening value) = 0 ppmv
SOCMI default-zero TOC emission rate (kg/hr/source)
= 7.5 x lO'6 (from Table 4.4-3)
VOC emissions per equipment ID (kg/yr)
= 7.5 X lO'6 kg/hr X (0.80/0.80) x 8,760 hr
= 0.066
• Stream A, Equipment ID: A-6
Equipment Type: Light-liquid Pumps
Hours of Operation: 8,760 hours
SV (Screening value) = 20 ppmv
SOCMI Correlation Equation:
TOC Leak Rate (kg/hr)
= 1.90 x 10-5(SV)0824 (from Table 4.4-3)
= 1.90 x 10-5 (20)°-824
= 2.24 x 10-4
VOC emissions (kg/yr)
= 2.24 x lO'4 kg/hr x 8,760 hr x (0.80/0.80)
= 2.0
• Stream A, Equipment IDs: A-7 and A-8
Equipment Type: Light-liquid Pumps
SV (Screening value) = 50 ppmv
SOCMI Correlation Equation:
TOC Leak Rate (kg/hr)
= 1.90 x 10-5 (SV)0824 (from Table 4.4-3)
= 1.90 x 10-5 (50)°824
= 4.77 x lO'4
VOC emissions (kg/yr)
= 4.77 x lO'4 kg/hr x 8,760 hr X (0.80/0.80)
= 4.2
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4.4-8 EIIP Volume II
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ALTERNATIVE METHODS FOR
ESTIMATING EMISSIONS
The alternative methods for estimating emissions from equipment leaks are the following (in
no specific order of preference):
• Average emission factor approach;
• Screening ranges approach; and
• Unit-specific correlation approach.
5.1 EMISSION CALCULATIONS USING THE AVERAGE EMISSION
FACTOR APPROACH
The average emission factor approach is commonly used to calculate emissions when
site-specific screening data are unavailable.
To estimate emissions using the average emission factor approach, the TOC concentration in
weight percent within the equipment is needed. The TOC concentration in the equipment is
important because equipment (and VOC or HAP concentrations if speciation is to be
performed) with higher TOC concentrations tend to have higher TOC leak rates. The
various equipment should be grouped into "streams," such that all equipment within a stream
has approximately the same TOC weight percent.
This approach for estimating emissions allows use of average emission factors developed by
the EPA in combination with unit-specific data that are relatively simple to obtain. These
data include: (1) the number of each type of component in a unit (valve, connector, etc.);
(2) the service each component is in (gas, light liquid, or heavy liquid); (3) the TOC
concentration of the stream; and (4) the tune period each component was in that service.
EPA average emission factors have been developed for SOCMI process units, refineries,
marketing terminals, and oil and gas production operations (EPA, November 1995). The
method used by the EPA to develop emission factors for individual equipment leak emission
sources is described in the Protocol for Equipment Leak Emission Estimates (EPA, November
1995). Tables 4.5-1 and 4.5-2 show the average emission factors for SOCMI process units
and refineries, respectively.
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TABLE 4.5-1
SOCM! AVERAGE EMISSION FACTORS"
Equipment Type
Valves
Pump seals0
Compressor seals
Pressure relief valves
Connectors
Open-ended lines
Sampling connections
Service
Gas
Light liquid
Heavy liquid
Light liquid
Heavy liquid
Gas
Gas
All
All
All
Emission Factor
(kg/hr per source)1"
0.00597
0.00403
0.00023
0.0199
0.00862
0.228
0.104
0.00183
0.0017
0.0150
a Source: EPA, November 1995, Table 2-1.
b These factors are for TOC emission rates.
c The light liquid pump seal factor can be used to estimate the leak rate from agitator seals.
4.5-2
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CHAPTER 4 - EQUIPMENT LEAKS
TABLE 4.5-2
REFINERY AVERAGE EMISSION FACTORS"
Equipment Type
Valves
Pump seals0
Compressor seals
Pressure relief valves
Connectors
Open-ended lines
Sampling connections
Service
Gas
Light liquid
Heavy liquidd
Light liquid
Heavy liquidd
Gas
Gas
All
All
All
Emission Factor
(kg/hr per source)5
0.0268
0.0109
0.00023
0.114
0.021
0.636
0.16
0.00025
0.0023
0.0150
" Source: EPA, November 1995, Table 2-2. Based on data gathered in the 1970's.
b These factors are for non-methane organic compound emission rates.
c The light liquid pump seal factor can be used to estimate the leak rate from agitator seals.
d The American Petroleum Institute is conducting a program to develop revised emission factors for
components in heavy liquid service. Contact state or local agencies to determine the appropriate
application of heavy liquid emission factors.
EIIP Volume II
4.5-3
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CHAPTER 4 - EQUIPMENT LEAKS 11/29/96
Although the average emission factors are in units of kilogram per hour per individual
source, it is important to note that these factors are most valid for estimating emissions from
a population of equipment. However, the average emission factor approach may present the
largest potential error, among the other approaches, when applied to estimate emissions from
equipment populations. The average factors are not intended to be used for estimating
emissions from an individual piece of equipment over a short time period (i.e., 1 hour).
When the average emission factors are used to estimate TOC mass emissions from refineries,
it is necessary to adjust the refinery emission factors because they represent only non-
methane emissions. To estimate TOC emissions, methane and non-methane organic
compounds must be included. Two guidelines for adjusting the refinery emission factors are
as follows:
• The adjustment should be applied only to equipment containing a mixture of
organic and methane, and
• The maximum adjustment for the methane weight fraction should not exceed
0.10, even if the equipment contains greater than 10 weight percent methane.
(This reflects that equipment in the Refinery Assessment Study (EPA, April
and July 1980) typically contained 10 weight percent or less methane).
Because the average emission factors for refineries must be adjusted when estimating TOC
emissions, there is one equation (Equation 4.5-1) for using the average emission factors to
estimate emissions from SOCMI marketing terminals, and oil and gas production operations
and a second equation (Equation 4.5-2) for using the emission factors to estimate emissions
from refinery operations.
These equations can be used to estimate TOC emission from all of the equipment of a given
equipment type in a stream:
ETOC = FA x WFTOC x N (4'5'1)
WF
ETOC = FA x TOC x WFTOC X N (4.5-2)
TOC A v _ vyp TOC
TOC ¥vr methane
where:
Emission rate of TOC from all equipment in the stream of a given
equipment type (kg/hr);
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CHAPTER 4 - EQUIPMENT LEAKS
WF.
WF,
WF
N
TOC
methane
TOC
Applicable average emission" factor1 for the equipment type
(kg/hr per source);
Average weight fraction of TOC in the stream;
= Average weight fraction of methane in the stream;
= Average weight fraction of TOC in the stream; and
= Number of pieces of the applicable equipment type in the stream.
If there are several streams at a process unit, the total VOC emission rate for an equipment
type is the sum of VOC emissions from each of the streams. The total emission rates for all
of the equipment types are summed to generate the process unit total VOC emission rate from
leaking equipment.
An example of the average emission factor approach is demonstrated for Streams A and B
included in Table 4.4-1. Note that Stream A contains water, which is not a TOC. Therefore,
this is accounted for when total TOC emissions are estimated from Stream A. Table 4.5-3
summarizes the average emission factor approach calculations.
TABLE 4.5-3
AVERAGE EMISSION FACTOR METHOD
Stream ID
A
B
Equipment
Count
15
12
TOC Emission
Factor
(kg/hr per source)
0.0199
0.0199
Weight
Fraction of
TOC
0.80
1.00
Hours of
Operation
(hr/yr)
8,760
4,380
Total Emissions
VOC
Emissions'
(kg/yr)
2,092
1,046
3,138
VOC Emissions = (no. of components) x (emission factor) x (wt. fraction TOC) x
(WPVOC/WPTOC) x (hours of operation).
1 Emission factors presented in the 1995 Protocol for Equipment Leak Emission Estimates (EPA, November
1995) are for TOC emission rates, except for refineries that are for non-methane organic compound emission
rates.
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4.5-5
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CHAPTER 4 - EQUIPMENT LEAKS 11/29/96
5.2 EMISSION CALCULATIONS USING THE SCREENING RANGES
APPROACH
The screening ranges approach requires screening data to be collected for the equipment in
the process unit. This approach is applied in a similar manner as the average emission factor
approach in that equipment counts are multiplied by the applicable emission factor.
However, because the screening value on which emissions are based is a measurement of
only organic compound leakage, no adjustment is made for inorganic compounds.
This approach may be applied when screening data are available as either "greater than or
equal to 10,000 ppmv" or as "less than 10,000 ppmv." As with the average factors, the
SOCMI, marketing terminal, and oil and gas production operations screening range factors
predict TOC emissions, whereas the refinery screening range factors predict non-methane
organic compound emissions. Thus, when using the average refinery screening range factors
to estimate TOC emissions from refineries, an adjustment must be made to the factors to
include methane emissions. The maximum adjustment for the methane weight factors should
not exceed 0.10, even if the equipment contains greater than 10 weight percent methane.
Because the average screening range factors for refineries must be adjusted when estimating
TOC emissions, there is one equation (Equation 4.5-3) for using the average screening range
factors to estimate emissions from SOCMI, marketing terminals, and oil and gas production
operations and a second equation (Equation 4.5-4) for using the screening range factors to
estimate emissions from refinery operations. These equations are described below:
ETOC = (F0 X NG) + (FL X NL) (4.5-3)
WF
(4.5-4)
WF - WF
vvrTOC vvr methane
where:
TOC emission rate for an equipment type (kg/hr);
Applicable emission factor1 for sources with screening values
greater than or equal to 10,000 ppmv (kg/hr per source);
1 Emission factors presented in the 7995 Protocol for Equipment Leak Emission Estimates (EPA, November
1995) are for TOC emission rates, except for refineries that are for non-methane organic compound emission
rates.
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11/29/96 CHAPTER 4 - EQUIPMENT LEAKS
WPToc = Average weight percent of TOC in the stream;
WPmethane = Average weight percent of methane in the stream;
NG = Equipment count (specific equipment type) for sources with
screening values greater than or equal to 10,000 ppmv;
FL = Applicable emission factor for sources with screening values less
than 10,000 ppmv (kg/hr per source); and
NL = Equipment count (specific equipment type) for sources with
screening values less than 10,000 ppmv.
Assuming all of the organic compounds in the stream are classified as VOCs, the total VOC
emission for each stream is calculated as the sum of TOC emissions associated with each
specific equipment type in the stream.
The screening range emission factors are a better indication of the actual leak rate from
individual equipment than the average emission factors. Nevertheless, available data indicate
that measured mass emission rates can vary considerably from the rates predicted by use of
these factors.
An example of the screening value ranges approach is demonstrated in Table 4.5-4 using the
example of a hypothetical chemical processing facility presented in Section 4 for Streams A
and B (Table 4.4-1). The calculations are similar to those used for the average emission
factor approach, except that a TOC emission factor for each screening value range is used.
Emissions from equipment that could not be screened are calculated using average emission
factors. VOC emissions using the screening value range approach are 1,480 kg/yr. In
comparison, VOC emissions using the average emission factor approach for the same
Streams A and B are 3,138 kg/yr, as shown in Table 4.5-3.
5.3 EMISSION CALCULATIONS USING UNIT-SPECIFIC CORRELATION
APPROACH
Correlation equations may be developed for specific units rather than using correlation
equations developed by the EPA. Once the correlations are developed, they are applied in
the same way as described for the EPA correlations.
Before developing unit-specific correlations it is recommended that the validity of the EPA
correlations to a particular process unit be evaluated because of the high cost of bagging.
This can be done measuring as few as four leak rates of a particular equipment type in a
particular service. The measured emission rate can be compared with the predicted rates
obtained using the EPA correlations. If there is a consistent trend (i.e., all measured values
are less than values predicted by the EPA correlation equation or all measured values are
larger) the EPA correlation equation may not provide reasonable emission estimates for the
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CHAPTER 4 - EQUIPMENT LEAKS
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TABLE 4.5-4
SCREENING VALUE RANGES METHOD"
Stream ID
Equipment
Count5
Emission Factor
(kg/hr per
source)
Hours of
Operation
(hr/yr)
voc
Emissions
(kg/yr)
Components screening > 10,000 ppmvc
B
1
0.243
4,380
1,060
Components screening < 10,000 pprnv0
A
B
15
10
0.00187
0.00187
8,760
4,380
246
82
Components not screenedd
B (TOC wt. fraction
equal to 1.0)
1
0.0199
4,380
Total emissions
87
1,480
" Source: EPA, November, 1995, Table A-3.
b It was assumed that none of the light liquid pumps in Stream A have a screening value greater than or equal to
10,000 ppmv, one of the light liquid pumps in Stream B screens greater than 10,000 ppmv, and one of the
pumps in Stream B could not be screened.
c VOC emissions = (no. of components) x (TOC emission factor) x (WPyoc/WP-roc) x
(hours of operation).
d VOC emissions = (no. of components) x (average TOC emission factor) x (WPVOC) x (hours of operation).
4.5-8
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/ 7/23/55 CHAPTER 4 - EQUIPMENT LEAKS
process unit. There is a more formal comparison, the Wilcoxon signed-rank test, which can
be performed by comparing the logarithm of the measured mass emission rates to the
logarithm of the corresponding rates predicted by the EPA correlation.
In developing new unit-specific correlations, a minimum number of leak rate measurements
and screening value pairs must be obtained. The Protocol for Equipment Leak Emission
Estimates (EPA, November 1995) provides detailed information on the methodology to be
followed. In general, the following consideration should be observed:
• Process unit equipment should be screened to know the distribution of screening
values at the unit;
• Mass emission data must be collected from individual sources with screening values
distributed over the entire range; and
• A random sample of a minimum of six components from each of the following
screening value ranges (in ppmv) should be selected for bagging: 1-100; 101-1,000;
1,001-10,000; 10,001-100,000; and > 100,000. Therefore, a minimum of 30
emissions rate/screening value pairs should be obtained to estimate emissions across
the entire range of screening values.
The Protocol document (EPA, November 1995) provides some alternatives to developing a
correlation equation with fewer than 30 bags. These alternatives are based on experience in
measuring leak rates and developing leak rate/screening value correlations. However, other
source selection strategies can be used if an appropriate rationale is given.
Methodologies for generating leak rate/screening value correlations with mass emissions data
and screening values are presented in Appendix B of the 7995 Protocol document. Once
correlations are developed using the methodologies outlined in Appendix B, they are applied
hi the same manner as described in the example for the EPA correlations.
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QUALITY ASSURANCE/QUALITY
CONTROL PROCEDURES
The consistent use of standardized methods and procedures is essential in the compilation of
reliable emission inventories. Quality assurance (QA) and quality control (QC) of an
inventory are accomplished through a set of procedures that ensure the quality and reliability
of data collection and analysis. These procedures include the use of appropriate emission
estimation techniques, applicable and reasonable assumptions, accuracy/logic checks of
computer models, checks of calculations, and data reliability checks. Chapter 4 of
Volume VI (the QA Source Document) of this series describes some QA/QC methods for
performing these procedures.
Volume II, Chapter 1, Introduction to Stationary Point Source Emission Inventory
Development, presents recommended standard procedures to follow that ensure the reported
inventory data are complete and accurate. Chapter 1, should be consulted for current EIIP
guidance for QA/QC checks for general procedures, recommended components of a QA
plan, and recommended components for point source inventories. The QA plan discussion
includes recommendations for data collection, analysis, handling, and reporting. The
recommended QC procedures include checks for completeness, consistency, accuracy, and
the use of approved standardized methods for emission calculations, where applicable.
6.1 SCREENING AND BAGGING DATA COLLECTION
To ensure that data quality is maintained while screening and data collection take place, it is
recommended that data be recorded on prepared data sheets. Figures 4.6-1 provides an
example data sheet that may be used to log measurements taken during a screening program.
To ensure highest quality of the data collected during the bagging program, QA/QC
procedures must be followed. Quality assurance requirements include accuracy checks of the
instrumentation used to perform mass emission sampling. Quality control requirements
include procedures to be followed when performing equipment leak mass emissions sampling.
Figures 4.6-2 and 4.6-3 present examples of data collection forms to be used when collecting
data hi the field. Accuracy checks on the instrumentation and monitoring devices used to
perform mass emission sampling include a leak rate check performed in the laboratory, blind
standards to be analyzed by the laboratory instrumentation, and drift checks on the portable
monitoring device.
EIIP Volume II 4.6-1
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EXAMPLE FIELD SHEET FOR EQUIPMENT SCREENING DATA
i
Detector Model No:
Operator Name:
Date:
Component
ID
Component
Type
Location/
Stream
Service
Operating
hr/yr
Screening
value (ppmv)
Background
(ppmv)
S
I
•H
r-
2
Comments:
i
FIGURE 4.6-1. EXAMPLE FIELD SHEET FOR EQUIPMENT SCREENING DATA
0)
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11/29/96 CHAPTER 4 - EQUIPMENT LEAKS
EXAMPLE DATA COLLECTION FORM FOR FUGITIVE EMISSIONS
BAGGING TEST (VACUUM METHOD)
Equipment Type ; - Component ID
Equipment Category Plant ID
Line Size Date •
Stream Phase (G/V, LL, HL) Analysis Team.
Barometric Pressure
Ambient Temperature Instrument ID _
Stream Temperature Stream Pressure,
Stream Composition (Wt. %) ,
Time Bagging Test Measurement Data
Initial Screening (ppmv) Equipment Piece3 Bkgd.
Background Bag Organic Compound Cone. (ppmv)b
Sample Bag 1 Organic Compound Cone, (ppmv)
Dry Gas Meter Reading (L/min)
Vacuum Check in Bag (Y/N) (Must be YES to collect sample.)
Dry Gas Meter Temperature' (°C)
Dry Gas Meter Pressure0 (mmHg)
Sample Bag 2 Organic Compound Cone, (ppmv)
Dry Gas Meter Reading (L/min)
Vacuum Check in Bag (Y/N) (Must be YES to collect sample.)
Dry Gas Meter Temperature' (°C) '
Dry Gas Meter Pressure0 (mmHg)
Condensate Accumulation: Starting Time Final Time
Organic Condensate Collected (mL)
Density of Organic Condensate (g/mL)
Final Screening (ppmv) Equip. Piece3 Bkgd.
" The vacuum method is not recommended if the screening value is approximately 10 ppmv or less.
b Collection of a background bag is optional.
c Pressure and temperature are measured at the dry gas meter.
FIGURE 4.6-2. EXAMPLE DATA COLLECTION FORM FOR FUGITIVE EMISSIONS
BAGGING TEST (VACUUM METHOD)
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CHAPTER 4 - EQUIPMENT LEAKS 11/29/96
EXAMPLE DATA COLLECTION FORM FOR FUGITIVE EMISSIONS BAGGING TEST
(BLOW-THROUGH METHOD)
Equipment Type Component ID
Equipment Category Plant ID
Line Size Date
Stream Phase (G/V, LL, HL) Analysis Team.
Barometric Pressure
Ambient Temperature Instrument ID _
Stream Temperature Stream Pressure
Stream Composition (Wt. %) ,
Time Bagging Test Measurement Data
Initial Screening (ppmv) Equipment Piece Bkgd.
Background Bag Organic Compound Cone, (ppmv)8
Sample Bag 1 Organic Compound Cone, (ppmv)
Dilution Gas Flow Rate (L/min)
02 Concentration (volume %)
Bag Temperature (°C)
Sample Bag 2 Organic Compound Cone, (ppmv)
Dilution Gas Flow Rate (L/min)
O2 Concentration (volume %)
Bag Temperature (°C)
Condensate Accumulation: Starting Time Final Time
Organic Condensate Collected (mL)
Density of Organic Condensate (g/mL)
Final Screening (ppmv) Equipment Piece Bkgd.
a Collection of a background bag is optional. However, it is recommended in cases where the screening
value is less than 10 ppmv and there is a detectable oxygen level in the bag.
FIGURE 4.6-3. EXAMPLE DATA COLLECTION FORM FOR FUGITIVE EMISSIONS
BAGGING TEST (BLOW-THROUGH METHOD)
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6.2 OTHER QA/QC ISSUES
At a minimum, the approach and data used to estimate emissions should be peer reviewed to
assure correctness. In addition, some sample calculations should be performed to verify that
calculations were done correctly.
If any of the methods that require screening or bagging data were used, the sample design
should be reviewed to assure that all relevant equipment types were sampled. Furthermore,
the adequacy of sample sizes should be verified.
6.3 DATA ATTRIBUTE RATING SYSTEM (DARS) SCORES
One measure of emission inventory data quality is the DARS score. Three examples are
given here to illustrate DARS scoring using the preferred and alternative methods. The
DARS provides a numerical ranking on a scale of 1 to 10 for individual attributes of the
emission factor and the activity data. Each score is based on what is known about the factor
and activity data, such as the specificity to the source category and the measurement
technique employed. The composite attribute score for the emissions estimate can be viewed
as a statement of the confidence that can be placed in the data. For a complete discussion of
DARS and other rating systems, see the QA Source Document (Volume VI, Chapter 4), and
Volume II, Chapter 1, Introduction to Stationary Point Sources Emission Inventory
Development.
For each example, assume emissions are being estimated for a petroleum marketing terminal.
Table 4.6-1 gives a set of scores for the preferred method, the EPA correlation approach.
Note that a perfect score (1.0) is not possible with any of the methods described in this
chapter because all are based on the use of surrogates rather than direct measurement of
emissions. The spatial congruity attribute is not particularly relevant for this category, and
thus is given a score of 1.0. Both measurement and specificity scores are relatively high
(0.8) because the correlation equation is based on a representative sample from the specific
category. The measurement attribute score assumes that the pollutants of interest were
measured directly. The temporal attribute scores are 0.7 because the data (for the correlation
equation and for the screening values) are presumed to be one time samples, but the
throughputs are assumed not to vary much over tune.
Tables 4.6-2 and 4.6-3 give DARS scores for the average emission factor approach and the
unit-specific correlation approach respectively. Not surprisingly, the first approach gets
lower DARS scores, while the second gets higher scores.
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CHAPTER 4 - EQUIPMENT LEAKS
11/29/96
TABLE 4.6-1
DARS SCORES: EPA CORRELATION APPROACH
Attribute
Measurement
Specificity
Spatial
Temporal
Composite Scores
Scores
Factor
0.8
0.8
1.0
0.7a
0.83
Activity
0.8
1.0
1.0
0.7"
0.88
Emissions
0.64
0.80
1.0
0.49
0.73
1 Assumes a one-time sampling of equipment and little variation in throughput.
TABLE 4.6-2
DARS SCORES: AVERAGE EMISSION FACTOR APPROACH
Attribute
Measurement
Specificity
Spatial
Temporal
Composite Scores
Scores
Factor
0.6
0.5
1.0
0.7
0.7
Activity
0.5
1.0
1.0.
0.7
0.8
Emissions
0.3
0.5
1.0
0.49
0.57
4.6-6
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CHAPTER 4 - EQUIPMENT LEAKS
TABLE 4.6-3
DARS SCORES: UNIT-SPECIFIC CORRELATION APPROACH
Attribute
Measurement
Specificity
Spatial
Temporal
Composite Scores
Scores
Factor
0.9
1.0
1.0
0.7
0.90
Activity
0.9
1.0
1.0
0.7
0.90
Emissions
0.81
1.0
1.0
0.49
0.83
These examples are given as an illustration of the relative quality of each method. If the
same analysis were done for an actual real site, the scores could be different but the relative
ranking of methods should stay the same. Note, however, that if the source is not truly a
member of the population used to develop the EPA correlation equations or the emission
factors, these approaches are less appropriate and the DARS scores will probably drop.
If sufficient data are available, the uncertainty in the estimate should be evaluated.
Qualitative and quantitative methods for conducting uncertainty analyses are described in the
QA Source Document (Volume VI, Chapter 4).
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4.6-8 EIIP Volume II
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DATA CODING PROCEDURES
This section describes the methods and codes available for characterizing fugitive emissions
from equipment leaks using Source Classification Codes (SCCs) and Aerometric Information
Retrieval System (AIRS) control device codes. Consistent categorization and coding will
result in greater uniformity among inventories. The SCCs are the building blocks on which
point source emissions data are structured. Each SCC represents a unique process or
function within a source category that is logically associated with an emission point. Without
an appropriate SCC, a process cannot be accurately identified for retrieval purposes. In
addition, the procedures described here will assist the reader preparing data for input into a
database management system. For example, the SCCs provided in Table 4.7-1 are typical of
the valid codes recommended for describing equipment leaks. This table does not include all
fugitive source SCCs, but does include those commonly used to identify equipment leaks.
Refer to the CHIEF bulletin board for a complete listing of SCCs.
While the codes presented here are currently in use, they may change based on further
refinement by the emission inventory community. As part of the EIIP, a common data
exchange format is being developed to facilitate data transfer between industry, states, and
EPA.
For equipment leaks, be careful to use only one SCC for each process or source category.
Many of these are designated for the entire process unit on an annual basis. In some cases,
the user may need to calculate emissions for multiple pieces of equipment and then sum up to
the unit total. The process-specific codes should be used as often as possible.
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CHAPTER 4 - EQUIPMENT LEAKS
11/29/96
TABLE 4.7-1
SOURCE CLASSIFICATION CODES AND DESCRIPTIONS FOR FUGITIVE EMISSIONS
FROM EQUIPMENT LEAKS
Source Description
Process Description
sec
Units
Industrial Processes
Chemical
Manufacturing
Adipic Acid - Fugitive
Emissions: General
Carbon Black Production;
Furnace Process: Fugitive
Emissions
Chlorine: Carbon
Reactivation/Fugitives
Sulfuric Acid (Contact
Process): Process Equipment
Leaks
Terephthalic Acid/ Dimethyl
Terephthalate: Fugitive
Emissions
Aniline/Ethanolamines :
Fugitive Emissions
Aniline/Ethanolamines :
Fugitive Emissions
Pharmaceutical Preparations:
Miscellaneous Fugitives
Pharmaceutical Preparations:
Miscellaneous Fugitives
Inorganic Chemical
Manufacturing (General):
Fugitive Leaks
Acetone/Ketone Production:
Fugitive Emissions (Acetone)
Maleic Anhydride: Fugitive
Emissions
Fugitive Emissions
(Formaldehyde)
3-01-001-80
3-01-005-09
3-01-007-05
3-01-023-22
3-01-031-80
3-01-034-06
3-01-034-14
3-01-060-22
3-01-060-23
3-01-070-01
3-01-091-80
3-01-100-80
3-01-120-07
Process Unit- Year
Tons Produced
Tons Produced
Tons 100% H2SO4
Process Unit- Year
Process Unit- Year
Process Unit- Year
Tons Processed
Tons Processed
Tons Product
Process Unit- Year
Process Unit- Year
Process Unit- Year
4.7-2
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CHAPTER 4 - EQUIPMENT LEAKS
TABLE 4.7-1
(CONTINUED)
Source Description
Process Description
sec
Units
Industrial Processes
Chemical
Manufacturing
Fugitive Emissions
(Acetaldehyde)
Fugitive Emissions
(Acrolein)
Chloroprene: Fugitive
Emissions
Chlorine Derivatives:
Fugitive Emissions (Ethylene
Dichloride)
Chlorine Derivatives:
Fugitive Emissions
(Chloromethanes)
Chlorine Derivatives:
Fugitive Emissions
(Perchloroethylene)
Chlorine Derivatives:
Fugitive Emissions
(Trichloroethane)
Chlorine Derivatives:
Fugitive Emissions
(Trichloroethylene)
Chlorine Derivatives:
Fugitive Emissions (Vinyl
Chloride)
Chlorine Derivatives:
Fugitive Emissions
(Vinylidene Chloride)
Fluorocarbons/
Chloroflourocarbons :
Fugitive Emissions
Organic Acid Manufacturing:
Fugitive Emissions
3-01-120-17
3-01-120-37
3-01-124-80
3-01-125-09
3-01-125-14
3-01-125-24
3-01-125-29
3-01-125-34
3-01-125-50
3-01-125-55
3-01-127-80
3-01-132-27
Process Unit- Year
Process Unit- Year
Process Unit- Year
Process Unit- Year
Process Unit- Year
Process Unit- Year
Process Unit- Year
Process Unit- Year
Process Unit- Year
Process Unit- Year
Process Unit- Year
Process Unit- Year
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CHAPTER 4 - EQUIPMENT LEAKS
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TABLE 4.7-1
(CONTINUED)
Source Description
Process Description
sec
Units
Industrial Processes
Chemical
Manufacturing
Acetic Anhydride: Fugitive
Emissions
Butadiene: Fugitive
Emissions
Cumene: Fugitive Emissions
Cyclohexane: Fugitive
Emissions
Cyclohexanone/
Cyclohexanol: Fugitive
Emissions
Vinyl Acetate: Fugitive
Emissions
Ethyl Benzene: Fugitive
Emissions
Ethylene Oxide: Fugitive
Emissions
Glycerin (Glycerol): Fugitive
Emissions
Toluene Diisocyanate:
Fugitive Emissions
Methyl Methacrylate:
Fugitive Emissions
Nitrobenzene: Fugitive
Emissions
Olefin Prod. : Fugitive
Emissions (Propylene)
Olefin Prod.: Fugitive
Emissions (Ethylene)
Phenol: Fugitive Emissions
Propylene Oxide: Fugitive
Emissions
Styrene: Fugitive Emissions
3-01-133-80
3-01-153-80
3-01-156-80
3-01-157-80
3-01-158-80
3-01-167-80
3-01-169-80
3-01-174-80
3-01-176-80
3-01-181-80
3-01-190-80
3-01-195-80
3-01-197-09
3-01-197-49
3-01-202-80
3-01-205-80
3-01-206-80
Process Unit- Year
Process Unit- Year
Process Unit- Year
Process Unit- Year
Process Unit- Year
Process Unit- Year
Process Unit- Year
Process Unit- Year
Process Unit- Year
Process Unit- Year
Process Unit- Year
Process Unit- Year
Process Unit- Year
Process Unit- Year
Process Unit- Year
Process Unit- Year
Process Unit- Year
4.7-4
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71/29/96
CHAPTER 4 - EQUIPMENT LEAKS
TABLE 4.7-1
(CONTINUED)
Source Description
Process Description
sec
Units
Industrial Processes
Chemical
Manufacturing
Caprolactam: Fugitive
Emissions
Linear Alkylbenzene:
Fugitive Emissions
Methanol/ Alcohol
Production: Fugitive
Emissions (Methanol)
Ethylene Glycol: Fugitive
Emissions
Glycol Ethers: Fugitive
Emissions
Nitriles, Acrylonitrile,
Adiponitrile Prod.: Fugitive
Emissions
Nitriles, Acrylonitrile,
Adiponitrile Prod.: Fugitive
Emissions
Benzene/Toluene/
Aromatics/Xylenes: Fugitive
Emissions (Aromatics)
Chlorobenzene: Fugitive
Emissions
Carbon Tetrachloride:
Fugitive Emissions
Allyl Chloride: Fugitive
Emissions
Allyl Alcohol: Fugitive
Emissions
Epichlorohydrin: Fugitive
Emissions
General Processes: Fugitive
Leaks
3-01-210-80
3-01-211-80
3-01-250-04
3-01-251-80
3-01-253-80
3-01-254-09
3-01-254-20
3-01-258-80
3-01-301-80
3-01-302-80
3-01-303-80
3-01-304-80
3-01-305-80
3-01-800-01
Process Unit- Year
Process Unit- Year
Process Unit- Year
Process Unit- Year
Process Unit- Year
Process Unit- Year
Process Unit- Year
Process Unit- Year
Process Unit- Year
Tons Product
Process Unit- Year
Process Unit- Year
Process Unit- Year
Process Unit- Year
EIIP Volume II
4.7-5
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CHAPTER 4 - EQUIPMENT LEAKS
11/29/96
TABLE 4.7-1
(CONTINUED)
Source Description
Process Description
sec
Units
Industrial Processes
Chemical
Manufacturing
Primary Metal
Production
Secondary Metal
Production
Petroleum Industry
Fugitive Emissions: Specify
In Comments Field
Fugitive Emissions: Specify
In Comments Field
Fugitive Emissions: Specify
In Comments Field
Fugitive Emissions: Specify
In Comments Field
Fugitive Emissions: Specify
In Comments Field
By-Product Coke
Manufacturing-Equipment
Leaks
Primary Metal Production -
Equipment Leaks
Secondary Metal
Production-Equipment Leaks
Pipeline Valves And Flanges
Vessel Relief Valves
Pump Seals Without Controls
Compressor Seals
Misc: Sampling/Non- Asphalt
Blowing/Purging/Etc .
Pump Seals With Controls
3-01-888-02
3-01-888-01
3-01-888-03
3-01-888-04
3-01-888-05
3-03-003-61
3-03-800-01
3-04-800-01
3-06-008-01
3-06-008-02
3-06-008-03
3-06-008-04
3-06-008-05
3-06-008-06
Tons Product
Tons Product
Tons Product
Tons Product
Process Unit- Year
Process Unit- Year
Facility-Annual
Facility-Annual
1000 Barrels Refined
1000 Barrels Refined
1000 Barrels Refined
1000 Barrels Refined
1000 Barrels Refined
1000 Barrels Refined
4.7-6
EIIP Volume II
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/1/29/96
CHAPTER 4 - EQUIPMENT LEAKS
TABLE 4.7-1
(CONTINUED)
Source Description
Process Description
sec
Units
Industrial Processes
Petroleum Industry
Blind Changing
Pipeline Valves: Gas Streams
Pipeline Valves: Light
Liquid/Gas Stream
Pipeline Valves: Heavy
Liquid Stream
Pipeline Valves: Hydrogen
Streams
Open-Ended Valves: All
Streams
Flanges: All Streams
Pump Seals: Light
Liquid/Gas Streams
Pump Seals: Heavy Liquid
Streams
Compressor Seals: Gas
Streams
Compressor Seals: Heavy
Liquid Streams
Drains: All Streams
Vessel Relief Valves: All
Streams
Fugitive Emissions - Specify
In Comments Field
Fugitive Emissions - Specify
In Comments Field
Fugitive Emissions - Specify
In Comments Field
3-06-008-07
3-06-008-11
3-06-008-12
3-06-008-13
3-06-008-14
3-06-008-15
3-06-008-16
3-06-008-17
3-06-008-18
3-06-008-19
3-06-008-20
3-06-008-21
3-06-008-22
3-06-888-01
3-06-888-02
3-06-888-03
1000 Barrels Refined
Valves In Operation
Valves In Operation
Valves In Operation
Valves In Operation
Valves In Operation
Flanges In Operation
Seals In Operation
Seals In Operation
Seals In Operation
Seals In Operation
Drains In Operation
Valves In Operation
1000 Barrels Refined
1000 Barrels Refined
1000 Barrels Refined
EIIP Volume II
4.7-7
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CHAPTER 4 - EQUIPMENT LEAKS
11/29/96
TABLE 4.7-1
(CONTINUED)
Source Description
Process Description
sec
Units
Industrial Processes
Petroleum Industry
Rubber And
Miscellaneous Plastics
Products
Oil And Gas
Production
Fugitive Emissions - Specify
In Comments Field
Fugitive Emissions - Specify
In Comments Field
Rubber And Miscellaneous
Plastic Parts - Equipment
Leaks
Crude Oil Production -
Complete Well
Crude Oil Production - Oil
Well Cellars
Crude Oil Production -
Compressor Seals
Crude Oil Production -
Drains
Natural Gas Production -
Valves
Natural Gas Production -
Drains
Fugitive Emissions - Specify
In Comments Field
Fugitive Emissions - Specify
In Comments Field
Fugitive Emissions - Specify
In Comments Field
Fugitive Emissions - Specify
In Comments Field
Fugitive Emissions - Specify
In Comments Field
Fugitive Emissions - Specify
In Comments Field
3-06-888-04
3-06-888-05
3-08-800-01
3-10-001-01
3-10-001-08
3-10-001-30
3-10-001-31
3-10-002-07
3-10-002-31
3-10-888-01
3-10-888-02
3-10-888-03
3-10-888-04
3-10-888-05
3-10-888-11
1000 Barrels Refined
1000 Barrels Refined
Facility-Annual
Wells/Year In
Operation
Sq Ft Of Surface
Area
Number Of Seals
Number Of Drains
Million Cubic Feet
Number Of Drains
Process-Unit/Year
Process-Unit/Year
Process-Unit/Year
Process-Unit/Year
100 Barrel Feed
Prod.
Million Cubic Feet
4.7-8
EIIP Volume II
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1/29/96
CHAPTER 4 - EQUIPMENT LEAKS
TABLE 4.7-1
(CONTINUED)
Source Description
Process Description
sec
Units
Industrial Processes
Transportation
Equipment
Transportation Equipment -
Equipment Leaks
3-14-800-01
Facility-Annual
Petroleum & Solvent Evaporation
Organic Solvent
Evaporation
Surface Coating
Operations
Organic Chemical
Transportation
Organic Solvent
Evaporation
Dry Cleaning - Misc.
Trichloroethylene Fugitives
Fugitive Emissions - Specify
In Comments Field
Fugitive Emissions - Specify
In Comments Field
Fugitive Emissions - Specify
In Comments Field
Fugitive Emissions - Specify
In Comments Field
Fugitive Emissions - Specify
In Comments Field
Fugitive Emissions - Specify
In Comments Field
Surface Coating Operations -
Equipment Leaks
Organic Chemical
Transportation - Equipment
Leaks
Waste Solvent Recovery
Operations - Fugitive Leaks
4-01-001-63
4-01-888-01
4-01-888-02
4-01-888-03
4-01-888-04
4-01-888-05
4-01-888-98
4-02-800-01
4-08-800-01
4-90-002-06
Tons Clothes
Cleaned
Tons Product
Tons Product
Tons Product
Tons Product
Tons Product
Gallons
Facility-Annual
Facility-Annual
Process-Unit/Year
Waste Disposal
Solid Waste Disposal
- Government
Solid Waste Disposal
- Commercial/
Institutional
Solid Waste Disposal
- Industrial
Solid Waste Disposal: Govt.
- Equipment Leaks
Solid Waste Disposal:
Comm./Inst. - Equipment
Leaks
Solid Waste Disposal: Indus.
- Equipment Leaks
5-01-800-01
5-02-800-01
5-03-800-01
Facility-Annual
Facility-Annual
Facility-Annual
EIIP Volume II
4.7-9
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CHAPTER 4 - EQUIPMENT LEAKS
11/29/96
TABLE 4.7-1
(CONTINUED)
Source Description
Process Description
sec
Units
Waste Disposal
Site Remediation
Site Remediation -
Equipment Leaks
5-04-800-01
Facility-Annual
MACT Source Categories
Styrene Or
Methacrylate-based
Resins
Cellulose-based Resins
Miscellaneous Resins
Vinyl-based Resins
Miscellaneous
Polymers
MACT Miscellaneous
Processes (Chemicals)
MACT Miscellaneous
Processes (Chemicals)
Styrene Or Methacrylate-
based Resins - Equipment
Leaks
Cellulose-based Resins -
Equipment Leaks
Miscellaneous Resins -
Equipment Leaks
Vinyl-based Resins -
Equipment Leaks
Miscellaneous Polymers -
Equipment Leaks
MACT Misc. Processes
(Chemicals) - Equipment
Leaks
MACT Misc. Processes
(Chemicals) - Equipment
Leaks
6-41-800-01
6-44-800-01
6-45-800-01
6-46-800-01
6-48-800-01
6-84-800-01
6-85-800-01
Facility-Annual
Facility-Annual
Facility-Annual
Facility-Annual
Facility-Annual
Facility-Annual
Facility-Annual
4.7-10
EIIP Volume II
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8
REFERENCES
America Petroleum Institute. 1993. Fugitive Hydrocarbon Emissions from Oil and Gas
Production Operations, API Publication No. 4589.
California Air Resources Board. August 1989. Technical Guidance Document to the
Criteria and Guidelines Regulation for AB-2588.
Chemical Manufacturer's Association (CMA). 1989. Improving Air Quality: Guidance for
Estimating Fugitive Emissions. Second Edition. Washington, D.C.
Code of Federal Regulations, Title 40, Part 60, Appendix A. July 1, 1987. Reference
Method 21, Determination of Volatile Organic Compound Leaks. Office of the Federal
Register. Washington, D.C.
EPA. April 1980. Assessment of Atmospheric Emissions from Petroleum Refining:
Volume 3, Appendix B. U.S. Environmental Protection Agency, 600/2-80-075c. Research
Triangle Park, North Carolina.
EPA. April 1982. Fugitive Emission Sources of Organic Compounds — Additional
Information on Emissions, Emission Reductions, and Costs. U.S. Environmental Protection
Agency, Office of Air Quality, Planning, and Standards, 450/3-82-010. Research Triangle
Park, North Carolina.
EPA. July 1992. Equipment Leaks Enabling Document. Final Report. Internal Instruction
Manual for ESD Regulation Development. U.S. Environmental Protection Agency, Office of
Air and Radiation, Office of Air Quality Planning and Standards, Reasearch Triangle Park,
North Carolina.
EPA. November 1995. Protocol for Equipment Leak Emission Estimates. U.S.
Environmental Protection Agency, Office of Air and Radiation, Office of Air Quality
Planning and Standards, 453/R-95-017. Research Triangle Park, North Carolina.
Epperson, D.L., Radian Corporation. January 27, 1995. Technical memorandum to
D. Markwordt, U.S. Environmental Protection Agency, Petroleum Industry Equipment
Leaks: Revised Correlations, Default Zero Emission Factors, and Pegged Emission Factors
Based on the 1993 Data from Refineries, Marketing Terminals, and Oil and Gas Production
Operations.
EIIP Volume II 4.8-1
-------
CHAPTER 4 - EQUIPMENT LEAKS 11/29/96
EPA. July 1980. Assessment of Atmospheric Emissions from Petroleum Refining: Volume 4.
Appendices C, D, and E. U.S. Environmental Protection Agency, 600/2-80-075d. Research
Triangle Park, North Carolina.
EPA. April 1980. Assessment of Atmospheric Emissions from Petroleum Refining: Volume
3. Appendix B. U.S. Environmental Protection Agency, 600/2-80-075c. Research Triangle
Park, North Carolina.
4.8-2 EIIP Volume II
-------
/1/29/96 CHAPTER 4 - EQUIPMENT LEAKS
APPENDIX A
ESTIMATING LEAK DETECTION AND
REPAIR (LDAR) CONTROL
EFFECTIVENESS
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CHAPTER 4 - EQUIPMENT LEAKS 11/29/96
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71/29/96 CHAPTER 4 - EQUIPMENT LEAKS
ESTIMATING LDAR CONTROL EFFECTIVENESS
Some process units/facilities may want to develop control efficiencies specific to their
process/facility if they have different leak definitions than what is hi the federal programs.
The LDAR monitoring frequency and leak definitions at some state equipment leak control
programs may also be significantly different from federal programs. Table 4.A-1 presents a
summary of controls required by federal requirement leak control programs.
The control efficiency of monitoring equipment at various leak definitions and monitoring
frequencies may be estimated from the leak frequency before and after an LDAR program is
implemented. Tables 4.A-2, and 4.A-3 present equations relating average leak rate to
fraction leaking at SOCMI facilities and petroleum refineries. Once the initial and final leak
frequencies are determined, they can be entered into the applicable equation to calculate the
corresponding average leak rates at these leak frequencies. The control effectiveness for an
LDAR program can be calculated from the initial leak rate and the final leak rate.
Eff = (ILR - FLR)/ILR X 100 (4tA-l)
where:
Eff = Control effectiveness (percent)
ILR = Initial leak rate (kg/hr per source)
FLR = Final leak rate (kg/hr per source)
The methodology for estimating leak frequencies is discussed in detail in Chapter 5 of the
Equipment Leaks Enabling Document (EPA, July 1992). The methodology requires
knowledge of screening data and equipment repair times.
REFERENCE
EPA. July 1992. Equipment Leaks Enabling Document. Final Report. Internal Instruction
Manual for ESD Regulation Development. U.S. Environmental Protection Agency, Office of
Air and Radiation, Office of Air Quality Planning and Standards, Reasearch Triangle Park,
North Carolina.
EHP Volume II 4.A-1
-------
4*.
>
TABLE 4.A-1
CONTROLS REQUIRED BY EQUIPMENT LEAK CONTROL PROGRAMS
i
TJ
3
I
Equipment
Type
Valves
Pumps
Compressors
Connectors
Service
Gas
Light
liquid
Light
liquid
Gas
Gas and
light
liquid
Petroleum
Refinery CTG*
Quarterly LDAR at
10,000 ppm
Annual LDAR at
10,000 ppm
Annual LDAR at
10,000 ppm;
weekly visual
inspection
Quarterly LDAR at
10,000 ppm
None
SOCMI CTG
Quarterly LDAR at
10,000 ppm
Quarterly LDAR at
10,000 ppm
Quarterly LDAR at
10,000 ppm;
weekly visual
inspection
Quarterly LDAR at
10,000 ppm
None
Petroleum Refinery
NSPSb
Monthly LDAR at
10,000 ppm; decreasing
frequency with good
performance
Monthly LDAR at
10,000 ppm; decreasing
frequency with good
performance
Monthly LDAR at
10,000 ppm; weekly
visual inspection; or
dual mechanical seals
with controlled
degassing vents
Daily visual inspection;
dual mechanical seal
with barrier fluid and
closed-vent system or
maintained at a higher
pressure than the
compressed gas
None
RON
Monthly LDAR with >2% leakers;
quarterly LDAR with <2% leakers;
decreasing frequency with good
performance. Initially at 10,000
ppm, annually at 500 ppm
Monthly LDAR with >2% leakers;
quarterly LDAR with <2% leakers;
decreasing frequency with good
performance. Initially at 10,000
ppm, annually at 500 ppm
Monthly LDAR; weekly visual
inspection. Leak definition
decreases from 10,000 ppm; or dual
mechanical seals or closed-vent
system
Daily visual inspection. Dual
mechanical seal with barrier fluid
and closed-vent system or
maintained at a higher pressure than
the compressed gas
Annual LDAR at 500 ppm with
>0.5% leakers; decreasing frequency
with good performance
c:
1
•H
r-
2
O)
-------
"
c:
1
•H
r—
52
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CHAPTER 4 - EQUIPMENT LEAKS
11/29/96
TABLE 4.A-2
EQUATIONS RELATING AVERAGE LEAK RATE TO FRACTION
LEAKING AT SOCMI UNITS
Equipment Type
Gas valve
Light liquid valve
Light liquid pump
Connector
Leak Definition
(ppmv)
500
1000
2000
5000
10000
500
1000
2000
5000
10000
500
1000
2000
5000
10000
500
2000
5000
10000
Equations'*
ALR = (0.04372) x (Lk Frac.) + 0.000017
ALR = (0.04982) x (Lk Frac.) + 0.000028
ALR = (0.05662) x (Lk Frac.) + 0.000043
ALR = (0.06793) x (Lk Frac.) + 0.000081
ALR = (0.07810) x (Lk Frac.) + 0.000131
ALR = (0.04721) x (Lk Frac.) + 0.000027
ALR = (0.05325) x (Lk Frac.) + 0.000039
ALR = (0.06125) x (Lk Frac.) + 0.000059
ALR = (0.07707) x (Lk Frac.) + 0.000111
ALR = (0.08901) x (Lk Frac.) + 0.000165
ALR = (0.09498) x (Lk Frac.) + 0.000306
ALR = (0.11321) x (Lk Frac.) + 0.000458
ALR = (0.13371) x (Lk Frac.) + 0.000666
ALR = (0.19745) x (Lk Frac.) + 0.001403
ALR = (0.24132) x (Lk Frac.) + 0.001868
ALR = (0.04684) x (Lk Frac.) + 0.000017
ALR = (0.07307) x (Lk Frac.) + 0.000035
ALR = (0.09179) x (Lk Frac.) + 0.000054
ALR = (0.11260) x (Lk Frac.) + 0.000081
* ALR = Average TOC leak rate (kg/hr per source).
b Lk Frac. = Fraction leaking.
4.A-4
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11/29/96
CHAPTER 4 - EQUIPMENT LEAKS
TABLE 4.A-3
EQUATIONS RELATING AVERAGE LEAK RATE TO FRACTION LEAKING
AT REFINERY PROCESS UNITS
Equipment Type
Gas valve
Light liquid valve
Light liquid pump
Connector
Leak Definition
(ppmv)
500
1000
10000
500
1000
10000
500
1000
10000
500
1000
10000
Equation1'1'
ALR = (0.1 1 140) x (Lk Frac.) + 0.000088
ALR = (0.12695) x (Lk Frac.) + 0.000140
ALR = (0.26200) x (Lk Frac.) + 0.000600
ALR = (0.03767) x (Lk Frac.) + 0.000195
ALR = (0.04248) x (Lk Frac.) + 0.000280
ALR = (0.08350) x (Lk Frac.) + 0.001700
ALR = (0.19579) x (Lk Frac.) + 0.001320
ALR = (0.23337) x (Lk Frac.) + 0.001980
ALR = (0.42500) x (Lk Frac.) + 0.012000
ALR = (0.01355) x (Lk Frac.) + 0.000013
ALR = (0.01723) x (Lk Frac.) + 0.000018
ALR = (0.03744) x (Lk Frac.) + 0.000060
" ALR = Average non-methane organic compound leak rate (kg/hr per source).
b Lk Frac. = Fraction leaking.
EIIP Volume II
4.A-5
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CHAPTER 4 - EQUIPMENT LEAKS 11/29/96
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4 A_g BIP Volume II
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11/29/96 CHAPTER 4 - EQUIPMENT LEAKS
APPENDIX B
SOURCE SCREENING — RESPONSE
FACTORS
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CHAPTER 4 - EQUIPMENT LEAKS 11/29/96
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11/29/96 CHAPTER 4 - EQUIPMENT LEAKS
SOURCE SCREENING — RESPONSE FACTORS
This appendix presents additional information on response factors and includes some
guidelines on how to evaluate whether a RF correction to a screening value should be made.
An RF is a correction factor that can be applied to a screening value to relate the actual
concentration to the measured concentration of a given compound. The RF is calculated
using the equation:
RF = AC/SV (4.B-1)
where:
RF = Response factor
AC = Actual concentration of the organic compound (ppmv)
SV = Screening value (ppmv)
The value of the RF is a function of several parameters. These parameters include the
monitoring instrument, the calibration gas used to calibrate the instrument, the compound(s)
being screened, and the screening value.
The EPA recommends that if a compound (or mixture) has an RF greater than 3, then the RF
should be used to adjust the screening value before it is used in estimating emissions. When
a compound has an RF greater than three for the recalibrated instrument, the emissions
estimated using the unadjusted screening value will, generally, underestimate the actual
emissions.
A detailed list of published RFs is presented in Appendix C of the Protocol document (EPA,
November 1995). These RFs, developed for pure compounds, can be used to estimate the
RF for a mixture by using the equation:
imp _ _ _
m ~ (4.B-2)
£ <*/HF|)
where:
RFm = Response factor of the mixture
n = Number of components in the mixture
Xj = Mole fraction of constituent "i" in the mixture
EIIP Volume II 4.B-1
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CHAPTER 4 - EQUIPMENT LEAKS 11/29/96
= Response factor of constituent i in the mixture
For more detail on the derivation of this equation, please refer to Appendix A of the Protocol
document (EPA, November 1995).
In general, RFs can be used to correct all screening values, if so desired. The following
steps can be carried out to evaluate whether an RF correction to a screening value should be
made.
1. For the combination of monitoring instrument and calibration gas used,
determine the RFs of a given material at an actual concentration of 500 ppmv
and 10,000 ppmv. When it may not be possible to achieve an actual
concentration of 10,000 ppmv for a given material, the RF at the highest
concentration that can be safely achieved should be determined.
2. If the RFs at both actual concentrations are below 3, it is not necessary to
adjust the screening values.
3. If either of the RFs are greater than 3, then the EPA recommends an RF be
applied for those screening values for which the RF exceeds 3.
One of the following two approaches can be applied to correct screening values:
1. Use the higher of either the 500 ppmv RF or the 10,000 ppmv RF to adjust all
screening values; or
2. Generate a response factor curve to adjust the screening values.
When it is necessary to apply RFs, site personnel should use engineering judgement to group
process equipment into streams containing similar compounds. All components associated
with a given stream can then be assigned the same RF, as opposed to calculating an RF for
each individual equipment piece. Appendix A of the Protocol document (EPA,
November 1995) presents an example about the application of response factors.
REFERENCE
EPA. November 1995. Protocol for Equipment Leak Emission Estimates. U.S.
Environmental Protection Agency, Office of Air and Radiation, Office of Air Quality
Planning and Standards, 453/R-95-017. Research Triangle Park, North Carolina.
4.B-2 EIIP Volume II
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11/29/96 CHAPTER 4 - EQUIPMENT LEAKS
APPENDIX C
MASS EMISSIONS SAMPLING —
METHODS AND CALCULATION
PROCEDURES
EIIP Volume II
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CHAPTER 4 - EQUIPMENT LEAKS 11/29/96
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/1/29/96 CHAPTER 4 - EQUIPMENT LEAKS
MASS EMISSIONS SAMPLING (BAGGING)
When bagging an equipment piece, two methods are generally employed in sampling source
enclosures: the vacuum method (Figure 4.C-1) and the blow-through method (Figure 4.C-2).
These two methods differ in the ways that the carrier gas is conveyed through the bag. In
the vacuum method, a vacuum pump is used to pull air through the bag. In the blow-through
method, a carrier gas such as nitrogen is blown into the bag. In general, the blow-through
method has advantages over the vacuum method. These advantages are as follows:
• The blow-through method is more conducive to better mixing in the bag.
• The blow-through method minimizes ambient air hi the bag and thus reduces
potential error associated with background organic compound concentrations.
(For this reason the blow-through method is especially preferable when
measuring the leak rate from components with zero or very low screening
values.)
• The blow-through method minimizes oxygen concentration in the bag
(assuming air is not used as the carrier gas) and the risk of creating an
explosive environment.
• In general, less equipment is required to set up the blow-through method
sampling train.
However, the blow-through method does require a carrier gas source, and preferably the
carrier gas should be inert and free of any organic compounds and moisture. The vacuum
method does not require a special carrier gas.
Figures 4.C-3 and 4.C-4 present the calculation procedures for leak rates when using the
vacuum and blow-through methods, respectively.
When choosing the bagging material, an important criteria is that it is impermeable to the
specific compounds being emitted from the equipment piece.
Example 4.C-1, for the vacuum method, and Example 4.C-2, for the blow-through method,
are presented in two parts. Part 1 shows the data sheets that were presented in Section 6
(Figures 4.6-2 and 4.6-3) filled out with the appropriate information, and Part 2 shows how
that information is used to calculate the mass emission rates, using the equations shown in
Figures 4.C-3 and 4.C-4.
EIIP Volume II 4.C-1
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CHAPTER 4 - EQUIPMENT LEAKS
'9m
17/29M6
Pressure
Read i ng
Dev ice
This Ii ne shouId
be as short
as possi bIe
Trap
:«, U
old Trap in Ice; Bath
COpt ionan
Hg Manometer
Jc
Control
Valve
Smal I
Diaphragm
Pump
Fi Iter
Vacuum
Pump
Sample Bag
Two-Way Valve
FIGURE 4.C-1. SAMPLING TRAIN FOR BAGGING A SOURCE
USING THE VACUUM METHOD
4.C-2
EIIP Volume /I
-------
I
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Teflon Tubir
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Sample Port for Collecting Data on
- Temperature
- Hydrocarbon Concentration
- Oxygen Concentration
Tape or Compressed Fo i I
i
1
n
U)
2
-------
CHAPTER 4 - EQUIPMENT LEAKS ft/29/96
CALCULATION PROCEDURES FOR LEAK RATE WHEN USING, THE VACUUM METHOD
T tD., *63 x 10i'°(Q)(MW)(GC)(P)
Leak Rate =
(kg/hr)) T+273J5 1
where::
£63; x 1IO"10 = A conversions factor using the gas constant:
°K x IQ*5 x kg-mol! x mini
L. x how x: mmHg;
Q = Flow rate out of bag (L/min)
.MW* = .Molecular weight, of organic: compounds) in the sample bag or alternatively in the
process stream contained1 within the equipment piece being bagged (kg/kg-mol))
GCb , = Sample bag organic compound concentration (ppmv) minus background1 bag organic
compound' concentration' (ppmv);
P = Absolute pressure at the dry gas meter (mmHg)
T = Temperature at the dry gas meter (°C);
p. = Density of organic liquid collected (g/mL)
VL = Volume of liquid collected1 (mH)
16.67 = A conversion factor to adjust term to units of kilograms per hour (g, x hr)/(kg; x min)
t = Time in which liquid' is collected (min)
8 For mixtures, calculate- MW as:
EX,
where:
i.=r
= Molecular weight of organic compound1 "i"
Xj = Mole fraction of organic: compound i
n = Number of organic compounds, in mixture.
b For mixtures, the value of GC is the total concentration of all the organic compounds in the mixture,
c Collection of a background bag is optional. If a bag of background air is not collected, assume the
background concentration is zero.
FIGURE 4.C-3. CALCULATION PROCEDURES FOR LEAK RATE WHEN USING THE
VACUUM METHOD
4.C-4 EHP Volume
-------
11/29/96
CHAPTER 4 - EQUIPMENT LEAKS
CALCULATION PROCEDURES FOR LEAK RATE WHEN USING THE
BLOW-THROUGH METHOD
Leak Rate
(kg/hr)
1.219 x 1Q-5(Q)(MW)(GC) + (P)(VL)
T + 273.15 + 16.67(t)
x
106 ppmv
106 ppmv - GC
where:
1.219 x 1CT5
A conversion factor taking into account the gas constant and assuming a
pressure in the bag of 1 atmosphere:
°K x 106 x kg-mol
flow rate out of bag (nrVhr);
N2 Flow Rate (L/min)
1 - [Bag Oxygen Cone, (volume %)/21]
[0.06 (mVmin)]
(L/hr)
MW = Molecular weight of organic compounds in the sample bag or alternatively in
the process stream contained within the equipment piece being bagged
(kg/kg-mol)
GCb = Sample bag organic compound concentration (ppmv), corrected for
background bag organic compound concentration (ppmv)c
T = Temperature in bag (°C)
p = Density of organic liquid collected (g/mL)
VL = Volume of liquid collected (mL)
16.67 = A conversion factor to adjust term to units of kilograms per hour (g x hr)/(kg
x min)
t = Time in which liquid is collected (min)
FIGURE 4.C-4. CALCULATION PROCEDURES FOR LEAK RATE WHEN USING THE
BLOW-THROUGH METHOD
EIIP Volume II
4.C-5
-------
CHAPTER 4 - EQUIPMENT LEAKS 1 1/29/96
CALCULATION PROCEDURES FOR LEAK RATE WHEN USING THE
BLOW-THROUGH METHOD (CONTINUED)
a For mixtures, calculate MW as:
E
where:
= Molecular weight of organic compound "i"
X; = Mole fraction of organic compound i
n = Number of organic compounds in mixture
b For mixtures, the value of GC is the total concentration of all the organic compounds in the mixture.
c Collection of a background bag is optional. If a bag of background air is not collected, assume the background
concentration is zero. To correct for background concentration, use the following equation:
GC f BAGxBG
(ppmv) 21
where:
SB = Sample bag concentration (ppmv);
BAG = Tent oxygen concentration (volume %); and
BG = Background bag concentration (ppmv)
FIGURE 4.C-4. (CONTINUED)
4.C-6 EIIP Volume II
-------
/1/29/96 CHAPTER 4 - EQUIPMENT LEAKS
EXAMPLE 4.C-1: PART 1
EXAMPLE DATA COLLECTION FORM FOR FUGITIVE EMISSIONS
BAGGING TEST (VACUUM METHOD)
Equipment Tvpe
Equipment Category
Line Size
Stream Phase (G/V, LL, HL)
Barometric Pressure
Ambient Temperature
Stream Temperature
Stream Composition (Wt. %)
Valve Component ID V0101
Plant ID P012
Date 10-15-95
LL Analysis Team
Instrument ID 101
Stream Pressure
100% TOC MW = 25.4735 ke/ks-mol
Time Bagging Test Measurement Data
Initial Screening (ppmv) Equipment Piecea 450 Bkgd._
Background Bag Organic Compound Cone. (ppmv)b
Sample Bag 1 Organic Compound Cone, (ppmv) 268
Dry Gas Meter Reading (L/min) 2.806
Vacuum Check in Bag (Y/N) (Must be YES to collect sample.)
Dry Gas Meter Temperature1 (°C) 17_
Dry Gas Meter Pressure0 (mmHg) 668
Sample Bag 2 Organic Compound Cone, (ppmv)
Dry Gas Meter Reading (L/min)
Vacuum Check in Bag (Y/N) (Must be YES to collect sample.)
Dry Gas Meter Temperature1 (°C)
Dry Gas Meter Pressure0 (mmHg)
Condensate Accumulation: Starting Time Final Time
Organic Condensate Collected (mL)
Density of Organic Condensate (g/mL)
Final Screening (ppmv) Equip. Piecea 450 Bkgd._
" The vacuum method is not recommended if the screening value is approximately 10 ppmv or less.
b Collection of a background bag is optional.
c Pressure and temperature are measured at the dry gas meter.
EHP Volume II 4.C-7
-------
CHAPTER 4 - EQUIPMENT LEAKS
11/29/96
EXAMPLE 4.C-1: PART 2
EQUATION FOR CALCULATING THE LEAK RATE USING THE DATA FROM PART 1
Leak Rate = f 9.63E-10 (Q)(MW)(GC)(P)
T + 273.15
x x
mn
L x hr x mmHg
(268 ppmv)(668 mmHg) ]
(17 + 273.15)°K j
= 4.25E-05 kg/hr
2.806
mm
25.4735
kg-mol
4.C-8
EIIP Volume II
-------
/1/29/96 CHAPTER 4 - EQUIPMENT LEAKS
EXAMPLE 4.C-2: PART 1
EXAMPLE DATA COLLECTION FORM FOR FUGITIVE EMISSIONS BAGGING TEST
(BLOW-THROUGH METHOD)
Equipment Type Valve Component ID V0102
Equipment Category Plant ID P012
Line Size Date 10-15-95
Stream Phase (G/V, LL, HL) LL Analysis Team.
Barometric Pressure
Ambient Temperature Instrument ID 101
Stream Temperature Stream Pressure
Stream Composition (Wt. %) 100% TOC MW=28.12 ke/ke-mol
Time Bagging Test Measurement Data
Initial Screening (ppmv) Equipment Piece 8 Bkgd..
Background Bag Organic Compound Cone. (ppmv)a
Sample Bag 1 Organic Compound Cone, (ppmv) 29.3
Dilution Gas Flow Rate (L/min) 5.21
O2 Concentration (volume %) 2.55
Bag Temperature (°C) 23.89
Sample Bag 2 Organic Compound Cone, (ppmv)
Dilution Gas Flow Rate (L/min)
O2 Concentration (volume %)
Bag Temperature (°C)
Condensate Accumulation: Starting Time Final Time
Organic Condensate Collected (mL)
Density of Organic Condensate (g/mL)
Final Screening (ppmv) Equipment Piece 8 Bkgd.
0 Collection of a background bag is optional. However, it is recommended in cases where the screening
value is less than 10 ppmv and there is a detectable oxygen level in the bag.
EIIP Volume II 4.C-9
-------
CHAPTER 4 - EQUIPMENT LEAKS
11/29/96
EXAMPLE 4.C-2: PART 2
EQUATION FOR CALCULATING THE LEAK RATE USING THE DATA FROM PART 1
Dilution Gas Flow Rate [0.06 mVmin]
•••-——— X "••••—••
L/hr
1 -
Bag 0, cone (vol%)
21%
5.21
1 -
min [ 0.06 m'/min]
2.55% 1 L/hr
21%
= 0.36 mVhr
Leak Rate = [ 1.219E-OS (Q) (MW) (GC)
106
T + 273.15 106 -
i •Jiop-ns °K x 1Q6 x kg~m°l x min
m3
G(
:J
036 m3
hr
(28 12 ^ (Wlmrnv)
kg-mol J
(23.89+273.15)°K
106
10° - 2*
= 1.22E-05 kg/hr
4.C-10
EIIP Volume II
-------
/1/29/96 CHAPTER 4 - EQUIPMENT LEAKS
APPENDIX D
EXAMPLE DATA COLLECTION FORM
FOR FUGITIVE EMISSIONS FROM
EQUIPMENT LEAKS
EIIP Volume II
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CHAPTER 4 - EQUIPMENT LEAKS 17/29/96
This page is intentionally left blank.
EIIP Volume II
-------
11/29/96 CHAPTER 4 - EQUIPMENT LEAKS
EXAMPLE DATA COLLECTION FORM INSTRUCTIONS
GENERAL
This form may be used as a worksheet to aid in collecting the information/data
necessary to estimate HAP and VOC emissions from equipment leaks.
The form is divided into five sections: General Information; Stream Composition
Data; Equipment Counts; Screening Data; and Equipment Leaks Controls.
Some of the sections require entry on a stream basis; for these, a separate copy of the
section will need to be made for each stream in the process unit.
If you want to modify the form to better serve your needs, an electronic copy of the
form may be obtained through the EIIP on the CHIEF bulletin board system (BBS) of
the OAQPS TTN.
STREAM COMPOSITION DATA SECTION
Weight percents may not need to be provided for constituents present in concentrations
less than 1.0 weight percent.
In the row labelled "OTHER," identify total weight percent of all constituents not
previously listed. The total weight percent of constituents labelled as "OTHER" must
not exceed 10 percent. Total weight percent of all constituents in the stream must
equal 100 percent.
SCREENING DATA SECTION
Complete the information/data for each screened stream.
EIIP Volume II 4.D-1
-------
CHAPTER 4 - EQUIPMENT LEAKS 11/29/96
EQUIPMENT COUNT SECTION
• Complete each blank form for each stream in the facility.
• The LDAR trigger concentration refers to the concentration level that the component is
considered to be leaking.
• Enter the control parameters for each component type in the stream. Provide the
percent of the total equipment type in the stream that has the controls listed in the
attached table.
• If other controls are used, specify what they are in the space left of the slash. Specify
the percent of each component type in the stream that use the other control in the
space to the right of the slash.
• Indicate any secondary control devices to which the closed vent system transports the
process fluid.
Example 4.D-1 shows how all of the sections of this form would be filled out for the example
presented in Section 4 (Tables 4.4-1 and 4.4-2) for a hypothetical chemical processing facility,
which is subject to an LDAR program.
4.D-2 EIIP Volume //I
-------
CD
Note: Complete this form for each type of fuel used and for each unit.
EXAMPLE DATA COLLECTION FORM - FUGITIVE EMISSIONS FROM EQUIPMENT LEAKS
GENERAL INFORMATION
Process Unit Capacity (Ib/yr)
Portable VOC Monitoring Instrument Used3
Calibration Gas of Monitoring Instrument3
STREAM COMPOSITION DATA
CAS
Number
—
—
.
—
Chemical Name
OTHER
Total HAPs
Total VOCs
Source0
Amount of Time Fluid in Stream (hr/yr)
Concentration (wt.%)
Stream 1
Stream 2
Stream 3
Stream 4
Stream 5
b
3 Collect information if screening data have been gathered at the process unit.
b CAS = Chemical Abstract Service.
c EJ = Engineering judgement; TD = Test data; LV = Literature values.
Oi
i
T>
Si
s
g
1
-------
EXAMPLE DATA COLLECTION FORM - FUGITIVE EMISSIONS FROM EQUIPMENT LEAKS
i
EQUIPMENT COUNTS
Component
Valves
Connectors
Pumps
Compressor
Open Lines
Sample Connections
Pressure Relief Valve
Service
gas/vapor
light liquid
heavy liquid
all
light liquid
heavy liquid
gas/vapor
all
all
gas/vapor
Count Sourceb
Stream 1
(A)
Stream 2
(B)
Stream 3
(C)
S
c:
1
^H
r-
2
?s
GO
a Do not include equipment in vacuum service.
b D = Design specifications; I = Inspection and maintenance tags; C = Actual count; and R = Ratio; if ratio, specify (i.e., 25 valves per
pump).
Oi
-------
EXAMPLE DATA COLLECTION FORM - FUGITIVE EMISSIONS FROM EQUIPMENT LEAKS
ft
SCREENING DATA
Stream ID:
Date Components Screened:
Component ID
Component Type:
Total Number of Components Screened
Screening Value (ppmv)
O)
i
t>
a
1
2
-------
I
EXAMPLE DATA COLLECTION FORM - FUGITIVE EMISSIONS FROM EQUIPMENT LEAKS
i
Tj
EQUIPMENT LEAKS CONTROLS
Stream ID:
Is the equipment in this stream subject to a LDAR program? (Yes/No)
Type of Monitoring System3:
Equipment
Valves
Pumps
Compressors
Connectors
Open-ended
lines
Sampling
Connections
Pressure
Relief Valves
Leak Detection and Repair Parameters
LDAR
Quantity in Trigger Monitoring Response
Program Cone. Frequency Timeb
NA
NA
NA
NA
Control Parameters
Closed Vent
Percent with Percent with Percent with Secondary
Control Ac Control Bc Control C= Other Control
NA
NAd
NA
NA
NA
NA
/
/
/
/
/
/
/
3
c;
i
a V = Visual; P = Portable; F = Fixed point; If other, please specify.
b IM = Immediately; D = 1 day; D3 = 3 days; W = 1 week; W2 = 2 weeks; and M = 1 month.
c See attached table, Controls by Equipment Type.
d NA = Not applicable.
-------
I
ct
EXAMPLE DATA COLLECTION FORM - FUGITIVE EMISSIONS FROM EQUIPMENT LEAKS
TABLE OF CONTROLS BY EQUIPMENT TYPE
O)
Control Option
A
B
C
Equipment
All
Valves
Pumps
Compressors
Open-ended lines
Sampling Connections
PRVs
Pumps
Sampling connections
Controls
Closed vent system
Sealless
Dual mechanical seal with barrier fluid
Mechanical seals with barrier fluid
Capped, plugged, blind-flagged
In-situ sampling
Rupture disk
Sealless
Closed loop sampling
i
t>
a
1
5
-------
b
•
oo
S3
f
EXAMPLE 4.D-1
EXAMPLE DATA COLLECTION FORM -
FUGITIVE EMISSIONS FROM EQUIPMENT FROM EQUIPMENT LEAKS
GENERAL INFORMATION
Process Unit Capacity (Ib/yr) 800,000
Portable VOC Monitoring Instrument Used3 Foxboro OVA Model 108
Calibration Gas of Monitoring Instrument2 Methane
STREAM COMPOSITION DATA
CAS
Number
140885
100425
74840
7732185
—
—
—
—
Chemical Name
ETHYL ACRYLATE
STYRENE
ETHANE
WATER
OTHER
Total HAPs
Total VOCs
Source1"
Amount of Time Fluid in Stream (hr/yr)
Concentration (wt%)
Stream 1
(A)
80
20
80
80
TD
8760
Stream 2
(B)
10
90
100
100
TD
4380
Stream 3
(Q
65
25
10
65
90
TD
8760
Stream 4
Stream 5
•
Collect information if screening data have been gathered at the process unit.
i
s
-H
r--
S
Ing
juo
Int;
estl
ILV
ra
luesj
NO
55
&
Oj
-------
EXAMPLE 4.D-1
(CONTINUED)
CO
0)
EQUIPMENT COUNTS
Component
Valves
Connectors
Pumps
Compressor
Open Lines
Sample Connections
Pressure Relief Valve
Service
gas/vapor
light liquid
heavy liquid
all
light liquid
heavy liquid
gas/vapor
all
all
gas/vapor
Count Sourceb
C
C
Stream 1
(A)
15
Stream 2
(B)
12
Stream 3
(Q
40
* Do not include equipment in vacuum service.
b D = Design specifications; I = Inspection and maintenance tags; C = Actual count; and R = Ratio; if ratio, specify (i.e., 25 valves per
pump).
1
-------
D
o
I
CD
EXAMPLE 4.D-1
(CONTINUED)
SCREENING DATA
Stream ID: A
Date Components Screened: 7-15-95
Component ID
A-l
A-2
A-3
A-4
A-5
A-6
A-7
A-8
A-9
A-10
A-ll
A-12
A-13
A-14
A-15
Component Type: Light Liquid Pump
Total Number of Components Screened: 15
Screening Value (ppmv)
0
0
0
0
0
20
50
50
100
100
200
400
1000
2000
5000
i
-o
3.
3
c:
I
-H
r-
2
CO
O)
-------
f
EXAMPLE 4.D-1
(CONTINUED)
CO
O)
SCREENING DATA
Stream ID: B
Date Components Screened: 7-15-95
Component ID
B-l
B-2
B-3
B-4
B-5
B-6
B-7
B-8
B-9
B-10
B-ll
Component Type: Light Liquid Pump
Total Number of Components Screened: 11
Screening Value (ppmv)
0
0
0
10
30
250
500
2000
5000
8000
25,000
I
t>
a
s
c:
i
2
-------
EXAMPLE 4.D-1
i
(CONTINUED)
SCREENING DATA
Stream ID: C
Date Components Screened: 7-15-95
Component ID
C-l
C-2
C-3
C-4
C-5
C-6
C-7
C-8
C-9
C-10
C-ll
C-12
C-13
C-14
C-15
Component Type: Gas/Vapor Valve
Total Number of Components Screened: 40
Screening Value (ppmv)
0
0
0
0
0
0
15
20
20
35
SO
50
120
150
200
8
-H
r—
2
NO
*5
(o
O)
-------
0
I
cc
EXAMPLE 4.D-1
(CONTINUED)
§
U)
SCREENING DATA
Stream ID: C
Date Components Screened: 7-15-95
Component ID
C-16
C-17
C-18
C-19
C-20
C-21
C-22
C-23
C-24
C-25
C-26
C-27
C-28
C-29
C-30
Component Type: Gas/Vapor Valve
Total Number of Components Screened: 40
Screening Value (ppmv)
500
550
575
600
610
700
800
1010
1200
1500
1550
1700
2000
5000
5100
i
T)
3l
g
i
-------
o
I—*
4^
EXAMPLE 4.D-1
(CONTINUED)
1
SCREENING DATA
Stream ID: C
Date Components Screened: 7-15-95
Component ID
C-31
C-32
C-33
C-34
C-35
C-36
C-37
C-38
C-39
C-40
Component Type: Gas/Vapor Valve
Total Number of Components Screened: 40
Screening Value (ppmv)
6100
7000
8000
8100
8150
8300
9000
10,000
15,000
50,000
o
c:
I
-H
r-
2
r
CO
01
-------
I
tb
EXAMPLE 4.D-1
(CONTINUED)
CO
Oi
EQUIPMENT LEAKS CONTROLS
Stream ID: A
Is the equipment in this stream subject to a LDAR program? (Yes/No) Yes
Type of Monitoring System3: P
Equipment
Valves
Pumps
Compressors
Connectors
Open-ended
lines
Sampling
Connections
Pressure
Relief Valves
Leak Detection and Repair Parameters
LDAR
Quantity in Trigger Monitoring Response
Program Cone. Frequency Timeb
15
NA
1 0,000 ppm
NA
monthly
NA
W
NA
Control Parameters
Closed Vent
Percent with Percent with Percent with Secondary
Control Ac Control Bc Control C Other Control
53%
7%
NA
NA"
40%
NA
NA
NA
NA
/
/
/
/
/
/
/
I
s
c
1
2
a V = Visual; P = Portable; F = Fixed point; If other, please specify.
b IM = Immediately; D = 1 day; D3 = 3 days; W = 1 week; W2 = 2 weeks; and M = 1 month.
c See attached table, Controls by Equipment Type.
d NA = Not applicable.
-------
o\
EXAMPLE 4.D-1
(CONTINUED)
1
CD
EQUIPMENT LEAKS CONTROLS
Stream ID: B
Is the equipment in this stream subject to a LDAR program? (Yes/No) Yes
Type of Monitoring System3: P
Equipment
Valves
Pumps
Compressors
Connectors
Open-ended
lines
Sampling
Connections
Pressure
Relief Valves
Leak Detection and Repair Parameters
LDAR
Quantity in Trigger Monitoring Response
Program Cone. Frequency Timeb
12
NA
10,000 ppm
NA
monthly
NA
IV
NA
Control Parameters
Closed Vent
Percent with Percent with Percent with Secondary
Control Ac Control Bc Control C° Other Control
67%
33%
NA
NAd
0%
NA
NA
• NA
NA
/
/
/
/
/
/
/
" V = Visual; P = Portable; F = Fixed point; If other, please specify.
b IM = Immediately; D = 1 day; D3 = 3 days; W = 1 week; W2 = 2 weeks; and M = 1 month.
c See attached table, Controls by Equipment Type.
d NA = Not applicable.
c:
i
-------
I
to
EXAMPLE 4.D-1
(CONTINUED)
CO
OJ
o
~J
EQUIPMENT LEAKS CONTROLS
Stream ID: C
Is the equipment in this stream subject to a LDAR program? (Yes/No) Yes
Type of Monitoring System3: P
Equipment
Valves
Pumps
Compressors
Connectors
Open-ended
lines
Sampling
Connections
Pressure
Relief Valves
Leak Detection and Repair Parameters
Quantity in LDAR Trigger Monitoring Response
Program Cone. Frequency Timeb
40
NA
10,000 ppm
NA
monthly
NA
w
NA
Control Parameters
Closed Vent
Percent with Percent with Percent with Secondary
Control Ac Control Bc Control C Other Control
50%
50%
NA
NA"
NA
NA
NA
NA
/
/
/
/
/
/
/
" V = Visual; P = Portable; F = Fixed point; If other, please specify.
b IM = Immediately; D = 1 day; D3 = 3 days; W = 1 week; W2 = 2 weeks; and M = 1 month.
e See attached table, Controls by Equipment Type.
d NA = Not applicable.
i
•"0
i
-H
i—
2
-------
CHAPTER 4 - EQUIPMENT LEAKS 11/29/96
This page is intentionally left blank.
4.D-18 EIIP Volume II
-------
VOLUME II: CHAPTERS
PREFERRED AND ALTERNATIVE
METHODS FOR ESTIMATING AIR
EMISSIONS FROM WASTEWATER
COLLECTION AND TREATMENT
March 1997
Prepared by:
Eastern Research Group
Prepared for:
Point Sources Committee
Emission Inventory Improvement Program
-------
DISCLAIMER
This document was furnished to the Emission Inventory Improvement Program and the
U.S. Environmental Protection Agency by Eastern Research Group, Inc., Morrisville,
North Carolina. This report is intended to be a final document and has been reviewed
and approved for publication. The opinions, findings, and conclusions expressed
represent a consensus of the members of the Point Sources Committee of the Emission
Inventory Improvement Program. Any mention of company or product names does not
constitute an endorsement; rather the names are used as examples.
-------
ACKNOWLEDGEMENT
This document was prepared by Eastern Research Group, Inc., for the Point Sources
Committee, Emission Inventory Improvement Program, and for Dennis Beauregard of
the Emission Factor and Inventory Group, U.S. Environmental Protection Agency.
Members of the Point Sources Committee contributing to the preparation of this
document are:
Bill Gill, Co-Chair, Texas Natural Resource Conservation Commission
Dennis Beauregard, Co-Chair, Emission Factor and Inventory Group, U.S. Environmental Protection Agency
Denise Alston-Guiden, Galsen Corporation
Bob Betterton, South Carolina Department of Health and Environmental Control
Alice Fredlund, Louisana Department of Environmental Quality
Karla Smith Hardison, Texas Natural Resource Conservation Commission
Gary Helm, Air Quality Management, Inc.
Paul Kim, Minnesota Pollution Control Agency
Toch Mangat, Bay Area Air Quality Management District
Ralph Patterson, Wisconsin Department of Natural Resources
Jim Southerland, North Carolina Department of Environment, Health, and Natural Resources
Eitan Tsabari, Omaha Air Quality Control Division
Bob Woolen, North Carolina Department of Environment, Health, and Natural Resources
EIIP Volume II 111
-------
CHAPTER 5 - WWCT 3/12/97
This page is intentionally left blank.
IV EIIP Volume II
-------
CONTENTS
Section Page
1 Introduction 5.1-1
2 General Source Category Description 5.2-1
2.1 Source Category Description 5.2-1
2.2 Industrial WWCT Devices 5.2-1
2.2.1 Drains (Collection Unit) 5.2-1
2.2.2 Manholes (Collection Unit) 5.2-2
2.2.3 Reaches (Collection Unit) 5.2-2
2.2.4 Junction Boxes (Collection Unit) 5.2-2
2.2.5 Lift Stations (Collection Unit) 5.2-2
2.2.6 Trenches (Collection Unit) 5.2-3
2.2.7 Sumps (Collection Unit) 5.2-3
2.2.8 Weirs (Collection Unit) 5.2-3
2.2.9 Oil/Water Separators (Treatment Unit) 5.2-3
2.2.10 Equalization Basins (Treatment Unit) 5.2-4
2.2.11 Clarifiers (Treatment Unit) 5.2-4
2.2.12 Biological Treatment Basins (Treatment Unit) 5.2-4
2.2.13 Sludge Digesters (Treatment Unit) 5.2-4
2.2.14 Treatment Tanks (Treatment Unit) 5.2-5
2.2.15 Surface Impoundments (Treatment Unit) 5.2-5
2.2.16 Air and Steam Stripping (Treatment Unit) 5.2-5
2.3 Emission Sources 5.2-6
2.4 Factors and Design Considerations Influencing Emissions 5.2-8
2.4.1 Process Operating Factors 5.2-8
2.4.2 Control Techniques 5.2-9
3 Overview of Available Methods 5.3-1
3.1 Emission Estimation Methodologies 5.3-1
3.1.1 Manual Calculations 5.3-1
3.1.2 Emission Models 5.3-1
3.1.3 Gas-phase Measurement 5.3-2
3.1.4 Emission Factors 5.3-2
3.1.5 Material Balance 5.3-2
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CONTENTS (CONTINUED)
Section Page
3.2 Comparison of Available Emission Estimation Methodologies 5.3-3
3.2.1 Manual Calculations 5.3-3
3.2.2 Emissions Models 5.3-3
3.2.3 Gas-phase Measurement 5.3-3
3.2.4 Emission Factors 5.3-4
3.2.5 Material Balance 5.3-4
4 Preferred Method for Estimating Emissions 5.4-1
4.1 WATER8/CHEMDAT8 (Treatment and Collection) 5.4-2
4.2 BASTE (Treatment Only) . . . 5.4-2
4.3 CORAL+ (Collection Only) 5.4-2
4.4 PAVE (Treatment Only) 5.4-2
4.5 CINCI (EPA - Cincinnati Model) (Treatment Only) 5.4-3
4.6 NOCEPM (Treatment Only) 5.4-3
4.7 TORONTO (Treatment Only) 5.4-3
4.8 TOXCHEM+ (Treatment and Collection) 5.4-4
5 Alternative Methods for Estimating Emissions 5.5-1
5.1 Emission Factors 5.5-1
5.2 Material Balance 5.5-2
5.3 Manual Calculations 5.5-2
5.4 Gas-phase Measurement 5.5-3
5.4.1 Direct Measurement 5.5-3
5.4.2 Indirect Measurement 5.5-4
6 Quality Assurance/Quality Control 5.6-1
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CONTENTS (CONTINUED)
Section Page
6.1 General Factors Involved in Emission Estimation
Techniques 5.6-1
6.1.1 Emissions Models 5.6-2
6.1.2 Gas-phase Measurement 5.6.2
6.1.3 Emission Factors 5.6-3
6.1.4 Material Balance 5.6-3
6.2 Data Attribute Rating System DARS Scores 5.6-3
7 References 5.7-1
Appendix A: Example Data Collection Forms - Wastewater Treatment Units
Appendix B: AP-42 Emission Estimation Algorithm and Example Calculations
Appendix C: Bibliography of Selected Available Literature on Emissions Models
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FIGURE AND TABLES
Figure Page
5.2-1 Typical Wastewater Collection and Treatment System 5.2-7
Tables Page
5.6-1 DARS Scores: Emission Models 5.6-4
5.6-2 DARS Scores: Gas-phase Measurement 5.6-4
5.6-3 DARS Scores: Emission Factors 5.6-5
5.6-4 DARS Scores: Material Balance 5.6-5
viii EHP Volume II
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1
INTRODUCTION
The purposes of the preferred methods guidelines are to describe emissions estimation
techniques for stationary point sources in a clear and unambiguous manner and to
provide concise example calculations to aid in the preparation of emission inventories.
This chapter describes the procedures and recommended approaches of estimating
volatile organic compound (VOC) emissions from wastewater collection and treatment
(WWCT).
Section 2 of this chapter contains a general description of the WWCT source category, a
listing of common emission sources associated with WWCT, and an overview of the
available air pollution control technologies for WWCT. Section 3 of this chapter
provides an overview of available emission estimation methods. It should be noted that
the use of site-specific emissions data is always preferred over the use of
industry-averaged data such as default data, available in several of the current WWCT
air emissions models. However, depending upon available resources, obtaining site-
specific data may not be cost effective. Section 4 presents the preferred emission
estimation methods for WWCT, while Section 5 presents alternative emission estimation
techniques. Quality assurance and quality control procedures are described in Section 6,
and Section 7 lists references. Appendix A contains an example data collection form for
WWCT sources, and Appendix B contains the AP-42 WWCT equations and example
calculations (Environmental Protection Agency [EPA], 1995). Appendix C contains a list
of references that may be consulted for more detailed, technical evaluations and
comparisons of the emission estimation techniques and emissions software models
discussed in this chapter.
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GENERAL SOURCE CATEGORY
DESCRIPTION
2.1 SOURCE CATEGORY DESCRIPTION
This section provides a brief overview discussion of the WWCT category. In addition to
wastewater generated at the municipal level, many industries generate large quantities of
contaminated water as a byproduct of production processes. These wastewaters typically
pass through a series of on-site collection and treatment units before discharge to a
receiving water body or publicly owned treatment works (POTW). Many of these
collection and treatment units are open to the atmosphere and allow for volatilization of
VOCs from the wastewater.
The information presented in this document is applicable to any source, municipality, or
industry treating wastewater on-site.
The following sections describe the various types of wastewater collection and treatment
devices. The type of unit (collection or treatment) is provided, as is a brief description
of each. Table A-l, Appendix A lists approximate physical dimensions of several units.
2.2 WWCT DEVICES
2.2.1 DRAINS (COLLECTION UNIT)
Wastewater streams from various sources throughout a given process are normally
introduced into the collection system through process drains. Drains may be of a
trapped or untrapped design. Individual drains are usually connected directly to the
main process sewer line. However, they may also drain to trenches, sumps, or ditches.
Some drains are dedicated to a single piece of equipment such as a scrubber, decanter,
or stripper. Others serve several sources. These types of drains are located centrally
between the pieces of equipment they serve and are referred to as area drains (EPA,
1990).
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2.2.2 MANHOLES (COLLECTION UNIT)
Manholes are service entrances into sewer lines that permit inspection and cleaning of
the sewer line. They are normally placed at periodic lengths along the sewer line. They
may also be located where sewers intersect or where there is a significant change in
direction, grade, or sewer line diameter. The lower portion of the manhole is usually
cylindrical, with a typical inside diameter of 4 feet to allow adequate space for workers.
The upper portion tapers to the diameter of the opening at ground level. The opening is
normally about 2 feet in diameter and covered with a heavy cast-iron plate with two to
four holes for ventilation and for cover removal.
2.2.3 REACHES (COLLECTION UNIT)
A reach is a segment of sewer channel that conveys wastewater between two manholes
or other sewer components such as lift stations or junction boxes. Sanitary sewers are
naturally ventilated through holes in manhole covers, gooseneck vents (which are
sometimes included to enhance ventilation), and vent risers on buildings that are
connected to sewers. (Sanitary sewers are sometimes mechanically ventilated; i.e., fans
or blowers are used to remove hydrogen sulfide.) Combined sanitary/storm sewers are
generally well-ventilated, and include openings associated with street-level storm drains.
2.2.4 JUNCTION BOXES (COLLECTION UNIT)
A junction box normally serves several process sewer lines. Process lines meet at the
junction box to combine the multiple wastewater streams into one stream that flows
downstream from the junction box. Liquid level in the junction box depends on the flow
rate of the wastewater. Junction boxes are either square or rectangular and are sized
based on the flow rate of the entering streams. They may also be water-sealed or
covered and vented.
2.2.5 LiFf STATIONS (COLLECTION UNIT)
Lift stations are usually the last collection unit prior to the treatment system, accepting
wastewater from one or several sewer lines. The main function of the lift station is to
provide sufficient head pressure to transport the collected wastewater to the treatment
system. A pump is used to provide the head pressure and is generally designed to
operate or cut off based on preset high and low liquid levels.
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2.2.6 TRENCHES (COLLECTION UNIT)
Trenches are used to transport wastewater from the point of process equipment
discharge to subsequent wastewater collection units such as junction boxes and lift
stations. This mode of transport replaces the drain scenario as a method for introducing
process wastewater into the downstream collection system. In older plants, trenches are
often the primary mode of wastewater transportation in the collection system. Trenches
are often interconnected throughout the process area to accommodate pad water runoff,
water from equipment washes and spill cleanups, as well as process wastewater
discharges. Normally, the length of the trench is determined by the general locations of
the process equipment and the downstream collection system units. This length typically
ranges from 50 to 500 feet. Trench depth and width are dictated by the wastewater flow
rate discharged from process equipment. The depth and width of the trench must be
sufficient to accommodate expected as well as emergency wastewater flows from the
process equipment.
2.2.7 SUMPS (COLLECTION UNIT)
Sumps are typically used for collection and equalization of wastewater flow from
trenches prior to treatment. They are usually quiescent and open to the atmosphere.
Typical diameters and depths are approximately 1.5 meters.
2.2.8 WEIRS (COLLECTION UNIT)
Weirs act as dams in open channels in order to maintain constant water level upstream.
The weir face is normally aligned perpendicular to the bed and walls of the channel.
Water from the channel normally overflows the weir but may pass through a notch, or
opening, in the weir face. Because of this configuration, weirs provide some control of
the level and flow rate through the channel. This control, however, may be insignificant
compared to upstream factors that influence the supply of water to the channel.
2.2.9 OIL/WATER SEPARATORS (TREATMENT UNIT)
Oil/water separators are often the first step in the wastewater treatment plant but may
also be found in the process area. The purpose of these units is to separate liquid
phases of different specific gravities; they also serve to remove free oil and suspended
solids contained in the wastewater. Most of the separation occurs as the wastewater
stream passes through a quiescent zone in the unit. Oils and scum with specific gravities
less than water float to the top of the aqueous phase. Heavier solids sink to the bottom.
Most of the organics contained in the wastewater tend to partition to the oil phase. For
this reason, most of these organic compounds are removed with the skimmed oil leaving
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the separator. The wastewater stream leaving the separator, therefore, is reduced in
organic loading.
2.2.10 EQUALIZATION BASINS (TREATMENT UNIT)
Equalization basins are used to reduce fluctuations in the wastewater flow rate and
organic content to the downstream treatment processes and may be covered, stirred, or
aerated. Equalization of wastewater flow rate results in more uniform effluent quality
from downstream settling units such as clarifiers. Biological treatment performance can
also benefit significantly from the damping of concentration and flow fluctuations. This
damping protects biological processes from upset or failure due to shock loadings of
toxic or treatment-inhibiting compounds.
2.2.11 CLARIFIERS (TREATMENT UNIT)
The primary purpose of a clarifier is to separate any oils, grease, scum, and solids
contained in the wastewater. Most clarifiers are equipped with surface skimmers to clear
the water of floating oil deposits and scum. Clarifiers also have sludge raking arms that
prevent accumulation of organic solids collected at the bottom of the tank.
2.2.12 BIOLOGICAL TREATMENT BASINS (TREATMENT UNIT)
Biological waste treatment is normally accomplished through the use of aeration basins.
Microorganisms that metabolize aerobically require oxygen to carry out the
biodegradation of organic compounds that results in energy and biomass production.
The aerobic environment in the basin is normally achieved by the use of diffused or
mechanical aeration. This aeration also serves to maintain the biomass in a well-mixed
regime. The goal is to maintain the biomass concentration at a level where the
treatment is efficiently optimized and proper growth kinetics are induced.
2.2.13 SLUDGE DIGESTERS (TREATMENT UNIT)
Sludge digesters are used to treat organic sludges produced from various treatment
operations. Two types of digesters are used: anaerobic digesters and aerobic digesters.
In the anaerobic digestion process, the organic material in mixtures of primary settled
and biological sludges is converted biologically, under anaerobic conditions, to a variety
of byproducts including methane (CH4), carbon dioxide (CO2), and hydrogen sulfide
(H2S). The process is carried out in an airtight reactor. Sludge, introduced continuously
or intermittently, is retained in the reactor for varying periods of time. The stabilized
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sludge, withdrawn continuously or intermittently from the reactor, is reduced in organic
and pathogen content and is nonputrescible.
In aerobic digestion, the sludge is aerated for an extended period of time in an open,
unheated tank using conventional air diffusers or surface aeration equipment. The
process may be operated in a continuous or batch mode. Smaller plants use the batch
system in which sludge is aerated and completely mixed for an extended period of time,
followed by quiescent settling and decantation. In continuous systems, a separate tank is
used for decantation and concentration. High-purity oxygen aerobic digestion is a
modification of the aerobic digestion process in which high-purity oxygen is used in lieu
of air. The resultant sludge is similar to conventional aerobically digested sludge
(Burton and Tchobanoglous, 1991).
2.2.14 TREATMENT TANKS (TREATMENT UNIT)
Flocculation tanks and pH adjustment tanks may be used for treatment of wastewater
after and before biological treatment, respectively. In flocculation tanks, flocculating
agents are added to the wastewater to promote formation of large-particle masses from
the fine solids formed during biological treatment. These large particles will then
precipitate out of the wastewater in the clarifier that typically follows. Tanks designed
for pH adjustment typically precede the biological treatment step. In these tanks, the
wastewater pH is adjusted, using acidic or alkaline additives, to prevent shocking of the
biological system downstream.
2.2.15 SURFACE IMPOUNDMENTS (TREATMENT UNIT)
Surface impoundments are typically used for evaporation, polishing, equalization, storage
prior to further treatment or disposal, leachate collection, and as emergency surge basins.
They may be either quiescent or mechanically agitated.
2.2.16 AIR AND STEAM STRIPPING (TREATMENT UNIT)
Air stripping and steam stripping may be used to remove organic constituents in
industrial wastewater streams prior to secondary and tertiary treatment devices.
Air stripping involves the contact of wastewater and air to strip out volatile organic
constituents. As the volume of air contacting the contaminated water increases, an
increase in the transfer rate of the organic compounds into the vapor phase is achieved.
Removal efficiencies vary with volatility and solubility of organic impurities. For highly
volatile compounds, average removal ranges from 90 to 99 percent, for medium- to
low-volatility compounds, removal ranges from less than 50 to 90 percent, though a
higher air flow rate may be needed (EPA, 1995).
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Steam stripping is the distillation of wastewater to remove volatile organic constituents,
with the basic operating principle being the direct contact of steam with wastewater.
The steam provides the heat of vaporization for the more volatile organic constituents.
Removal efficiencies vary with the amount of steam applied for a given wastewater flow
rate and the volatility and solubility of the organic impurities. For highly volatile
compounds (Henry's Law constant [HLC] greater than 10"3 atm-m3/gmol), VOC removal
ranges from 95 to 99 percent and can easily be achieved with a sufficient amount of
steam. For medium-volatility compounds (HLC between 10"5 and 10~3 atm-m3/gmol),
average VOC removal ranges from 90 to 95 percent and would require more steam than
needed for more volatile compounds. For low-volatility compounds (HLC less than
10~5 atm-m3/gmol), average removal ranges from less than 50 to 90 percent (EPA, 1995).
2.3 EMISSION SOURCES
Wastewater streams are collected and treated in a variety of ways. Many of these
collection and treatment system units are open to the atmosphere and allow organic-
containing wastewaters to contact ambient air. Whenever this happens, there is a
potential for VOC emissions. The organic pollutants volatilize in an attempt to exert
their equilibrium partial pressure above the wastewater. In doing so, the organics are
emitted to the ambient air surrounding the collection and treatment units. The
magnitude of VOC emissions depends greatly on many factors such as the physical
properties of the pollutants, pollutant concentration, flow rate, the temperature of the
wastewater, and the design of the individual collection and treatment units. All of these
factors, as well as the general scheme used to collect and treat facility wastewater, have a
major effect on VOC emissions.
Collection and treatment schemes are facility specific. The flow rate and organic
composition of wastewater streams at a particular facility are functions of the processes
used. The wastewater flow rate and composition, in turn, influence the sizes and types of
collection and treatment units that must be employed at a given facility.
Figure 5.2-1 illustrates a typical scheme for collecting and treating process wastewater
generated at a facility and the opportunity for volatilization of organics.
Drains are often open to the atmosphere and provide an opportunity for volatilization of
organics in the wastewater. The drain is normally connected to the process sewer line
that carries the wastewater to the downstream collection and treatment units.
Figure 5.2-1 illustrates the wastewater being carried past a manhole and on to a junction
box where two process wastewater streams are joined. The manhole provides an escape
route for organics volatilized in the sewer line. In addition, the junction box may also be
open to the atmosphere, allowing organics to volatilize. Wastewater is discharged from
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PROCESS A PROCESS C
Drain
PROCESS B
Clarifier )_^ Discharge
Waste
Sludge
FIGURE 5.2-1. TYPICAL WASTEWATER COLLECTION AND TREATMENT SYSTEM
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the junction box to a lift station where it is pumped to the treatment system. The lift
station is also likely to be open to the atmosphere, allowing volatilization of organics.
The equalization basin, the first treatment unit shown in Figure 5.2-1, regulates the
wastewater flow and pollutant compositions to the remaining treatment units. The
equalization basin also typically provides a large area for wastewater contact with
ambient air. For this reason, emissions may be relatively high from this unit. Suspended
solids are removed in the clarifier, and the wastewater then flows to the aeration basin
where microorganisms act on the organic constituents. Both the clarifier and the
aeration basin may be open to the atmosphere. In addition, the aeration basin is
normally aerated either mechanically or with diffused air. Wastewater leaving the
aeration basin normally flows through a secondary clarifier for solids removal before it is
discharged from the facility. The secondary clarifier is also likely to be open to the
atmosphere. The solids that settle in the clarifier are discharged partly to a sludge
digester and partly recycled to the aeration basin. Finally, waste sludge from the sludge
digester is generally hauled off for land treatment or to a landfill.
In addition to VOC emissions from volatilization, sulfur oxides (SOX) emissions from the
thermal destruction of hydrogen sulfide can occur if methane gas from digesters is used
in on-site combustion equipment. Chlorine and chlorinated compounds may be released
if the wastewater stream is disinfected using chlorine prior to discharge.
2.4 FACTORS AND DESIGN CONSIDERATIONS INFLUENCING
EMISSIONS
2.4.1 PROCESS OPERATING FACTORS
During wastewater treatment, the fate mechanisms of volatilization/stripping, sorption,
and biotransformation primarily determine the fate of VOCs (Mihelcic et al., 1993). Of
these, it is volatilization and stripping that result in air emissions. Biodegradation and
sorption onto sludge serve to suppress air emissions.
Stripping may be defined as pollutant loss from the wastewater due to water movement
caused by mechanical agitation, head loss, or air bubbles, while volatilization may be
defined as quiescent or wind-driven loss (Mihelcic et al., 1993). The magnitude of
emissions from volatilization/stripping depends on factors such as the physical properties
of the pollutants (vapor pressure, Henry's Law constants, solubility in water, etc.), the
temperature of the wastewater, and the design of the individual collection and treatment
units. WWCT unit design is important in determining the surface area of the air-water
interface and the degree of mixing occurring in the wastewater.
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Biodegradation by microorganisms occurs in biological treatment devices such as
aeration basins. Due to the high level of biomass present in aeration basins, organic
compounds may also be removed via sorption mechanisms. Parameters important in
determining the rate of biodegradation and sorption occurring in aeration basins include
the degree of biodegradability of the compound, the affinity of the compound for the
organic or aqueous phase, and the biomass concentration in the basin (EPA, 1990).
EPA has developed several methods for determining site-specific biodegradation rates
for regulatory purposes. These include batch tests (aerated reactor and sealed reactor),
as well as EPA Test Methods 304A and 304B. However, if site-specific rate constants
are not available, default biodegradation rates are available for many pollutants in
several of the emissions models used to estimate emissions. The use of site-specific
biodegradation rates will result in a more accurate emission estimate.
Detailed information on the rates of organic removal through biodegradation, sorption,
and volatilization are required for accurate emission estimates.
2.4.2 CONTROL TECHNIQUES
The types of control technologies generally used in reducing VOC emissions from
wastewater include: steam stripping or air stripping (when followed by a collection
device such as a carbon adsorber or a control device such as a flare), carbon adsorption
(vapor or liquid phase), chemical oxidation, biotreatment (aerobic or anaerobic), and
process modifications. Several of the control techniques (steam/air stripping and carbon
adsorption) do not destroy the VOCs, they capture them. VOCs captured by these
methods should be recovered or destroyed to prevent air emission releases to the
environment.
For efficient control, all control elements should be placed as close as possible to the
point of wastewater generation, with all collection, treatment, and storage systems ahead
of the control technology being covered to suppress emissions. Tightly covered,
well-maintained collection systems can suppress emissions by 95 to 99 percent. However,
if there is explosion potential, it can be reduced by a low-volume flow of inert gas into
the collection component, followed by venting to a device such as an incinerator or
carbon adsorber.
The following are brief descriptions of the control technologies listed above and of any
secondary controls that may need to be considered for fugitive air emissions.
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Air and Steam Stripping
Steam stripping and air stripping off gases most often are vented to a secondary control
or collection device, such as a combustion device or gas-phase carbon adsorber, in order
to prevent air emissions. Combustion devices may include incinerators, boilers, and
flares. Vent gases of high fuel value can be used as an alternative fuel and may be
combined with other fuels such as natural gas and fuel oil. If the fuel value of the vent
gas stream is very low, vent gases may be preheated and combined with combustion air.
Liquid-phase Carbon Adsorption
Liquid-phase carbon adsorption takes advantage of compound affinities for activated
carbon. Activated carbon is an excellent adsorbent because of its large surface area and
because it is usually in granular or powdered form for easy handling. Two types of
liquid-phase carbon adsorption are the fixed-bed and moving-bed systems. The fixed-bed
system is used primarily for low-flow wastewater streams with contact times around
15 minutes, and it is a batch operation (i.e., once the carbon is spent, the system is takei
off line). Moving-bed carbon adsorption systems operate continuously with wastewater
typically being introduced from the bottom of the column and regenerated carbon from
the top (countercurrent flow). Spent carbon is continuously removed from the bottom o
the bed. Liquid-phase carbon adsorption is usually used to recover compounds present
in low concentrations or for high concentrations of nondegradable compounds. Remova
efficiencies depend on the compound's affinity for activated carbon. Average removal
efficiency ranges from 90 to 99 percent, but is dependent on compound concentrations
(EPA, 1995).
Chemical Oxidation
Chemical oxidation involves a chemical reaction between the organic compound and an
oxidant such as ozone, hydrogen peroxide, permanganate, or chlorine dioxide. Ozone is
usually added to the wastewater through an ultraviolet-ozone reactor. Permanganate an
chlorine dioxide are added directly into the wastewater. It is important to note that
adding chlorine dioxide can form chlorinated hydrocarbons in a side reaction. The
applicability of this technique depends on the reactivity of the individual organic
compound.
Biotreatment
Biotreatment is the aerobic or anaerobic chemical breakdown of organic chemicals by
microorganisms. Removal of organics by biodegradation is highly dependent on the
compound's biodegradability, volatility, and ability to be adsorbed onto solids. Removal
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efficiencies range from almost 0 to 100 percent. In an acclimated biotreatment system,
the microorganisms easily convert available organics into biological cells or biomass, or
CO2. This often requires a mixed culture of organisms, where each organism utilizes the
food source most suitable to its metabolism. The organisms will starve and the organics
will not be biodegraded if a system is not acclimated (i.e., the organisms cannot
metabolize the available food source).
Process Modifications
Emissions from wastewater collection or treatment units may also be reduced by process
modifications such as the use of level control gates, closed piping, or covered process
units. These techniques reduce emissions by minimizing weir drops, turbulence, and
contact with air.
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OVERVIEW OF AVAILABLE METHODS
3.1 EMISSION ESTIMATION METHODOLOGIES
Several methodologies are available for calculating fugitive emissions from industrial and
municipal wastewater treatment systems. The method used is dependent upon available
data, available resources, and the degree of accuracy required in the estimate.
This section discusses the methods available for calculating emissions from WWCT and
identifies the preferred method of calculation. The discussion focuses on estimating
emissions that occur from stripping mechanisms and the volatilization of pollutants
present in wastewater streams.
3.1.1 MANUAL CALCULATIONS
Several EPA documents are available that provide theoretical equations that may be
used to calculate emissions from WWCT. These include Industrial Wastewater Volatile
Organic Compound Emissions - Background Information for BACT/LAER Determinations
(EPA-450/3-90-004), AP-42, and Air Emissions Models for Waste and Wastewater
(EPA-453/R-94-080A). The equations are based on mass transfer and liquid-gas
equilibrium theory and use individual gas-phase and liquid-phase mass transfer
coefficients to estimate overall mass transfer coefficients. Calculating air emissions using
these equations is a complex procedure, especially if several systems are present, because
the physical properties of the numerous contaminants must be individually determined.
Because of the great deal of complexity involved, computer programs are available that
incorporate these equations to estimate emissions from WWCT.
3.1.2 EMISSION MODELS
Some emission models currently available are based on measured or empirical values.
The computer model may be based on theoretical equations that have been calibrated
using actual data. Or, the models may be purely empirical, in which case the equations
are usually based on statistical correlations with independent variables. Emissions
estimated using models are a function of the WWCT system configuration, the properties
of the specific compounds present in the wastewater streams, and the emission
estimation approaches used in the model algorithms.
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3.1.3 GAS-PHASE MEASUREMENT
Measuring air emissions from large open surfaces common at industrial and municipal
wastewater treatment facilities is extremely difficult and perhaps one of the most
challenging air quantification problems. Several techniques have been developed for this
purpose, including surface emission isolation flux chambers, and transect and fenceline
methods. If the industrial process is enclosed and vented, it is possible to directly
measure emissions using standard measurement techniques. (Refer to Chapter 1 of this
volume for a discussion of available methods.) In particular, POTWs may be covered or
enclosed to reduce odor and/or prevent freezing in which case gas-phase measurement
may be appropriate.
3.1.4 EMISSION FACTORS
Emission factors have been or are being developed for WWCT for several source
categories. These factors have been developed as part of regulatory development
projects such as the National Emissions Standards for Hazardous Air Pollutants
(NESHAP) for the pulp and paper industry and for petroleum refineries. In some cases,
emission factors are based on emissions estimates obtained using models, but have been
reduced to a more simplistic form (mass of pollutant per process rate).
In addition, emission factors were developed by a consortium of California
POTW operators as part of the Pooled Emissions Estimation Program (PEEP). These
factors are not publicly available but may be obtained through Jim Bewley of the South
Bayside System Authority at (415) 594-8411.
The PEEP emission factors were developed from field samples at 20 POTWs and cover
18 compounds and 18 processes. Liquid- and gas-phase samples were collected to
complete mass balances at plants with similar processes. The emission factors are
medians of the measured offgas mass emissions divided by the influent mass. When no
data were available, because of "nondetects" or other causes, emission factors were
extrapolated by averaging the known emission factors of either chlorinated or
nonchlorinated compounds. PEEP factors usually predict significantly lower emissions
than BAAT or fate models.
3.1.5 MATERIAL BALANCE
The simplest estimation method, material balance, relies on wastewater flow rate and
influent and effluent liquid-phase pollutant concentrations. Compound mass that cannot
be accounted for in the effluent is assumed to be volatilized. However, it needs to be
noted that this method does not account for biodegradation or sorption onto solids or
other removal mechanisms.
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3.2 COMPARISON OF AVAILABLE EMISSION ESTIMATION
METHODOLOGIES
3.2.1 MANUAL CALCULATIONS
Estimating emissions from WWCT by hand (or by spreadsheets) using the equations
presented in the various literature is a very labor-intensive process and increases the
potential for manual calculation error. For this reason, the use of manual calculations is
not a preferred method, and should only be used in cases where access to models is
prohibitive. It should be noted that the equations presented in the EPA document Air
Emissions Model for Waste and Wastewater (EPA, 1994) have been incorporated into
EPA's WATERS model (discussed in Section 4) to alleviate the burden of performing
the calculations by hand.
3.2.2 EMISSIONS MODELS
The use of emissions software models to calculate emissions from WWCT provides a
widely accepted method of calculation. Most models are based on the theoretical
equations presented in various literature and provide an automated means of performing
the calculations. It should be noted that models estimate average emissions over a
period of time. Peak or maximum emission rates over a short term may be more
accurately assessed using gas-phase measurement or material balance approaches. Also,
an in-depth knowledge of the WWCT schemes including pollutant concentrations and
flow rate information are needed in order to obtain an accurate emission estimate.
3.2.3 GAS-PHASE MEASUREMENT
Direct and indirect gas-phase measurements are alternative methods of calculating
emissions from WWCT. Once pollutant concentrations are known at a specific point,
atmospheric dispersion modeling equations may be used to estimate an emission rate.
Two potential sources of uncertainty, pollutant measurement error and the
representativeness of the statistical dispersion equations for this type of application, are
present in this method. In addition, the monitoring equipment needed to perform this
method may be cost-prohibitive unless already in place.
If the treatment plant is enclosed and vented through a limited number of vents,
traditional stack testing may be used to estimate emissions and would be considered a
preferred method.
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3.2.4 EMISSION FACTORS
Emission factors may be used to calculate emissions where approximate figures are
acceptable. However, due to the variability of emissions based on site-specific
operational, physical, and chemical parameters, emission factors should be carefully
chosen that are based on similar-type sources.
3.2.5 MATERIAL BALANCE
Material balance calculations are a simple method of estimating emissions where inlet
and outlet pollutant concentrations are known.
Other variables also may affect an estimate. Effluent data can be used to account for
compounds passing through the plant, but if chlorine is added during treatment,
chlorinated compounds that form can result in higher emissions than predicted by a
material balance approach. To compensate, intermediate samples must be taken to
quantify chlorinated compound emissions.
As mentioned before, material balance does not account for fate mechanisms other than
volatilization. For example, it can overestimate emissions if the compound is
biodegradable or adsorbs onto sludge.
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PREFERRED METHOD FOR
ESTIMATING EMISSIONS
The preferred method for estimating emissions from WWCT is the use of computer-
based emissions models. There are numerous emissions estimation models available to
calculate emissions from WWCT. These include publicly available models as well as
proprietary models. Differences in the models include applicability to the types of
collection and treatment systems, the level of site-specific data accepted, the level of
default data provided, and whether or not the models account for the full spectrum of
pollutant pathways (volatilization, biodegradation, and sorption). Models may also
contain different default data (e.g., Henry's Law constants, biodegradation rate
constants).
Many of these models allow for user input of data. The use of site-specific data is
always preferred over the use of default data. Typically, the types of data needed are
the chemical and physical properties of the wastewater stream, as well as collection and
treatment device parameters. At a minimum, wastewater stream characteristics are
needed at the inlet to the treatment plant or collection device. However, if data are
available for various points within the treatment plant, a more accurate emissions
estimate may be obtained.
In order to obtain a reliable emissions estimate using a software model, the modeler
needs to understand both the configuration and wastewater stream characteristics of the
collection and/or treatment units, as well as the emissions estimation algorithm used by
the model. Not all models can handle all collection/treatment devices and results are
likely to vary between models. A more accurate emissions estimate will result if the user
has confidence in the input data and understands the emission estimation approach used
by the model.
NOTE: A brief summary of some currently available models is provided below. Work
is ongoing to improve some of the current models and to develop new ones. The
discussion presented in this document is not to be interpreted as an endorsement of one
model over another, but is provided for informational purposes only. The reader should
consult with their state regulatory agency for guidance on the selection and use of an
appropriate model. Also, Appendix C contains a reference list of technical articles
providing qualitative as well as quantitative comparisons between models and emission
estimation techniques.
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4.1 WATER8/CHEMDAT8 (TREATMENT AND COLLECTION)
WATERS is a publicly available computer program model developed by EPA that
models the fate of organic compounds in various wastewater treatment units, including
collection systems, aerated basins, and other units. WATERS contains useful features
such as the ability to link treatment units to form a treatment system, the ability for
recycle among units, and the ability to generate and save site-specific compound
properties. WATERS has a database with compound-specific data for over 950
chemicals. The mathematical equations used to calculate emissions in this model are
based on the approaches described in Air Emissions Models for Waste and Wastewater
(EPA, 1994). The WATERS model is publicly available on the Clearinghouse for
Inventories and Emission Factors (CHIEF) bulletin board system (BBS), (919) 541-5742.
Many of the emissions models contained in WATERS are also presented in spreadsheet
form in CHEMDAT8.
4.2 BASTE (TREATMENT ONLY)
This model was developed to estimate sewage treatment emissions from treatment plants
in the Bay Area of California. BASTE is a computer-based model with menu-driven
input and is structured to allow significant flexibility in simulating a wide range of
treatment processes. It can simulate the fate of organic compounds in well-mixed to
plug-flow reactors, diffused bubble and surface aeration, and emissions from weirs and
drops. BASTE is available through the CH2M Hill Company.
4.3 CORAL+ (COLLECTION ONLY)
CORAL+ is a model that predicts emissions from sewer reaches based on actual data
from field experiments. CORAL+ allows for continuous or slug discharges to sewers,
variations in depth of flow and temperature, sewer physical conditions, and retardation ol
mass transfer by gas accumulation in the sewer headspace. Emissions are based on
inputs of ventilation rates and patterns. CORAL+ also estimates losses at sewer drop
structures and is available through the Enviromega Ltd. Company.
4.4 PAVE (TREATMENT ONLY)
This model was developed for the Chemical Manufacturers Association. It simulates the
fate of contaminants in both surface-aerated and diffused-air activated sludge systems.
The PAVE model offers a selection of different biological kinetic models. It is based on
traditional kinetic process modelling for biological reactors and performs the traditional
calculations of dissolved oxygen concentration and waste-activated sludge flow. The
PAVE model works with compounds that have low volatilities and, therefore, may be
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gas-phase mass transfer limited. Most other models use oxygen as a mass transfer
surrogate so that only liquid-phase mass transfer resistance is considered. PAVE is
available through the Chemical Manufacturers Association.
4.5 CINCI (EPA - CINCINNATI MODEL) - INTEGRATED MODEL FOR
PREDICTING THE FATE OF ORGANICS IN WASTEWATER
TREATMENT PLANTS (TREATMENT ONLY)
This model was developed with support from the EPA Risk Reduction Engineering
Laboratory. The physical properties database of the model includes 196 chemicals and
metals, Henry's Law constants, sorption coefficients, biodegradation rate constants, and
diffusivities. Removal mechanisms included are stripping/volatilization, stripping, surface
volatilization, sorption, and biodegradation. Unit operations included are primary
treatment followed by secondary treatment with sludge recycle, secondary treatment with
sludge recycle, and secondary treatment without sludge recycle. The model is written in
FORTRAN and has three built-in default cases. CINCI is available at no charge
through the U.S. EPA Risk Reduction Engineering Laboratory.
4.6 NOCEPM - NCASI ORGANIC COMPOUND ELIMINATION
PATHWAY MODEL (TREATMENT ONLY)
This model was developed by the National Council of the Paper Industry for Air and
Stream Improvement, Inc. (NCASI); components were chosen from published literature.
This model is also in the public domain. The physical properties database includes
11 chemicals, Henry's Law constants, sorption coefficients, biodegradation rate constants,
and diffusion coefficients for 9 chemicals. Conceptual removal mechanisms are stripping,
surface aeration, subsurface aeration, surface volatilization, sorption, and biodegradation.
NOCEPM simulates only the secondary treatment step, but can represent activated
sludge or aerated stabilization. It is written in QuickBasic™ and has no built-in default
cases. The model was validated with chloroform for activated sludge and aerated
stabilization processes and is available through NCASI.
4.7 TORONTO - A MODEL OF ORGANIC CHEMICAL FATE IN A
BIOLOGICAL WASTEWATER TREATMENT PLANT (TREATMENT
ONLY)
This model was developed with the support of the Ontario Ministry of the Environment,
from which copies are available. There are 18 chemicals, Henry's Law constants,
sorption coefficients, and biodegradation rate constants in the physical properties
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database. Removal mechanisms include stripping, surface volatilization, sorption, and
biodegradation. TORONTO simulates primary sedimentation and secondary (biological)
treatment. According to the report, this is a relatively simple model that uses a
"fugacity" approach that "takes advantage of the linear relationship of fugacity to
concentration to derive a relatively simple set of linear material balance expressions."
Fugacity capacities and rate parameters are calculated for the air, water, and biomass
phases. TORONTO is available through the Ontario Ministry of the Environment.
4.8 TOXCHEM + - Toxic CHEMICAL MODELING PROGRAM FOR
WATER POLLUTION CONTROL PLANTS (TREATMENT AND
COLLECTION)
This model was developed by Enviromega Ltd. Company (Campbellville, Ontario), in
cooperation with the Environment Canada Wastewater Technology Centre. The
database includes 204 chemicals (including metals) and detailed information on physical
properties. The model also includes Henry's Law constants, sorption coefficients, and
biodegradation rate constants. The model simulates volatilization, stripping, sorption,
and biodegradation removal mechanisms from weirs, surface volatilization, surface
aeration, and subsurface aeration. A wide variety of wastewater unit operations can be
represented including grit chambers, primary clarifiers, collection reaches, sludge
digestion, aeration basins, and secondary clarifiers. Both steady-state and dynamic
results can be obtained. TOXCHEM + is available through the Enviromega Ltd.
Company.
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ALTERNATIVE METHODS FOR
ESTIMATING EMISSIONS
5.1 EMISSION FACTORS
Emission factors for WWCT are presented in the literature in two forms: traditional
emission factors that relate emissions of a particular pollutant to a process rate, and
fraction emitted (Fe) emission factors that relate emissions of a particular pollutant to
the total amount of that pollutant present in the wastewater stream.
Examples 5.5-1 and 5.5-2 show how process rate emission factors and Fe emission factors
may be used to calculate emissions from WWCT.
Example 5.5-1
This example shows how toluene emissions can be calculated using Fe and the
wastewater stream characteristics provided:
Wastewater flow into
collection system = 4,575,000 gal/day
Toluene concentration = 4 fig/L
Fe = 0.35 (for the collection system)
Toluene mass flow rate = 4,575,000 gal/day * 3.785 L/gal * 4 /*g/L *
10-6 g//*g * lb/453.6 g
0.153 Ib/day
Toluene emissions = 0.35 * 0.153 Ib/day
0.054 Ib/day
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Example 5.5-2
This example shows how VOC emissions can be calculated using process rate-based
emission factors (EFs) and the process parameters provided:
EFVOC = 0.17 kg VOC/Mg pulp
Process rate = 27 Mg pulp/hr
VOC emissions = 27 Mg pulp/hr * 0.17 kg VOC/Mg pulp * 1,000 g/1 kg
* lb/453.6 g
10.1 Ib VOC/hr
5.2 MATERIAL BALANCE
Using a material balance approach to calculate emissions from WWCT is straightforward
if the data are available and if the emissions estimate does not require extreme accuracy.
In most cases, a material balance calculation will provide an emission estimate that is
biased toward overestimating emissions due to the fact that the other (nonair) pollutant
removal mechanisms (sorption and biodegradation) are not considered. This approach
may be a viable option for collection systems and nonbiologically activated treatment
where inlet and outlet pollutant concentrations are known. Example 5.5-3 shows how a
material balance approach may be used to calculate emissions from WWCT.
5.3 MANUAL CALCULATIONS
Appendix B provides example calculations using the mass transfer equations presented in
AP-42. The equations, along with guidance on how to use them, are included. (Please
note that while the AP-42 section still refers to the SIMS model, this has been
superseded by the WATERS model, which is available on the CHIEF BBS. Therefore,
as of the writing of this document, AP-42 is not consistent with EPA's method of choice
for estimating emissions from wastewater treatment.)
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Example 5.5-3
This example shows how toluene emissions can be calculated using a material
balance approach. The wastewater stream is the same as that considered in
Example 5.5-1. However, in this example, it is known that the wastewater
stream exiting the collection system has a toluene concentration of 2 //g/L:
Wastewater flow =
Toluene concentration at inlet =
Toluene concentration at outlet =
Toluene lost through system =
Toluene emissions =
4,575,000 gal/day
4
4 /*g/L - 2 fig/L = 2 ftg/L
4,575,000 gal/day * 3.785 L/gal *
2 /ig/L * 10-6 g/^g * lb/453.6 g
0.0764 Ib/day
5.4 GAS-PHASE MEASUREMENT
5.4.1 DIRECT MEASUREMENT
The surface isolation flux chamber is the only commonly accepted direct measurement
technique available for open wastewater surfaces. When properly placed and operated,
the flux chamber accurately measures surface emissions. Total surface emissions are
calculated by multiplying the values from the individual flux chamber measurements by
the surface area each measurement represents. This can be quite challenging for
processes that are not completely mixed and may have unique emissions at every point
on the surface. For these cases, modeling can be used to interpolate surface emission
values between flux chamber measurement points. This method is not suitable for
estimating emissions of compounds with low volatility.
Treatment processes that are enclosed or covered may lend themselves to traditional
stack testing methods for emission estimation purposes. If a collection system or
treatment plant is well covered and vented through a limited number of openings, direct
measurement (such as the use of EPA Method 25) may be considered a preferred, rather
than an alternative, method of emission estimation.
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5.4.2 INDIRECT MEASUREMENT
Indirect measurement techniques, including transect and fenceline sensing, primarily are
used for estimating fugitive emissions from area sources.
Transect and fenceline methods are both indirect measurement techniques that rely on
dispersion modeling to predict the emission rate based on measurements of the ambient
pollutant concentrations in the emission plume.
The transect method typically uses both vertically and horizontally dispersed
measurement points positioned close to the source.
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QUALITY ASSURANCE/QUALITY
CONTROL
The consistent use of standardized methods and procedures is essential in the
compilation of reliable emission inventories. Quality assurance (QA) and quality control
(QC) of an inventory are accomplished through a set of procedures that ensure the
quality and reliability of data collection and analysis. These procedures include the use
of appropriate emission estimation techniques, applicable and reasonable assumptions,
accuracy/logic checks of computer models, checks of calculations, and data reliability
checks. Depending upon the technical approach used to estimate emissions, a checklist
with all of the particular data needs should be prepared to verify that each piece of
information is used accurately and appropriately.
This section discusses QA/QC procedures for specific emission estimation methods
presented in Sections 4 and 5 of this chapter. Volume VI, Quality Assurance Procedures,
of this series describes additional QA/QC methods and tools for performing these
procedures. Also, Volume II, Chapter 1, Introduction to Stationary Point Source Emission
Inventory Development, presents recommended standard procedures to follow to ensure that
the reported inventory data are complete and accurate.
6.1 GENERAL FACTORS INVOLVED IN EMISSION ESTIMATION
TECHNIQUES
All calculations, whether done manually or electronically, should be verified by repeating at
least one complete set of calculations. If a computer model is being used, verification that
the calculations are done correctly need only be done once (until the model is updated or
modified). The model verification process should be documented carefully (see Volume VI,
Chapter 3, Section 4). Although this level of checking for a program can require a
significant amount of time, it is necessary. Furthermore, given that these programs are
generally used many times over, the effort required to check the algorithms is relatively
small.
Manual calculations should be checked even more carefully, although completely replicating
the set of equations is overly burdensome. Because manual calculations introduce more
possibility for errors, are difficult to quality assure, and are harder to revise or update later,
use of a spreadsheet or other electronic tool is strongly advised.
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Often, emissions inventories are developed and/or compiled in computerized emissions
databases or models. Presumably, the methods, assumptions, and any data included with the
software are documented in a user's or a technical manual. If not, the user should conduct
extensive and careful QA of the model or find a better documented system.
Even if the validation of the system is well-documented, the user will need to provide
information about the input data. Comment fields, if available and sufficiently large, can be
used to record assumptions, data references, and any other pertinent information.
Alternatively, this information can be recorded in a separate document, electronically or
otherwise. If at all possible, the electronic database should record a cross-reference to the
document. This cross-reference could be a file name (and directory or disk number), a
notebook identification number, or other document.
6.1.1 EMISSIONS MODELS
Use of emission models and equations generally involves more effort than use of emission
factors. The level of effort is related to the complexity of the equation, the types of data that
must be collected, and the diversity of products manufactured at a facility. Typically, the
use of emission models involves making one or more conservative assumptions if a complete
set of site-specific data is unavailable. As a result, the use of models may result in an
overestimation of emissions. However, the accuracy and reliability of models can be
improved by ensuring that data collected for emission calculations (e.g., material speciation
data) are of the highest possible quality.
The EIIP recommends that sensitivity analyses be used as part of the QA program for
emissions models. A sensitivity analysis is a process for identifying the magnitude,
direction, and form of the effect of an individual parameter on the model's result. It is
usually done by repeatedly running the model and changing the value of one variable while
holding the others constant. Sensitivity analyses may be used to select the most appropriate
model for a given situation. For example, one model may be particularly sensitive to errors
in a variable that is not reliably measured. An alternative model may be found that is better
suited to the available data. Sensitivity analyses also aid QC by identifying the key variables
to be checked.
6.1.2 GAS-PHASE MEASUREMENT
When applying this technique for estimating emissions, sampling and analytical procedures,
use of data, preparation and use of a QA plan, and report preparation should be described
and understood by the team conducting the test. A systems audit should be conducted on-site
as a qualitative review of the various aspects of a total sampling and analytical system to
assess its overall effectiveness. For detailed information pertaining to specific test methods,
procedures described in the published reference methods should be reviewed, as well as,
Chapter 1 of this volume.
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6.1.3 EMISSION FACTORS
The use of emission factors is straightforward when the relationship between process data
and emissions is direct and relatively uncomplicated. When using emission factors, the user
should be aware of the quality indicator associated with the value. Emission factors
published within EPA documents and electronic tools have a quality rating applied to them.
The lower the quality indicator, the more likely that a given emission factor may not be
representative of the source type. The reliability and uncertainty of using emission factors as
an emission estimation technique are discussed in detail in the QA/QC section of Chapter 1
of this volume.
6.1.4 MATERIAL BALANCE
As stated in Section 5, the accuracy and reliability of emission values calculated using the
material balance approach are biased toward overestimation. Uncertainty of emissions using
the material balance approach is also related to the quality of material speciation data, which
is typically extracted from Material Safety Data Sheets (MSDSs). To assess the level of
uncertainty of such data, the user should verify if a standard analytical test method (e.g., one
using a gas chromatograph) has been used to measure the concentrations of the constituents.
6.2 DATA ATTRIBUTE RATING SYSTEM (DARS) SCORES
One measure of emission inventory data quality is the DARS score. Four examples are
given here to illustrate DARS scoring using the preferred and alternative methods presented
in this document. The DARS provides a numerical ranking on a scale of 0.1 to 1.0 for
individual attributes of the emission factor and the activity data. Each score is based on what
is known about the factor and activity data, such as the specificity to the source category and
the measurement technique employed. The composite attribute score for the emissions
estimate can be viewed as a statement of the confidence that can be placed in the data. For a
complete discussion of DARS and other rating systems, see the Quality Assurance
Procedures (Volume VI, Chapter 4) and Introduction to Stationary Point Sources Emission
Inventory Development (Volume II, Chapter 1).
Each of the examples below is hypothetical. A range is given where appropriate to cover
different situations. Table 5.6-1 shows scores developed from the use of emission models.
Table 5.6-2 demonstrates scores determined for gas-phase measurement. Table 5.6-3 gives a
set of scores for an estimate made with an emission factor. Table 5.6-4 demonstrates scores
developed from a material balance approach. The activity data are assumed to be measured
directly or indirectly. These examples are given as an illustration of the relative quality of
each method. If the same analysis were done for an actual site, the scores could be different
but the relative ranking of methods should stay the same.
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TABLE 5.6-1
DARS SCORES: EMISSION MODELS
Attribute
Measurement
Specificity
Spatial
Temporal
Composite Scores
Scores
Factor* ,
0.3 - 0.9
0.5 - 0.9
1.0
1.0
0.75 - 0.95
Activity1'
1.0
0.9
1.0
0.5 - 0.9
0.85 - 0.95
Emissions
03 - 0.9
0.45 - 0.81
1.0
0.5 - 0.9
056 - 0.90
a Lower scores apply to purely theoretical models and/or use of defaults rather than site-specific input
values.
b Scores assume activity is volume of wastewater processed and that it is measured.
TABLE 5.6-2
DARS SCORES: GAS-PHASE MEASUREMENT
Attribute
Measurement
Specificity
Spatial
Temporal
Composite Scores
Scores
Factor*
0.5 - 1.0
0.7 - 1.0
0.5 - 1.0
0.5 - 1.0
0.55 - 1.0
Activity1'
1.0
0.9
1.0
0.7 - 1.0
0.9 - 0.98
Emissions
0.5 - 1.0
0.63 - 0.9
0.5 - 1.0
035 - 1.0
0 JO - 0.98
a Exact score will depend on sample size, method used, and whether scales are appropriate to inventory.
Assumes activity is wastewater processed and measured.
5.6-4
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TABLE 5.6-3
DARS SCORES: EMISSION FACTORS
Attribute
Measurement
Specificity
Spatial
Temporal
Composite Scores
Scores
Factor
0.3 - 0.5
0.3 - 0.7
1.0
0.8
0.45 - 0.85
Activity"
1.0
0.9
1.0
0.8
0.78 - 0.98
Emissions
0.3 - 0.5
0.21 - 0.63
1.0
0.5 - 0.9
0.40 - 0.76
a Scores assume activity is volume of wastewater processed and that it is measured.
TABLE 5.6-4
DARS SCORES: MATERIAL BALANCE
Attribute
Measurement8
Specificity
Spatial
Temporal
Composite Scores
Scores
Factor
0.5 - 0.7
1.0
1.0
0.5 - 1.0
0.75 - 0.93
Activity
1.0
1.0
1.0
0.5 - 1.0
0.88 - 1.0
Emissions
0.5 - 0.7
1.0
1.0
0.25 - 1.0
0.69 - 0.93
a Score increases as sample sizes (influent and effluent) increase.
b If influent/effluent concentrations are scaled up or down, lower DARS scores.
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REFERENCES
Burton, F.L. and G. Tchobanoglous. 1991. Wastewater Engineering: Treatment, Disposal,
and Reuse; Metcalf & Eddy, Inc. 3rd ed. McGraw-Hill Publishing Company, New York,
New York.
EPA. 1990. Industrial Wastewater Volatile Organic Compound Emissions • Background
Information for BACT/LAER Determinations. U.S. Environmental Protection Agency,
EPA-450/3-90-004. Research Triangle Park, North Carolina.
EPA. 1992. Documentation for Developing the Initial Source Category List.
U.S. Environmental Protection Agency, EPA-450/3-91-030. Research Triangle Park,
North Carolina.
EPA. 1994. Air Emissions Models for Waste and Wastewater. U.S. Environmental
Protection Agency, EPA-453/R-94-080A. Research Triangle Park, North Carolina.
EPA. 1995. Compilation of Air Pollutant Emission Factors. Volume I: Stationary Point
and Area Sources, Fifth Edition, AP-42. U.S. Environmental Protection Agency, Office of
Air Quality Planning and Standards. Research Triangle Park, North Carolina.
Mihelcic, James R., C. Robert Baillod, John C. Crittenden, and Tony N. Rodgers.
January 1993. Estimation of VOC Emissions from Wastewater Facilities by
Volatilization and Stripping. Air & Waste, Journal of the Air & Waste Management
Association. 43: 97-105.
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APPENDIX A
EXAMPLE DATA COLLECTION FORMS
WASTEWATER TREATMENT UNITS
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EXAMPLE DATA COLLECTION FORMS
INSTRUCTIONS
1. These forms may be used as work sheets to aid the plant engineer in collecting the
information necessary to calculate emissions from wastewater treatment units. The
information requested on the forms relates to the methods (described in Sections 3
through 5) for quantifying emissions. These forms may also be used by regulatory
agency personnel to assist in area-wide inventory preparation.
2. The completed forms should be maintained in a reference file by the plant engineer
with other supporting documentation.
3. If the information requested is unknown, write "unknown" in the blank. If the
information requested does not apply to a particular unit, write "NA" in the blank.
4. If you want to modify the form to better serve your needs, an electronic copy of the
form may be obtained through the EIIP on the Clearinghouse for Inventories and
Emission Factors bulletin board system (CHIEF BBS).
5. Table A-l can be used as a reference for typical dimensions associated with each
unit design parameter.
6. Use the comments field on the form to record all useful information that will allow
your work to be reviewed and reconstructed.
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TABLE A-1
DIMENSIONS FOR WASTE STREAM COLLECTION AND TREATMENT UNITS"
Component
Drain
Manhole
Junction Box
Lift Station
Trench
Weir
Oil/Water Separator
Design Parameter
riser height (m)
riser diameter (m)
process drain pipe diameter (m)
effective diameter of riser (m)
riser cap thickness (cm)
sewer diameter (m)
diameter (m)
height (m)
cover diameter (m)
diameter of holes in cover (cm)
cover thickness (cm)
sewer diameter (m2)
effective diameter (m)
grade height (m)
water depth (m)
surface area (m2)
effective diameter (m)
width (m)
grade height (m)
water depth (m)
surface area (m2)
length (m)
water depth (m)
depth (m)
width (m)
height (m)
length (m)
width (m)
retention time (hr)
Typical
Dimensions
0.6
0.2
0.1
0.1
0.6
0.9
1.2
1.2
0.6
2.5
0.6
0.9
0.9
1.5
0.9
0.7
1.5
1.8
2.1
1.5
1.8
15.2
0.6
0.8
0.6
1.8
13.7
7.6
0.8
5.A-2
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TABLE A-1
(CONTINUED)
Component
Clarifier
Sump
Equalization Basin
Aeration Basin
Treatment Tank
Design Parameter
diameter (m)
depth (m)
retention time (hr)
effective diameter (m)
water depth (m)
surface area (m2)
effective diameter (m)
water depth (m)
surface area (m2)
retention time (days)
effective diameter (m)
water depth (m)
surface area (m2)
retention time (days)
effective diameter (m)
water, depth (m)
surface area (m2)
retention time (hr)
Typical
Dimensions
18.3
3.5
4.0
1.5
1.5
1.8
109
2.9
9,290
5
150
2.0
17,652
6.5
11
4.9
93
2
a EPA. 1990. Industrial Wastewater Volatile Organic Compound Emissions-Background Information for
BACT/LAER Determinations. U.S. Environmental Protection Agency, EPA-450/3-90-004. Research
Triangle Park, North Carolina.
BIP Volume II
5.Ar3
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CHAPTER 5 - WWCT 3/12/97
EXAMPLE DATA COLLECTION FORM - WASTEWATER UNITS
GENERAL INFORMATION
Facility/Plant Name:
SIC Code:
SCC:
SCC Description:
Location:
County: City: State:
Plant Geographical Coordinates:
Latitude:
Longitude:
UTM Zone:
UTM Easting:
UTM Northing:
Contact Name:
Title:
Telephone Number: Facsimile Number:
Source ID Number: Unit ID Number:
Permit Number:
Permitted Hours of Operation (per year):
Actual Hours of Operation:
Hours/Day: Days/Weeks: Weeks/Year:
5.A-4 EIIP Volume U
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3/12/97 CHAPTER 5 - WWCT
EXAMPLE DATA COLLECTION FORM - WASTEWATER UNITS
UNIT DESCRIPTION"
RNIT NUMBER of
Function box:
Reach:
>ram:
Drain type:
station:
Sump:
teir:
)ther:
)NFIGURATION
i
owthrough:
isposal:
f
CHANICAL AERATION
iffused air:
iiodegradation:
)il film layer:
iSIGN PARAMETERS
Volume flow rate (units):
[urface area (units):
Liquid depth (units):
idth (units):
i
'etch length (units):
etention time (turnover/yr):
)llutant of interest:
Concentration before treatment:
Mfer to Table A-l for typical dimensions associated with design parameters.
EIIP Volume II 5.A-5
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CHAPTER 5 - WWCT
3/12/97
INPUT DATA FOR MODELING WASTEWATER TREATMENT SYSTEMS
COLLECTION SYSTEM
Please fill out the following information for each unit. Attach additional sheets as needed.
TRUNK/REACH
Wastewater flow:
Open or closed channel:
Reach (channel) diameter:
Reach surface roughness:
(e.g., smooth, concrete, tile,
pipe)
Reach slope:
Reach length:
Wastewater temperature:
Water concentration of
known organics:
Manholes and drop
structures:
Manhole gas volume:
Tailwater depth in
manhole:
Air concentration of VOCs
(if available):
Water drop height in drop
structure (height of
splashing flow):
Wind speed or ventilation
rate in sewer:
UNIT NUMBER
UNIT NUMBER
UNIT NUMBER
5.A-6
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Aifl
Rec
3/12/97 CHAPTER 5 - WWCT
INPUT DATA FOR MODELING WASTEWATER TREATMENT SYSTEMS (CONTINUED)
BASINS & TANKS COMMENTS
rates and composition:
uent flow rate to unit (gal/hr):
ecycle flow rate from clarifier (gal/hr):
f
'eed influent organics:
Major components (mg/L):
— Total organics (mg/L):
Microorganism level in recycle (mg/L MLVSS8):
licroorganism level in basin (mg/L MLVSS):
licroorganism level in feed (mg/L MLVSS):
I
icroorganism level in clarifier effluent (mg/L MLVSS):
'xygen concentration in feed (ppm):
)xygen concentration in basin (ppm):
sin geometry and characteristics:
i
plume (gal):
lepth (ft):
Surface area (ft2):
imperature of liquid in basin (°C):
Number of turbines:
pirbine speed (rpm):
Delivered power of turbine (hp/turbine):
gen transfer rating of turbine (Ib of O^/hp-hr):
Diameter of turbine blade (ft):
ogubsurface aeration:
Air flow to basin (ft/min):
id injection rate (ft3/hr):
iodegradation rates:
yerall removal efficiency (%):
Compound-specific biorates (if known):
SS = mixed liquor volatile suspended solids.
EIIP Volume II 5.A-7
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00
EMISSION ESTIMATION RESULTS
Pollutant
VOC
Hazardous Air
Pollutants (list
individually)
Emission
Estimation
Method8
Annual
Emissions
Emissions
Units
Emission
Factor*
Emission
Factor
Units
Comments
i
01
a Use the following codes to indicate which emission estimation method is used for each pollutant:
Emission Factor = EF; Other (indicate) = O; Model (indicate which model was used) = M.
b Where applicable, enter the emission factor and provide the full citation of the reference or source of information from where the emission
factor came. Include edition, version, table, and page numbers if AP-42 is used.
Please copy blank form and attach additional sheets as needed.
ss
^
(o
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3/12/97 CHAPTER 5 - WWCT
APPENDIX B
AP-42 EMISSION ESTIMATION
ALGORITHM AND EXAMPLE
CALCULATIONS
«ource: EPA. January 1995. "Waste Water Collection, Treatment and Storage"
Section 4.3.2). In: Compilation of Air Pollutant Emission Factors, Volume I: Stationary
Point and Area Sources, Fifth Edition, AP-42. U.S. Environmental Protection Agency,
•Office of Air Quality Planning and Standards. Research Triangle Park, North Carolina.
I
bte: AP-42 refers to the SIMS model although it has been superseded by the
ATER8 model, which is available on the CHIEF BBS.
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CHAPTER 5 - WWCT 3/12/97
This page is intentionally left blank.
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3/12/97 C.HAPTER 5 - WWCT
EMISSIONS
Volatile organic compounds (VOCs) are emitted from wastewater collection, treatment,
and storage systems through volatilization of organic compounds at the liquid surface.
Emissions can occur by diffusive or convective mechanisms, or both. Diffusion occurs
when organic concentrations at the water surface are much higher than ambient
concentrations. The organics volatilize or diffuse into the air, in an attempt to reach
equilibrium between aqueous and vapor phases. Convection occurs when air flows over
the water surface, sweeping organic vapors from the water surface into the air. The rate
of volatilization relates directly to the speed of the air flow over the water surface.
Other factors that can affect the rate of volatilization include wastewater surface area,
temperature, and turbulence; wastewater retention time in the system(s); the depth of
the wastewater in the system(s); the concentration of organic compounds in the
wastewater and their physical properties, such as volatility and diffusivity in water; the
presence of a mechanism that inhibits volatilization, such as an oil film; or a competing
mechanism, such as biodegradation.
The rate of volatilization can be determined by using mass transfer theory. Individual
gas phase and liquid phase mass transfer coefficients (kg and kt, respectively) are used to
estimate overall mass transfer coefficients (K, K^,, and KD) for each VOC.1"2
Figure 5.B-1 presents a flow diagram to assist in determining the appropriate emissions
model for estimating VOC emissions from various types of wastewater treatment,
storage, and collection systems. Tables 5.B-1 and 5.B-2, respectively, present the
emission model equations and definitions.
VOCs vary in their degree of volatility. The emission models presented in this section
can be used for high-, medium-, and low-volatility organic compounds. The Henry's Law
constant (HLC) is often used as a measure of a compound's volatility, or the diffusion of
organics into the air relative to diffusion through liquids. High-volatility VOCs are
HLC > 10-3 atm-m3/gmol; medium-volatility VOCs are 1(T3 < HLC <
10'5 atm-m3/gmol; and low-volatility VOCs are HLC < 10'5 atm-m3/gmol.1
Fhe design and arrangement of collection, treatment, and storage systems are facility-
specific; therefore the most accurate wastewater emissions estimate will come from
actual tests of a facility (i.e., tracer studies or direct measurement of emissions from
openings). If actual data are unavailable, the emission models provided in this section
can be used.
Emission models should be given site-specific information whenever it is available. The
most extensive characterization of an actual system will produce the most accurate
EIIP Volume II 5.B-1
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CHAPTER 5 - WWCT
3/12/97
Equations Used to Obtain
Yes
/
| Flowthrough
//\Ye.
<^ BiologicalK/\
\^^ Active?^/'
^ °
' Disposal
I Flowthrough
-I
^^. ' — - Disposal
Kj Kg
1 2
1 2
1 2
1 2
Kofl Kp K
7
7
.7
7
a
N
20
19
14
13
/ Diffused \
Yes
N^ Air? /
N
No
Wastewater ./ '» \.
^*^v. > 1 cm? ^s^
\^^ No
— Disposal
I Flowthrough
aNumbered equations are presented in Table 4.3-1 |
K( n individual liquid phase mess transfer coefficient, m/s Disposal
KQ
"oil
N
2
2
2
2
9
9
e
9
18
17
22
23
= Individual gas phase mass transfer coefficient, m/s
= Overall mass transfer coefficient In the oil phase, m/s
° Volatilization - reaeration theory mass transfer coefficient 0
= Overall mass transfer coefficient, m/s I Junction Box
= Emissions, g/s
Lift station
x\ No
Wastewator Collection ,/ \. ' Sump
\^ weirr /
^^/YM I — w«lr
' ClarlfierWeir
3 2
3 2
1 2
5 6
7
7
10
8
12
12
12
21
24
Figure 5.B-1. Flow diagram for estimating VOC emissions from wastewater collection,
treatment, and storage systems.
a Citation refers to table assignment number inAP-42.
5.B-2
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3/12/97 CHAPTER 5 - WWCT
TABLE 5.B-1
MASS TRANSFER CORRELATIONS AND EMISSIONS EQUATIONS3
Equation
No. Equation
Individual liquid (kt) and gas (kg) phase mass transfer coefficients
1 k, (m/s) = (2.78 x 10^)(Dw/Dether)2/3
For: 0 < U10 < 3.25 m/s and all F/D ratios
k, (m/s) = [(2.605 x 10'9)(F/D) + (1.277 x 10-7)](U10)2(Dw/Dethcr)2/3
For: U10 > 3.25 m/s and 14 < F/D < 51.2
k, (m/s) = (2.61 x 10-7)(U10)2(Dw/Dether)2/3
For: U10 > 3.25 m/s and F/D > 51.2
kt (m/s) = 1.0 x 10-6 + 144 x W4 (U*)22 (Sc,)^\ U» <
kt (m/s) = 1.0 x 10-* + 34.1 x 10"4 U* (ScJ"0-5; U* > 0.3
0.3
L3
For: U10 > 3.25 m/s and F/D < 14
where:
U* (m/s) = (0.01)(U10)(6.1 + 0.63(U10))OJ
ScL = /tJ(pLDw)
F/D = 2 (A/r)°*
kg (m/s) = (4.82 x 10-3)(U10)a78 (ScG)^67 (d.)*11
where:
ScG =
de(m) =
kt (m/s) = [(8.22 x 10-9)(J)(POWR)(1.024)cr-20)(Ot)(106) *
(MWL)/(VavPL)](Dw/D02iW)°-5
where:
POWR (hp) = (total power to aerators)(V)
Va^ft2) = (fraction of area agitated)(A)
kg (m/s) = (1.35 x 10-7)(Re)U2 (P)04 (ScG)OJ5 (Fr)-°-21(Da MWa/d)
where:
Re = d2 w Pa/f4a
P = [(0.85)(POWR)(550 ft-lbf/s-hp)/N,]
ScG =
Fr =
///> vo/t/me // 5.B-3
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CHAPTER 5 - WWCT 3/12/97
TABLE 5.B-1
(CONTINUED)
Equation
No. Equation
kt (m/s) = (fair>t)(Q)/[3600 s/min (hc)(Tdc)]
where:
fairt = 1 - 1/r
V = exp
kg (m/s) = 0.001 + (0.0462(U'*)(ScG)-°67)
where:
U** (m/s) = [6.1 -I- (0.63)(U10)]OJ(U10/100)
ScG =
Overall mass transfer coefficients for water (K and oil (K hases and for weirs
7 K= (kt Keq y/(Keq kg + kt)
where:
Keq = H/(RT)
8 K (m/s) = [[MWL/(kt,L«(100 cm/m)] + [MWa/(ky,aH*
55,555(100 cm/m))]]-1 MW^KIOO cm/m)pj
^ = k_Keqoil
where:
Keqoil = P'paMWoil/(PoiI MWa P0)
10 KD = 0.16h (DW/D02>W)075
Air emissions (N)
11 N(g/s) = (1 - Ct/Co) V Co/t
where:
Ct/Co = exp[-K A t/V]
5.B-4 £///* VWu/ne //
I
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3/12/97 CHAPTER 5 - WWCT
TABLE 5.B-1
(CONTINUED)
Equation
No. Equation
12 N(g/s) = K CL A
where:
CL(g/m3) = Q Co/(KA + Q)
13 N(g/s) = (1 - Ct/Co) V Co/t
where:
Ct/Co = exp[-(KA + KeqQa)t/V]
14 N(g/s) = (KA + QaKeq)CL
where:
CL(g/m3) = QCo/(KA + Q + QaKeq)
15 N(g/s) = (1 - Ct/Co) KA/(KA + Kmax b; V/KJ V Co/t
where:
Ct/Co = exp[-Kmax bf t/K, - K A t/V]
16 N(g/s) = K CL A
where:
CL(g/m3) = [-b + (b2 - 4acn/(2a)
and:
a = KA/Q + 1
b = K^KA/Q + 1) + Kmax bt V/Q - Co
c = -
17 N(g/s) = (1 - aoil/Cooil)Voi,Cooil/t
where:
Ctoil/Cooil = expl-K,,, t/Doil]
and:
Cooil = Kow Co/[l - FO + FO(Kow)]
Voil = (FO)(V)
Doil = (FO)(V)/A
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CHAPTER 5 - WWCT 3/12/97
TABLE 5.B-1
(CONTINUED)
Equation
No. Equation
18 N(g/s) =
where*
and:
Cooi, = Kow Co/[l - FO + FO(Kow)]
Qoi. = (FO)(Q)
19 N(g/s) = (1 - Ct/Co)(KA + QaKeq)/(KA + QaKeq + Kmax b( V/KJ
VCo/t
where:
Q/Co = exp[-(KA + KeqQa)t/V - Kmax bf t/K,]
20 N(g/s) = (KA + QaKeq)CL
where*
CL(g/m3) =[-b+(b2-4ac)°-5]/(2a)
and:
a = (KA + QaKeq)/Q + 1
b = ^[(KA + QaKeq)/Q + 1] + Kmax b; V/Q -
Co
c =-
21 N (g/s) = (1 - exp[-KD])Q Co
22 N(g/s) = K.i.C^.A
where*
C^nCg/m3) = CUCo^'VCK^A + Qoil)
and:
Cooil" =Co/FO
QOH = (FO)(Q)
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3/12/97 CHAPTER 5 - WWCT
TABLE 5.B-1
(CONTINUED)
Equation
No.
23
24
Nfe/s) = (1 - Ctoil/Cooil
where:
Ctoil/Cooil»
and:
Cooil*
voil
Don
N (g/s) = (1 - exp[-K T
Equation
')(voil)(c0oil')/t
= expt-K,,, t/Doil]
= Co/FO
= (FO)(V)
= (FO)(V)/A
dc hc/Q])Q Co
* All parameters in numbered equations are defined in Table 5.B-2.
EIIP Volume II 5.B-7
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CHAPTER 5 - WWCT 3/12/97
TABLE 5.B-2
PARAMETER DEFINITIONS FOR MASS TRANSFER CORRELATIONS
AND EMISSIONS EQUATIONS
Parameter
A
b,
CL
CUoa
Co
Co,*
Co,**
Ct
CX
d
D
d'
D.
dc
d.
D^
DOZ.W
Drf
Definition
Wastewater surface area
Biomass concentration (total biological solids)
Concentration of constituent in the
Concentration of constituent in the
Initial concentration of constituent
phase
liquid phase
oil phase
in the liquid
Initial concentration of constituent in the oil
phase considering mass transfer resistance
between water and oil phases
Initial concentration of constituent in the oil
phase considering no mass transfer resistance
between water and oil phases
Concentration of constituent in the
at time = t
Concentration of constituent in the
time = t
Impeller diameter
Wastewater depth
Impeller diameter
Diffusivity of constituent in air
Clarifier diameter
Effective diameter
Diffusivity of ether in water
Diffusivity of oxygen in water
Oil film thickness
liquid phase
oil phase at
Units
m'orft2
g/m3
g/m3
g/m3
g/m3
g/m3
g/m3
g/m3
g/m3
cm
m or ft
ft
cm2/s
m
m
cm2/s
cm2/s
m
Code1
A
B
D
D
A
D
D
D
D
B
A,B
B
C
B
D
(8.5x10*)"
(2.4X10-5)"
B
5.B-8 BIP Volume li
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3/12/97
CHAPTER 5 - WWCT
TABLE 5.B-2
(CONTINUED)
Parameter
Dw
£,.,
FID
FO
Fr
ge
h
h.
H
J
K
KD
Keq
Keq,
k.
k,
Kmax
K-i
Definition
Diffusivity of constituent in water
Fraction of constituent emitted to the air,
considering zero gas resistance
Fetch to depth ratio, de/D
Fraction of volume which is oil
Froude number
Gravitation constant (a conversion factor)
Weir height (distance from the wastewater
overflow to the receiving body of water)
Clarifier weir height
Henry's Law constant of constituent
Oxygen transfer rating of surface aerator
Overall mass transfer coefficient for transfer of
constituent from liquid phase to gas phase
Volatilization-reaeration theory mass transfer
coefficient
Equilibrium constant or partition coefficient
(concentration in gas phase/concentration in
liquid phase)
Equilibrium constant or partition coefficient
(concentration in gas phase/concentration in
oil phase)
Gas phase mass transfer coefficient
Liquid phase mass transfer coefficient
Maximum biorate constant
Overall mass transfer coefficient for transfer of
constituent from oil phase to gas phase
Units
cm2/s
dimensionless
dimensionless
dimensionless
dimensionless
Ib.-ft/s'-lbr
ft
m
atm-m3/gmol
Ib O2/(hr-hp)
m/s
dimensionless
dimensionless
dimensionless
m/s
m/s
g/s-g biomass
m/s
Code-
C
D
D
B
D
32.17
B
B
C
B
D
D
D
D
D
D
A,C
D
fUP Volume II
5.B-9
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CHAPTER 5 - WWCT
3/12/97
TABLE 5.B-2
(CONTINUED)
Parameter
Kow
K.
MWa
MW^
MWL
N
N,
ot
P
P-
Po
POWR
Q
Q.
Qoa
r
R
Re
Sc0
ScL
Definition
Octanol-water partition coefficient
Half saturation biorate constant
Molecular weight of air
Molecular weight of oil
Molecular weight of water
Emissions
Number of aerators
Oxygen transfer correction factor
Power number
Vapor pressure of the constituent
Total pressure
Total power to aerators
Volumetric flow rate
Diffused air flow rate
Volumetric flow rate of oil
Deficit ratio (ratio of the difference between the
constituent concentration at solubility and
actual constituent concentration in the
upstream and the downstream)
Universal gas constant
Reynolds number
Schmidt number on gas side
Schmidt number on liquid side
Units
dimension! ess
g/m3
g/gmol
g/gmol
g/gmol
g/s
dimensionless
dimension! ess
dimensionless
atm
atm
hp
m'/s
mVs
m3/s
dimensionless
atm-m3/gmol-K
dimensionless
dimensionless
dimensionless
Code'
C
A,C
29
B
18
D
A,B
B
D
C
A
B
A
B
B
D
8.21xlO-s
D
D
D
5.B-10
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CHAPTER 5 - WWCT
TABLE 5.B-2
(CONTINUED)
Parameter
T
t
U*
ir
ulo
V
Va,
V,*
w
P.
PL
Poa
M,
ML
Definition
Temperature of water
Residence time of disposal
Friction velocity
Friction velocity
Wind speed at 10 m above the liquid surface
Wastewater volume
Turbulent surface area
Volume of oil
Rotational speed of impeller
Density of air
Density of water
Density of oil
Viscosity of air
Viscosity of water
Units
°C or Kelvin
(K)
s
m/s
m/s
m/s
m3 or ft3
ft2
m3
rad/s
g/cm3
g/cm3 or Ib/ft3
g/m3
g/cm-s
g/cm-s
Code'
A
A
D
D
B
A
B
B
B
(1.2xlO-3)b
lb or 62.4b
B
(l.SlxlO-4)"
(8.93xlO-3)b
a Code:
A = Site-specific parameter.
B = Site-specific parameter. For default values, see Table 5.B-3.
C = Parameter can be obtained from literature. See Table 5.B-4 for a list of ~ 150 compound
chemical properties at T = 25°C (298eK).
D = Calculated value.
b Reported values at 25°C (298°K).
EIIP Volume II
5.B-11
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CHAPTER 5 - WWCT 3/12/97
estimates from an emissions model. In addition, when addressing systems involving
biodegradation, the accuracy of the predicted rate of biodegradation is improved when
site-specific compound biorates are input. Reference 3 contains information on a test
method for measuring site-specific biorates, and Table 5.B-4 presents estimated biorates
for approximately 150 compounds.
To estimate an emissions rate (N), the first step is to calculate individual gas phase and
liquid phase mass transfer coefficients k and kt. These individual coefficients are then
used to calculate the overall mass transfer coefficient, K. Exceptions to this procedure
are the calculation of overall mass transfer coefficients in the oil phase, K^,, and the
overall mass transfer coefficient for a weir, KD. K^, requires only kp and KD does not
require any individual mass transfer coefficients. The overall mass transfer coefficient is
then used to calculate the emissions rates. The following discussion describes how to use
Figure 5.B-1 to determine an emission rate. An example calculation is presented in
Part B-l below.
Figure 5.B-1 is divided into two sections: wastewater treatment and storage systems, and
wastewater collection systems. Wastewater treatment and storage systems are further
segmented into aerated/nonaerated systems, biologically active systems, oil film layer
systems, and surface impoundment flowthrough or disposal. In flowthrough systems,
wastewater is treated and discharged to a publicly owned treatment works (POTW) or a
receiving body of water, such as a river or stream. All wastewater collection systems are
by definition flowthrough. Disposal systems, on the other hand, do not discharge any
wastewater.
Figure 5.B-1 includes information needed to estimate air emissions from junction boxes,
lift stations, sumps, weirs, and clarifier weirs. Sumps are considered quiescent, but
junction boxes, lift stations, and weirs are turbulent in nature. Junction boxes and lift
stations are turbulent because incoming flow is normally above the water level in the
component, which creates some splashing. Wastewater falls or overflows from weirs and
creates splashing in the receiving body of water (both weir and clarifier weir models).
Wastewater from weirs can be aerated by directing it to fall over steps, usually only the
weir model.
Assessing VOC emissions from drains, manholes, and trenches is also important in
determining the total wastewater facility emissions. As these sources can be open to the
atmosphere and closest to the point of wastewater generation (i.e., where water
temperatures and pollutant concentrations are greatest), emissions can be significant.
Currently, there are no well-established emission models for these collection system
types. However, work is being performed to address this need.
5.B-12 £HP Volume II
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3/12/97 CHAPTER 5 - WWCT
Preliminary models of VOC emissions from waste collection system units have been
developed.4 The emission equations presented in Reference 4 are used with standard
collection system parameters to estimate the fraction of the constituents released as the
wastewater flows through each unit. The fractions released from several units are
estimated for high-, medium-, and low-volatility compounds. The units used in the
estimated fractions included open drains, manhole covers, open trench drains, and
covered sumps.
The numbers in Figure 5.B-1 under the columns for kt, k~ K^,, KD, K, and N refer to the
appropriate equations in Table 5.B-1." Definitions for all parameters in these equations
are given in Table 5.B-2. Table 5.B-2 also supplies the units that must be used for each
parameter, with codes to help locate input values. If the parameter is coded with the
letter A, a site-specific value is required. Code B also requires a site-specific parameter,
but defaults are available. These defaults are typical or average values and are
presented by specific system in Table 5.B-3.
Code C means the parameter can be obtained from literature data. Table 5.B-4 contains
a list of approximately 150 chemicals and their physical properties needed to calculate
emissions from wastewater, using the correlations presented in Table 5.B-1. All
properties are at 25°C (77°F). A more extensive chemical properties data base is
contained in Appendix C of Reference 1.) Parameters coded D are calculated values.
Calculating air emissions from wastewater collection, treatment, and storage systems is a
complex procedure, especially if several systems are present. Performing the calculations
by hand may result in errors and will be time consuming. A personal computer program
called the Surface Impoundment Modeling System (SIMS) is now available for
estimating air emissions. The program is menu driven and can estimate air emissions
from all surface impoundment models presented in Figure 5.B-1, individually or in series.
The program requires for each collection, treatment, or storage system component, at a
minimum, the wastewater flow rate and component surface area. All other inputs are
provided as default values. Any available site-specific information should be entered in
place of these defaults, as the most fully characterized system will provide the most
accurate emissions estimate.
a All emission model systems presented in Figure 5.B-1 imply a completely mixed or uniform waste
water concentration system. Emission models for a plug flow system, or system in which there is
no axial, or horizontal mixing, are too extensive to be covered in this document. (An example of
plug flow might be a high waste water flow in a narrow channel.) For information on emission
models of this type, see Reference 1.
EIIP Volume II 5.B-13
-------
CHAPTER 5 - WWCT
3/12/97
TABLE 5.B-3
SITE-SPECIFIC DEFAULT PARAMETERS"
Default
Parameter1*
General
T
U10
Biotreatment Systems
bi
POWR
W
d(<0
Va,
J
0,
N,
Diffused Air Systems
a
Definition
Temperature of water
Windspeed
Biomass concentration (for biologically active
systems)
Quiescent treatment systems
Aerated treatment systems
Activated sludge units
Total power to aerators
(for aerated treatment systems)
(for activated sludge)
Rotational speed of impeller
(for aerated treatment systems)
Impeller diameter
(for aerated treatment systems)
Turbulent surface area
(for aerated treatment systems)
(for activated sludge)
Oxygen transfer rating to surface aerator
(for aerated treatment systems)
Oxygen transfer correction factor
(for aerated treatment systems)
Number of aerators
Diffused air volumetric flow rate
Default Value
298°K
4.47 m/s
50 g/m3
300 g/m3
4000 g/m3
0.75 hp/1000 ft3 (V)
2 hp/1000 ft3 (V)
126 rad/s (1200 rpm)
61 cm (2 ft)
0.24 (A)
0.52 (A)
3 Ib O2/hp«hr
0.83
POWR/75
0.0004(V) m3/s
5.B-14
£IIP Volume II
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3/12/97
CHAPTER 5 - WWCT
TABLE 5.B-3
(CONTINUED)
Default
Parameter1*
Oil Film Layers
M^
Drf
Voa
QoU
P«]
FO
Junction Boxes
D
N,
Lift Station
D
N,
Sump
D
Weirs
dc
h
hc
Definition
Molecular weight of oil
Depth of oil layer
Volume of oil
Volumetric flow rate of oil
Density of oil
Fraction of volume which is oil0
Depth of Junction Box
Number of aerators
Depth of Lift Station
Number of aerators
Depth of sump
Clarifier weir diameter*1
Weir height
Clarifier weir height*
Default Value
282 g/gmol
0.001 (V/A) m
0.001 (V) m3
0.001 (Q) m3/s
0.92 g/cm3
0.001
0.9m
1
1.5m
1
5.9m
28.5 m
1.8m
0.1 m
a Reference 1.
b As defined in Table
c Reference 4.
d Reference 2.
e Reference 5.
5.B-2.
EIIP Volume II
5.B-15
-------
CHAPTER 5 - WWCT 3/12/97
The SIMS program with user's manual and background technical document can be
obtained through state air pollution control agencies and through the U.S.
Environmental Protection Agency's Control Technology Center in Research Triangle
Park, North Carolina, telephone (919) 541-0800. The user's manual and background
technical document should be followed to produce meaningful results.
The SIMS program and user's manual also can be downloaded from EPA's
Clearinghouse for Inventories and Emission Factors bulletin board system (CHIEF BBS).
The CHIEF BBS is open to all persons involved in air emission inventories. To access
this BBS, one needs a computer, modem, and communication package capable of
communicating at up to 14,400 baud, 8 data bits, 1 stop bit, and no parity (8-N-l). This
BBS is part of EPA's Office of Air Quality Planning and Standards (OAQPS)
Technology Transfer Network (TTN) system and its telephone number is (919) 541-5742.
First-time users must register before access is allowed.
^
Emissions estimates from SIMS are based on mass transfer models developed by
Emissions Standards Division (ESD) during evaluations of treatment, storage, and
disposal facilities (TSDFs) and VOC emissions from industrial wastewater. As a part of
the TSDF project, a Lotus* spreadsheet program called CHEMDAT7 was developed for
estimating VOC emissions from wastewater land treatment systems, open landfills, closed
landfills, and waste storage piles, as well as from various types of surface impoundments.
For more information about CHEMDAT7, contact the ESD's Chemicals And Petroleum
Branch (MD-13), U.S. Environmental Protection Agency, Research Triangle Park, North
Carolina 27711.
EXAMPLE CALCULATION
An example industrial facility operates a flowthrough, mechanically aerated biological
treatment impoundment that receives wastewater contaminated with benzene at a
concentration of 10.29 g/m3.
The following format is used for calculating benzene emissions from the treatment
process:
I. Determine which emission model to use
II. User-supplied information
III. Defaults
IV. Pollutant physical property data and water, air, and other properties
V. Calculate individual mass transfer coefficient
VI. Calculate the overall mass transfer coefficients
VII. Calculate VOC emissions
5.B-16 EHP Volume II
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3/12/97 CHAPTER 5 - WWCT
I. Determine Which Emission Model To Use - Following the flow diagram in
Figure 5.B-1, the emission model for a treatment system that is aerated, but not by
diffused air, is biologically active, and is a flowthrough system, contains the following
equations:
Equation Nos.
Parameter Definition from Table 5.B-1
K Overall mass transfer coefficient, m/s 7
kt Individual liquid phase mass transfer coefficient, 1,3
m/s
kg Individual gas phase mass transfer coefficient, m/s 2, 4
N VOC emissions, g/s 16
II. User-supplied Information - Once the correct emission model is determined, some
site-specific parameters are required. As a minimum for this model, site-specific
flow rate, wastewater surface area and depth, and pollutant concentration should be
provided. For this example, these parameters have the following values:
Q = Volumetric flow rate = 0.0623 m3/s
D - Wastewater depth = 1.97 m
A = Wastewater surface area = 17,652 m2
Co = Initial benzene concentration in the liquid phase = 10.29 g/m3
[II. Defaults - Defaults for some emission model parameters are presented in
Table 5.B-3. Generally, site-specific values should be used when available. For this
facility, all available general and biotreatment system defaults from Table 5.B-3 were
used:
U]0 = Wind speed at 10 m above the liquid surface = e = 4.47 m/s
T = Temperature of water = 25°C (298°K)
bj = Biomass concentration for aerated treatment systems = 300 g/m3
J = Oxygen transfer rating to surface aerator = 3 Ib O2/hp-hr
POWR = Total power to aerators = 0.75 hp/1,000 ft3 (V)
O, = Oxygen transfer correction factor = 0.83
Vay = Turbulent surface area = 0.24 (A)
d = Impeller diameter = 61 cm
d* = Impeller diameter = 2 ft
w = Rotational speed of impeller = 126 rad/s
N, = Number of aerators = POWR/75 hp
&IP Volume II 5.B-17
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CHAPTER 5 - WWCT 3/12/97
IV. Pollutant Physical Property Data, And Water, Air and Other Properties - For each
pollutant, the specific physical properties needed by this model are listed in
Table 5.B-4. Water, air, and other property values are given in Table 5.B-2.
A, Benzene (from Table 5.B-4)
Dwbenzene = Diffusivity of benzene in water = 9.8 x 10"6 cm2/s
^a benzene = Diffusivity of benzene in air = 0.088 cm2/s
"benzene = Henry's Law constant for benzene = 0.0055 atm- mVgmol
^maxbeiizene = Maximum biorate constant for benzene = 5.28 x 10 g/g-s
Ks,benzene = Half saturation biorate constant for benzene = 13.6 g/m3
B. Water, Air, and Other Properties (from Table 5.B-2)
pa = Density of air = 1.2 x 103 g/cm3
PL = Density of water = 1 g/cn? (62.4 lbm/ft3)
/ia = Viscosity of air = 1.81 x 10"4 g/cm-s
Do2w = Diffusivity of oxygen in water = 2.4 x 10"5 cm2/s
Dether = Diffusivity of ether in water = 8.5 x 10* cm2/s
MWL = Molecular weight of water = 18 g/gmol
MWa = Molecular weight of air = 29 g/gmol
g,. = Gravitation constant = 32.17 lbm-ft/lbrs2
R = Universal gas constant = 8.21 x 10"5 atm-m3/gmol
V. Calculate Individual Mass Transfer Coefficients - Because part of the impoundment
is turbulent and part is quiescent, individual mass transfer coefficients are
determined for both turbulent and quiescent areas of the surface impoundment.
Turbulent area of impoundment - Equations 3 and 4 from Table 5.B-1.
A. Calculate the individual liquid mass transfer coefficient, kt:
kt(m/s) = [(8.22 x 10-9)(J)(POWR)(1.024)cr-20) *
(Ot)(106)MWL/(VavPL)](Dw/D02>wr
The total power to the aerators, POWR, and the turbulent surface area, Va^ are
calculated separately [Note: some conversions are necessary.]:
1. Calculate total power to aerators, POWR (Default presented in III):
POWR (hp) = 0.75 hp/1,000 ft3 (V)
V = wastewater volume, m3
V (m3) = (A)(D) = (17,652 m2)(1.97 m)
V = 34,774 m3
POWR = (0.75 hp/1,000 ft3)(ft3/0.028317 m3)(34,774 m3)
= 921 hp
5.B-18 EHP Volume II
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3/12/97 CHAPTER 5 - WWCT
2. Calculate turbulent surface area, Vav (default presented in III):
V^ (ft2) = 0.24 (A)
= 0.24(17,652 m2)(10.758 ft2/m2)
= 45,576 ft2
Now, calculate kt, using the above calculations and information from II, III, and
IV:
kt (m/s) = [(8.22 x 10'9)(3 Ib O2/hp-hr)(921 hp) *
(1.024)^25-20>(0.83)(106)(18g/gmol)/
((45,576 ft2)(l g/cm3))] *
[(9.8 x 10-6 cm2/s)/(2.4 x 10'5 cm2/s)]0:5
= (0.00838)(0.639)
kt = 5.35 x 10° m/s
B. Calculate the individual gas phase mass transfer coefficient, kg:
^ (m/s) = (1.35 x 10-7)(Re)142(P)a4(ScG)°-5(Fr)-°-21(Da MWa/d)
The Reynolds number, Re, power number, P, Schmidt number on the gas side,
ScG, and Froude's number, Fr, are calculated separately:
1. Calculate Reynolds number, Re:
Re = d2 w pa//*a
= (61 cm)2(126 rad/s)(1.2 x 10'3 g/cm3)/(1.81 x W4 g/cm-s)
= 3.1 x 106
2. Calculate power number, P:
P = [(0.85)(POWR)(550 ft-lbf/s-hp)/N,] g,./(pL(d*)s w3)
N, = POWR/75 hp (default presented in III)
P = (0.85)(75 hp)(POWR/POWR)(550 ft-lbf/s-hp) *
(32.17 Ib -ft/lbrs2)/[(62.4 Ibm/ft3)(2 ft)5(126 rad/s)3]
= 2.8 x 10"*
3. Calculate Schmidt number on the gas side, ScG:
ScG =
= (1.81 x 10-4 g/cm-s)/[(1.2 x 10'3 g/cm3)(0.088 cm2/s)]
= 1.71
HP Volume II 5.B-19
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CHAPTER 5 - WWCT _ _ 3/12/97
4. Calculate Froude number, Fr:
Fr =
= (2 ft)(126 rad/s)2/(32.17 lbm-ft/lbrs2)
= 990
Now, calculate k_ using the above calculations and information from II, III, and
IV:
kg (m/s) = (1.35 x 10-7)(3.1 x
(990)-°21(0.088 cm2/s)(29 g/gmol)/(61 cm)
= 0.109 m/s
Quiescent surface area of impoundment - Equations 1 and 2 from Table 5.B-1.
A. Calculate the individual liquid phase mass transfer coefficient, kt:
F/D = 2(A/r)M/D
= 2(17,652 m2/T)°-5/(1.97 m)
= 76.1
U10 = 4.47 m/s
For U10 > 3.25 m/s and F/D > 51.2 use the following:
kt (m/s) = (2.61 x 10-7)(U10)2(Dw/Dether)2/3
= (2.61 x 10-7)(4.47 m/s)2[(9.8 x 10"6 cm2/s)/
(8.5 x 10-6 cm2/s)]2/3
= 5.74 x 10"6 m/s
B. Calculate the individual gas phase mass transfer coefficient, k :
kg = (4.82 x 10-3)(U10)°-78(ScG)^67(de)^11
The Schmidt number on the gas side, ScG, and the effective diameter, de, are
calculated separately:
1. Calculate the Schmidt number on the gas side, ScG:
^CG = /*a/(paDa) = 1.71 (same as for turbulent impoundments)
2. Calculate the effective diameter, de:
5.B-20 EHP Volume
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1/12/97 CHAPTER 5 • WWCT
de (m) =
= 2(17,652 mVx)0-5
= 149.9 m
k (m/s) = (4.82 x 10'3)(4.47 m/s)0'78 (1.71)-067 (149.9 m)"0'11
= 6.24 x lO'3 m/s
Calculate The Overall Mass Transfer Coefficient - Because part of the
impoundment is turbulent and part is quiescent, the overall mass transfer coefficient
is determined as an area-weighted average of the turbulent and quiescent overall
mass transfer coefficients. (Equation 7 from Table 5.B-1).
Overall mass transfer coefficient for the turbulent surface area of impoundment. KT
KT (m/s) = (ktKeqkg)/(Keqkg + k,)
Keq = H/RT
= (0.0055 atm-m3/gmol)/[(8.21 x 10'5 atm-m3/ gmol-°K)
(298°K)]
= 0.225
KT (m/s) = (5.35 x 10'3 m/s)(0.225)(0.109)/[(0.109 m/s)(0.225) +
(5.35 x 10-6 m/s)]
= 4.39 x 10'3 m/s
Overall mass transfer coefficient for the quiescent surface area of impoundment.
KQ (m/s) = (ktKeqkg)/(Keqk + k,)
= (5.74 x 10-6 m/s)(0.225)(6.24 x 10'3 m/s)/
[(6.24 X 10'3 m/s)(0.225) + (5.74 x W* m/s)]
= 5.72 x 10-6 m/s
Overall mass transfer coefficient. 1C weighted by turbulent and quiescent surface
areas. AT and
K (m/s) = (KTAT
AT = 0.24(A) (Default value presented in III: AT =
AQ = (1 - 0.24) A
K (m/s) = [(4.39 x 10'3 m/s)(0.24 A) + (5.72 x IV* m/s)
(1 - 0.24)A]/A
= 1.06 x 10'3 m/s
Volume II 5.B-21
-------
CHAPTER 5 - WWCT 3/12/97
VII. Calculate VOC Emissions For An Aerated Biological Flowthrough Impoundment
Equation 16 from Table 5.B-1:
N (g/s) = K CL A
where:
CL (g/m3) = [-b + (b2 - 4ac)°-5]/(2a)
and:
a = KA/Q + 1
b = K^KA/Q + 1) + Kmax b; V/Q - Co
c = -K.CO
Calculate a, b, c, and the concentration of benzene in the liquid phase, Q, separately:
1. Calculate a:
a = (KA/Q + 1) = [(1.06 x 10'3 m/s)(17,652 m2)/(0.0623 m3/s)] + 1
= 301.3
2. Calculate b (V = 34,774 m3 from IV):
b = K, (KA/Q + 1) + Kmax b( V/Q - Co
= (13.6 g/m3)[(1.06 x lO'3 m/s)(17,652 m2)/(0.0623 m3/s)] -h
[(5.28 x 10^ g/g-s)(300 g/m3)(34,774 m3)/(0.0623 m3/s)] - 10.29 g/m
= 4,084.6 + 884.1 - 10.29
= 4,958.46 g/m3
3. Calculate c:
c = -K.CO
= -(13.6 g/m3)(10.29 g/m3)
= -139.94
5.B-22 CIIP Volume
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12/97
CHAPTER 5 - WWCT
t. Calculate the concentration of benzene in the liquid phase, Q, from a, b, and c
above:
CL (g/m3) = [-b + (b2 - 4acn/(2a)
= [(4,958.46 g/m3) + [(4,958.46 g/m3)2 -
[4(301.3)(-139.94)]]°-5]/(2(301.3))
= 0.0282 g/m3
Now calculate N with the above calculations and information from II and V:
N (g/s) = K A CL
= (1.06 x lO'3 m/s)( 17,652 m2)(0.0282 g/m3)
= 0.52 g/s
GLOSSARY OF TERMS
Basin - an earthen or concrete-lined depression used to hold liquid.
Completely mixed - having the same characteristics and quality throughout or at all
times.
Disposal -
-Drain -
f lowthrough -
d?lug flow •
Jtorage -
treatment -
the act of permanent storage. Flow of liquid into, but not out of a
device.
a device used for the collection of liquid. It may be open to the
atmosphere or be equipped with a seal to prevent emissions of
vapors.
having a continuous flow into and out of a device.
having characteristics and quality not uniform throughout. These
will change in the direction the fluid flows, but not perpendicular to
the direction of flow (i.e., no axial movement).
any device to accept and retain a fluid for the purpose of future
discharge. Discontinuity of flow of liquid into and out of a device.
the act of improving fluid properties by physical means. The
removal of undesirable impurities from a fluid.
Volume II
5.B-23
-------
CHAPTER 5 - WWCT 3/12/97
VOC - volatile organic compounds, referring to all organic compounds
except the following, which have been shown not to be
photochemically reactive: methane, ethane, trichlorotrifluoroethane,
methylene chloride, 1,1,1,-trichloroethane, trichlorofluoromethane,
dichlorodifluoromethane, chlorodifluoromethane, trifluoromethane,
dichlorotetrafluoroethane, and chloropentafluoroethane.
5.B-24 EHP Volume \
-------
1)
Chemical Name
ACETALDEHYDE
ACETIC ACID
ACETIC ANHYDRIDE
ACETONE
ACETONITRILE
ACROLEIN
ACRYLAMIDE
ACRYLIC ACID
ACRYLONITRILE
ADIPIC ACID
ALLYL ALCOHOL
AMINOPHENOL(-O)
AMINOPHENOL(-P)
AMMONIA
AMYL ACETATE(-N)
ANILINE
BENZENE
BENZO(A)ANTHRACENE
BENZO(A)PYRENE
CAS
Number
75-07-0
64-19-7
108-24-7
67-64-1
75-05-8
107-02-8
79-06-1
79-10-7
107-13-1
124-04-9
107-18-6
95-55-6
123-30-8
7664-41-7
628-37-8
62-53-3
71-43-2
56-55-3
50-32-8
Molecular
Weight
44.00
60.05
102.09
58.00
41.03
56.10
71.09
72.10
53.10
146.14
58.10
109.12
109.12
17.03
130.18
93.10
78.10
228.30
252.30
Vapor Pressure
At25°C
(mm Hg)
760
15.4
5.29
266
90
244.2
0.012
5.2
114
0.0000225
23.3
0.511
0.893
7470
5.42
1
95.2
0.00000015
0.00568
Henry's Law
Constant At 25eC
(atnvmVmol)
0.000095
0.0627
0.00000591
0.000025
0.0000058
0.0000566
0.00000000052
0.0000001
0.000088
0.00000000005
0.000018
0.00000367
0.0000197
0.000328
0.000464
0.0000026
0.0055
0.00000000138
0.00000000138
Diffusivity Of
Chemical In
Water
At25°C
(cmVs)
0.0000141
0.000012
0.00000933
0.0000114
0.0000166
0.0000122
0.0000106
0.0000106
0.0000134
0.00000684
0.0000114
0.00000864
0.00000239
0.0000693
0.0000012
0.0000083
0.0000098
0.000009
0.000009
Diffusivity Of
Chemical In
Air At25°C
(cmVs)
0.124
0.113
0.235
0.124
0.128
0.105
0.097
0.098
0.122
0.0659
0.114
0.0774
0.0774
0.259
0.064
0.07
0.088
0.051
0.043
i
Ol
to
&
-------
w
TABLE 5.B-4 (PART 1)
(CONTINUED)
Chemical Name
CRESYLIC ACID
CROTONALDEHYDE
CUMENE (ISOPROPYLBENZENE)
CYCLOHEXANE
CYCLOHEXANOL
CYCLOHEXANONE
DI-N-OCTYL PHTHALATE
DIBUTYLPHTHALATE
DICHLORO(-2)BUTENE(1 ,4)
DICHLOROBENZENE(1,2) (-O)
DICHLORQBENZENE(1,3) (rM)
DICHLOROBENZENE0.4) (-P)
DICHLORODIFLUOROMETHANE
DICHLOROETHANE(1 ,1)
DICHLOROETHANE(1 ,2)
DICHLOROETHYLENEO ,2)
DICHLOROPHENO1X2.4)
DICHLOROPHENOXYACETie ACID(2,4)
DICHLOROPROPANE(1 ,2)
CAS Number
1319-77-3
4170-30-0
98-82-8
110-82-7
108-93-0
108-94-1
117-84-0
84-74r2
764-41-0
95-50-1
541-73-1
106-46-7
75-71-8
75-34-3
107-06-2
156-54-2
120-83-2
94-75-7
78-87-5
Molecular
Weight
108.00
70.09
120.20
84.20
100.20
98.20
390.62
278.30
125.00
147.00
147.00
147.00
120.92
99.00
99.00
96.94
163.01
221.00
112.99
Vapor Pressure
At25eC
(mm Hg)
0.3
30
4.6
100
1.22
4.8
0
0.00001
2.87
1.5
2.28
1.2
5000
234
80
200
Q.I
290
40
Henry's Law
Constant At 25°C
(atm-mVmol)
0.0000017
0.00000154
0.0146
0.0137
0.00000447
0.00000413
0.137
0.00000028
0.000259
0.00194
0.00361
0.0016
0.401
0.00554
0.0012
0.0319
0.0000048
0.0621
0.0023
Diffusivity Of
Chemical In
Water
At25°C
(cm2/s)
0.0000083
0.0000102
0.0000071
0.0000091
0.00000831
0.00000862
0.0000041
0.0000079
0.00000812
0.0000079
0.0000079
0.0000079
0.00001
0.0000105
0.0000099
0.000011
0.0000076
0.00000649
. 0.0000087
Diffusivity Of
Chemical In
Air At 25°C
(cmVs)
0.074
0.0903
0.065
0.0839
0.214
0.0784
0.0409
0.0438
0.0725
0.069
0.069
0.069
0.0001
0.0914
0.104
0.0935
0.0709
0.0588
0.0782
i
O)
o
-s
-------
TA
ITINUED)
Chemical Name
DIETHYL (N,N) ANILINE
DIETHYL PHTHALATE
DIMETHYL FORMAMIDE
DIMETHYL HYDRAZINE(l.l)
DIMETHYL PHTHALATE
DIMETHYLBENZ(A)ANTHRACENE
DIMETHYLPHENOL(2,4)
DINITROBENZENE (-M)
DINITROTOLUENE(2(4)
DIOXANE(1,4)
DIOXIN
DIPHENYLAMINE
EPICHLOROHYDRIN
ETHANOL
ETHANOLAMINE(MONO-)
ETHYL ACRYLATE
ETHYL CHLORIDE
ETHYL-(2)PROPYL-(3) ACROLEIN
ETHYLACETATE
CAS Number
91-66-7
84-66-2
68-12-2
57-14-7
131-11-3
57-97-6
105-67-9
99-65-0
121-14-2
123-91-1
NOCAS2
122-39-4
106-89-8
64-17-5
141-43-5
140-88-5
75-00-3
645-62-5
141-78-6
Molecular
Weight
149.23
222.00
73.09
60.10
194.20
256.33
122.16
168.10
182.10
88.20
322.00
169.20
92.50
46.10
61.09
100.00
64.52
92.50
88.10
Vapor Pressure
At25°C
(mm Hg)
0.00283
0.003589
4
157
0.000187
0
0.0573
0.05
0.0051
37
0
0.00375
17
50
0.4
40
1200
17
100
Henry's Law
Constant At 25eC
(atm-m'/mol)
0.0000000574
0.0111
0.0000192
0.000124
0.00000215
0.00000000027
0.000921
0.000022
0.00000407
0.0000231
0.0000812
0.00000278
0.0000323
0.0000303
0.000000322
0.00035
0.014
0.0000323
0.000128
Diffusivity Of
Chemical In
Water
At25eC
(cmVs)
0.00000587
0.0000058
0.0000103
0.0000109
0.0000063
0.00000498
0.0000084
0.00000764
0.00000706
0.0000102
0.0000056
0.00000631
0.0000098
0.000013
0.0000114
0.0000086
0.0000115
0.0000098
0.00000966
Diffusivity Of
Chemical In
Air At 25'C
(cmj/s)
0.0513
0.0542
0.0939
0.106
0.0568
0.0461
0.0712
0.279
0.203
0.229
0.104
0.058
0.086
0.123
0.107
0.077
0.271
0.086
0.0732
^
-*
CO
i
s
01
ta
-------
w
^
00
TABLE 5.B-4 (PART 1)
(CONTINUED)
Chemical Name
ETHYLBENZENE
ETHYLENEOXIDE
ETHYLETHER
FORMALDEHYDE
FORMIC ACID
FREONS
FURAN
FURFURAL
HEPTANE (ISO)
HEXACHLOROBENZENE
HEXACHLOROBUTADIENE
HEXACHLOROCYCLOPENTADIENE
HEXACHLOROETHANE
HEXANE(-N)
HEXANOL(-1)
HYDROCYANIC ACID
HYDROFLUORIC ACID
HYDROGEN SULFIDE
ISOPHORONE
CAS Number
10041-4
75-21-8
60-29-7
50-00-0
64-18-6
NOCAS3
110-00-9
96-01-1
142-82-5
118-74-1
87-68-3
77-47-4
67-72-1
100-54-3
111-27-3
74-90-8
7664-39-3
7783-06-4
78-59-1
Molecular
Weight
106.20
44.00
74.10
30.00
46.00
120.92
68.08
96.09
100.21
284.80
260.80
272.80
237.00
86.20
102.18
27.00
20.00
34.10
138.21
Vapor Pressure
At25°C
(mm Hg)
10
1250
520
3500
42
5000
596
2
66
1
0.15
0.081
0.65
150
0.812
726
900
15200
0.439
Henry's Law
Constant At 25CC
(atnvm'/mol)
0.00644
0.000142
0.00068
0.0000576
0.0000007
0.401
0.00534
0.0000811
1.836
0.00068
0.0256
0.016
0.00000249
0.122
0.0000182
0.000000465
0.000237
0.023
0.00000576
Diffusivity Of
Chemical In
Water
At25cC
(cmVs)
0.0000078
0.0000145
0.0000093
0.0000198
0.00000137
0.00001
0.0000122
0.0000104
0.00000711
0.00000591
0.0000062
0.00000616
0.0000068
0.00000777
0.00000753
0.0000182
0.000033
0.0000161
0.00000676
Difiusivity Of
Chemical In
Air At25°C
(cmVs)
0.075
0.104
0.074
0.178
0.079
0.104
0.104
0.0872
0.187
0.0542
0.0561
0.0561
0.00249
0.2
0.059
0.197
0.388
0.176
0.0623
i
•*>
a
-------
TABLE 5.B-4 (PART II
Chemical Name
METHANOL
METHYL ACETATE
METHYL CHLORIDE
METHYL ETHYL KETONE
METHYL ISOBUTYL KETONE
METHYL METHACRYLATE
METHYL STYRENE (ALPHA)
METHYLENE CHLORIDE
MORPHOLINE
NAPHTHALENE
NITROANILINE(-O)
NITROBENZENE
PENTACHLOROBENZENE
PENTACHLOROETHANE
PENTACHLOROPHENOL
PHENOL
PHOSGENE
PHTHALIC ACID
PHTHALIC ANHYDRIDE
CAS Number
67-56-1
79-20-9
74-87-3
78-93-3
108-10-1
80-62-6
98-83-9
75-09-2
110-91-8
91-20-3
88-744
98-95-3
608-93-5
76-01-7
87-86-5
108-95-2
75-44-5
100-21-0
85-44-9
Molecular
Weight
32.00
74.10
50.50
72.10
100.20
100.10
118.00
85.00
87.12
128.20
138.14
123.10
250.34
202.30
266.40
94.10
98.92
166.14
148.10
Vapor Pressure
At25eC
(mm Hg)
114
235
3830
100
15.7
39
0.076
438
10
0.23
0.003
0.3
0.0046
4.4
0.00099
0.34
1390
121
0.0015
Henry's Law
Constant At 25°C
(atnvmVmol)
0.0000027
0.000102
0.00814
0.0000435
0.0000495
0.000066
0.00591
0.00319
0.0000573
0.00118
0.0000005
0.0000131
0.0073
0.021
0.0000028
0.000000454
0.171
0.0132
0.0000009
Difiusivity Of
Chemical In
Water
At25°C
(cmVs)
0.0000164
0.00001
0.0000065
0.0000098
0.0000078
0.0000086
0.0000114
0.0000117
0.0000096
0.0000075
0.000008
0.0000086
0.0000063
0.0000073
0.0000061
0.0000091
0.00000112
0.0000068
0.0000086
Diffusivity Of
Chemical In
Air At 25eC
(cmVs)
0.15
0.104
0.126
0.0808
0.075
0.077
0.264
0.101
0.091
0.059
0.073
0.076
0.057
0.066
0.056
0.082
0.108
0.064
0.071
i
"0
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-------
ba
u>
o
TABLE 5.B-4 (PART 1)
(CONTINUED)
Chemical Name
PICOLINE(-2)
POLYCHLORINATED BIPHENYLS
PROPANOL GSO)
PROPIONALDEHYDE
PROPYLENE GLYCOL
PROPYLENE OXIDE
PYRIDINE
RESORCINOL
STYRENE
TETRACHLOROETH ANE( 1 , 1 , 1 ,2)
TETRACHLOROETHANE(1, 1,2,2)
TETRACHLOROETH YLENE
TETRAHYDROFURAN
TOLUENE
TOLUENE DIISOCYANATE(2,4)
TRICHLORO(1,1,2)TRIFLUOROETHANE
TRICHLOROBENZENE(1 ,2,4)
TRICHLOROBUTANEO ,2,3)
TRICHLOROETHANE(1 , 1 ,1)
CAS Number
108-99-6
1336-36-3
71-23-8
123-38-6
57-55-6
75-66-9
110-86-1
108-46-3
100-42-5
630-20-6
79-34-5
127-18-4
109-99-9
109-88-3
584-84-9
76-13-1
120-82-1
NOCAS5
71-55-6
Molecular
Weight
93.12
290.00
60.09
58.08
76.11
58.10
79.10
110.11
104.20
167.85
167.85
165.83
72.12
92.40
174.16
187.38
181.50
161.46
133.40
Vapor Pressure
At25°C
(mm Hg)
10.4
0.00185
42.8
300
0.3
525
20
0.00026
7.3
6.5
6.5
19
72.1
30
0.08
300
0.18
4.39
123
Henry's Law
Constant At 25°C
(atm-m'/mol)
0.000127
0.0004
0.00015
0.00115
0.0000015
0.00134
0.0000236
0.0000000188
0.00261
0.002
0.00038
0.029
0.000049
0.00668
0.0000083
0.435
0.00142
4.66
0.00492
Diffusivity Of
Chemical In
Water
At25cC
(cm2/s)
0.0000096
0.00001
0.0000104
0.0000114
0.0000102
0.00001
0.0000076
0.0000087
0.000008
0.0000079
0.0000079
0.0000082
0.0000105
0.0000086
0.0000062
0.0000082
0.0000077
0.0000072
0.0000088
Diffusivity Of
Chemical In
AirAt25eC
(cmVs)
0.075
0.104
0.098
0.102
0.093
0.104
0.091
0.078
0.071
0.071
0.071
0.072
0.098
0.087
0.061
0.078
0.0676
0.066
0.078
i
-------
53
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f
-------
Cd
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TABLE 5.B-4
SIMS CHEMICAL PROPERTY DATA FILE (PART 2)
Chemical Name
ACETALDEHYDE
ACETIC ACID
ACETIC ANHYDRIDE
ACETONE
ACETONITRILE
ACROLEIN
ACRYLAMIDE
ACRYLIC ACID
ACRYLONITRILE
ADIPIC ACID
ALLYL ALCOHOL
AMINOPHENOL(-O)
AMINOPHENOL(-P)
AMMONIA
AMYL ACETATE(-N)
ANILINE
BENZENE
BENZO(A)ANTHRACENE
Antoine's
Equation Vapor
Pressure
Coefficient
A
8.005
7.387
7.149
7.117
7.119
2.39
11.2932
5.652
7.038
0
0
0
-3.357
7.5547
0
7.32
6.905
6.9824
Antoine's
Equation Vapor
Pressure
Coefficient
B
1600.017
1533.313
1444.718
1210.595
1314.4
0
3939.877
648.629
1232.53
0
0
0
699.157
1002.711
0
1731.515
1211.033
2426.6
Antoine's
Equation
Vapor Pressure
Coefficient
C
291.809
222.309
199.817
229.664
230
0
273.16
154.683
222.47
0
0
0
-331.343
247.885
0
206.049
220.79
156.6
Maximum
Biodegradation
Rate Constant
(g/g Biomass-s)
0.0000228944
0.0000038889
0.0000026944
0.0000003611
0.00000425
0.0000021667
0.00000425
0.0000026944
0.000005
0.0000026944
0.0000048872
0.00000425
0.00000425
0.00000425
0.0000026944
0.0000019722
0.0000052778
0.0000086389
Half Saturation
Constant
(g/m3)
419.0542
14.2857
1.9323
1.1304
152.6014
22.9412
56.2388
54.7819
24
66.9943
3.9241
68.1356
68.1356
15.3
16.1142
0.3381
13.5714
1.7006
Octanol-Water
Partition
Coefficient
At25°C
2.69153
0.48978
1
0.57544
0.45709
0.81283
6.32182
2.04174
0.12023
1.20226
1.47911
3.81533
3.81533
1
51.10801
7.94328
141.25375
407380.2778
i
"0
si
O)
<0
NJ
-------
Chemical Name
BENZO(A)PYRENE
BENZYL CHLORIDE
BIS(2-CHLOROETHYL)ETHER
BIS(2-CHLOROISOPROPYL)ETHER
BIS(2-ETHYLHEXYL)PHTHALATE
BROMOFORM
BROMOMETHANE
BUTADIENE-(1,3)
BUTANOL (ISO)
BUTANOL-0)
BUTYL BENZYL PHTHALATE
CARBON DISULFIDE
CARBON TETRACHLORIDE
CHLORO(-P)CRESOL(-M)
CHLOROACETALDEHYDE
CHLOROBENZENE
CHLOROFORM
CHLORONAPHTHALENE-(2)
Antoine's
Equation Vapor
Pressure
Coefficient
A
9.2455
0
0
0
0
0
0
6.849
7.4743
7.4768
0
6.942
6.934
0
0
6.978
6.493
0
Antoine's
Equation
Vapor Pressure
Coefficient
B
3724.363
0
0
0
0
0
0
930.546
1314.19
1362.39
0
1169.11
1242.43
0
0
1431.05
929.44
0
Antoine's
Equation
Vapor Pressure
Coefficient
C
273.16
0
0
0
0
0
0
238.854
186.55
178.77
0
241.59
230
0
0
217.55
196.03
0
Maximum
Biodegradation
Rate Constant
(g/g Biomass-s)
0.0000086389
0.0000049306
0.0000029889
0.0000029889
0.0000002139
0.0000029889
0.0000029889
0.0000042534
0.0000021667
0.0000021667
0.0000086389
0.0000042534
0.0000004167
0.0000029889
0.0000029889
0.0000001083
0.0000008167
0.0000029889
Half Saturation
Constant
S (g/m3)
1.2303
17.5674
20.0021
8.3382
2.2
10.653
30.4422
15.3
70.9091
70.9091
14.1364
5.8175
1
5.2902
49.838
.039
3.7215
2.167
Octanol-Water
Partition
Coefficient
At25eC
954992.58602
199.52623
38.01894
380.1894
199526.2315
199.52623
12.58925
74.32347
5.62341
5.62341
60255.'95861
1
524.80746
1258.92541
3.4405
316.22777
91.20108
13182.56739
to
NJ
Oi
I/I
fad
-------
b
£5
TABLE 5.B-4 (PART 2)
(CONTINUED)
Chemical Name
CHLOROPRENE
CRESOL(-M)
CRESOL(-O)
CRESOL(-P)
CRESYLIC ACID
CROTONALDEHYDE
CUMENE (ISOPROPYLBENZENE)
CYCLOHEXANE
CYCLOHEXANOL
CYCLOHEXANONE
DI-N-OCTYL PHTHALATE
DIBUTYLPHTHALATE
DICHLORO(-2)BUTENE(1 ,4)
DICHLOROBENZENE(1,2) (-O)
DICHLOROBENZENE(1,3) (-M)
DICHLOROBENZENE(1,4) (-P)
DICHLORODIFLUOROMETHANE
DICHLOROETHANE(U)
DICHLOROETHANE(1 ,2)
Antoine's
Equation Vapor
Pressure
Coefficient
A
6.161
7.508
6.911
7.035
0
0
6.963
6.841
6.255
7.8492
0
6.639
0
0.176
0
0.079
0
0
7.025
Antoine's
Equation
Vapor Pressure
Coefficient
B
783.45
1856.36
1435.5
1511.08
0
0
1460.793
1201.53
912.87
2137.192
0
1744.2
0
0
0
0
0
0
1272.3
Antoine's
Equation Vapor
Pressure
Coefficient
C
179.7
199.07
165.16
161.85
0
0
207.78
222.65
109.13
273.16
0
113.59
0
0
0
0
0
0
222.9
Maximum
Biodegradation
Rate Constant
(g/g Biomass-s)
0.0000029968
0.0000064472
0.0000063278
0.0000064472
0.0000041667
0.0000026944
0.0000086458
0.0000042534
0.0000026944
0.0000031917
0.000000083
0.0000001111
0.0000029889
0.0000006944
0.0000017778
0.0000017778
0.0000029889
0.0000029889
0.0000005833
Half
Saturation
Constant
(g/mj)
6.3412
1.3653
1.34
1.3653
15
27.6285
16.5426
15.3
18.0816
41.8921
0.02
0.4
9.8973
4.3103
2.7826
2.7826
12.0413
4.6783
2.1429
Octanol-Water
Partition
Coefficient
At25eC
1
93.32543
95.49926
87.09636
1
12.36833
1
338.0687
37.74314
6.45654
141253.7
158489.31925
242.1542
2398.83292
2398.83292
2454.70892
144.54398
61.6595
61.6595
i
t>
si
Ol
-------
ONTINUED)
Chemical Name
DICHLOROETHYLENE(1 ,2)
DICHLOROPHENOL(2,4)
DICHLOROPHENOXYACETIC ACID(2,4)
DICHLOROPROPANE(1 ,2)
DIETHYL (N,N) ANILINE
DIETHYL PHTHALATE
DIMETHYL FORMAMIDE
DIMETHYL HYDRAZINE(l.l)
DIMETHYL PHTHALATE
DIMETHYLBENZ(A)ANTHRACENE
DIMETHYLPHENOL(2,4)
DINITROBENZENE (-M)
DINITROTOLUENE(2,4)
DIOXANE(1,4)
DIOXIN
DIPHENYLAMINE
EPICHLOROHYDRIN
ETHANOL
ETHANOLAMINE(MONO-)
Antoine's
Equation Vapor
Pressure
Coefficient
A
6.965
0
0
6.98
7.466
0
6.928
7.408
4.522
0
0
4.337
5.798
7.431
12.88
0
8.2294
8.321
7.456
Antoine's
Equation
Vapor Pressure
Coefficient
B
1141.9
0
0
1380.1
1993.57
0
1400.87
1305.91
700.31
0
0
229.2
1118
1554.68
6465.5
0
2086.816
1718.21
1577.67
Antoine's
Equation
Vapor Pressure
Coefficient
C
231.9
0
0
22.8
218.5
0
196.43
225.53
51.42
0
0
-137
61.8
240.34
273
0
273.16
237.52
173.37
Maximum
Biodegradation
Rate Constant
(g/g Biomass-s)
0.0000029889
0.0000069444
0.0000029889
0.0000047222
0.00000425
0.000000753
0.00000425
0.00000425
0.0000006111
0.0000086389
0.0000029722
0.00000425
0.00000425
0.0000026944
0.0000029968
0.0000052778
0.0000029968
0.0000024444
0.00000425
Half
Saturation
Constant
(g/m*)
6.3294
7.5758
14.8934
12.1429
27.0047
1.28
15.3
15.3
0.7097
0.3377
2.2766
29.9146
19.5233
24.7001
6.3412
8.4103
6.3412
9.7778
223.0321
Octanol-Watcr
Partition
Coefficient
At25eC
1
562.34133
82.61445
1
43.57596
1412.537
1
1
74.13102
28680056.33087
263.0268
33.28818
102.3293
16.60956
1
1659.58691
1.07152
0.47863
0.16865
§
CO
i
1
en
-------
is
TABLE 5.B-4 (PART 2)
(CONTINUED)
Chemical Name
ETHYL ACRYLATE
ETHYL CHLORIDE
ETHYL-{2)PROPYL-<3) ACROLEIN
ETHYLACETATE
ETHYLBENZENE
ETHYLENEOXIDE
ETHYLETHER
FORMALDEHYDE
FORMIC ACID
FREONS
FURAN
FURFURAL
HEPTANE (ISO)
HEXACHLOROBENZENE
HEXACHLOROBUTADIENE
HEXACHLOROCYCLOPENTADIENE
HEXACHLOROETHANE
HEXANE(-N)
HEXANOLH)
Antoine's
Equation Vapor
Pressure
Coefficient
A
7.9645
6.986
0
7.101
6.975
7.128
6.92
7.195
7.581
0
6.975
6.575
6.8994
0
- 0.824
0
0
6.876
7.86
Antoine's
Equation
Vapor Pressure
Coefficient
B
1897.011
1030.01
0
1244.95
1424.255
1054.54
1064.07
970.6
1699.2
0
1060.87
1198.7
1331.53
0
0
0
0
1171.17
1761.26
Antoine's
Equation
Vapor Pressure
Coefficient
C
273.16
238.61
0
217.88
213.21
237.76
228.8
244.1
260.7
0
227.74
162.8
212.41
0
0
0
0
224.41
196.66
Maximum
Biodegradation
Rate Constant
(g/g Biomass-s)
0.0000026944
0.0000029889
0.000004425
0.0000048833
0.0000018889
0.0000011667
0.0000026944
0.0000013889
0.0000026944
0.0000029968
0.0000026944
0.0000026944
0.0000042534
0.0000029889
0.000003
0.0000029968
0.0000029889
0.0000042534
0.0000026944
Half
Saturation
Constant
(g/ms)
39.4119
22.8074
15.3
17.58
3.2381
4.6154
17.1206
20
6.3412
6.3412
14.1936
18.0602
15.3
0.6651
6.3412
0.3412
3.3876
15.3
15.2068
Octanol-Water
Partition
Coefficient
At25eC
4.85667
26.91535
1
1
1412.53754
0.50003
43.57596
87.09636
0.1191
1
71.37186
37.86047
1453.372
295120.92267
5495.408
9772.372
4068.32838
534.0845
59.52851
Ol
to
NJ
-------
Chemical Name
HYDROCYANIC ACID
HYDROFLUORIC ACID
HYDROGEN SULFIDE
ISOPHORONE
METHANOL
METHYL ACETATE
METHYL CHLORIDE
METHYL ETHYL KETONE
METHYL ISOBUTYL KETONE
METHYL METHACRYLATE
METHYL STYRENE (ALPHA)
METHYLENE CHLORIDE
MORPHOLINE
NAPHTHALENE
NITROANILINE(-O)
NITROBENZENE
PENTACHLOROBENZENE
PENTACHLOROETHANE
PENTACHLOROPHENOL
Antoine's
Equation Vapor
Pressure
Coefficient
A
7.528
7.217
7.614
0
7.897
7.065
7.093
6.9742
6.672
8.409
6.923
7.409
7.7181
7.01
8.868
7.115
0
6.74
0
Antoine's
Equation
Vapor Pressure
Coefficient
B
1329.5
1268.37
885.319
0
1474.08
1157.63
948.58
1209.6
1168.4
2050.5
1486.88
1325.9
1745.8
1733.71
336.5
1746.6
0
1378
0
Antoine's
Equation
Vapor Pressure
Coefficient
C
260.4
273.87
250.25
0
229.13
219.73
249.34
216
191.9
274.4
202.4
252.6
235
201.86
273.16
201.8
0
197
0
Maximum
Biodegradation
Rate Constant
(g/g Biomass-s)
0.0000026944
0.0000026944
0.0000029889
0.00000425
0.000005
0.0000055194
0.0000029889
0.0000005556
0.0000002056
0.0000026944
0.0000008639
0.0000061111
0.00000425
0.0000117972
0.00000425
0.0000030556
0.0000029889
0.0000029889
0.0000361111
Half
Saturation
Constant
(g/mj)
1.9323
1.9323
6.3294
25.6087
90
159.2466
14.855
10
1.6383
109.2342
11.12438
54.5762
291.9847
42.47
22.8535
4.7826
0.4307
0.4307
38.2353
Octanol-Water
Partition
Coefficient
At25°C
1
1
I
50.11872
0.19953
0.81285
83.17638
1.90546
23.98833
0.33221
2907.589
17.78279
0.08318
1
67.6083
69.1831
925887.02902
925887.02902
102329.29923
-------
ca
U)
oo
TABLE 5.B-4 (PART 2)
(CONTINUED)
Chemical Name
PHENOL
PHOSGENE
PHTHALIC ACID
PHTHALIC ANHYDRIDE
PICOLINE(-2)
POLYCYLORINATED BIPHENYLS
PROPANOL (ISO)
PROPIONALDEHYDE
PROPYLENE GLYCOL
PROPYLENE OXIDE
PYRIDINE
RESORCINOL
STYRENE
TETRACHLOROETHANE(1,1,2)
TETRACHLOROETHANE(1,1,2,2)
TETRACHLOROETHYLENE
TETRAHYDROFURAN
TOLUENE
TOLUENE DIISOCYANATE(2,4)
Antoine's
Equation Vapor
Pressure
Coefficient
A
7.133
6.842
0
8.022
7.032
0
8.117
16.2315
8.2082
8.2768
7.041
6.9243
7.14
6.898
6.631
6.98
6.995
6.954
0
Antoine's
Equation
Vapor Pressure
Coefficient
B
1516.79
941.25
0
2868.5
1415.73
0
1580.92
2659.02
2085.9
1656.884
1374.8
1884.547
1574.51
1365.88
1228.1
1386.92
1202.29
1344.8
0
Antoine's
Equation
Vapor Pressure
Coefficient
C
174.95
230
0
273.16
211.63
0
219.61
-44.15
203.5396
273.16
214.98
186.0596
224.09
209.74
179.9
217.53
226.25
219.48
0
Maximum
Biodegradation
Rate Constant
(g/g Biomass-s)
0.0000269444
0.00000425
0.0000026944
0.0000048872
0.00000425
0.000005278
0.0000041667
0.0000026944
0.0000026944
0.0000048872
0.0000097306
0.0000026944
0.0000086389
0.0000029889
0.0000017222
0.0000017222
0.0000026944
0.0000204111
0.0000425
Half
Saturation
Constant
(g/mj)
7.4615
70.8664
34.983
3.9241
44.8286
20
200
39.2284
109.3574
3.9241
146.9139
35.6809
282.7273
6.3294
9.1176
9.1176
20.3702
30.6167
15.3
Octanol-Water
Partition
Coefficient
At25°C
28.84032
3.4405
6.64623
0.23988
11.48154
1
0.69183
4.91668
0.33141
1
4.4684
6.30957
1445.43977
1
363.07805
398.10717
27.58221
489.77882
1
i
t>
01
-------
23
TINUED
Chemical Name
TRICHLORO(1 , 1 ,2)TRIFLUOROETH ANE
TRICHLOROBENZENE(1 ,2,4)
TRICHLOROBUTANE(1 ,2,3)
TRICHLOROETHANE(1,1,1)
TRICHLOROETHANE(1,1,2)
TRICHLOROETHYLENE
TRICHLOROFLUOROMETHANE
TRICHLOROPHENOL(2,4,6)
TRICHLOROPROPANE(1, 1 ,1)
TRICHLOROPROPANE(1 ,2,3)
UREA
VINYL ACETATE
VINYL CHLORIDE
VINYLIDENE CHLORIDE
XYLENE(-M)
XYLENE(-O)
Antoine's
Equation Vapor
Pressure
Coefficient
A
6.88
0
0
8.643
6.951
6.518
6.884
0
0
6.903
0
7.21
3.425
6.972
7.009
6.998
Antoine's
Equation
Vapor Pressure
Coefficient
B
1099.9
0
0
2136.6
1314.41
1018.6
1043.004
0
0
788.2
0
1296.13
0
1099.4
1426.266
1474.679
Antoine's
Equation
Vapor Pressure
Coefficient
C
227.5
0
0
302.8
209.2
192.7
236.88
0
0
243.23
0
226.66
0
237.2
215.11
213.69
Maximum
Biodegradation
Rate Constant
(g/g Biomass-s)
0.0000029889
0.0000029889
0.0000029968
0.0000009722
0.0000009722
0.0000010833
0.000003
0.0000425
0.0000029889
0.0000029889
0.00000425
0.0000026944
0.000003
0.0000029968
0.0000086389
0.0000113306
Half
Saturation
Constant
(g/ms)
3.3876
2.4495
6.3412
4.7297
4.7297
4.4318
6.3412
58.8462
10.7719
10.7719
4.8169
31.8363
6.3412
6.3412
14.0094
22.8569
Octanol-Water
Partition
Coefficient
At25°C
4068.32838
9549.92586
1450901.06626
309.02954
1
194.98446
338.8441
4897.78819
193.7827
193.7827
4068.32838
8.51722
1.14815
1
1584.89319
891.25094
i
t>
a
Oi
L/i
w
-------
CHAPTER 5 • WWCT 3/12/97
REFERENCES
/. Hazardous Waste Treatment, Storage, and Disposal Facilities (TSDF)-Air Emission
Models, EPA-450/3-87-026, U.S. Environmental Protection Agency, Research
Triangle Park, NC, April 1989.
2. Wastewater Treatment Compound Property Processor Air Emissions Estimator
(WATER 7), U.S. Environmental Protection Agency, Research Triangle Park, NC,
available early 1992.
3. Evaluation of Test Method for Measuring Biodegradation Rates of Volatile Organics,
Draft, EPA Contract No. 68-D90055, Entropy Environmental, Research Triangle
Park, NC, September 1989.
4. Industrial Wastewater Volatile Organic Compound Emissions-Background
Information for BACT/LAER Determinations, EPA-450/3-90-004, U.S.
Environmental Protection Agency, Research Triangle Park, NC, January 1990.
5. Evan K. Nyer, Ground Water Treatment Technology, Van Nostrand Reinhold
Company, New York, 1985.
5.B-40 EIIP Volume II
-------
3/12/97 CHAPTER 5 - WWCT
APPENDIX C
BIBLIOGRAPHY OF SELECTED
AVAILABLE LITERATURE ON
EMISSIONS MODELS
EIIP Volume II
-------
CHAPTER 5 - WWCT 3/12/97
This page is intentionally left blank.
EIIP Volume W
-------
12/97 CHAPTER 5 - WWCT
, T.R. 1995. Comparison of Mass Transfer Models with Direct Measurement for Free
Liquid Surfaces at Wastewater Treatment Facilities. Presented at the 88th Annual AWMA
Meeting, San Antonio, Texas. June 18-23.
Card, T.R., and P. Benson. 1992. Modeling the Air Emissions from an Industrial
iWastewater Treatment Facility. Presented at the 1992 AWMA Convention, Kansas City,
•vlissouri. June 21-26.
•Corsi, R.L. 1989. Volatile Organic Compound Emissions from Wastewater Collection
my stems. Dissertation. University of California, Davis.
•Corsi, R.L., and C.J. Quigley. 1995. "VOC emissions from sewer junction boxes and
Hrop structures: Estimation of methods and experimental results." In: Proceedings of the
88th Annual Meeting of the Air & Waste Management Association. Air & Waste
•Management Association, Pittsburgh, Pennsylvania.
Ferro, A. and A.B. Pincince. 1996. Comparison of Computer Programs for Estimating
^missions of Volatile Organic Compounds from Wastewater Treatment Facilities.
Proceedings of the Water Environment Federation 69th Annual Conference and
Exposition, Dallas, Texas, October 5-9.
I
ones, D.L., J.W. Jones, J.C. Seaman, R.L. Corsi, and C.F. Burklin. 1996. Models to
Estimate Volatile Organic Hazardous Air Pollutant Emissions from Municipal Sewer
•Systems. Journal of the Air & Waste Management Association 46:657.
Pincince, A.B. and A. Ferro. 1996. Estimating VOC Emissions from Primary Clarifiers.
WVater Environment & Technology 8(6):47.
^chroy, J.S. 1994. Estimation of Emissions from Wastewater Treatment Systems: A
^Comparison of Available Software Performance. Paper and Session ID, presented at the
AIChE 1994 Summer National Meeting, "VOC and Air Toxics Emissions - Estimating
id Control," August 15, 1994.
JUli
Ta
ata, P., S. Solszynski, D.P. Lordi, D.R. Zenz, C. Lue-Hign. 1994. Volatile Organic
'ompound Emissions from the Water Reclamation Plants of the Metropolitan Water
'.eclamation District of Greater Chicago. Presented at the Odor and Volatile Organic
mpound Emission Control for Municipal and Industrial Treatment Facilities
Conference, Jacksonville, Florida. April.
EUP Volume II 5.C-1
-------
CHAPTER 5 - WWCT 3/12/97
Tata, P., S. Solszynski, D.P. Lordi, D.R. Zenz, C. Lue-Hign. 1995. Prediction of Volatile
Organic Compound Emissions from Publicly Owned Treatment Works. Presented at the
68th Annual WEFTEC Meeting, Miami Beach, Florida. October.
Thompson, D., J. Bell, L. Sterne, and P. Jann. 1996. Comparing Organic Contaminant
Emission Estimates Using WATERS" and 'TOXCHEM+". Proceedings of the Water
Environment Federation 69th Annual Conference and Exposition, Dallas, Texas,
October 5-9.
5.C-2 EIIP Volume II
•&U.S. GOVERNMENT PRINTING OFFICE: 19»7 -52941M
-------
TECHNICAL REPORT DATA
(PLEASE READ INSTRUCTIONS ON THE REVERSE BEFORE COMPLETING)
REPORT NO.
>A-454/R-97-004b
3. RECIPIENT'S ACCESSION NO.
TLE AND SUBTITLE
Emission Inventory Improvement Program
Bint Sources
sferred And Alternative Methods
5. REPORT DATE
7/25/97
6. PERFORMING ORGANIZATION CODE
AUTHOR(S)
Iission Inventory Improvement Program
nt Source Committee
8. PERFORMING ORGANIZATION REPORT NO.
, PERFORMING ORGANIZATION NAME AND ADDRESS
Environmental Protection Agency
ce Of Air Quality Planning And Standards (MD-14)
Research Triangle Park, NC 27711
10. PROGRAM ELEMENT NO.
.(POP*
11. CONTRACT/GRANT NO.
68-D2-0160
2. SPONSORING AGENCY NAME AND ADDRESS
Office Of Air Quality Planning And Standards, Office Of Air And Radiation,
^S. Environmental Protection Agency
•search Triangle Park, NC 27111
13. TYPE OF REPORT AND PERIOD COVERED
Technical
14. SPONSORING AGENCY CODE
EPA/200/04
5. SUPPLEMENTARY NOTES
TRACT
ie Emission Inventory Improvement Program (EIIP) was established in 1993 to promote the
jvelopment and use of standard procedures for collecting, calculating, storing, reporting, and
[aring air emissions data. The EIIP is designed to promote the development of emission
rentories that have targeted quality objectives, are cost-effective, and contain reliable and
¥:essible data for end users. To this end, the EIIP is developing inventory guidance and
terials which will be available to states and local agencies, the regulated community, the public
and the EPA.
\Jilume II presents preferred and alternatives methods for estimating emissions from point
sources.
4 KEY WORDS AND DOCUMENT ANALYSIS
CRIPTORS
Air Emisisons
» Pollution
ission Inventory
jntory Guidance
TRIBUTION STATEMENT
b. IDENTIFIERS/OPEN ENDED TERMS
Air Pollution Control,
Emission, Inventory
Guidance
c. COSATI FIELD/GROUP
21. NO. OF PAGES
565
22. PRICE
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