EPA/450/1-89/002
                 id States       Office of Air Quality         EPA-450/1-89-002
                Environmental Protection   Planning and Standards       January 1989
                Agency          Research Triangle Park NC 27711
                Air/Superfund
  OEPA       AIR / SUPERFUND
                NATIONAL TECHNICAL
                GUIDANCE STUDY SERIES
                Volume II - Estimation
                of Baseline Air
                Emissions at
                Superfund Sites

                Interim Final

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                   VOLUME II

     ESTIMATION OF BASELINE AIR EMISSIONS
              AT SUPERFUND SITES

                 INTERIM FITAL
                      by

              Radian Corporation
          10395 Old Placerville Road
         Sacramento, Califom'a  95827
                 Prepared for:

            Ms. Margaret McDonough
     U.S. ENVIRONMENTAL PROTECTION AGENCY
 OFFICE OF AIR QUALITY PLANNING AND STANDARDS
RESEARCH TRIANGLE PARK, NORTH CAROLINA  27711
                 January 1989

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                                   PREFACE


     This is one in a series of manuals dealing with air pathway analysis at
hazardous waste sites.  This document was developed for the Office of Air
Quality Planning and Standards in cooperation with the Office of Emergency
and Remedial Response (Superfund).  It has been reviewed by the National
Technical Guidance Study Technical Advisory Committee and an expanded review
group consisting of State agencies, various groups within the U.S. Environ-
mental Protection Agency, and the private sector.  This document is an
interim final manual offering technical guidance for use by a diverse
audience including EPA Air and Superfund Regional and Headquarters staff,
State Air and Superfund program staff, Federal and State remedial and removal
contractors, and potentially responsible parties in analyzing air pathways at
hazardous waste sites.  This manual is written to serve the needs of in-
dividuals having different levels of scientific training and experience in
designing, conducting, and reviewing air pathway analyses.  Because assump-
tions and judgments are required in many parts of the analysis, the in-
dividuals conducting air pathway analyses need a strong technical background
in air emission measurements, modeling, and monitoring.  Remedial Project
Managers, On Scene Coordinators, and the Regional Air program staff,
supported by the technical expertise of their contractors, will use this
guide when establishing data quality objectives and the appropriate
scientific approach to air pathway analysis.  This manual provides for flexi-
bility in tailoring the air pathway analysis to the specific conditions of
each site, the relative risk posed by this and other pathways, and the pro-
gram resource constraints.

     Air pathway analyses cannot be reduced to simple "cookbook" procedures.
Therefore, the manual is designed to be flexible, allowing use of profes-
sional judgment.  The procedures set out in this manual are intended solely
for technical guidance.  These procedures are not intended, nor can they be
relied upon, to create rights substantive or procedural, enforceable by any
party in litigation with the United States.

     It is envisioned that this manual will be periodically updated to incor-
porate new data and information on air pathway analysis procedures.  The
Agency reserves the right to act at variance with these procedures and to
change them as new information and technical tools become available on air
pathway analyses without formal public notice.  The Agency will, however,
attempt to make any revised or updated manual available to those who
currently have a copy through the registration form included with the manual.

     Copies of this report are available, as supplies permit, through the
Library Services Office (MD-35), U.S.  Environmental Protection Agency,
Research Triangle Park, North Carolina 27711 or from the National Technical
Information Services, 5285 Port Royal  Road, Springfield, Virginia 22161.

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                                                                                  i
                                  DISCLAIMER

     Mention of trade names or commercial  products does not constitute
endorsement or recommendation for use by the Air Management Division, U.S.
Environmental Protection Agency.
                                                                                  i
                                      11

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                                 CONTENTS

                                                                       Page

Disclaimer	    11
Tables	    v1
F1 gures	  vi 11
Glossary of Frequently Used Terms and Acronyms	    x
Ac know! edgements	  xi i i


1.0  Introducti on	    1
     1.1  The Problem	    1
     1.2  The Objective	    3
     1.3  Manual Organization	    3

2.0  Air Emissions From Hazardous Waste Sites	    5
     2.1  General Description	    5
          2.1.1  Landfills	    5
          2.1.2  Lagoons	    10
          2.1.3  Equivalent Units	    11
     2.2  Routes of Exposure	    12
          2.2.1  Key Parameters and Critical Factors Affecting
                   Emissions from Contaminated Soils (Landfills
                   and Lagoons)	    15
          2.2.2  Key Parameters Affecting Emissions
                   from Lagoons	    15
     2.3  Magnitude of Air Emissions	    17
     2.4  Emissions of Potential Interest at NPL Sites	    17
     2.5  Summary of Potential Receptors	    21

3.0  Protocol for Baseline Emission Estimates	    23
     3.1  Protocol Steps for Developing BEEs	    23
          3.1.1  Define the APA Objective	    25
          3.1.2  Site Scoping	    30
          3.1.3  Evaluate Available Site Data	    31
          3.1.4  Design and Conduct the Site Screening Study	    31
          3.1.5  Design and Conduct the In-Depth Site Characterization   47
     3.2  Use of the BEEs in the Mitigation Process	    55

4.0. Air Emission Measurement Techniques	    58
     4.1  Direct Emission Measurement Technologies	    58
          4.1.1  Head Space Samplers (Screening Technology)	    60
          4.1.2  Head Space Analysis of Bottled Samples (Screening
                 Techno! ogy)	    63
          4.1.3  Emission Isolation Flux Chamber (In-Depth Technology    66
          4.1.4  Portable Wind Tunnels (In-Depth Technology)	    70
          4.1.5  Soil  Vapor (Ground) Probes (In-Depth Technology)....    75
          4.1.6  Soil  Vapor Monitoring Wells (In-Depth Technology)...    78
          4.1.7  Downhole Emissions Flux Chamber (In-Depth
                 Technol ogy)	    81
          4.1.8  Vent Sampling (In-Depth Technology)	    85
                                      ill

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                           Contents (Continued)
                                                                      Page

     4.2  Indirect Emission Measurement Technologies	   86
          4.2.1  Upwind/Downwind (Screening Technology)	   87
          4.2.2  Mass Balance (Screening Technology)	   89
          4.2.3  Real-Time Instrument Survey (Screening Technology)..   90
          4.2.4  Concentration-Profile (In-Depth Technology)	   92
          4.2.5  Transect (In-Depth Technology)	   95
          4.2.6  Exposure Profile (In-Depth Technology)	  100
     4.3  A1r Monitoring Technologies	  101
     4.4  Emissions  (Predictive) Modeling	  102
          4.4.1  Emission Models for Closed Landfills without
               .  Internal Gas Generation...	  105
          4.4.2'  Emission Models for Closed Landfills with Internal
                 Gas Generation	  115
          4.4.3  Emission Models for Open Landfills	  120
          4.4.4  Emission Models for Land Treatment	;	  125
          4.4.5  Fugitive Dust	  128
          4.4.6  Additional  Models	".	  130
          4.4.7  Non-Aerated Lagoons	  130
          4.4.8  Aerated Lagoons	  136

5.0  Case Study	  137
     5.1  Case Study 1:  Petroleum Waste Landfill/Lagoon	  137
          5.1.1  Site History	  137
          5.1.2  Objectives	  138
          5.1.3  Scoping	  140
          5.1.4  Overview of Fieldwork for Site  Characterization	  142
          5.1.5  Undisturbed Emissions Survey	  143
          5.1.6  Disturbed Emissions Survey	;..  154
          5.1.7  Development of BEEs	  155
          5.1.8  Summary	  158
     5.2  Case Study 2:  Bruin Lagoon	  158
          5.2.1  Site History	  158
          5.2.2  Objecti ves	  162
          5.2.3  Scoping	  162
          5.2.4  Overview of Fieldwork for Site  Characterization	  162
          5.2.5  Undisturbed Emissions Survey	  164
          5.2.6  Disturbed Emissions Survey	  164
          5.2.7  Development of BEEs	  168
          5.2.8  Summary	  169
     5.3  Case Study 3:  Lowry Landfill	  169
          5.3.1  Site History	  169
          5.3.2  Objectives	  172
          5.3.3  Scoping	  172
          5.3.4  Overview of Fieldwork for Site  Characterization	  172
          5.3.5  Undisturbed Emissions Survey	  173
          5.3.6  Disturbed Emissions Survey	  174
          5.3.7  Development of BEEs	  177
          5.3.8  Summary	  177
                                      1v

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                      Contents (Continued)
                                                                  Page

5.4  Case Study 4:  Western Processing Landfill	  178
     5.4.1  Site History	  178
     5.4.2  Objectives	  179
     5.4.3  Overview of Fieldwork for Site Characterization	  179
     5.4.4  Scoping	  182
     5.4.5  Undisturbed Emissions Survey	  182
     5.4.6  Disturbed Emissions Survey	  184
     5.4.7  Development of BEEs	  184
     5.4.8  Summary	  184
5.5  Case Study 5:  Outboard Marine Corp.  Lagoon/Landfill	  185
     5.5.1  Site History	  185
     5.5.2  Objectives	  187
     5.5.3  Scoping	  188
     5.5.4  Overview of Fieldwork for Site Characterization	  188
     5.5.5  Undisturbed Emissions Survey	  189
     5.5.6  Disturbed Emissions Survey	'.	  190
     5.5.7  Development of BEEs	  190
     5.5.8  Summary	  190

6.0  References	  191
     Appendices
          A - Annotated Bibliography

          B - Chemical and Physical  Properties Affecting Baseline
              Emission Estimates

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TABLES
Number
1

2

3

4

5
6
7
8
9
10

11

12

13

14
15
Important Parameters 1n Determining A1r Emissions and Their
Qualitative Effects on Baseline Emission Estimates (BEEs) 	
Summary of Average Baseline Emissions for Various Emission
Sources 	
Most Frequently Reported Substances at 546 National Priority
L1 st Sites 	
Toxic Pollutants Most Commonly Addressed by State and Local
Agend es 	
Examples of APA Objectives for BEEs 	
Potential Air Contaminants by Generic Type of Contaminant* 	
Activities for Developing BEEs: Evaluate Available Site Data...
Factors to Consider In Selecting an Indicator Species for Study.
Examples of Broad-Band, Class, and Indicator Species 	
Screening Technologies Applicable to Site Screening APA for
Landf 1 11s and Lagoons 	
Summary Table of Information on the Various Classes of Assessment
Technologies and Screening Assessment Technologies 	
In-depuh Technologies Applicable to Site Characterization for
Landf 1 lls and Lagoons 	
Summary Table of Information on the Various Classes of
Assessment Technologies and In-Depth Assessment Technologies 	
APA Activities Conducted at the Site 	
Summary of Screening Measurements of Undisturbed Waste 	
Page

16

18

19

20
27
29
32
37
38

40

41

49

50
141
147
  V1

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                              TABLES (Continued)
Number                                                                  Page
16   Case Study 1:  Summary of Undisturbed Site Emissions Data	   148
17   Downwind/Border Monitoring Results	   153
18   Summary of Downhole Emissions Data	   154
19   APA Activities Conducted at the Case Study 12 Site	   159
20   APA Activities Conducted at the Case Study 13 Site	   170
21   Summary of A1r Monitoring at Lowry Landfill	   175
22   Maximum and Average Concentrations in Soil for Selected
     Contaminants	   183
                                      vii

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OSHA
OVA

Particulate
Matter

PEL
ppb

ppm

Probe
Quality
Assurance

Quality
Control

RI
RPM


Sampling




SARA
Screening
Technologies

Undisturbed
Condition
VOCs
Occupational Safety and Health Administration, U.S. Department
of Labor.

Organic vapor analyzer.

Airborne solid or liquid matter.
OSHA permissible exposure limit, expressed as ppm or mg/m3 of
substance in air.

Parts per billion.

Parts per million.

A tube used for gas phase concentration sampling or for
measuring pressures at a distance from the actual collection
or measuring apparatus.

A system of activities designed to assure that the quality
control system is performing adequately.

A system of specific efforts designed to test and control the
quality of data obtained.

Remedial Investigation.  Field investigations of hazardous
waste sites to determine pathways and nature and extent of
contamination.

Remedial.Project Manager, equivalent to a site manager at
non-NPL sites.

The process of withdrawing or isolating a fractional part of
the whole.  In air or gas analysis,  it is the separation or a
portion of an ambient atmosphere with or without the
simultaneous isolation of selected components.

Superfund Amendments and Reauthorization Act.  Modifications
of CERCLA enacted on October 17, 1986.

Quick and simple methods for estimating baseline emissions.
The condition in which a hazardous waste site is discovered
or may be left if a no-action remedial  alternative is
selected.

Volatile organic compounds.   An organic compound (containing
carbon) that evaporates (volatilizes)  readily at room
temperature.
                                      xii

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FIGURES
Number
1
2
3

4

5

6
7
8
9
10

11

12
13
14
15
16
17
18
19
20
21

Conceptual schematic of a landfill 	
Conceptual schematic of a lagoon 	
Conceptual schematic showing air contaminant pathways from a
landfill 	
Conceptual schematic showing air contaminant migration pathways
from a 1 agoon 	
Flowchart of activities for developing screening and 1n-depth
baseline emission estimates 	
Checklist of factors affecting air emissions per unit 	 : 	
Undisturbed site BEE equations 	
Use of the BEEs data 1n site mitigation 	
Schematic diagram of a soil core sample sleeve 	
A cutaway diagram of the emission Isolation flux chamber and
support equl pment 	
A cutaway diagram of the surface emission Isolation flux chamber
and support equipment for liquid surfaces 	
Illustration of MRI wind tunnel 	
Schematic of portable wind tunnel 	
Schematic diagram of a simple ground probe 	
Ground probe design with minimal Internal volume 	 	
Vapor monitoring well constructions 	
Schematic diagram of the downhole emissions flux chamber 	
Real -time instrument survey 	
Mast sample collection system for C-P sampling 	 :.
Example of transect technique sampling 	
Flck's correction factor, Fv, plotted against equivalent vapor
pressure, Ce 	

Page
6
7

13

14

24
35
46
56
65

67

68
71
74
76
77
80
82
91
93
96

121
viii

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                              FIGURES  (Continued)
Number                                                                   Page
22   Location of suspected disposal area	    139
23   Location of waste soil coreholes	    151
24   Generalized flow regime of perched zone and bedrock aquifer	    161
25   Monitor well and soil boring locations at the Bruin Lagoon Site.    166
26   Western Processing site	    180
27   Map of Case Study 5 site	    186
                                      1x

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                 GLOSSARY  OF  FREQUENTLY USED TERMS AND ACRONYMS
ACGIH


Adsorption
Air
Monitoring
APA


BEEs



Calibration
CERCLA
Co-disposal
Site

Detection
Limit
Direct
Emissions
Measurement
American Conference of Governmental Industrial Hygienists,
6500 Glenway Ave., Building D-5, Cincinnati, OH  45211.

A physical process in which molecules of gas, dissolved
substances, or liquids adhere in an extremely thin layer to the
surfaces of solid bodies with which they are in contact.

A gas phase sampling technique where ambient air is sampled.
It can be used to develop emission rate estimates and is
similar to indirect emission measurement except measurements
usually are taken at greater distances from the waste site.

Air Pathway Analyses.  APA are designed to assess the potential
for air emissions from a hazardous waste site.

Baseline Emission Estimates.  These are estimates of baseline
emission rates from a hazardous waste site in its undisturbed
conditions.

Establishment of a relationship between the response of a
measurement system obtained by Introducing various calibration
standards into the system.  The calibration levels should
bracket the range of levels for which actual measurements are
to be made.

Comprehensive Environmental Response, Compensation and
Liability Act of 1980.  Modified by SARA in 1986.  The Acts
created a special tax that goes into a trust fund, commonly
known as Superfund, to investigate and clean up abandoned or
uncontrolled hazardous waste sites.

A waste site that has received and mixed municipal and
hazardous wastes.

The minimum quantity of a compound which yields a "measureable
response."  Measurable response has many statistical
definitions.  Be careful  to differentiate "instrumental
detection limit," which refers to the minimum quantity of
material introducible into a measurement system that can be
detected, from "method detection limit," which means the
minimum concentration of a compound in a sample which, when put
through the entire sampling and analysis process, can be
detected.

A measurement made directly on or above the waste to determine
the emission rate of volatile species from a liquid or solid
surface.

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 Disturbed
 Condition
 Emissions


 EPA

 FS


,Fugitive Dust
    »



 Hazardous
;In-depth
."Technologies

 Indicator
 Species

 Indirect
 Emissions
 Measurement
 Lagoon
 Landfill
 mg/m3
 NIOSH
 NPL
Changes in a hazardous waste site as remediation takes place
that usually involve increasing the emission rate of volatile
species and particulate matter.

The total of substances discharged into the air from a discrete
source.

U.S. Environmental Protection Agency.

Feasibility Study.  Analysis and selection of alternative
remedial actions for hazardous waste sites.

Atmospheric dust arising from disturbance of granular matter
exposed to the air; called "fugitive" because it is not
released to the atmosphere in a confined flow stream.

Those wastes that are regulated or "listed" under RCRA (40
CFR Part 261) or wastes that are ignitable, corrosive,
reactive, or toxic.

Very detailed methods for measuring emissions.   These
technologies produce detailed, reliable data.

Species found in hazardous waste that can be used to represent
a group of species in determining emissions from a site.

A gas phase sampling technology that measures ambient air
concentrations at short distances down-wind of a hazardous
waste site.  Data are collected to satisfy specific needs of
specialized models used to estimate air emissions.

In this manual, lagoon encompasses surface impoundments or
impoundments designed to hold liquid wastes or wastes
containing free liquids.

For purposes of this manual, a landfill is a facility,
usually an excavated pit, into which wastes are placed for
permanent disposal.

Milligrams per cubic meter.  This is a measure of mass per
unit volume.  The units mg/m3 are commonly used to describe
concen-tra-tions of particulates, dusts, fumes, and mists.

National Institute for Occupation Safety and Health, Centers
for Disease Control, Public Health Service, U.S Department of
Health and Human Services.

National Priorities List.  A list of waste sites for which EPA
has assessed the relative threat of site contamination on soil,
air, surface water, ground water, and the population at risk.
Site listing is found under CERCLA (Section 105) and is updated
three times a year.
                                       XI

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                               ACKNOWLEDGEMENTS


     This manual was prepared for the U.S. Environmental Protection Agency  by
Radian Corporation, Sacramento, California.  Mr. Leigh Hayes (project manager)
and Ms. Susan Fernandes (contract manager) managed the project.  Dr. Charles
E. Schmidt served as project director and author of several sections.  Other
contributors included Mr. John Clark, Mr. Mark Galloway, Ms. Susan Penner,  and

Mr. Bart Eklund.  Radian reviewers included Messrs. Bart Eklund and David

Balfour.


     Mr. Joe Padgett and his staff at the Office of Air Quality Planning and
Standards, U.S. Environmental Protection Agency, provided overall program
direction.  Ms. Margaret McDonough and Mr. Tom D'Avanzo, of the U.S. EPA Air
Management Division, Region I, directed efforts on this particular manual.


     Other support was provided by the program's Technical Advisory Committee,

the members of which include:


          Mr. Joe Padgett, U.S. EPA OAQPS
          Mr. Jim Durham, U.S. EPA OAQPS
          Mr. Stan Sleva, U.S. EPA OAQPS
          Mr. Joe Tikvart, U.S. EPA OAQPS
          Mr. Ed Lillis, U.S. EPA OAQPS
          Mr. Jim Southerland, U.S. EPA OAQPS
          Mr. David Dunbar, PEI Associates, Inc.
          Mr. Jim Vickery, U.S. EPA HSCD
          Mr. Abe Ferdas, U.S. EPA Region III
          Mr. Joe Lafornara, Chief, Emergency Response Team, NOA
          Mr. John Summerhays, U.S. EPA Region V
          Ms. Margaret McDonough, U.S. EPA Region I
          Mr. Mark Garrison, U.S. EPA Region III
          Mr. Al Cimorelli, U.S. EPA Region III
          Mr. Ron Stoner, NUS Corporation
          Mr. Tom Pritchett, Emergency Response Team
          Mr. Bart Eklund, Radian Corporation
          Dr. Chuck Schmidt, Radian Corporation


     This program also received support from the Regional Air Superfund
Program and its participants.


                                      xiii

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                                  SECTION 1
                                 INTRODUCTION

     The United States Environmental Protection Agency (EPA) Is responsible
for the assessment and cleanup of the National Priority List (NPL) sites under
CERCLA and SARA.  EPA's Remedial Program Managers (RPMs) are required to
assess the potential for air emissions and air quality impacts caused by NPL
sites prior to and during cleanup.  To date, no standard approach for
assessing the air pathway at NPL or other hazardous waste sites has been
available.  As a result, performing air pathway analyses (APA) -has been less
straightforward than evaluating other pathways such as the impacts on ground
water or surface water quality.  This manual assists RPMs in determining if an
uncontrolled site has the potential for significant air emissions and, if so,
how to characterize the baseline air emissions potential from the site.

     This volume is one in a series of manuals prepared for EPA to assist
its RPMs in the assessment of the air contaminant pathway and developing input
data for risk assessment.  Volume I (1) of the series provides overview and
directional information for the RPM in the overall  Superfund process.  This
manual (Volume II) provides guidance on developing  baseline emission estimates
from hazardous waste sites.  Baseline emission estimates (BEEs) are defined as
emission rates estimated for a site in its undisturbed state.  Applications of
BEEs are found in additional volumes: Volume III (2) provides guidance on
estimating emissions from cleanup activities using  these baseline emission
estimates and other means; and Volume IV (3) provides guidance on ambient air
monitoring and on dispersion modeling using baseline emissions or other source
term data to predict ambient concentrations at locations of concern.

1.1  THE PROBLEM

     CERCLA and SARA mandate the characterization of all  contaminant migration
pathways from the waste or hazardous material  to the environment and

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evaluation of the resulting environmental  Impacts.   However,  air pathway
analyses are often overlooked because many sites emit little  or no perceptible
air emissions In their baseline or undisturbed state.  Exposure to the
elements over time often causes surface materials to develop  a type of surface
crust which tends to Impede volatile emissions.   This type of surface can also
reduce emissions of part1culate matter.  However, all sites have the potential
to generate air emissions at some level during cleanup,  and It Is essential to
anticipate these emissions.   Emissions of potential  concern  Include volatile
and semi-volatile organlcs, acid gases, part1culate matter, and toxics
associated with windblown particulate matter such as metals,  PCBs or dioxins.

     A remedial Investigation Is typically necessary to  either provide data on
air emissions from the site directly, or to provide chemical  and physical data
that can be used as Inputs to model the emissions.   Remedial  investigations
(RIs) often Include ambient air monitoring to assess baseline air quality
Impacts from the site, but measurements of emission rates  or  soil-gas
concentrations are less widely employed.  An Introduction  to  these techniques
is a major emphasis of this manual.  Emission rate  or soil-gas data can be
useful for: 1) identifying "hot spots" e.g. areas of higher than average waste
content or pockets of subsurface gases, 2) serving  as model inputs (source
terms) to estimate ambient air concentrations under meteorological conditions
other than those encountered during the RI, and  3)  estimating emissions during
remediation.  For this last use, the air emissions  investigation during the RI
stage would Include emission measurements  of both the undisturbed wastes and
the exposed or disturbed wastes.

     While not strictly part of baseline emission estimates,  measurements of
emissions from exposed or disturbed wastes can generally be performed during
the RI using the same techniques presented in this  manual  for performing
baseline emission measurements.  These data along with the BEEs can be used in
the procedures outlined 1n Volume III of this series to  help  to evaluate
remediation options, design an engineering approach to the site mitigation,
and determine whether air emission control technologies  or an air monitoring
program may be necessary as part of the remedial alternatives.

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1.2  THE OBJECTIVE

     The overall objective of this manual Is to assist RPMs or site managers
1n assessing the Impacts on air quality from the site In Its undisturbed
condition.  Specifically the manual 1s Intended to:

          Present a protocol for selecting the appropriate level of effort to
          characterize baseline air emissions.

          Assist site managers in designing an approach for estimating
          baseline emissions.

     •    Describe useful technologies for developing site-specific baseline
          emission estimates (BEEs).

     •    Help site managers select the appropriate  technologies for
          generating site-specific BEEs.

     However, this manual has limitations:

          The manual is a decision making tool but it is not intended to
          relieve the site managers of their decision making responsibility.

     •    The protocol is not a "cookbook" for designing air pathway
          investigations or for determining BEEs.

          The determination of BEEs for a site will  not by itself,  yield an
          assessment of actual  or potential air impacts, but it is  a useful
          part of that evaluation process.

1.3  MANUAL ORGANIZATION

     This manual (Volume II) provides general  information on the potential  for
air contaminant emissions from hazardous  waste sites in Section 2.   Section 3
offers a protocol for determining if BEEs are  required and how to develop

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site-specific BEEs.  Information on technologies used to obtain BEEs Is
provided In Section 4.  Section 5 describes case studies In which BEEs were
needed and/or determined for hazardous waste sites.

     References are given 1n Section 6.  An annotated bibliography of the
Information reviewed for this project 1s Included as Appendix A.  This
literature was Identified during a computer-assisted search of 15 databases
and a telephone survey of regional EPA personnel, employees of EPA research
offices, EPA contractors, university researchers, and referrals from those
contacted.  Appendix B Identifies chemical  and physical  properties of waste
material that may affect 1s emissions potential.

     For this manual, all types of uncontrolled solid waste sites, land
                                                              •
disposal sites 1n particular, will be referred to as "landfills" and all  types
of uncontrolled liquid waste sites will be  referred  to as "lagoons."  The
technologies described for application to landfills  and lagoons may generally
be applied to solid and liquid hazardous waste, respectively.
                                                                                 1

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                                   SECTION 2
                    AIR EMISSIONS FROM HAZARDOUS  WASTE  SITES

      This section presents information on  landfills  and  lagoons,  the two
 general  types of sites used in this  manual to  demonstrate  methods for
"estimating the potential for air emissions.  This  section  addresses  potential
 emission sources and potential air quality impacts.  Discussion of potential
 air quality impacts covers the general types of  air  quality impacts  by waste
 site category, and the basic transport mechanisms  involved with the  movement
 of contamination from lagoons and landfills.   Where  not  otherwise specified,
 the general term hazardous waste site is used  to refer to  both landfills and
 lagoons  that contain hazardous wastes and/or substances.   Figures 1  and 2
 depict these two types of sites in generalized schematic drawings.

      The site, and contaminant characteristics  discussed  below are general
 background information for working with the protocol presented in Section 3.
 The information provided will assist the site  manager  in developing  conceptual
 models of landfills and lagoons.  Based on this  conceptual  understanding, the
 site manager can then develop strategies for assessing the potential  impacts
 and for  estimating potential  air emissions from  these  sites.  The references
 cited in this section and those listed in  the  annotated  bibliography contain
 further  background material.

 2.1  GENERAL DESCRIPTION

 2.1.1 Landfills

      Landfills are facilities into which wastes  are  placed  for permanent
 disposal,  and usually are simply an  excavated  pit.   Landfills may vary in size
 from a few tenths of an acre  to several hundred  acres  and  other landfill
 characteristics can also vary greatly from one site  to the  next.   Most
 variations are attributable to the types of stored wastes,  the operating
 practices  and the age of the  facility,  and hence,  its  design.
                                       5

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     Commercial landfills can be categorized by design  criteria such as liners
and gas-venting systems.  Older landfills are usually unlined.   Newer landfill
designs may specify liner systems to retard transport of leachate and  wastes
Into soils and ground water.  Some landfills have  built-in  gas  venting systems
to prevent build up of landfill gases.

     Landfills can be further differentiated by the  types of waste they store.
Commercial landfills are commonly classified as municipal or hazardous,
depending on the types of waste accepted.  Municipal  landfills  accept solid,
semi-solid, and liquid nonhazardous wastes, including garbage,  glass,
plastics, paper, plant matter, ashes,  some Industrial wastes, and demolition
and construction wastes.

     Hazardous waste landfills accept hazardous sludge,  liquids,  semi-solids,
residues, concentrates, or leachate or ash originating  from a waste.  Much of
the hazardous waste originates from manufacturing, petrochemical,  and chemical
industries.  Federal, state, and local  regulations establishing minimum design
standards and restricting types of acceptable landfill  wastes have evolved
over the last 25 years.  In the past,  mixtures of  liquid and solid waste were
common practice.  Today, landfills can no longer accept liquid  wastes or
solids that contain free liquids unless they've been  treated with fixatives
and stabilizers to eliminate the free liquids prior  to  disposal.

     Co-disposal landfills are sites that have received and mixed municipal
and hazardous wastes.  Any available disposal records may relate types of
wastes and location/mixing within the landfill.

     Most landfills that are selected as Superfund sites have undergone some
form of closure.  In some cases, currently operating  facilities may have
abandoned hazardous landfills at the same site. The  appearance of a closed
landfill will depend on when it was closed.  Closure  may mean that the site is
covered with vegetation or that no waste is exposed.  Telltale  signals of
covered waste are seeping leachate and odors.  In  the past, landfills were
often sited in"unpopulated areas ^lose to the industry  or industries
                                      8

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  generating the wastes, but population growth and development may result in
  people living or working in close proximity to the site.

       Superfund sites may differ 1n significant ways from the types of
  commercial landfills discussed above.  In some cases, the site history will be
  one of relatively  Indiscriminate disposal of hazardous substances.  The sites
  may contain burled drums or pockets of dumped/spilled wastes that are not
 , uniformly distributed across the disposal area.  Information on waste types,
 , disposal practices, date of disposal, etc. may be limited or non-existent.
  However, the protocol and measurement techniques presented in this manual are
  sufficiently generalized that they can be applied to such uncontrolled sites.
  Conversely, the emission models presented here may be of only limited use for
  sites where the chemical and physical parameters that serve as"model inputs
  are poorly defined.

  Potential Site Conditions--
3      The site conditions encountered when investigating landfill  sites will
fe vary from site to  site because of the siting, landfill design, landfill use,
 , and difference in  landfill operations among each of the sites.  Figure 1
  presents a conceptual schematic of a landfill site.  The condition of the site
  cover material will vary greatly.  It will depend, to a large extent, on the
  landfill's operational history.  In the best situation, the landfill cover
  will extend over the entire land disposal area; the cover will have been
  constructed to minimize rainfall percolation into the waste body  and regulated
  to minimize erosion of the cover.  The degree to which the air, the
  surrounding native soils, and the ground water are protected from
  contamination from the wastes stored in the landfill  will depend  both on the
  landfill design and on the construction and operation of the waste storage
  facility.  If the wastes have been disposed of into an unlined storage area,
  the likelihood of contamination of surrounding soils  and eventual
  contamination of the ground-water beneath the landfill increases.   If the
  landfill has been constructed at or below the ground-water table,  the
  transport of pollutants Into the ground water further increases.   Waste
  material 1n the landfill may be stratified by age of  disposal  and/or settling
  of the more dense waste."

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       Emission of air pollutants from landfills  1s  dependent  on  the chemical
  and physical properties of the stored wastes and on  the landfill  design
  components which may have been Implemented to reduce air emissions.  Municipal
  landfills are sources of significant amounts of methane and  carbon dioxide,
  and variable amounts of other non-methane hydrocarbons.  Hazardous waste
  landfills often are sources of non-methane hydrocarbons,  including volatile
  organic compounds (VOCs), semi-volatiles, and pesticides.  Co-disposal  sites
  combine the emission potentials of both municipal  and hazardous waste sites.
  The methane gases generated often can Increase  the migration potential  of the
  high concentrations of non-methane hydrocarbons by acting as a  carrier medium
  during bulk flow transport of these contaminants.  For this  reason,
  co-disposal sites may generate very high emission  rates compared  to other
  types of landfills.

  2.1.2  Laaoons

       For purposes of this discussion, the term  "lagoon" refers  to the class  of
  facility also known as surface impoundment or impoundment.   This  type of
  facility generally includes a natural topographic  depression, a man-made
  excavation, or a diked area formed primarily of earthen materials.   Lagoons
  are designed to hold liquid wastes or wastes containing free liquids.   Lagoons
  include holding, storage, settling, and aeration ponds.

       These waste sites may range in surface area from a few  tenths of an acre
  to hundreds of acres.  Man-made lagoons typically  range in depth  anywhere from
 > 2 to 30 or more feet below land surface.

       In some cases, for certain wastes, lagoons may  be lined to minimize any
  fluid seepage.  Clay, asphalt, soil sealant, and synthetic membranes are
  typical lining materials.

       To prevent migration of pollutants into the native soils and ground water
r  beneath the lagoon, lagoons are usually built above  the naturally occurring
  water table and take advantage of any impermeable  surface or subsurface soils.
                                        10

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  In  areas  with  high  ground-water tables, lagoons may be constructed on the land
  surface to minimize ground-water contact.  Of course, use of liners and
  building  above the  water table will not prevent the release of contaminated
  air emissions  from  the  surface of the lagoon, but these practices limit the
  possible  routes of  air  emissions (see Section 2.2).  Equally as Important are
  operating practices and waste types 1n the lagoon.  The Importance of these
  factors tends  to parallel the landfill discussion above, as does the
  Importance of  lagoon siting practices.

  Potential  Site Conditions--
      Actual  site conditions that will be encountered when investigating
  hazardous waste site lagoon sites will vary because of siting, lagoon design,
  lagoon  usage,  and differences in lagoon operations.  Figure 2 presents a
  conceptual  schematic of a lagoon site.  The condition of the lagoon will
  depend, 1n large part,  on the wastes stored there and the lagoon's operational
  history.   Mixed wastes  within the lagoon will often have separated into
  stratified layers.   The lighter materials are near the surface, the denser
sliquids,  sludges, and sediments have settled to the lagoon bottom.
  Contaminated soils  around and beneath the lagoon are likely, as well as
 : contamination  of the underlying ground water.

  2.1.3   Equivalent Units

      NPL  sites containing mixed wastes or having other types of inherent
  variability may require separate remedial options to be considered for each
  equivalent area.  During the remedial investigation, the site should be ••--
  theoretically  divided into units of equivalent waste for estimating baseline
  emissions  and  evaluating potential emissions during remediation.  For example,
  a site  containing an abandoned landfill, sludge pits, and buried drums would
  have at least  three  distinct units and maybe more.  If the type,
  concentration,  or distribution of a given form of contamination varies,  then
  further subdivision  of  the units should be considered.  Similarly, if the soil
  media or  proximity  of receptors varies significantly across the site,  then
  further subdivision  of  the units may be warranted.
                                       11

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2.2  ROUTES OF EXPOSURE

     Waste site characterizations performed during a remedial  Investigation
are Intended to determine potential or existing contaminant migration by the
direct contact, surface water, ground water, and air pathways.   Each pathway
represents a potential route of exposure to the public and the  general
environment.  Figures 3 and 4 show the potential routes for contaminant
migration from landfills and lagoons, respectively.   The focus  of this  manual
1s the air pathway, and several routes exist for contaminant emissions  within
this one pathway.

     Emissions from surface wastes may occur as gaseous volatile organics and
Inorganics as gases, aerosols, and contaminated particulate matter.   Where gas
migration controls, (e.g., gas venting systems) have been installed, volatile
emissions from the controls are likely to be higher than emissions from the
site surface.  The lateral migration of solid and liquid wastes into the
surrounding soils and beneath the containment area can create  large  areas of
contaminated subsurface soils.  The contaminated soils also represent a source
of potential air emissions via the transfer of contaminants into the air-
filled spaces in the soil matrix.  The contaminated soil  gas can then transfer
contaminants into the atmosphere at the surface soil/atmosphere interface.

     The generation of leachate from landfills and lagoons can  accelerate the
pollutant migration into the ground water below and provide an  additional
source of air emissions resulting from the volatilization of dissolved
contaminants in the ground water.  The contaminated ground-water also can
transfer contaminants Into the soil gas and hence the atmosphere.
                                      12

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  2.2.1  Kev Parameters and Critical Factors Affecting Emissions from Landfills

            The generation of emissions from landfills depends on several key
  chemical and physical properties of the waste materials stored at these sites.
  Table 1 presents these key factors along with the qualitative effects these
  factors may have on baseline emissions.  These data can be used to help
  estimate the potential air emissions from the site, given critical factors
  imposed by the site.  A discussion of each parameter is outside the scope of
 • this document, but in general, for volatile compounds the rate limiting step
  is the movement of vapors through the soil.  Volatilization into the soil pore
  spaces and transfer from the soil -gas into the atmosphere once the soil/air
  interface has been reached, are usually quite rapid.  Additional information
  about the key physical and chemical properties of the waste material are
  presented in Appendix 8.  Users should consult the references cited below and
  those listed in the annotated bibliography (Appendix A) for additional
 - background material.  General reading materials that may prove helpful
  include:  Guidance Document for Cleanup of Surface Impoundment Sites. (4)
... Model Prediction of Volatile Emissions. (5)  Air Pollution Assessment of "toxic
 'Emissions from Hazardous Waste Lagoons and Landfills. (6)  Air Quality
           «•
  Assessment for Land Disposal of Industrial Wastes. (7)  Estimating Air
  Emissions 'from Disposal Sites. (8V  and Air Pollution Problems of Uncontrolled
  Hazardous *jaste Sites.
  2.2.2  Kev Parameters Affecting Emissions from Lagoons

       Figure 4 presents a generalized schematic of the volatilization process
  from lagoons.  In general, the process consists of two  steps:  vaporization
  from the surface liquid layer Into the boundary air layer and  then mass
  transfer from the boundary layer to the bulk atmosphere.   The  rate of
  vaporization is dependent on factors such as the compound's  concentration,
  Henry's Law constant, water solubility and the system temperature.  Mass
  transfer into the bulk atmosphere is dependent on compound properties such as
  molecular weight and diffusion coefficient,  and site-related factors such as
                                        15

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          TABLE-1.  IMPORTANT PARAMETERS IN DETERMINING AIR EMISSIONS
                    AND THEIR QUALITATIVE  EFFECTS ON BASELINE EMISSION
                    ESTIMATES (BEEs)
 Parameter
                                        Qualitative Effect on BEEsa
     Volatile;
Participate Matter
 Site Conditions

 Size of Landfill  or Lagoon
 Amount of Exposed Waste
 Depth of Cover on Landfills
 Presence of Oil  Layer
 Compaction of Cover on Landfills
-Aeration of Lagoons
 Ground Cover

 Weather Conditions

 Wind Speed
 Temperature
 Relative Humidity
 Barometric Pressure
 Precipitation
 Solar Radiation

 Soil/Waste Characteristics

 Physical Properties of Waste
 Adsorption/Absorption
  Properties of Soil
 Soil  Moisture Content
 Volatile Fraction of Waste
 Semi-Volat11e/Non-Volati1e
  Fraction of Waste
 Organic Content  of Soil
  and Microbial Activity
Effects overall          Effects overall
magnitude of emissions  magnitude of
but not rate per area,  emissions, but not
                        rate per area.
      High
     Medium
      High
     Medium
      High
     Medium
     Medium
     Medium
      Low
     Medium
      High
      Low
      High

     Medium
      High
      High

      Low

      High
     High
     High
     High
     Low
     High
     High
     High
     Low
     Low
     Low
     High
     Low
     High

     Low
     High
     Low

     High

     Low
 8 High, medium,  and low  in this table refer to the qualitative effect that the
   listed  parameter typically has  on  baseline emissions.
                                       16

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 temperature, pressure, and wind speed.   Berms,  wind breaks,  and lagoon
 geometry affect the wind speed at the liquid surface and can thereby control
 the rate of mass transfer.  In general,  low molecular weight compounds are
 more volatile than high molecular weight compounds.

 2.3  MAGNITUDE OF AIR EMISSIONS

       The magnitude of baseline air emissions from landfills and lagoons is
 dependent on waste-specific chemical and physical  factors and site-specific
 environmental factors.  Limited data are available on measured air emission
 fluxes (rate per area) from previously studied  waste sites (Table 2).   These
 data can be used to give the site manager some  idea of typical  baseline
 emission estimation (BEEs) and a limited comparison of BEEs  for* different
 types of waste sites.  Emission flux data for disturbed or exposed wastes are
 included to demonstrate the potential  for increased emissions for volatiles
 during waste remediation.

-2.4   EMISSIONS OF POTENTIAL INTEREST AT NPL SITES

       The types of emissions at a hazardous waste  site are dependent on the
 types of waste present, and these in turn are dependent on the  types of
 industries and manufacturers that produced the  waste.   A listing of the
 typical wastes generated by 30 various  industries  and manufacturers can be
 found in the Handbook of Industrial  Waste in California (II).   The 25  most
 frequently detected compounds at 546 hazardous  waste sites are  summarized in
 Table 3 according to the type of media,  i.e., groundwater, surface water,  or
 air.   The table shows the number of sites where each contaminant was detected
 and the contaminant's relative rank for  each type  of media.   Another useful
 listing for selecting contaminants with  the potential  for emissions of
 concern,  is the list of toxic compounds  most commonly addressed by state and
 local  regulatory agencies given as Table 4.
                                       17

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 TABLE 2.  SUMMARY OF AVERAGE BASELINE EMISSIONS FOR VARIOUS EMISSION SOURCES
                                                                i
Waste Type
Source Type
    Baseline
Emission Estimate
   For TNMHC*
  (ug/m -min)
Industrial Waste  TSDFC Facilities

                  Active Landfills
                   Site E
                   Site F
                   Site G

                  Inactive Landfills
                   Site H (covered)
                   Site I (covered)

                  Land Treatments
   Disturbed
   or Exposed
Waste Emissions
   For TNMHC
  (ug/mz-min)
NPL/Hazardous
Waste Sites




Landfills
Site A
Site B
, Site C
Laooons
Site D

360
740
29

43

190,000
26,000
170,000

640,000
                                                 44-150
                                                     47
                                                      9
Site J
Lagoons
Site K
Site L
Site M
Site N
—

120
570
9-31b
630
610-9600

—
_ __
—

a  TNMHC - Total Non-Methane Hydrocarbons.
   Different assessment techniques were used.
c  Transfer, storage, and disposal facilities  (RCRA)  - Reference 10.
                                      18

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      TABLE 3.  MOST FREQUENTLY  REPORTED SUBSTANCES AT 546 NATIONAL PRIORITY
                AIST SITES
Substance Identified at
   Hazardous Waste
   Disposal Sites
Sites"
Ground Water

Sites (Rank)b
Surface Water

Sites (Rank)b
                                                                      Air
Sites (Rank)bc
Most Frequently Occurring
1. Trlchloroethylene
2. Lead
3. Toluene
4. Benzene
5. Polychlorlnated Blphenlys (PCBs)
6. Chloroform
7. Tetrachloroethylene
8. Phenol
9. Arsenic
10. Cadmium
11. Chromium
12. 1.1.1-THchloroethane
13. Zinc and Compounds
14. Ethylebenzene
15. Xylene
16. Hethylene Chloride
17. Trans-l,2-D1chloroethylene
18. Mercury
19. Copper and Compounds
20. Cyanides (Soluble Salts)
21. Vinyl Chloride
22. l,2-D1chloroethane
23. Chlorobenzene
24. l.l-D1chloroethane
25. Carbon Tetrachlorlde
179
162
153
143 ,
121
111
90
84
84
82
80
79
74
73
71
63
59
54
47
46
44
44
42
42
40
127 (1)
77 (4)
81 (3)
84 (2)
29 (21)
70 (6)
57 (7)
43 (9)
45 (8)
28 (16)
34 (14)
58 (6)
28 (17)
36 (12)
32 (15)
36 (13)
42 (10)
27 (20)
17 (24)
16 (25)
28 (18)
25 (21)
23 (23)
28 (19)
25 (22)
49 (3)
84 (1)
40 (4)
36 (5)
54 (2)
24 (11)
17 (14)
28 (8)
35 (6)
28 (9)
33 (7)
20 (12)
27 (10)
14 (20)
8 (25)
17 (15)
17 (16)
20 (13)
16 (18)
16 (19)
10 (23)
17 (17)
9 (23)
8 (24)
12 (21)
8
7
16
18
6
1
3
3
2
31
1
3
2
7
9
2
1
4
6
2
4
2
0
0
2
"Number of sites at which  substance 1s present.  Substances  may be present  In
 one,  two, or all three environmental  media at all sites  at  which it is known
 to  be rpesent.  Therefore,  the number of sites at which  each substance is
 detected in environmental media may not equal the number in this column.

bNot all  ranks will be represented in  all media because not  all chemicals
 found in media are among  those found  most frequently at  site.

cVolatile organics not otherwise specified were reported  as  being detected
 most  often (rank 1) in the  air medium.

Source: Air  Quality Engineering Manual  for Hazardous  Waste Site Mitigation
        Activities.17
                                       19

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TABLE 4.  TOXIC POLLUTANTS MOST COMMONLY ADDRESSED BY STATE AND LOCAL AGENCIES
Acetaldehyde
Acroleln
Acrylonltrile
Ally! Chloride
Arsenic
Asbestos
Benzene
Benzidine
Benzo(a)pyrene
Benzyl Chloride
Beryllium
Bis(chloromethyl)ether
1,3-Butadiene
Cadmium
Carbon Tetrachloride
Chlordane
Chlorobenzene
Chloroform
Chloroprene
Chromium
Cresol
1,4-Di chlorobenzene
3,3-Dichlorobenzidine
Dimethyl Sulfate
1,3-Dioxane
Dioxins
Epichlorohydrin
Ethylene Dibromide
Ethylene Dichloride
Ethylene Oxide
Ethylenimine (azridine)
Formaldehyde
Heptachlor
 Hexachlorocylopentad i ene
 Hydrazine
 Hydrogen Sulfide
 Lead
 Lindane
 Maleic Anhydride
. Manganese
 Mercury
 Methyl Bromide
 Methyl Chloride
 Methyl Chloroform
 Methylene Chloride
 beta-Naphthylamine
 Nickel
 Nitrobenzene
 n-Ni trosodimethylami ne
 Nitrosomorpholine
 Parathion
 Perchloroethylene
 Phenol and Chlorinated Phenols
 Phosgene
 Polychorinated Biphenyls (PCBs)    *<
 Polycyclic Aromatic Hydrocarbons (PAH)
 Propylene Oxide
 Radionuclides
 Styrene
 1,1,2,2-Tetrachlorethane
 Tetrahydrofuran
 1,1,2-Trichloroethane  (vinyl  trichloride)
 Toluene
 Trichoroethylene
 Vinyl Chloride
 Vinylidene Chloride
 Xylene
Source:  Reference 12.
                                      20

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2.5  SUMMARY OF POTENTIAL RECEPTORS

     Receptors can be divided Into three broad categories:

     •On-site workers;
     •Off-site populace; and
     •Non-human receptors.

     The on-site workers are in the closest proximity to the hazardous waste
site and are potentially subject to the most acute exposure to hazardous
substances.  The use of personal protective equipment, real-time field
Instruments, personnel monitoring, site controls, and designated work zones
are designed to ensure that field personnel are properly protected against the
hazards present at the work site.

     The off-site (and any on-site) population in close proximity to the
hazardous waste site Is another receptor of primary concern.  These people are
often acutely aware of the hazardous waste site and the potential for   •*
contaminant exposure.  Section 3 provides an approach for estimating emissions
which can subsequently be used to predict the airborne contaminant
concentration for downwind receptors to assist in the establishment of
appropriate action levels.  Use of this r Jtocol, coupled with an effective
monitoring and modeling program, will provide useful  information for the
site's community relations program.

     Non-human receptors also may be a concern at some hazardous waste sites.
Disturbance of the site may lead to exposure through  inhalation of
contaminated air or exposure through ingestion of or  direct contact with
contaminants deposited on plant and inert surface.  The possibility of
Inhalation exposure may affect feral  or domesticated  animals downwind of the
site.  This also impacts humans in that animal  exposure to pollutants can lead
to contamination accumulation in the food chain.
                                      21

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     Certain gaseous pollutants (e.g., ozone,  oxides  of sulfur and nitrogen),
If present In high concentrations, also can affect plant and  animal  growth.
Deposition of airborne contaminants may cause  stressed vegetation, release
pesticides and herbicides, or Impact the value/usability of agricultural
crops.  Also, deposition of metals or other pollutants In surface waters  may
Impact marine life.  Copper and some other metals  can cause fish  kills at very
low concentrations.
                                      22

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                                   SECTION 3
                   PROTOCOL FOR BASELINE  EMISSION ESTIMATES

     This section presents a protocol for developing baseline emission
estimates (BEEs).  This protocol 1s a component of an air pathway analyses
(APA) program to assess potential air quality Impacts from hazardous waste
site landfills and lagoons.  While not all  sites will require BEEs, the first
three steps in the protocol should be Implemented to see if BEEs are necessary
for a given site.  The protocol Is a recommended guideline;  the level of
effort that Is required or the need to develop BEEs for Individual sites must
be determined on a case-by-case basis.

3.1  PROTOCOL STEPS FOR DEVELOPING BEEs

     Figure 5 diagrams a protocol for developing BEEs.  The  protocol was
developed to help the site manager to determine baseline emission rates and
absolute emissions.  These values can be used as Inputs to dispersion models
to assess the air Impacts for receptor locations of Interest.  The activities
Identified in this flow chart are consistent with tfr steps  of the CERCLA
remedial investigation process that involve  the assessment of the air
contaminant migration pathway.  Although the protocol was developed for NPL
sites, it also applies to assessing air emissions from other hazardous waste
sites.  The flow chart is applicable to all  sites,  regardless of the type of
site (landfill, lagoon, waste pile, etc.), type of waste, or the potential for
the site to generate air emissions.  Each step of the protocol  is described
below.
                                      23

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   f  WA« ^vw v-v^q*  ~-ffA 2

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                                          Site Scoping
                                       Evaluate the Available
                                            Site Data
                                        Potential Exists for
                                     Air Pathway Contamination
                                              I
                                       Design and Conduct a
                                    Screening APA to Determine If
                                     In-Depth Baseline Emission
                                    Estimate Data Are Necessary
                                     Design and Conduct Detailed
                                     APA To Determine In-Depth
                                     Baseline Emission Estimate
                                                               No
                                                               Potential
                                                                             Document
                                                                           N<5 Potential for
                                                                             Air Pathway
                                                                            Contamination
                                                              In-Depth Baseline
                                                              Emission Estimate
                                                                  Data Are Not
                                                             	Necessary
                                     In-Depth Baseline Emission   I
                                    Estimate Data Are Necessary  I
                                                                    Document
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                                                              Baseline Emission
                                                                 Estimate Data
                                      Report In-Depth Baseline
                                         Emission Estimate
                                                             Sufficient
                                                             APA Data
                                                                                Site
                                                                              Mitigation
Figure 5.   Flowchart of activities  for developing  screening and  in-depth
               baseline  emission  estimates.
                                               24

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3.1.1  Define the APA Objective

     CERCLA and SARA legislation highlight the basic objectives for all
remedial investigations.  Simply stated,.these objectives are to provide data
that are "necessary and sufficient" to characterize the "nature and extent" of
contamination on site.  In addition, they mandate that "all  potential
migration pathways for contaminations" require characterization.  As the first
step of the protocol to assess baseline emissions,  site-specific objectives
should be developed; this will generally occur simultaneously with the
performance of Steps 2 and 3 (data collection :and review) of the protocol.
The site manager should consider the following issues when formulating
site-specific objectives:

          What information is already available?  As described in Section
          3.1.2, available information should first be reviewed before
          developing final site-specific objectives.  This preliminary review
          of information will provide necessary background information and aid
          1n Identifying data gaps.   '       '                          *

     •    What pathways must be considered?  Except in rare cases, all
          pathways, namely air, soil, and water, must be considered.

          What is technically possible?  Site and situational  factors  that may
          adversely affect the air pathway investigation should be identified
          to avoid establishing unrealistic objectives.   These factors can
          range from complexity in site geology/hydrogeology and complex '
          terrain to the feasibility of detecting the contaminants of
          interest.          :

     •    What time deadlines exist?  Schedule constraints can affect  the
          nature of the investigation and must be balanced with technical
          concerns.

          What data quality ob.iectives are required?  Data must be of  a known
          accuracy and precision for use in evaluating the air pathway.
                                      25

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      •     What program is most  cost  effective?  The type, level, and extent  of
           contamination per migration  pathway will primarily determine  how the
           available resources are  apportioned.  It Is also necessary to
           collect,  Integrate, and  consider  a variety of types of data,
           Including technical Information,  Institutional Issues, political
           Issues,  public protection, community relations Issues, and community
           concerns.

      •     What contaminants must be  considered?  The Investigation will
           typically Involve Identifying  and characterizing the extent of  the
           contamination.  Concentrations of Individual or summed indicator
           compounds are often selected to represent the extent of total
           contamination.  Site-specific  objectives should neither identify
           specific Indicator compounds nor  require characterization of  all
           compounds.

      Table 5 provides examples  of  objectives related to baseline emissions
 estimates.  The first step in developing site-specific APA objectives is  to
 collect and review readily available site historical records.  The potential
,for air emissions  can be inferred  from the  review of preliminary site
 information.  While baseline emiss'nns may  be low, during remediation sites
 have the potential  for air emissions of  particulate matter (semi-volatile
 organics,  metals,  and other Inorganic  contaminants) and enhanced volatile
 organic emissions.

      Among the types of information  that can be reviewed and used to develop
 site-specific APA  objectives are:  waste characteristics; distribution  of the
 waste;  orientation of the general  public to the emission source concerns;
 technical  feasibility; and program resources.  The first three items are
 discussed below.
                                       26

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            TABLE 5.   EXAMPLES OF APA OBJECTIVES FOR  BEEs
     Characterize the air emissions potential  for volatile species and
     participate matter from the undisturbed site.
•    Characterize the air emissions potential  for volatile species and
     particulate matter from the disturbed site.
     Identify contaminants of concern.
     Provide baseline emission estimates that can be used to assess the
     health risk and the need to mitigate.
•    Provide baseline emission estimates that can be used to assess the
     need for on-site or fenceline ambient monitoring.
                                 27

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Waste^ Characteristics.  Knowledge of the Industrial  process or the
waste source Involved can suggest the types of chemicals or agents
that may be 1n the waste.  For example,  volatile emissions are
likely from waste sites with organic solvents or petroleum waste.
Wastes In liquid form tend to have higher baseline emissions than
wastes In solid form.  In addition, Identifying common decomposition
products of the chemicals Identified 1n  the waste may be useful.  It
Is helpful to categorize potential air contaminants  by their generic
volatility: volatlles, semi-volatlies, and non-volatiles.  Examples
of the-types of compounds in each category are listed in Table 6.
The categories group together compounds  with similar physical
behavior in the atmosphere and thus are  useful  for predicting
emissions potential.

Distribution of the Waste.  The relative position of the waste can
Influence the potential for air emissions and,  thus,  the APA
objectives.  The amount and nature of overburden strongly influences
the baseline emissions at a site.  Semi-volatiles and non-volatiles
present near the surface can be emitted  as windblown particulate
matter.  Waste piles may have relatively high emissions of both
volatile organics and particulate matter due to their geometry and
surface area to volume ratio.

Location of the Affected Population and  Community Concerns.  The
population potentially at risk from exposure to toxic air emissions
from the site must be identified and the exposure characterized.
The close proximity of residential areas may require the addition of
measurement and monitoring activities for health and safety purposes
that are beyond what is necessary to develop BEEs for the site.
Thus, the site-specific objectives may Include a component related
to determining the potential impact on the nearest population (e.g.,
air monitoring at the site boundary).
                            28

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      TABLE 6. '"POTENTIAL AIR CONTAMINANTS BY GENERIC TYPE OF CONTAMINANT

VolatHes  (>1 mm mercury vapor pressure)
          All monochlorlnated solvents; also trlchloroethylene,
          tr1chloroethane, tetrachloroethane
      •    Most simple aromatic solvents; benzene,  xylene,  toluene,
          ethyl benzene
      •    Some normal alkane; up to decane
      •     Inorganic gases; hydrogen sulfide, chlorine, .sulfur dioxides
Semivolatlles fl-10'7 mm mercury vapor pressure)
                                                               *
     •    Most polychlorinated biphenyls; dichlorobenzenes,  aroclors,  dieldrin
     •    Most pesticides; aniline, toxaphene,  nitroanillne,  parathi on,
          phthalates
          Most complex alkanes; dodecane, octadecane,  hexacosane
     •    Most polynuclear aromatic's;  napthalene,  phenanthrene,
          benz(a)anthrencene
Non VolatHes or Partlculate Matter f<10"7 mm mercury vapor pressure)
     •    Larger polynuclear aromatics;  chrysene,  coronene
          Metals; lead, mercury, chromium
     •    Other Inorganics; asbestos,  arsenic,  cyanides
                                      29

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     The APA objectives should be documented and circulated for peer review by
staff members that have knowledge of the site,  APA,  and the site mitigation
process.  The review process may also help Identify  site characterization data
needs.  Developing site-specific objectives Is  an Iterative process; more than
one round of data gathering, review, and discussion  may be needed to develop
satisfactory objectives.

3.1.2  Site Scoping

     The second step in the development of BEEs 1s collecting available
Information about the site.  This should be a quick, straightforward
information search, Involving but not limited to the collection of records,
reports, shipping manifests, newspaper clippings, and Information from
interviews with people living close to or affiliated with the site.   For NPL
sites, data should be available from the preliminary assessment and site
inspection conducted prior to Inclusion on the  NPL.   The type of information
to be collected parallels, for the most part, the factors considered in
creating the objective.  These include:                                  :

     •    Source of the waste (type of industry);

          Connositlon of the waste (organlc-volatile/semi-organic;
          Inorganic-metals, others; biological; radioactive);

     •    Distribution of the waste and cover material  limiting volatilization
          and uptake of particulate matter from the  waste;

     •    Distance from the waste to the property fenceline; and

     •    Representative meteorological data.
                                      30

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 3.1.3  Evaluate Available Site Data

      The existing site Information should be evaluated to determine the
 potential for air pathway contamination.  Examples of types of contaminants
 and situations to be evaluated are provided in Table 7.  If it is determined
 through this assessment that the site poses no potential  for air pathway
 contaminant migration, then no further evaluation of the  baseline emissions is
 required.  The site manager must record the basis for this decision and
 include these data in the site Investigation documentation.  In most cases,
 insufficient Information will be available at this stage, and further work
 will be warranted.  If air emissions are a potential concern, the next step of
 the protocol (site screening study) should be implemented to provide
 additional Information to make a judgement regarding the  potential  for air
 emissions from the site.  At this point the site-specific APA objectives
•should be reviewed to ensure they are still realistic,  attainable,  and
 applicable.

>3.1.4  Design and Conduct the Site Screening Study                       "*

      Designing a site screening study to assess the air emissions potential
 involves the selection of an air emissions measurement/assessment technology.
 The four broad categories of measurement/assessment technologies include:

      •    Direct emissions measurement;
           Indirect emissions measurement;
      •    Air monitoring/modeling;  and
           Emissions (predictive)  modeling.

      Each technology can be further categorized according to its level  of
 complexity as screening (quick and  simple) or in-depth  (very detailed).

      The activities necessary to  design and conduct the site screening study
 are:
                                       31

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     TABLE 7.  EXAMPLES OF TYPES  OF CONTAMINANTS AND SITUATIONS THAT MAY
               INDICATE A POTENTIAL FOR AIR PATHWAY CONTAMINATION
Situation/Condition
           Participate
Volatile*    Matter
          Comment
• Site Odors,           J
  Neighborhood
  Complaints

• Observation of Dust
  Clouds During Wind

• Evidence of Metal      J
  Corrosion

• Vent pipes            J
• Seeps of Waste        J

• Weathered Waste       J
  Surface

• Aged and Layered      J
  Waste
  Aerated Lagoons       J

  Exposed Waste         J

  Industrial  Wastes     J



  Petroleum Wastes      J
  Industrial Wastes/
  Paint Wastes          J
          J


          J
          J

          J
                      Indicates moderate  to  high
                      levels of BEEs.
Check soil cover and look for
waste piles.

Look for corrosive agents.
Check records to determine if
the site 1s a codisposal
facility.

Probable burled wastes.

Emissions of disturbed waste
may be very high.

Likely that volatiles are
higher in underlying lay
chemicals possible.

Increased emissions.

Increased emissions.

Waste mixtures likely, check
for particular solvent types,
aromatic and halogenated
organic solvents.

Tar/wastes with volatile
emissions likely.

Organic volatiles likely.
                                                              (Continued)
                                     32

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                           TABLE 7.  (Continued)
Situation/Condition
           Participate
Volatile*    Matter
                  Comment
• Industrial Wastes
  Works or Plating

• Municipal Wastes
• Hospital Wastes



• Chemical Product


. Site "Walk-Overs"




. Site "Walk-Overs"
 J
 J


 J
J
                     Metal-contaminated particulate
                     matter likely.
        Methane/carbon dioxide
        volatiles likely; look
        Industrial waste.
                                                                      for
Solvent used likely;
biological hazards and
radioactive waste possible.

High concentrations of
specific chemicals likely.

Gas detection results indicate
the presence of gas species
and the potential for
emissions.

Visual Inspection and particle
counting/detection results
indicate the potential for
particulate matter emissions.
                                     33

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     •    Determine the feasibility of obtaining the screening data.
          (Identify any site factors that may limit this activity.)

     •    Select appropriate tracer species, screening technologies, and
          appl1cab!e equ1pment/1nstrumentat1on.

          Design the site Inspection technical approach and test plan,
          Including the Quality Assurance/Quality Control  Program.  Make sure
          that all units of a combined site are studied.

          Circulate the site screening approach for review and ensure the
          screening addresses the site-specific objectlve(s).

     •    Modify the site screening program, as necessary.

     •    Conduct the site screening study and document the findings.

     •    Determine 1f the site screening study was adequate to characterize
          the air contamination migration pathway and If detailed BEE data are
          necessary.  If detailed BEEs are necessary, Initiate the In-depth
          site characterization study.  If not,  document the site inspection
          survey results and the basis for discontinuing the APA.

One preliminary step 1s to evaluate those key factors that affect the air
emissions of volatiles and particulate matter.  The factors were presented in
Section 2 and are summarized in the check-list presented in Figure 6.  This
figure can be used to summarize site information and facilitate the decisions
regarding selecting and Implementing screening technologies.  If the site
contains a waste type that has the potential to create air emissions, the most
Important factors which determine the baseline emissions are typically site
conditions and weather conditions.  Once the checklist (Figure 6) has been
completed and some knowledge of the factors affecting air emission processes
1s gained, the site manager must select appropriate indicator species and
select air emission screening technologies, equipment, and instrumentation.
                                      34

-------An error occurred while trying to OCR this image.

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     Indicator species are species found in the waste that  can be used to
represent a group of species 1n determining emissions.   If  little 1s known
about which specific species are present at the site, select an Indicator that
represents a family or class of species so that gross data  on emissions can be
obtained and then later refined.  Table 8 provides  Information that will  aid
in this selection process.  The Ideal Indicator species  or  class of species
is:

          Present in the air emissions in a fixed ratio;

          A non-reactive or stable species;

     •    Present at levels above analytical  detection limits;*

          Unique to the site (not in background air samples);

     •    Representative of the "worst case"  toxicity for compounds at the
          site; and

          Applicable for existing measurement and monitoring technologies; and

     •    Of known toxicity and exposure criteria.

     A 11st of candidate Indicator species can be developed from those species
previously Identified in analysis of the waste or by identifying broad-band
type indicators that represent the type of waste identified in the scoping.
Candidate species should match as closely as possible the characteristics of
an ideal indicator species.  The two main required  characteristics are
presence in the air emissions from the site and the ability to measure/monitor
the species using commercially available methods and instruments.  Examples of
broad-band, class and indicator species are given in Table  9.
                                      36

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TABLE 8.  FACTORS TO CONSIDER IN SELECTING AN INDICATOR SPECIES FOR STUDY
     1)   Homogeneity of waste and representativeness  of proposed
          Indicator species;
     2)   Variety of types of air contaminants (organic, Inorganic,
          blohazard, radioactive);
     3)   Physical state of air contaminants (gas,  liquid,  solid);
     4)   Level of air contaminant emission;
     5)   APA objectives;
     6)   Feasibility of air monitoring for proposed Indicator species;
     7)   Availability of standard sampling/analytlcal/monltorlng
          techniques;
     8)   Potential interferences for the proposed  Indicator species;
          and
     9)   Health effects.
                                     37

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        TABLE 9.  EXAMPLES OF BROAD-BAND,  CLASS,  AND INDICATOR SPECIES
  BROAD BAND
Volatile Organ1cs
CLASSES OF COMPOUNDS
Aliphatics

Aromatics
INDICATOR SPECIES
Alkanes, Total
Hydrocarbons as Pentane
Benzene, Xylene, Toluene
Volatile Inorganics
Semi-Volatile Organics
Non-Volatiles
                           Halogenated Species
Oxygenated Species
Sulfur Containing
Species
Nitrogen Containing
Species
Acid Gases
Sulfur Containing
Polynuclear Aromatics
(PAH)
Polychlorinated
Biphenols (PCBs)
Metals
Trichloroethene,
Trichloroethane, Vinyl
Chloride
Ethanol, Formaldehyde
Mercaptans, Thiophenes
Benzonitrile
Sulfur Dioxide, Hydrogen
Chloride
Hydrogen Sulfide
Napathalene, Benzo-
(a)Pyrene
PCBs As Aroclor 1254
Lead, Chromium, Zinc
                                      38

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     In addition to selecting Indicator species,  the site manager must select
the most suitable air emissions screening technology.   Screening technologies
are summarized 1n Table 10 and described in Table 11.   A1r emissions
measurement/assessment technologies are described in detail  in Section 4.  The
four categories of screening technologies are described below.

          Direct Emissions Measurement.  Concentration measurements can be
          made of the air directly above the waste,  either the "head space" or
          air space of a sampler placed on the waste,  or the head space of a
          sample bottle half-filled with waste material.  The screening
          provides a relative measure of the emission  potential  of various
          wastes/locations.  High concentrations  of  volatile species (Ci) in
          the head space can Indicate high potential  for air emissions from
          the site.  Likewise, low concentrations can  Indicate low potential
          for air emissions.  The advantage of these screening technologies is
          that they are relatively quick, easy and Inexpensive to perform.
          They also can have the highest sensitivity (i.e.,  detect the
          contaminants even at low concentrations),  since they measure
          concentrations at the source.  The techniques are  only applicable to
          volatile gas species.  These data can be used to estimate emission
          factors to Indicate the potential  for air  emissions.

          Indirect Emissions Measurement.  This class  of technologies can be
          used for any type of contaminant such as volatiles and/or
          participate matter.  It is probably the most common screening
          technology used, though it is usually not  used to  develop emission
          estimates.  Screening measurements can  be  made upwind  and downwind
          and directly above waste material  using real-time  instruments to
          estimate potential for air emissions.   Air concentration
          measurements made at short distances (<40  meters)  downwind of the
          waste can be used to indicate the  potential  for air emissions from
          the site.  Downwind measurements should be corrected for any
          Instrument bias and upwind interferences.  Meteorological  factors
                                      39

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      TABLE ID.' SCREENING TECHNOLOGIES APPLICABLE TO  SITE  SCREENING APA
                 FOR LANDFILLS AND LAGOONS*
     •    Direct Emissions Measurement

          •  Head Space Sampler (Refer to 4.1.1)
          -  Head Space Analysis of Bottled Sample (Refer to 4.1.2)


     •    Indirect Emissions Measurement

          -  Upwind/Downwind (Refer to 4.2.1)
          -  Mass Balance (Refer to 4.2.2)
          -  Real-time Instrument Survey (Refer to 4.2.3)


     •    A1r Monitoring/Modeling

          -  Upwind/Downwind (Refer to 4.2.1)


          Emissions (Predictive) Modeling

          •  Any model using literature values and assumed concentrations,
          -  Thlbodeaux-Hwang (Landfills)
          -  Mackay (Lagoons)


*See Section 4 for more detail.
                                      40

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   TABLE  11.   SUMMARY  TABLE OF  INFORMATION ON THE VARIOUS CLASSES OF ASSESSMENT
              TECHNOLOGIES AND  SCREENING ASSESSMENT TECHNOLOGIES
Class of or
Assessment
Technology
Application
Advantages
Disadvantages
  •  Direct  Emission
    Measurement
 Head  Space
 Sampler
 Head Space Sample
- in a Bottle
Landfills and
Lagoons,
especially 1f
Identification of
BEEs per unit on
a combined site
Is required.
All landfills;
lagoons (non-
aerated) with
flotation device.

All landfills and
lagoons where you
have a sample of
the waste.
High precision
and accuracy,
measures
undisturbed or
disturbed BEE
without modeling,
can distinguish
between units if
combined site.

Representative of
volatile
emissions
potential.

Rapid Screening
technology that
1s easy to
perform.
Heterogeneous
waste will
require higher
number of
measurement
points for
representative
BEE.
Sampling devices
required.
Can lose a
significant
fraction of the
volatile species.
    Indirect
    Emission
    Measurement
 Upwind/Downwind
Larger landfills
and lagoons and
sites with waste
handling
activities,
combined sites.
Landfills and
Lagoons (any area
source).
Assess BEE from
an area source,
regardless of
homogeniety and
site activity.
Can be used for
Inaccessible
sites.
Broadly
applicable and
can provide an
estimate of
emissions.
Limitations
imposed by
modeling,
techniques are
Influenced by
meteorological
conditions, may
not be able to
distinguish
between units of
a combined site
or up-wind
interference.

Single point
ambient
measurements may
not represent the
emission source.

       (Continued)
                                       41

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                            TABLE 11.  (Continued)
   Class of or
   Assessment
   Technology
 Application
 Advantages
 Disadvantages
Mass Balance
Lagoons and some
landfills.
Real-time
Instrument Survey
Landfills and
lagoons (any area
source).
Limited resources
are required.
Rapid, real-time
data that can be
used to Indicate
emissions
potential.
Requires
concentration
data over time,
Inherent
Insensltlvity due
to low mass of
volatile species.

Highly variable,
quality control
program for
analyzers
required.
  A1r Monitoring/
  Modeling
Landfills and
lagoons (any area
sources).
Upwind/Downwind
Landfills and
Lagoons (any area
source).
Typically
provides data
that represents
air
concentrations
the community is
exposed to
(fenceline).
Broadly
applicable,
provides
community ambient
concentration
data.
Limitations
Imposed by
modeling,
techniques are
influences by
meteorological
conditions,
analytical
sensitivity may
be a limiting
factor.

Low
concentrations
with high
variability,
measurement
subject to
meteor!ogical
influences.
                                                                   (Continued)
                                      42

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                          TABLE 11.  (Continued)
Class of or
Assessment
Technology
Application
Advantages
Disadvantages
Emissions         Landfills and       Provide rapid,      Accuracy,
(Predictive)      lagoons,            Inexpensive         precision
Modeling          especially          assessment,         dependent  on
                  applications with   particularly        qulaiyt of site-
                  site-specific       where only a few    specific data  or
                  Information.        species are of      assumptions.
                                      concern.  Model     Most models have
                                      Inputs can be       limited
                                      assumed or taken    validation.
                                      from literature
                                      1f site-specific
                                      data is not
                                      available.
                                   43

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           can Influence the air concentration  of volatiles  and particulate
           matter so field notes must Include on-slte  observations and
           meteorological conditions during testing.

      •    A1r Mon1tor1no/Modeling.   A1r monitoring and modeling technologies
           are equivalent to the Indirect emissions measurement technologies
           except that the samples are collected  at greater  distances from the
           waste, typically at the fencellne or property line,  and the sampling
           locations are not as clustered.   If  meteorological data are
           collected concurrently, these data can be used to validate
           dispersion model estimates and estimate the potential  for
           contaminants to reach off-site receptors.   However,  they may be
           limited by the sensitivity of the Instrumental  measurement used and
:           the dispersion and dilution of the air emission.  Unless estimates
           of off-site Impact potential  are needed, fenceline monitoring is not
           recommended for the screening study.

      •    Emissions (Predictive) Modeling. Emissions modeling can be used if
           the preliminary assessment has provided fairly detailed Information
           that can be Input into a model.   The model  estimates can usually be
           Improved by using air emissions  data from the site.   The
           Thibodeaux-Hwang model 1s appropriate  as a  screening technology for
           landfills, and the Mackay model  1s appropriate for lagoons.
           Modeling has the obvious advantage of  being an off-site activity.

      Once an appropriate screening technology  and associated equipment/
 instruments are selected, a technical approach to applying  the technology
 should be developed.  The Data Quality Ob.iective For  Remedial  Response
 Activities (13) can provide assistance in  designing the site screening.
 Again, each unit of a combined site must be studied independently.  This may
 Involve the use of different screening technologies for the various site
 units.
                                       44

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'      Quality control should be an Integral  part of any screening study, and
  direction in developing and documenting a quality assurance project plan can
  be obtained from the Interim Guidelines and Specifications For Preparing
  Quality Assurance Pro.lect Plans.(14)  One very useful  exercise In the design
  of the screening study is a "dry-run" survey,  Including a mock exercise
  involving data use.  This will help in determining if  the technical approach
 - will satisfy the Intended objective of obtaining an estimate of the potential
 - for air emissions from the site.
 P
       After design 1s completed, the site screening approach should be
  circulated for review and then modified, as necessary.

       Once the site screening has been completed,  the screening tlata should be
  evaluated to determine if further data (in-depth measurements) are required
  for the site characterization.  Screening data may consist of a  concentration
 -number representing volatile content (headspace sampler or analysis of
  headspace above the waste in a bottled sample) or a preliminary  BEE (indirect
 Remission measurement/model estimate, air monitoring/model  estimate, predictive
 * model  estimate).  The equations in Figure 7 show how these data  should be
  organized.  Note that the BEE should be an  addition of  all  of the site units
  if the units are studied Individually.   Any emissions data for disturbed waste
  should not be included in the BEE and do >ot have to be summed separately
  since  the site mitigation planning will  probably  use the disturbed site
  emission estimates on a unit basis in developing  mitigations  for "operable
  units."

      Absolute criteria against which to compare these BEE  data are not
  available.  Estimated ambient levels (determined  from the  BEEs)  can be
  compared to  state ambient air toxic levels  and to EPA cancer  risk values if
  available.
                                       45

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Undisturbed Site BEE

     Unit1   Cj                                                       (Eq.  1)

     Unit!  UEEi|t>a                                                 (Eq.  2)

where, Unit1 = a waste site or a discrete component of a waste site  (com-
               bined site with multiple units);
          Cj = concentration of species above the undisturbed waste  in a
               sampler; or concentration of species in the air above or
               downwind of the undisturbed waste;
           i = species or group of species;
           t = time duration of emission measurement;
           a = area of exposed waste per unit; and
    UEEIi.t.a = site emission estimate for species; for unit U (mass/time-
               area) for exposed waste surface (expressed per unit surface
               area).

     For sites with multiple units, the BEE expression is:

     BEE = Unitj Emissions +
                Unit2 Emissions + Unit3 Emissions...                 (Eq.  3)
or
     BEE = UlEEi>tta + U2EEittfa + U^^...                       (Eq.  A)

where, UjEE^ t a = undisturbed site emission estimate for Unit*.
                  Figure  7.   Undisturbed  site  BEE  equations
                                      46

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       If high levels of air emissions from the  site  are  possible 'and more
  detailed Information Is required to meet  the APA objectives,  then  site
  characterization should be conducted using 1n-depth technologies to develop
  representative BEEs.  If, however,  little or no potential  for air  emissions
  surfaces from the data or If screening  BEEs provide enough Information for a
  site manager to evaluate air emissions, In-depth BEEs development  may not be
  necessary In the site characterization.

t  3.1.5  Design and Conduct the In-Deoth  Site Characterization

       The activities to design and conduct an in-depth study are similar to
  those described in Section 3.1.4 for the  screening  APA  except that in-depth
  assessment technologies rather than screening  technologies are-used.   The
  steps are:

            Determine the feasibility of  obtaining the detailed BEEs.

       •    Select appropriate detailed technologies, indicator species,  and
            appl1cable equlpment/instrumentat1on.

            Design the site characterization  technical approach and  test  plan,
            including the QA/QC program.

            Circulate the detailed  technical  approach and test  plan  for review
            and ensure it addresses the site-specific objective(s).

            Conduct the site characterization program and document the  findings.

       •    Determine if the BEE data are sufficient  and adequate for  site
            mitigation decisions.   If adequate, document them;  if inadequate,
            evaluate the data needs and reiterate, as necessary.  Re-evaluate
            and document.
                                       47

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     In-depth-technologies for developing BEEs  are  summarized In  Table 12 and
presented In detail 1n Section 4.  Information  that may  be  useful  1n selecting
the appropriate assessment technology 1s summarized 1n Table 13.   In general,
direct emissions measurement technologies offer several  advantages over the
other technology categories and are considered  to be the preferred
technologies for most sites.  With the exception of the  wind tunnel, the
direct measurement technologies applicable to landfills  and lagoons are
limited to volatlles.  These technologies generate  BEEs  as  a function of the
site conditions and can be used with a variety  of analytical  techniques.
Measurements at the source (waste) will be the  highest 1n concentration
compared to the other measurement techniques.  The  direct emission measurement
technologies are not suited to sites that are heterogeneous.

     For those applications where the waste Is  not  homogeneous, 1s
Inaccessible, or consists of multiple sources which need not be individually
studied, the Indirect technologies are preferable to direct technologies.
Total site air emissions can be obtained and used to estimate BEEs and
disturbed waste emission data.  Indirect technologies are  susceptible to
meteorological Influences and require analytical techniques with  greater
sensitivity than those used for direct measurements. Also, upwind
Interferences can create problems.

     Air monitoring/modeling technologies are similar to indirect
technologies, but used farther downwind.  They  have the  same applicability and
limitations, except that even lower air concentrations can  be expected farther
downwind.  This approach is not generally recommended unless fenceline data
are required for other needs.  Air monitoring/modeling technologies are
discussed in detail in Volume IV of this series of  guidance manuals.

     Emissions (predictive) modeling can be used; however,  site-specific data,
particularly diffusion coefficient data, are often  necessary to obtain
representative BEEs.  These data may be difficult and expensive to gather.
                                      48

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TABLE 12. -UN-DEPTH TECHNOLOGIES APPLICABLE TO SITE CHARACTERIZATION
           FOR LANDFILLS AND LAGOONS
     Direct Emissions Measurement

     -  Surface Emission Isolation Flux Chamber (Refer to 4.1.3)
     -  Portable Wind Tunnels (Refer to 4.1.4)
     -  Soil Vapor Probe (Refer to 4.1.5)
     -  Soil Vapor Monitoring Well (Refer to 4.1.6)
     -  Downhole Emission Flux Chamber (Refer to 4.1.7)
     -  Vent Sampling (Refer to 4.1.8)

     Indirect Emissions Measurement

     -  Concentration Profile (Refer to 4.2.4)
     -  Transect (Refer to 4.2.5)
     Ai r Mon1tori ng/Model1ng

     -  Concentration Profile (Refer to 4.2.4)
     -  Transect (Refer to 4.2.5)
     -  Exposure Profile (Refer to 4.3.1)
     Emissions (Predictive) Modeling

     -  Any model using site-specific values
     -  RTI. (Landfills)
     -  Thibodeaux, Parker, and Heck (Lagoons)
                                 49

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       TABLE 13.  SUMMARY TABLE OF INFORMAITON ON THE VARIOUS CLASSES OF
                  ASSESSMENT TECHNOLOGIES AND IN-DEPTH ASSESSMENT TECHNOLOGIES
Class of or
Assessment
Technology         Application          Advantages
                                          Disadvantages
• Direct
  Emission
  Measurement
Emission
Isolation Flux
Chamber
(Volatiles)
Soil Probe
(Volatiles)
Downhole
Emission Flux
Chamber
(Volatiles)
Landfills and
lagoons, especially
1f Identification
of BEEs per unit on
a combined site Is
required.
Landfills-active,
inactive, soil
contamination,
waste piles;
Lagoons
(nonaerated) with
flotation on
device.
Landfills-active,
Inactive, soil
contamination,
waste piles;
Lagoons-berms
around lagoons,
heavy sludges.
Landfills-active,
inactive, soil
contamination,
waste piles;
Lagoons-berms
around lagoons,
heavy sludges.
High precision
and accuracy,
measures
undisturbed or
disturbed BEE
without modeling,
can distinguish
between units if
combined site.

High precision
and accuracy,
measures
undisturbed or
disturbed BEE
without modeling,
can distinguish
between units if
combined site.

Can obtain a
subsurface
distrubed BEE 1-
to-10 feet below
land surface
without
excavation.
Can obtain a
subsurface
disturbed BEE 1
to 100 feet or
more below land
surface with a
hollow stem auger
drill rig.
Heterogeneous
waste will
require higher
number of
measurement
points for
representative
BEE.
Heterogeneous
waste will
require higher
number of
measurement
points for
representative
BEE.
Heterogeneous
waste will
require higher
number of
measurement
points for
representative
BEE.

Layered or
stratified waste
will require BEE
for each discrete
layer.
                                                               (Continued)
                                      50

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                            TABLE 13.   (Continued)
Class of or
Assessment
Techno!ogy
 Application
Advantages
Disadvantages
Vent Sampling
(Volatlles)
Crack Sampling
(VolatHes)
Wind Tunnel
Measurement
(Volatiles
and/or
Particulate
Matter)
Waste repositories
with passive or
active venting
system, common at
municipal, and co-
disposal landfills.
Covered landfills
or subsurface
contamination.
Special'zed for
particulate
emissions from
waste piles and
solid surfaces,
landfills, lagoons
(non-aerated) with
flotation on
device.
 Simple BEE
 measurement
 procedure.
 Identifies gross
 estimate of
 emissions from
 covered
 landfills.
 BEE  for
 particulate
 matter and/or
 volatlles as a
 function of wind
 speed.
 Often difficult
 to measure low
 gas flow rates
 which causes
 Imprecision and
 Inaccuracy,
 include sampling
 schedule that
 Identifies
 ddiurnal
 variations/other
 fattors that
 influence gas
 production.

 Only provides an
 estimate of
 emissions rate,
 must include
 sampling at other
 locations to
 assess emissions
 potential.

 Heterogeneous
 waste will
 require higher
 number of
 measurement
 points for
 representative
 BEE, additional
 support equipment
 needed to produce
 simulated wind
 speed.
                                                               (Continued)
                                      51

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                             TABLE  13.   (Continued)
 Class  of or
 Assessment
 Technology
 Application
Advantages
Disadvantages
 •  Indirect
   Emission
   Measurement
 Concentration
 Profile
T(Volat1les)
Transect
(VolatUes/
Particulate
Matter)
Larger landfills
and lagoons and
sites with waste
handling
activities,
combined sites.
Assess BEE from
an  area source,
regardless of
homogenlety and
site activity.
Can be used for
Inaccessible
sites.
Lagoons, Landfills-
large solid waste
site and
contaminated soil.
Lagoons, Landfills-
large or small
sites.
Specialized
measurement and
modeling
technique, high
precision and
accuracy for an
Indirect
technique.
Specialized
measurement and
modeling
technique, can be
used for
particulate
matter from waste
handling.
 Limitations
 imposed by
 modeling,
 techniques are
 influenced by
 meteorological
 conditions, may
 not be able to
 distinguish
 between units of
 a combined site
 or up-wind
 Interference.

 Must meet
 meteorological
 conditions of
 technique, not
 well suited for
 small  waste
 areas,
 sophisticated
 support equipment
 required.

 Must meet
 meteorlogical
 conditions of
 technique,
 technique
 influenced by
 meteorological
 conditions.
  Air
  Monitoring/
  Modeling
Landfills and
Lagoons, complete
site emissions,
monitoring at
downwind distances
greater than
Indirect emission
measurements.
Typically
provides data
that represent
air
concentrations
the community is
exposed to
(Fenceline).
 Limitations
 imposed by
 modeling,
 techniques are
 influenced by
 meterological
 conditions,
 analytical
 sensitivity may
 be  a  limiting
 factor.
                                                               (Continued)
                                      52

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                            TABLE 13.   (Continued)
Class of or
Assessment
Technology
Concentration
Application
Not typically used
Advantages
None.
Disadvantages
Modeling may not
Profile
(Volatlles)
Transect
(Volatlles/
Particulates
Matter)
for downwind
measurements.
Lagoons, Landfills
(any waste site or
waste handling
treatment for total
site emissions).
Generally
applicable to
most situations,
predict emissions
from data taken
downwi nd.

Limitations
imposed by
modeling,
techniques are
influenced by
meterological
conditions,
analytical
sensitivity may
be a limiting
factor.
• Emissions
  (Predictive)
  Modeling
  (Volatiles/
  Particulate
  Matter)
AP-42 Dust
Emissions for
Vehicles
(Participate
Matter)
Landfills and
lagoons, especially
applications with
site-specific
Information.
Road Dust
Provide rapid,
inexpensive
assessment,
particularly
where only a few
species are of
concern.  Model
Inputs can be
assumed or taken
from literature
if site-specific
data are not
available.

Established EPA-
approved model.
Accuracy,
precision
dependent on
quality of site-
specific data or
assumptions.
Most models have
limited
validation.
Accuracy depends
on quality site-
specific data.
                                                                (Continued)
                                      53

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                            TABLE 13.  (Continued)
Class of or
Assessment
Technology
Covered
Application
Covered Landfills
Advantages
Provide rapid,
Disadvantages
Accuracy,
Landfill Models
(Volatlles)
Open Dump
Models
(Volatlles)
Open Landfills
Lagoon Models
(Volatiles)
Lagoons, with or
without generation.
Inexpensive
assessment.
Models can be
selected based on
available input
data.  Can
account for bio-
gas generation at
co-disposal
sites.

Account for non-
steady state
emission (i.e.,
declining
emission) over
time.
Provide rapid,
inexpensive
assessment.
Models can be
selected based on
available data.
                                           precision,
                                           dependent on
                                           qualiyt  of  input
                                           data.  Do not
                                           account  for
                                           losses to other
                                           pathways.
Accuracy,
precision
dependent on
quality of input
data.  Do not
account for
losses to other
pathways.  Do not
account for bio-
gas generation.

Accuracy,
precision
dependent on
quality of input
data.  Do not
account for
losses to other
pathways.  Assume
constant source
strength over
time.
                                      54

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In addition, demonstrating the validity of the models for specific
applications nay be difficult.  It Is emphasized that site-specific data are
required for site characterization; the use of literature data should be
limited, if possible.

     Once the in-depth site characterization has been designed and conducted,
the BEEs should be evaluated and documented.  Data should be organized like
the screening assessment data generating the detailed undisturbed site BEE
(Eq. 4).  These equations are Identical to the screening assessment equations
but are generally better estimates of the emissions potential  since more
sophisticated technologies are used.

     If the baseline emission estimates are considered necessary and
sufficient to satisfy the project needs, then the field studies for the APA
are complete and these data are documented.  If the BEEs are considered
inadequate or additional APA data are required, then follow on-site
characterization should be designed and conducted.

3.2  USE OF THE BEEs IN THE MITIGATION PROCESS

     Figure 8 Illustrates how the BEEs fit In the CERCLA mitigation process.
Data uses for non-NPL sites will probably be very similar to those identified
in Figure 8.  BEEs generated in the remedial investigation can be used in two
ways.  First, BEE data provide Information regarding the potential air quality
impact and health risk(s) posed by the site should the no-action remedial
alternative be selected.  Essentially, this is the air impact that can be
expected from the site over time if the site is left alone.  Thus, the BEEs
used in this way may help justify the decision to mitigate the site.  These
data may also indicate the need for an immediate removal action to protect the
public from possible air contaminants.
                                      55

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     Second, data for the disturbed site are  necessary to  estimate short-term
Impacts to air quality and risks to on-slte workers  and  neighboring residents
during cleanup.  These data assist 1n the evaluation of  remedial  alternatives
considered 1n the feasibility study.  Remember that  this protocol  1s designed
specifically to develop BEEs (and disturbed emission estimates).   These data,
along with dispersion modeling,  can be used to assess off-site  Impacts to air
quality.  Assessing off-site Impacts 1s one of the topics  addressed in Volume
IV.
                                      57

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                                   SECTION 4
                      AIR  EMISSION MEASUREMENT TECHNIQUES

      Section 4 describes recommended air emission  assessment technologies for
 landfills and lagoons.   The recommended technologies  are  organized  into four
 generic categories: direct emission  measurement  technologies,  indirect
 emission measurement technologies,  air monitoring/modeling  technologies,  and
 emissions (predictive)  modeling technologies.  Each category is  further
 divided Into two classes:   screening technologies, and  in-depth  assessment
 technologies.  The screening technologies provide  some  level  of  air emission
 assessment but may not  accurately represent  the  site's  potential  for air
 emissions.  The in-depth assessment  technologies are  much more rigorous and
 generally provide a more accurate estimate of the  potential  for  air emissions
 from the site.  Screening  technologies are typically  used in the site
 inspection stage of the RI, whereas  in-depth assessment technologies are
 typically used during site characterization.

      Where possible, "preferred" technologies are  identified and recommended
 for use.  However, the  preferred technology  will not  always  be the  best choice
 of assessment technology for every application.  The  intent  of identifying
 preferred technologies  is  to assist  the RPM  or site manager  by identifying
 those technologies that are preferable from  a technical standpoint  for the
 majority of sites.

 4.1  DIRECT EMISSION MEASUREMENT TECHNOLOGIES

      A general discussion  of direct  measurement  technologies  is  followed  by
.descriptions of the individual  techniques.   The  direct emission  measurement
 technologies presented  in  this  section are:

      Screening Technologies —
      4.1.1     Head Space  Sampler
      4.1.2     Head Space  Analysis of Bottled Sample
                                      58

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      In-Depth Technologies--
      4.1.3     Emission Isolation Flux Chamber
      4.1.4     Portable Wind Tunnels
      4.1.5     Soil Vapor Probes
      4.1.6     Soil Vapor Monitoring Well
      4.1.7     Downhole Chamber
      4.1.8     Vent Sampling

      Direct emission measurement technologies are often the preferred
 technologies for investigating the air pathway.  The technologies  generally
 consist of isolating or covering a small  section of the site  surface or
 subsurface using a chamber or enclosure.   The concentration of emissions
 produced by the isolated surface is measured within the chamber or from an
 outlet line.  These concentration measurements, along with other
 technology-specific parameters, are then  used to calculate an emission  flux or
 relative concentration valve.  The emission flux (rate per area) can generally
 be related to an emission rate for the entire source.

      The types of volatile or particulate species that can be measured  by the
 technologies are essentially unrestricted; their measurement  depends on the
 sampling media selected and analysis' technique rather than the emission
"measurement technology.  However, few of  the technologies are applicable to
 both volatile and particulate emission rate measurement.  Selection of
 sampling media and analysis techniques is outside the scope of this document,
 but is addressed in Volume IV of this series.  The direct emission measurement
 technologies can be used to determine the emission rate variability of  afsite
 by performing multiple measurements at selected locations across the site.   In
 addition, these technologies allow for the evaluation of individual waste
 areas at the site so that the investigation can focus on those areas with the
 greatest potential emissions.

      The cost of the direct emission measurement technologies varies
 considerably.  However, most of the technologies are cost-effective, allowing
 for several measurements in a given day.   Real-time instruments can be  used
 with all the direct technologies to provide immediate data for decision-making
                                       59

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during  the  sampling  program,  and for the relative ranking of the emission rate
at locations  across  the  site.  This procedure can be used to reduce the number
of samples  requiring laboratory analysis by screening for those samples with
significant concentrations.

      Direct  emission measurement technologies, as a class of assessment
technologies,  are generally preferable to other classes of technologies
because they  have been proven to be a cost-effective approach for obtaining
emission rate and concentration data and they avoid the necessity of modeling
to develop  BEEs. 'Direct emission measurement technologies and equipment -are
generally relatively simple and straightforward.

4.1.1   Head Space Samplers (Screening Technology)

     Head space samplers are  in-situ screening technologies that use a chamber
,to isolate  part of the emission source surface.(15,16,17)  The quantity or
concentration  of vapors  and/or gas emitted from the surface that build up in
the chamber over a period of time is measured, rather than measuring a rate.
The head space sampler technology was a predecessor to the emission isolation
flux chamber  described in 4.1.3.

     Head space samplers may be operated in one of two modes, referred to as
static  and  dynamic modes.  In the static mode, the sampling enclosure is
placed  over the emitting surface for a given period of time.(15)  The
enclosure may  be purged  initially with clean air or nitrogen.  Surface
emissions then enter  the chamber from the exposed surface and are all owed-to
concentrate in the chamber before sample collection.

     A  time-integrated emission flux for the static mode is calculated as:(15)

                              Ei - (C,  VE)/(t  A)                        (Eq.  5)

     where     E,  -  emission  flux  for component  1  (ug/m2-sec);
               C,  -  concentration  of component 1  (ug/m3);
               ^VE  •  volume of the ..enclosure  (m3);
                                      60

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               -\  • length of time enclosure  1s  1n place  (sec);  and
                A  - surface area enclosed  by  chamber  (m2).

      The build-up of gas species within  the chamber Improves the sensitivity
 of the method relative to ambient air sampling.  However, the  accuracy of the
 calculated emission rate 1s dependent on the  duration of  sampling relative to
-the time required to reach steady-state  concentrations within  the chamber.
 For long sampling periods, the concentration  gradient of  the soil/air
 interface 1s reduced and the emission flux 1s underestimated.  Also,
 Instantaneous changes in the flux cannot be measured.

      In the dynamic mode, the sampling enclosure also is  placed  over  the
 emitting surface for a given time period and  the chamber  may be* initially
 purged with clean air or nitrogen.   However,  collected emissions are
 continuously withdrawn from the enclosure.(15)  The chamber can  be operated
 with a second port allowing ambient air  to enter the chamber to  prevent a
 negative pressure within the chamber.  The emitted species is  concentrated on
 sampling media or may be continuously monitored.  When the sample is
 concentrated on the sampling media (i.e.,  sorbent), the emission flux is
 calculated as:(15)

                               E, • (C, VS)/(A t)                        (Eq.  6)

      where     Ei  - emission flux  for  component i (ug/m2-sec);
                C,  - concentration of component i (ug/m3);
                Vs  - total  volume of sample withdrawn (m3);
*               t  - length of sampling interval  (sec); and
                A  - surface area enclosed  by  chamber  (m2).

      An advantage of the dynamic mode is that the sampling duration and air
 sampling rate can be varied to adjust the  volume of air sampled  in order to
 achieve the required analytical  sensitivities.  The disadvantage of operating
 in the dynamic mode is that as the atmosphere within the  enclosure is
 withdrawn, the emission flux value may be  affected.  This can  occur by the
 addition of bulk flow of the soil  gas Into the chamber or, alternately, air
                                       61

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  entrapment occurring within the enclosure  because of leakage  at  the
  enclosure's bottom edge, or by air moving through the soil  at  the enclosure's
  bottom edge.  If a second port 1s used to allow atmospheric air to enter,  a
  means of removing volatlles from the atmospheric air must be used.

       The major advantage of the technology  Is that the emissions  process does
? not have to be fully evaluated to employ the technology.  Determining whether
  the emission rate 1s controlled by diffusion through the soil  cover,
  volatilization at the surface/air Interface, etc., to employ the  technology is
  not necessary.  Site-specific conditions, such  as depth of  soil cover or'soil
  porosity, do not have to be determined to employ the technology.   Although
  desireable, knowledge of the waste composition  and exact spacial  boundaries of
  the waste are not necessary to use the technology to assess the air pathway.
  However, both of these factors will help 1n the selection of appropriate
  emission concentration measurement instruments  or sampling  techniques and  the
 -.selection of sampling locations.

  4ppl1cability--
       The emission Isolation flux chamber Is preferred to head  space samplers
  except where the emission flux is expected  to be extremely  low.   Under these
  conditions, use of head space samplers in static mode for long intervals
  (possibly days) may allow emission fluxes to be measured by the head  space
  sampling technology where other technologies may fail to produce  a  measurable
  emission flux.

       Head space samplers are applicable to  emission flux measurement  from  all
  forms of solid area sources including landfills, open dumps, and  waste piles,
  and for homogenous, quiescent lagoons.   The technology can  be  used  at open and
  closed landfills,  with or without internal  gas  generation.   The technology can
  be used to assess emission rates  from cracks in  the surface  cover and from
  vents that have minimal  or no volumetric flow.   The technology is  applicable
  both for undisturbed and disturbed site conditions.
                                       62

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  Llnritatlons--
      As previously mentioned, head space samplers may enhance (dynamic mode)
*  or suppress  (static mode) the emission flux.  The dynamic mode also may be
  subject to air entrapment resulting in deceptively low emission flux values.
  The technology does not assess the effects of wind speed on the emission flux.
  For lagoons, removal of air from the chamber will induce a pressure change
  unless make-up air 1s able to enter the chamber.   The chamber will require
  some type of support of flotation system, and this may be affected by waves or
  agitation.

      Head space samplers are not applicable to the measurement of particulate
  emission fluxes.  Also, the technology has not been reported as a validated
  technology.
3
  4.1.2  Headsoace Analysis of Bottled Samples (Screening Technology)

      Headspace analysis of bottled sample is a preferred technology for field
  screening of wastes and soils to determine their  relative emissions potential.
  In this method, liquid, soil, or waste from the site surface or subsurface is
  collected.   The material 1s Immediately placed in a sampling container,
,.typically 1-liter or a 40 ml volatile organic analysis (VOA) vial with septa;
  and the container sealed.  Transferring the soil  or waste immediately after
Collection Into the sample container to prevent loss of volatiles is the key
'to successful use of the technology.  The container is allowed to stand for a
  given period of time, typically 5 to 30 minutes.   The container lid is then
  cracked open and the probe of a field Instrument  is inserted to determine if
^soil-vapors  are present.  Syringes can be used to withdraw gas samples via
  parts of the VOA vial septa for more sophisticated analysis techniques.
  Typical field instruments used include portable flame ionization detectors,
  photolonization detectors, combustion meters, and colorimetric tubes.

      A second type of headspace analysis involves analyzing the headspace gas
  or extracted solids of a soil waste core.  To obtain a sample to measure the
  headspace, an undisturbed core 1s collected using an auger or by driving a
                                       63

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 tube Into the ground.  The sample 1s then  sealed  1n a sample container  with
 minimal headspace.

      The core sampler shown In Figure 9 consists  of a brass core  sleeve which
 1s pressed Into the soil  to a sufficient depth to fill the sampler  but  not
 compress the sample.  After excess soil  is removed, the  sleeve  is sealed with
 a Teflon-lined cap.  The  samples are stored at room temperature.  Headspace
 gas is removed from the core by a syringe  and analyzed by GC.

 Appl 1 cablli ty-
      The headspace analysis is an excellent screening technology  for  all  types
 of soil or waste which have a volatile component.  Some  experimentation may  be
 required to determine the optional time to allow  for volatilization to  occur
 before measurement.  The  technology can be used to identify surface
 contamination boundaries, select sampling  locations for  detailed  technologies,
 and identify health and safety concerns.

'Limitations--
      The technology does  not provide for calculation of  an emission rate, but
 rather Identifies soils and wastes which are potential source of  air
 emissions.  The technology generally only  provides qualitative  data on  species
 type, however, species specific data can be obtained if  suitable  analytical
 techniques are selected.   The technology is not applicable to particulate
 emissions.

      The technology is best suited for measuring  adsorbed organics, although
 it can also be effective  with free organics in the pore  space if  the  material
 is rapidly transferred to the sample container, or if tube or core  samplers
 are used.

 Preferred  Technology--
      Headspace analysis of bottled samples  is one of the two preferred
 technologies for the emission screening  study.  This direct approach  is
 preferred  because 1t 1s simple to Implement and effective at identifying
 volatile content, which represents volatile emissions potential.  Chemical
                                      64

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-WING NUT
                        END CAP
                                SCREENS
                                                         THREADED ROD
                                           I BRASS CORE SLEEVE)
                              TEFLON RING




                      TEFLON CAP LINER
Figure 9.  Schematic diagram of.a  soil core sample sleeve.
                                65

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analysis of the waste will Identify the potential for contaminated participate
matter emissions.  Thus, the headspace analysis and the analysis of the waste
can provide effective screening of emissions potential.  The other preferred
screening technology is an indirect technology, simple upwind/downwind
sampling.

4.1.3  Emission Isolation Flux Chamber (In-Deoth Technology)

     The emission Isolation flux chamber Is one of the preferred in-depth
technologies for the direct measurement of volatile species emission
rates.(18-23)  The technology uses a surface enclosure (flux chamber) to
isolate a known surface area for emission flux (rate per area) measurement.
The emission Isolation flux chamber for solid surfaces is illustrated in
Figure 10 and for liquid surfaces in Figure 11.

     Emissions enter the open bottom of chamber from the exposed surface.
Clean, dry sweep air is.added to the chamber at a metered rate.  Within the
chamber, the sweep air is mixed with emitted vapors and gases by the physical
design of the sweep air Inlet.  The sweep air creates a slight wind velocity
at the emitting surface, preventing a build up of the emission concentration
in the boundary layer directly above the surface.  The exit port is used for
measurement of the concentration of the air with the chamber or for sampling
and subsequent analysis.  A pressure relief port in the enclosure prevents
pressure build up within the chamber that might otherwise occur when sampling
liquid surfaces.  A positive or negative pressure in the enclosure could
affect the emission event and, thus, the assessment of the emission flux.  For
lagoons, a support or flotation system is necessary.

     The technology directly measures essentially an instantaneous emission
flow (flux) from that surface.  The emission flux is calculated from the
surface area isolated, the sweep air flow rate, and the emission
concentration.  Statistical  methods are used to determine the number of
measurement locations required to characterize the emission from an area
source.  These methods are based on the surface area of the source and the
variability (precision)-of the measured emission rate at randomly selected
                                      66

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                           TEMPERATURE
                             READOUT
                                               THERMOCOUPLE
                                                                         SYRINGE/CANISTER
                                                                          SAMPLING PORT
                                                                               REAL TIME
                                                                               ANALYZER
CARRIER
  GAS
                                                                    OUTLET LINE
STAINLESS STEEL
 OR PLEXIGLAS
€
                                       CUT AWAY TO SHOW
                                      SWEEP AIR INLET LINE
                                      AND THE OUTLET LINE
     Figure 10.  A cutaway diagram of the emission isolation flux chamber
                  and  support equipment.
                                         67

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                        TEMPERATURE
                          READOUT
                                             THERMOCOUPLE

                                               PLEXIGLASS
SAMPIE COLLECTION
 AND/OR ANALYSIS
                                                                       GRAB SAMPLE
                                                                           PORT
                                                                  \CONTROL
                                                                  /  VALVES
                                                               PERFORATED
                                                               OUTLET LINE
                                       SWEEP AW INLET LINE
                                       AND THE OUTLET LINE
Figure  11.  A  cutaway diagram of the surface  emission  isolation  flux chamber
             and support  equipment  for liquid  surfaces.
                                         68

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  locations  across  the  site.  Use of the emission Isolation flux chamber Is
  described  1n  the  draft  "Measurement of Gaseous Emission Rates from Land
'"'Surfaces Using  an Emission  Isolation Flux Chamber User's Guide (23)."  The
  emission Isolation flux chamber was validated for EPA (using standard methods)
  for measuring volatile  emissions from landfills.(22,23)

      The emission flux  1s calculated as  (23):

                                E, - (C,  Q)/A                         (Eq.  7)

      where     E,  - emission flux of component 1 (ug/m2-min);
                 C{  » concentration of component 1 at chamber outlet (ug/m3);
                 Q   - sweep air flow rate  into chamber (m3/min);  and
                 A   - surface area enclosed by chamber (m2).

  Appl 1 cabill ty~
      The emission isolation flux chamber is applicable to emission flux
  measurement from  all  types of area sources Including lagoons, landfills^pen
  dumps,  and waste  piles.  The technology  can be used at open and closed
  landfills, with or without  internal gas  generation.  The technology can be
  used to assess  emission rates from cracks in the surface cover and from vents
  that have  minimal  or  no volumetric flow.

      The technology is  applicable both for undisturbed and disturbed site
 ^conditions, and for the testing of emissions control technologies.  The  .
  technology can  be used  to satisfy data needs for all phases of the RI/FS *
^process, as well  as post-remediation monitoring and, therefore, can provide
  directly comparable data throughout the  process.

  Umitations--
      The emission fluxes of volatile species may be enhanced or suppressed
  since the  flux  chamber  alters the environmental conditions (e.g., wind speed)
  at the  sampling locations.  The technology does not assess the effects of wind
.  speed on the  emission rate.
                                       69

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      The technique 1s not particularly well suited to large emission sources
 with a high degree of heterogeniety.  Comparison of sample data and
 variability estimates can determine the number of sampling locations needed to
 determine representative area emissions.  Also, the technique is not
 applicable to the measurement of part icul ate emission fluxes.

^Preferred Techno! ogy--
      The emission isolation flux chamber Is a preferred technology for
 developing in-depth BEEs.  As discussed, the advantages generally out-weigh
 the limitations of the technique.  The technique is well  documented in the
 user's guide and well characterized.

 4.1.4  Portable Wind Tunnels (In-Deoth Technology)

      Wind tunnels are 1n-depth technologies used to directly measure the
 emission rate of credible material.  They also can be used to measure the
 emission flux of volatile compounds.  In either application, measurements can
 be made under varying wind conditions to examine the effect of wind speed Ion
remissions.  The required equipment consists of portable,  open-bottomed
 enclosures used to Isolate a known surface area, a blower used to simulate
      conditions, and sampling devices.
      The Cowherd wind tunnel, shown in Figure 12 is  a  portable wind tunnel
 developed for "in situ measurement of emissions  from representative test
 surfaces under predetermined wind conditions"(24).   The  tunnel  was  developed
 to measure particulate matter emissions from open waste  piles.   "The    ^
 open-floored test section of the portable wind tunnel  is placed directly over
 the surface to be tested.  Air is drawn through  the  tunnel  at  controlled
 velocities.  The exit air stream from the test section passes  through  a
 circular duct fitted with a sampling probe at the down-stream  end.   Air is
 drawn through the probe Isokinetically by a high-volume  sampling train"(24).
 The sampling train consists of a trapper probe,  cyclone  precollector,
 parallel-slot cascade Impactor,  backup filter, and high  volume motor.   Air
 flow is provided by a blower located downstream  of the sampling train.
                                       70

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Figure 12.  Illustration of MRI  wind tunnel
                     71

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     The  authors  state  that,  "although a portable wind tunnel does not
generate  the  larger  scales of turbulent motion found in the atmosphere, the
turbulent boundary layer formed within the tunnel simulates the smaller scales
of atmospheric turbulence.   It is the smaller scale turbulence which
penetrates the wind  flow in direct contact with the pile surface and
contributes to the particle entrainment mechanisms"(24).

     The  emission flux  is calculated from the isolated surface area, emission
concentration, simulated wind speed, and time period during which particulates
are collected. Because  the emission concentration is collected over time, the
technology measures  the overall (time integrated) emission rate rather than
the emission  flux.   Varying the simulated wind speed between measurements
allows for development  of a weighted average emission rate.  Th-is is preferred
to using  an average  wind speed because the total erosion may be greatly
influenced by infrequent periods of high wind speed.

     The  loss of erodible material is calculated as (24):

                                E<  -  (C, Q t)/A                      (Eq. 8)

     where     E, - emission rate of component i  (g/m2);
               C1 » average particulate  concentration  of component  i  in tunnel
                     exit stream (g/m3);
               Q  -  tunnel flow rate (m3/sec);
               t  -  duration  of sampling (sec); and
               A  •  exposed test area (m2).

     Elimination of  the time  factor in the calculation will provide an
emission  flux on a unit area  per time basis (g/m2-sec).   The average
particulate concentration (C,) may be reduced  to  account for background dust
levels by sampling under light wind conditions and subtracting the  resulting
average concentration from C, values  generated during  simulations of higher
wind conditions.
                                      72

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     The Astle wind tunnel, shown 1n Figure 13, 1s a form of surface enclosure
developed for "measurement of odor source strength"(25); but 1t also may be
applicable to volatile emissions measurement.  This portable wind tunnel
consists of an open-bottom enclosure that 1s placed over the emitting surface.
Ambient air 1s blown through the chamber at typical wind speed rates (e.g., 1
to 15 mph) and collected near the enclosure outlet.  Test results for volatile
emission rate measurement were not Identified in the literature.

     The emission flux 1s calculated from the simulated wind speed, emission
concentration, and surface area Isolated.  Varying the wind speed between
measurements allows for development of a weighted average emission rate.  The
measurement is essentially instantaneous.
                                                               *
     The emission flux calculation 1s (25):

                                E, - 
-------
               Mwk TMct
               •cttf^nlitwt
Figure 13.  Schematic of  portable wind tunnel.

                      74

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 4.1.5  Soil Vapor (Ground) Probes (In-Deoth Technology)

      Soil vapor or ground probes are a preferred 1n-depth technology for
 mapping the horizontal extent of soil gas plumes in near-surface soils
 (26,27,28).  The technology directly measures the emission rate potential from
 a small area of exposed subsurface soils.  One variation of a ground probe is
 shown in Figure 14.  Probes with small chambers or openings at the probe end
 have also been used (see Figure 15).  Reference 27 Includes descriptions of a
 wide variety of ground probe designs.

      The probe assembly is driven into the ground to the desired sampling
 depth.  Emissions enter the probe from the exposed subsurface soil, depending
 on the design via existing openings or by raising the pipe away from the drive
 tip.  Generally, either a small aliquot of soil gas is collected to avoid
 disturbing the soil gas equilibrium or a known amount of soil-gas is pumped
 from the probe.  The concentration measured is used as a relative indicator of
 contamination and potential emissions.  Clean, dry sweep air can be added to
 the probe at a metered rate if a relative emission "flux" is desired.  No true
 flux can be measured since the exact surface area of exposed waste is not
 known.

      The major advantage of the technology is that it allows for rapid mapping
 of the horizontal extent of soil gas plumes in near-surface soils.  Generally,
• v
'mapping is performed by measuring the soil gas concentration without use of
 sweep air.  The mapping can be used to determine the approximate subsurface
 boundaries of buried waste or immiscible liquids floating on the water table.
 Ground probes are very useful for investigating the migration of soil vapors
 as part of the air pathway analyses.

      It is not necessary, although desirable, to know the waste composition to
 use the technology.  Knowing the waste composition will help in the selection
 of appropriate instrumentation or sampling apparatus.
                                       75

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                                                     two A* C
                               0.25 in. Teflon co«t*d at**!
                               pip* 6 ft Motion
                            Driving:  Tip di«a«c«r Is s«a* M
                                     plp« 0.9.  Sh«p* e*nt*rs
                            •        tip durlni driving
                            '         Mil catty to pip*
                                   • SAMFLISC:  Tub* t* rali«d 2 in.
                                               to acc**t toil
                                               vaper<.
Figure  14.   Schematic  diagram  of a  simple ground  probe.
                                76

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                              syringe
                              3 way valve
                              Tenax GC  trap
                              fitting
                                     pounding plate
                               pipe
                               tubing
                              coupling
                              air holes

                              point
Figure  15.  Ground probe design with minimal  Internal volume.
                           77

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Appll cabin ty--
     The technology can be used to map soil gas plumes to Indicate approximate
waste boundaries or soil gas migration routes.  Ground probes are also
applicable to the measurement of potential volatile emissions from disturbed
subsurface soil and waste.  The technology measures the emissions that would
occur 1f the subsurface soil or waste were disturbed by excavation.  The
technology also can be used to measure the soil gas concentration by operating
the probe without sweep air.  Soil gas concentration measurements can be used
as an Input to predictive models, as discussed 1n Section 4.4.

     The technology Is applicable for estimating emissions from solid waste
sites, Including open and closed landfills, with or without internal gas
generation, open dumps, and waste piles.  The technology also can be used to
estimate emissions below the edges of tanks, buildings, ponds, etc., by
driving the probe into the soil at an angle.  In addition, ground probes can
be hand- or machine-driven.  Hand-driven probes allow measurements to be
performed in areas where surface access by machines 1s not available.

Limitations--
     Ground probes do not measure the undisturbed emission rate or flux from a
waste site.  Rather, the technology measures the potential emissions that
would occur during site disturbance.

     Use of ground probes is generally limited to near-surface soils,
typically less than 12 feet deep.  However, the operational depth will depend
on site and equipment characteristics which limit the ability to insert the
probe.  Ground probes do not measure particulate emission rates.

4.1.6  Soil Vapor Monitoring Wells fln-Deoth Technology)

     Soil  vapor monitoring wells (29) are used to measure the emission flux
from subsurface soil and waste and to monitor soil  vapor concentrations and
the effects of soil  vapor remedial actions.  The in-depth technology uses a
monitoring well consisting of a screened chamber installed during drilling
activities.  As such, the soil vapor monitoring well  is a permanent or
                                      78

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semi-permanent structure.  Figure 16 illustrates a typical  soil  vapor
monitoring well.

     Soil vapor monitoring wells are installed through the  annul us of a
hollow-stem auger.  The well consists of an enclosed,  screened chamber with
sampling lines leading to the surface.  The chamber is enclosed in a sand
pack.  The well casing is used to provide support during well  construction and
protection for the sampling lines, but soil vapors and gases do not contact
the well casing.  Soil vapors and gases enter the soil vapor monitoring well
through the chamber screen.  Within the chamber, the vapor  and gases are mixed
with clean, dry sweep air.  The resulting mixture is withdrawn through the
exit port to measure the emission concentration and/or for  sampling and
subsequent analysis.  The sweep air flow rate is selected to approximate the
instrumentation or sampling apparatus flow rate.

     Because the measured emission concentration is directly related to an
emissions event from an isolated surface over an essentially instantaneous
time period, the technology can be used to estimate the emission flux from the
isolated soil surface.  The estimated emission flux is calculated from the
assumed surface area isolated, the sweep air flow rate, and the emission
concentration.

     The emission flux is calculated as (26):

                                   E, - _£l?                         (Eq-  10)
                                          A

     where     E1 - emission flux for component i  (ug/m2-min);
               C1 - concentration of component i  (ug/m3);
               Q  • sweep air flow rate (m3/min);  and
               A  - exposed surface area (m2) - *dh
                    d « screen diameter (m); and
                    h - height of sand pack (m).

     Typically, soil vapor monitoring wells are used to measure the soil vapor
concentration, rather than the emission flux.  The soil vapor concentration is
measured by operating the well without sweep air.
                                      79

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Figure 16.  Vapor monitoring well constructions.   (Not to scale)
                               80

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     The technology Is not dependent on knowledge of the emissions process or
the waste composition, although knowledge of the waste composition will  help
In selecting appropriate Instrumentation and/or sampling apparatus.

Applicability--
     Soil vapor monitoring wells are applicable to the estimation of the
potential emission flux from subsurface soil and waste.   The technology does
not measure the undisturbed emission flux, but rather estimates the emission
flux that would occur during site disturbance.  Therefore,  the technology is
suitable for determining emissions potential for remedial  alternative
evaluation.  Soil vapor monitoring wells also are applicable to the monitoring
of soil vapor concentrations and vapor migration, and are the preferred method
for monitoring the effects of soil vapor extraction systems.   •

     The technology is applicable to the estimation of emission fluxes and
concentrations from open and closed landfills, with and without internal gas
generation, and open dumps.  The technology also is applicable to measurement
of emission concentration from immiscible liquids floating  on the water table.

Limitations--
     Soil vapor monitoring wells do not measure the undisturbed emission flux,
but rather the flux that would occur during site disturbance.  The technology
1s not applicable to the measurement of particulate emission fluxes.
Determining the actual exposed surface area is an assumed or estimated value.

4.1.7  Downhole Emissions Flux Chamber (In-Depth Technology)

     The downhole emissions flux chamber is one of the preferred in-depth
technologies for direct measurement of potential volatile emissions from
subsurface soils (30).  The technology uses a flux chamber to measure emission
fluxes from subsurface soils exposed by drilling operations.   The chamber
isolates a known area of soil at a desired depth within the annulus of a
hollow-stem auger.  Figure 17 depicts the downhole emissions flux chamber.       *m
                                      81

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         0.25 in. in
           UNE. TEFLON
      7 in.  length of
        TEFLON nusi "~"*>
               GLASS
              •END
                                             suwoirr
                                              CABLf
                                           /

                                           /I
                                        t
  0.25 in. outout
  LINE. TEFLON
•WEIGHTS
Figure 17.  Schematic diagram of the downhole  emissions flux chamber.
                                   82

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     Emissions tenter the chamber from the exposed surface.   Clean, dry sweep
air 1s added to the chamber at a metered rate.   Within the  chamber, the sweep
air Is mixed with emitted vapors and gases by the physical  design of the air
Inlet.  The mixture of sweep air and emitted vapors and gases 1s withdrawn
through the exit port for measurement of the emission concentration or for
sampling and subsequent analysis.  The sweep air flow rate  must match the flow
rate of the analytical Instrumentation or sampling apparatus that 1s used to
withdraw sample gas.

     Because the measured emission concentration 1s directly related to an
emissions event from an Isolated surface over an essentially instantaneous
time period, the technology directly measures the emission  flow (flux) from
the surface.  The emission flux 1s estimated from the assumed surface area
exposed, the sweep air flow rate, and the emission concentration.

     The emission flux is calculated as (30):
                                .   E, -_.                         (Eq. 11)
                                          A
     where     E, - emission flux of component  i  (ug/m2-min);
               C, - concentration of component  1  (ug/m3);
               Q  • sweep air flow rate (m3/«irin);  and
               A  » exposed surface area (m2).

     The major advantage of the technology 1s that it  allows the investigation
of subsurface areas without excavation.

     Although desireable, knowledge of the waste composition is not necessary
to use the technology to assess the air pathway.   However, knowledge of the
waste composition will help in the selection of appropriate emission
concentration measurement Instruments.
                                      83

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*
  Applicability—
       The downhole flux chamber Is applicable to measurement of the potential
  emissions from subsurface soil and waste.  The technology estimates the
  emission flux that would occur if the subsurface soil  or waste were exposed by
  excavation.  Therefore, the technology is most suitable for determining
  emissions potential for remedial alternatives evaluation and/or site
/ disturbances.  The technology also can be used to measure the soil gas
  concentration by operating the chamber without sweep air.  However, for
  shallow depths, ground probes are preferred for gas concentration measurements
  (see Section 4.1.5).

       The technology 1s applicable for estimating emission fluxes from all
  materials that can be investigated using hollow-stem auguring techniques.  The
  technology can be used at open and closed landfills, with or without internal
  gas generation, and at open dumps.

  Limitations--
       The downhole emissions flux chamber does not measure the baseline
  emission flux from a waste site.  Rather, the technology measures the
  potential emission rate that would occur during site disturbance.

       The emission flux of volatile species may be enhanced or suppressed if
  the sweep air flow rate does not closely match the flow rate of the sample gas
  extraction system.  The downhole flux chamber cannot be used to measure
  particulate emission rates.

  Preferred Technology--
       The downhole emissions flux chamber is a preferred technology for
  developing emissions estimates for subsurface disturbed waste.   Most
  investigations Involve subsurface sampling using a hollow-stem auger and drill
  rig and downhole flux chamber work can be incorporated in the Investigation.
                                        84

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4.1.8  Vent Sampling (In-Depth Technology)

     Vent sampling for emissions measurement have been well  documented
elsewhere (32), and will not be discussed 1n detail  here.   Vent sampling Is
performed when the waste site contains vents with measurable flow rates (I.e.,
active venting, not passive venting), such as vent systems at some landfills.
The In-depth technology requires measuring the emission concentration and the
volumetric flow rate, typically as the exhaust velocity and cross-sectional
area of the vent.  Volumetric flow rates for vents (or ducts) can be obtained
using the procedures given 1n 40 Code of Federal  Regulations (CFR) Part 60.
Those procedures indicate how to determine the exhaust velocity and
appropriate sampling location.  The emission rate for a vent 1s calculated as
(31):
                                  E,  - C, U A                        (Eq. 12)

     where     E1 • emission rate of component i  (ug/sec);
               C, - concentration of component 1  (ug/m3);
               U  -gas velocity through vent (m/sec); and              §
               A  - cross-sectional area of vent  (m2).

Applicability-
     Vent sampling is applicable to any waste site that contains active or
passive venting systems.  However, active venting systems  are not typical of
uncontrolled hazardous waste sites.  Vent sampling can be  applied to landfill
vents, tanks, building vents, machinery, and equipment. Where present, vents
may be a major source of air emissions from the site.                   ,,;

Limitations--
     Vent sampling using standard stack sampling  technology is not applicable
when the vent has minimal or no flow.  For these  situations, the emissions
Isolation flux chamber technology 1s preferred, provided that the chamber's
cross-sectional area is larger than the vent's.  When the  vent is too large
for use of the flux chamber, emission rate estimates may be based on head
space concentration measurements at the vent outlet and diffusion in air
modeling.
                                      85

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 4.2  INDIRECT EMISSION MEASUREMENT TECHNOLOGIES

      A general discussion of Indirect measurement  techniques  1s followed by a
 description of specific techniques.  The Indirect  emission  measurement
 technologies presented 1n this section are:

 Screening Techno!ogies--
      4.2.1  Upwind/Downwind
      4.2.2  Mass Balance
      4.2.3  Real-Time Instrument Survey

 In-Depth Techno!ogies--
      4.2.4  Concentration-Profile (C-P)
      4.2.5  Transect
      4.2.6  Boundary Layer Emission Monitoring

      Indirect emission measurement technologies generally consist  of measuring
.the atmospheric,concentration of the emitted  species  and then  applying these
 data to an equation (air model)  to determine  the emission rate.  Many of the
 equations were developed to determine downwind  concentrations  resulting from
 stack emissions.  For area emission sources,  the source is  treated as a
 virtual point source or line source.

      The in-depth technologies are very similar as all involve clusters of
 ambient air samplers.   The C-P technique Involves  a vertical array of samplers
 directly over the source.   The transect technique  involves  vertical  and
 horizontal arrays of samplers within the downwind  plume.  The  boundary layer
 technique 1s a simplified version of the transect  technique and  involves
 several downwind samplers each at a different height.

      A disadvantage of indirect  emission measurement  technologies  is that the
 results are highly dependent on  meteorological  conditions.  The  Indirect
 technologies require meteorological  monitoring  to properly  align the sampling
 systems and to analyze the data  following sample analysis.  Changing
 meteorological conditions significantly affect  the efficiency  of collecting
                                      86

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                1"
 useful data.  Unacceptable meteorological conditions may Invalidate much of
 the data collected, requiring an additional  sampling effort.   The technologies
 also may produce false negative results 1f the emitted species are present In
 low concentrations which are below the sampling and analysis  detection limits,
 or 1f upwind sources cannot be fully accounted for.  The technologies also may
 not be feasible at some sites where the source area 1s excessively large, or
 where Insufficient space exists downwind of the source to set up the sampling
 array without disturbance of the air flow pattern by obstructions (e.g.,
 buildings, tanks).

      The types of volatile and particulate species that can be measured by the
 technologies are essentially unrestricted, they depend on the sampling media
 selected and analysis technique rather than the emission measurement
 technology.  Sampling media and analysis techniques are not discussed here.

      Indirect emission measurement technologies generally do  not provide
 significant data on the emission rate variability for different locations
 across a site.  This 1s because the emission concentration is measured
 downwind of the site after some atmospheric mixing.  The technologies
 generally do not allow for the evaluation of individual contaminated areas at
 the site unless the areas are separated from one another and  are not located
 upwind of one another.
 {
      The costs of the indirect emission measurement technologies vary
 considerably.  The screening technologies are relatively simple and
 straight-forward to implement, and require minimal labor and  analytical costs.
7 The in-depth technologies are complex and require considerable equipment,
 labor, and analysis costs.  All of the technologies are subject to data loss
 or sampling delay due to Inappropriate meteorological conditions.

 4.2.1  Upwind/Downwind (Screening Techno!oovl

      The upwind/downwind technology is an Indirect screening  technology (33).
 As the name Implies, in this approach one or more monitors are located upwind
 of the area source and a second monitor or set of monitors are located

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downwind.  The monitoring stations Include detectors or samplers for the
species of Interest as well as devices for measuring wind speed and direction.
The upwind monitor serves as a blank or background sampling location.
Concentration 1s measured primarily along the downwind axis only.  The average
surface emission flux for a particular trajectory 1s equal to the Increase In
column concentration (downwind minus upwind) divided by the transit time
across the source.  Transit time Is a function of the distance between the
source and downwind location, and the average wind velocity.


                            E.R.1  - (CD-CU) KO  az 0                  (Eq.  13)
                                                    ..2
     where     E.R.1 - emission flux of species (ug/m -sec);
               *o
CD - downwind concentration of species 1  (ug/m3);
               Cy » upwind concentration of species  1  (ug/m3);
                * - 3.141 ...
               oy - lateral  extent of Gaussian  plume;
               az « vertical extent of Gaussian plume;  and
                U - mean wind speed (m/sec).

Applicability--
     The upwind/downwind technology is applicable to emission flux measurement
from all forms of area sources, including lagoons, landfills, open dump, and
waste piles.  The technology can be used at open and closed landfills, with or
without Internal gas generation.  The technology.is applicable both for
undisturbed and disturbed site conditions, and  for testing  emission control
technologies.  The technology can be used for both volatile and particulate
emission flux assessment.
Limitations--
     Upwind/downwind requires that meteorological  conditions during sampling,
particularly wind speed and variability,  match the predetermined conditions
used to select the sampling locations.  The sampling  locations must be on the
approximate plume centerline.

-------
     The technology also assumes that the site Is fairly homogeneous and
that the plume Is well mixed at the downwind sampling location.   Therefore,
the technology may not be applicable to heterogeneous sites.   The technology
also may not adequately collect emissions from point sources  within an area
source, such as cracks in landfill covers or vents,  unless the plume 1s well
mixed at the downwind sampling location.  The technology 1s not  applicable
during quiescent or unstable wind conditions, and may produce false negative
results during these conditions.

Preferred Technology—
     The upwind/downwind screening technology 1s  a preferred  indirect
assessment technology.  The technology 1s similar to a simple real-time
                                                              •
inspection survey, however, it is superior 1n that 1t specifies  data
collection consistent with a model that can be used  to estimate  emissions from
a variety of area sources.

4.2.2  Mass Balance (Screening Technology)

     Mass balance technology can be used to Indirectly determine emission
rates by accounting for material in and out of a  system and assuming the
difference is lost as air emissions (31).  The use of mass balance for
baseline emission estimates at uncontrolled landfill or lagoon sites was not
identified, but it might be applicable to waste lagoons that  have minimal
leaching losses.  To apply the technology at an uncontrolled  site, the
concentration of the species contained in the lagoon (or landfill) would £e
measured Infrequently over time, and the emission rate would  be  estimated as
the loss of species over time.

Applicability--
     The technology would be best suited for homogenous sources  containing
highly volatile wastes.  Application of the technology to "fresh waste", when
emission rates are typically highest, 1s more feasible than application to
"weathered" waste.  The technology does not appear applicable to particulate
matter emission assessment.
                                      89

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Limitatlons--
     The technology 1s generally unsulted to uncontrolled waste sites because
of the source types and since losses of material  are difficult to Identify due
to the precision of the sampling and analytical methods.   In addition, the
mass balance technology does not distinguish between material  lost to other
pathways.

4.2.3  Real-Time Instrument Survey (Screening Technology)

     Real-time Instrument surveys are a preferred screening technology for
determining the volatile emissions potential for  hazardous waste sites.  The
survey consists of Inspecting the site with real-time instruments to determine
the average species concentration in the air layer directly above the site,
and to Identify "hot spots" with above average emission concentration.
Real-time instrument surveys can also include taking headspace concentration
measurements in cracks and vents.  They can be used for both volatile species
and particulate matter, but.it is typically used  for volatile species
emission.

     The site 1s inspected by placing the inlet of the real-time instrument at
a specified height above the surface, typically 2-3 inches to several feet
above the site surface.  The site 1s walked on a  25-foot  grid as shown in
Figure 18, although the grid may be adjusted to accommodate site size.  Upwind
measurements are made before and after Inspecting the site by measuring the
ambient air at 5-feet above the site at an upwind location.   Sampling should
be performed during quiescent wind conditions (i.e.,  average wind speed less
than 5 miles per hour).
                                      90

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                     100'
     500'
Figure 18.  Real-time Instrument survey.
                   91

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Appl 1 cabin ty-
     The real-time Instrument survey is applicable to all types of hazardous
waste sites, assuming sampling personnel can reach all areas of the site.

Limitations--
     The technology does not provide for calculation of an emission rate, but
rather determines the site's potential for air emissions including particulate
matter emissions can be measured using aerosol/dust counting devices.

4.2.4  Concentration-Profile fln-Deoth Technology)

     The concentration-profile (C-P) technology measures the concentration of
the emitted species at logarithmically spaced heights at a downwind location
on the anticipated plume centerline (21,34).  This technology has been tested
under a variety of waste site conditions and has been shown to produce valid
results.  Figure 19 illustrates the C-P sampling approach.

     The C-P technology was developed by L.J. Thibodeaux and co-workers at the
University of Arkansas under an EPA contract.  The technology is based on
measurements of wind velocity,  volatile species concentration, and temperature
profiles in the boundary layer above the waste body.   These measurements are
used to estimate the vertical flux of the volatile species as (31):
                    E
                             H20
(Eq.  14)
     where     E1 » emission rate  (flux) of organic species i  (g/cm2-sec);
               D, - molecular diffusivity of organic species i  in air
                    (cm2/sec);
               H20 • molecular diffusivity of water vapor in air (cm2/sec);
                 n - exponent for  diffusivity ratio;
                Sv - logarithmic slope of the air velocity profile  (cm/sec);
                S, • logarithmic slope of the concentration-profile for
                     organic species i  (g/cm3);
                                      92

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157"
         SENSOR
          ARMS
89'
   52"
                              WIND DIRECTION
                                 SENSOR
                                            SAMPLINQ
                                              MAST
T-   =U           \
 I  ...1S* TT^^A^A^>s-^X>\>\^A^>>os>V
                                               MAST SIDE
                                                 PANEL
                                                 POND
                                                SURFACE
                                                          COMPUTER
                                                         DATA SYSTEM
       Figure 19.   Hast sample collection system for C-P sampling.
                                   93

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                  K - von (Carman's constant;
                 tfm - Businger wind shear parameter;  and
                 Sc - turbulent Schmidt number.

      The term (^S,.)"1 represents an atmospheric  stability  correction factor
 and 1s expressed as a function of the Richardson  number.  The function is an
 empirical correlation which corrects the estimated emission rate for water
 vapor to measured values under various atmospheric stabilities.   For this
 reason, the correction factor 1s valid only  under specific  meteorological
 conditions.

      The sampling equipment consists of  a 4-meter mast  with a wind direction
 indicator, wind speed sensors, temperature sensors,  and air collection probes
 at six logarithmically spaced heights above  the area source;  a continuous
 real-time data collection system; and a  thermocouple for measuring water
 temperature.  Prior to sample collection,  meteorological conditions must be
 monitored to determine if sampling conditions meet the  necessary
-meteorological criteria.  Once acceptable meteorological conditions are
 documented, the sample collection period 1s  Initiated.  During the sample
 collection period, wind speed, air temperature, and  relative  humidity are
 measured.

 Applicability--
      The C-P technology is applicable to emission rate  measurement from many
 types of large area sources including landfills,  lagoons, and areas of
 contaminated soils.  The technology is applicable for both  volatile and
 particulate emission rate measurement.   It is applicable both for undisturbed
 and disturbed site conditions, and for testing emission control  technologies.

 Limitations--
      The technology requires that meteorological  conditions during sampling,
 particularly wind speed and direction, match the  predetermined conditions used
 to select the sampling location.   The sampling location must  be  on the
 approximate plume centerline.
                                      94

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     The technology also assumes that the site 1s fairly homogeneous;
therefore, the technology may not be applicable to heterogeneous sites.  The
technology 1s not applicable to sites where there 1s Insufficient distance
downwind to set up the sampling equipment.  The technology also may not
adequately collect emissions from point sources within an area source, such as
cracks 1n landfill covers or vents.

     The technology requires upwind sampling to account for other potential
sources.  Finally, the technology 1s not applicable during quiescent or
unstable wind conditions, and may produce false negative results during these
conditions.

4.2.5  Transect (In-Deoth Technology^

     The transect technology, also referred to as plume mapping, measures the
concentration of the emitted species at several downwind locations aligned
perpendicular to the anticipated plume centerline (21,35).  The in-depth
transect technology is an Indirect emission measurement approach that has been
used to measure fugitive particulate and gaseous emissions from area and line
sources.  This technology has been successfully tested at a variety of waste
sites, including landfills.  Figure 20 illustrates the transect sampling
array.

     The transect technology uses horizontal and vertical arrays of samplers
to measure concentrations of species within the effective cross-section of the
emission plume.  The volatile species emission flux is then obtained by
spatial integration of the measured concentrations over the assumed plume
area.  For volatile species, the emission flux is calculated as (21):
                          E, - _U_  / /  C<(h,w) dhdw                (Eq. 15)
                                      95

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                                                            E
                                                            re
                                                            V)

                                                            0)

                                                            cr
                                                            o
                                                            o>
                                                            (J
                                                            o>
                                                            VI
                                                            c
                                                            re
                                                             
-------
     where     *E, • emission flux of component 1 (ug/m2-sec);
               u • wind  speed  (m/sec);
               A, • surface area of emitting source (m2);
               Ap - effective cross-sectional area of the plume (m2);
               C, - concentration of component 1 at point (h,w), corrected  for
                    upwind background  (ug/m3);
                h * vertical distance  coordinate (m); and
                w - horizontal distance coordinate (m).

     For particulates, the emission flux Is calculated as (36):

                                         mfh.wl dh dw                (Eq.  16)
     where     E - emission flux  (ug/m2-sec);
               t * sampling time  (sec);
               As - surface area of emitting source (m2);
               Ap - effective cross-sectional area of plume (m2);
               m « mass of particulates collected after correction  for back-
                   ground concentration (ug);
               h « vertical distance coordinate (m);
               w * horizontal distance coordinate (m); and
               a « intake area of sampler  (m2).

     The cross-sectional area of the source  (As) term can be eliminated from
both equations, if only the total site emission per time is required.   An
alternative equation for volatile species, based on diffusion theory and
measurements, is (33):
                                  n
                          E.R., - 2 * X,^  oyoz  C U                 (Eq. 17)

     where     E.R., * emission rate of species i (gm/sec);
                  Xt - peak concentration of species 1 (Gaussian Fit Curve);
                  K, « conversion factor gm/ppm for species 1;
                  ay - lateral extent of Gaussian plume;

                                      97

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                  oz • vertical  extent of Gaussian plume;
                  C  - Instrument reponse factor;
                  *  - 3.141;  and
                  0  - mean wind speed.

 All parameters are obtained from field measurements.   (In some Instances, az
 1s estimated from ay).

      The sampling equipment consists of a central 3.5-meter mast supporting
 three equally spaced air sampling probes, and single  wind direction, wind
 speed, and temperature sensors at the top; and five 1.5 meter masts with
 single air sampling probes.  The central mast Is aligned downwind along the
                                                                »
 expected plume center-line.  Two masts are placed on  each side of the central
 mast perpendicular to the plume center-line at equal spaclngs; and one mast is
 used to collect air samples at an upwind location.  The spacing of the
 associated masts 1s selected to cover the expected  horizontal plume
-cross-section, as defined by observation and/or profiling with real-time
^analyzers.  Additional sampling locations, both vertically and horizontally,
'can be added as required to provide sufficient coverage of the plume
 cross-section.  Prior to sample collection, meteorological  parameters must be
 monitored to determine if sampling conditions meet  the predetermined
 meteorological criteria.

      The transect technology is somewhat less susceptible to changing
 meteorological conditions than the concentration profile technology, but it
 does not account for the vertical dispersion of the emitted species due to
 their varying molecular weights.  A more complex array of samplers can be
-employed to overcome this shortcoming, if necessary.   The transect Is often
 the preferred technology because the technology 1s  applicable to a variety of
 some types and the resulting data can be more useful  since the data are
 collected across the plume area.
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Applicability—&
     The transect technology 1s applicable to emission  rate  measurement
from all forms of area sources, Including lagoons,  landfills,  open dumps,  and
waste piles.

     The technology can be used for both volatile and participate matter
emission rate assessment.   The technology 1s applicable  both  for undisturbed
and disturbed site conditions, and for testing of emission control
technologies.  The technology 1s applicable to emissions  measurement during
all phases of the RI/FS process and can, therefore,  provide  directly
comparable data throughout the process, Including post  remediation monitoring.

     While the method assumes a relatively homogeneous  site  and  a well  mixed
plume, these conditions are not necessarily required to use  the  method. The
placement of sufficient sampling stations across the plume can allow the
technology to be used at a heterogeneous site, or where the  distance downwind
for equipment set up 1s limited.  However, data collected under  these
conditions should be carefully evaluated before use.                     4

Limltatlons--
     The technology requires that meteorological conditions  during sampling,
particularly wind speed and direction, match the predetermined conditions  used
to select the sampling locations.  The center mast  should be on  the
approximate plume center!ine.  The technology may not adequately collect
emissions from point sources within an area source,  such  as  cracks 1n landfill
covers or vents, unless the plume 1s fairly well mixed  at the  sampling
locations.  The technology provides only limited vertical profiling of the
plume.  The technology 1s not applicable during quiescent or unstable wind
conditions; 1t may produce false negative results during  these conditions.

Preferred Techno!ogy--
     The transect technology 1s a preferred Indirect emission  assessment
technology.  The technology has been used for several different  types of area
sources and Is documented 1n the literature.  The applicability  of the
technique, the conditions required for sampling, and the  moderate level of
                                      99

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equipment and man-power needs suggest this technology as a preferred
technology relative to other Indirect approaches.

4.2.6  Boundary  Laver Emission Monitoring

     Boundary layer emission monitoring can be used to determine the emission
rate of pollutants from large heterogenous area sources (37).  The technique
1s similar to the transect technique 1n that samples are collected along an
array that 1s perpendicular to the emission plume.  However, rather than fixed
sampling locations, the boundary layer technique Involves a cart with three or
more samplers traversing the plume with each sampler at a different height.
During the plume traversing the sampling rate 1s adjusted to be proportional
to the sine of the angle between the wind vector and the direction of the
traverse path.   Each run takes about an hour.  The average concentrations are
adjusted for any upwind concentration and then used to calculate an average
vertical concentration profile.  This profile 1s numerically Integrated (with
the' wind velocity profile) over the contaminant boundary layer to derive an
emission rate for the source.

     The emission rate is (37):
                [E -  C0 WV0 x 10 -6jyo    (z/10)"(l-z/Zb)b  dz        (Eq. 18)

     where     E  « emission rate (g/sec);
               C0 » ground level concentration (ug/m3);
               W  » cross-wind distance (m);
               V0 - average wind speed at 10m (m/sec);
               Zb « boundary layer thickness (m);
               p  • exponent of wind-velocity profile;  and
               b  • exponent of concentration profile.

Applications--
     The technique can be used for measuring an emission rate from any type of
source with constant emissions.
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Limitations--
     The method assumes that both the contaminant emission rate and the wind
speed and direction are reasonably steady while sampling 1s conducted.  The
major sources of error are 1n the average measured wind velocity and 1n
accounting for upwind contamination.  The method should be limited to area
sources that do not have significant plume buoyancy,  to periods of 1-10 m/sec
winds, and to sampling heights less than the depth of the mixing layer.  The
technique has not been validated by the EPA.

4.3  AIR MONITORING TECHNOLOGIES

     A1r monitoring technologies that measure the ambient air concentration
resulting from area emission sources are combined with air dispersion modeling
to calculate the area source emission rate.  The primary difference between
Indirect emission measurement technologies and air monitoring technologies 1s
the distance at which measurements are made downwind  from the source.
In-direct measurements are made near the source or units of a combined site
(usually on site) and may be able to distinguish between multiple units within
a site, depending on the spacing between units.  Air  monitoring 1s generally
performed at considerable distance downwind from the  source and usually cannot
distinguish between multiple units within a combined  site.  Air monitoring
typically measures lower concentrations because the contaminant plume is
subject to additional air dispersion.

     The first step to use the ambient air sampling data to develop emission
rate estimates 1s to select an air dispersion model which accurately reflects
the site-specific conditions, Including regional and  local terrain, typical
wind stability, etc.  Guidance for selecting an appropriate model is given in
the EPA's Guideline on Air Quality Models (38).  Preferred models given in the
guidance document Include the Cllmatologlcal Dispersion Model (COM 2.0),
Gaussian Plume Multiple Source Air Quality Algorithm  (RAM), Industrial Source
Complex Model (ICS), and Single Source (CRSTER) Model.  A number of other
potentially applicable models are Included In the guidance document.  Models
not Included 1n EPA's manual also may be applicable at uncontrolled hazardous
                                      101

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  waste sites,  Including the Point Plume Model (PTPLU), and the Gifford and
  Hanna Simple  Box Model (39). The models are used with air monitoring and
  meteorological monitoring data to estimate emission rates.

       A1r monitoring and air dispersion models are used to determine the
  emission rate through an Iterative process.  An emission rate Is first
  estimated for the area source.  This estimated emission rate, along with
  meteorological data collected during air monitoring, 1s used to calculate a
  predicted downwind concentration.  The predicted concentration 1s then
  compared to the measured downwind concentration.  Based on this comparison,
  the estimated emission rate 1s adjusted appropriately, and the process 1s
  repeated until acceptable agreement 1s reached between the measured and
  predicted downwind air concentrations.

       The air  monitoring technologies that can be used to develop BEEs are
  listed below.  These technologies were described In Section 4.2 and can be
- used at greater distances downwind of the emission source as air monitoring
  technologies.

  Screening Technologies--

       4.2.1  Upwind/Downwind

  In-Depth Techno!ogles--

       4.2.4  Concentration-Profile
       4.2.5  Transect
       4.2.6  Boundary Layer Emission Monitoring

  4.4  EMISSIONS (PREDICTIVE) MODELING

       Emissions models have been developed to predict emission rates for a
  variety of waste site types Including landfills without Internal  gas
  generation, landfills with Internal gas generation (typically co-disposal
  sites), open  dumps, waste piles, spills, land treatment operations, aerated
                         >-i   ,  t.
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lagoons, non-aerated lagoons, and lagoons with an oil  film.   These models are
almost exclusively theoretical, and each model Is generally  applicable to only
one type of waste site.

     The predictive models can be used as screening or 1n-depth technologies.
Emissions models, used as screening technologies, use  data that can be
obtained or calculated from Information available 1n the literature, or can be
assumed with some level of confidence.  Emissions models,  used as 1n-depth
technologies, require site-specific site and waste characterization data.  The
selection of model Input sources (site-specific,  literature  value, or assumed)
should be based on the requirements of the decision-making process and the
level of resources available.  Site-specific data should be  used whenever
                                                               *
possible to Increase the accuracy of emission rate estimates.

     Several predictive models are presented below to  acquaint the reader with
the types of available models for emission rate estimation.   The models
presented do not Include all available models.  Specific methods for
calculating the model Input variables, such as diffusion coefficients, have
been presented by the authors of the models, but are not Included here for
sake of brevity.  Each model requires estimating the emission rate of the
Individual components of the waste; and then summing the emission rates to
determine the overall emission rate.  For complex waste, application of the
models 1s best performed on a computer to speed the calculation.  An emission
flux can be calculated by dividing the emission rate by the  emitting area.

     A wide variety of variables are associated with each of the predictive
models; however, a number of key Inputs are required by many of the models.
These key Inputs for landfills Include:  the vapor diffusion coefficient
through the soil or mass transfer coefficient across the air/soil boundary for
waste constituents; the physical size of the source expressed as area, length,
and/or width, depending on the model used; physical parameters of the landfill
cover, such as depth of cover, permeability, and soil  porosity (total,
air-filled, and/or effective porosity); physical/chemical  parameters of the
waste, Including chemical composition, weight or mole  fraction for
constituents, vapor concentration of constituents at the waste surface or
                                      103

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within the soil cover, and partial pressures of constituents; atmospheric
conditions, such as temperature, wind speed and direction, and barometric
pressure; and estimates of the soil gas velocity through the soil cover.  The
key Inputs for lagoons include:  mass transfer coefficients; physical/chemical
parameters of the waste, Including chemical composition, weight or mole
fractions, partial pressures, and Henry's Law Constants; physical dimensions
of the lagoon surface; atmospheric conditions, such as temperature, and wind
speed and direction; layering of waste within the lagoon; and physical/
chemical parameters of a surface crust.

     While all of these parameters can be estimated with varying levels of
confidence, it 1s best, when possible, to collect site-specific data.
Physical/chemical measurements of waste constituents can be obtained from
sampling and analysis programs, although a records review is advisable to
identify key constituents and ensure representative sampling.  Likewise a
sampling and analysis program combined with a records search 1s desirable to
determine the physical size and shape of the source and the porosity and
permeability of any soil cover.  Atmospheric conditions are easily obtained
from various weather services which can provide regional data; however,
collecting some site-specific meteorologic data to ensure representativeness
is desirable.  Diffusion and mass transfer coefficients are typically
calculated based on the wastes' chemical composition and their known chemical
properties, such as Henry's Law Constants, although tabulated diffusion
coefficients are now available.  The referenced literature includes suggested
methods for calculating the diffusion coefficients as well as some tabulated
data.   Diffusion and mass transfer coefficients can also be determined
experimentally In the lab;  however, disturbance of the waste and landfill
cover to obtain site-specific materials would probably introduce uncertainty.

     The landfill models presented here can be categorized into five types:

          Closed landfills  without Internal gas generation--Farmer Model, Shen
          Model, Thibodeaux a Model, Logarithm Gradient Model, and RTI Closed
          Landfill Model;
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          Closed landfills with Internal gas generation--(Thibodeaux)
          Convective "Add On" Model, Thibodeaux b Model,  and (Thibodeaux)
          Exact Model;

          Open landfills--Arnold's Open Landfill  Model,  Shen Open Landfill
          Model, and RTI Open Landfill Model;

          Landfarming--RTI Landtreatment Model  and Thibo-deaux-Hwang Model;
          and

          Fugitive dust -- AP-42.

     The lagoon models presented here can be categorized into two types:

          Non-aerated lagoons -- Mackay-Lienonen; Thibodeaux, Parker, and
          Heck; Smith, Bomberger, and Haynes; Shen; and  RTI.

          Aerated lagoons -- Thibodeaux, Parker,  and Heck;  and RTI.              ^B

     The bases for most of the landfill models are Pick's First Law of
steady-state diffusion, Pick's Second Law of unsteady-state diffusion, the
Equation of Continuity, and Darcy's Law.

4.4.1  Emission Models for Closed Landfills without Internal Gas Generation

Parmer Model--
     The Parmer Model (40-43) was one of the first models developed and
generally accepted to predict emission rates from covered landfills.  The rate
at which a compound is lost to the atmosphere from the land surface is
controlled by the compound's molecular diffusion through the soil covering the
waste.  Fanner et al. developed this model to determine  hexachlorobenzene
vapor diffusion through a soil cover.  They found that the two prime factors
controlling/determining vapor movement through the soil  were soil depth and
soil air-filled porosity.  The model should be applicable to other compounds
as wel1.
                                      105
i

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     The  Farmer Model  combined Pick's First Laws for steady-state diffusion
with the  Milling ton and Quirk evaluation of the diffusion coefficient.   The
latter  Included a porosity term accounting for the soil's geometric  effects on
diffusion for  a given  compound.

     The  Farmer equation Is (41):

                            J - D1(CrC2)(P.10/3/PT2)A                  (Eq. 19)

     where      J • volatilization vapor flux through the soil cover
                     (ug/cmz-day);
                D, - vapor diffusion coefficient In air (cnrYday}-;
                Pa - air-filled soil porosity (cm3/cm3);
                PT « total soil porosity (cm3/cm3);
                C2 » concentration of volatilizing material  at the surface of
                     soil  layer (ug/cm3);
                C, - concentration of the volatilizing material at the bottom
                     of the  soil layer (ug/cm3); and
                 L  • depth  of the soil layer (cm).

     Farmer et  al.  simplified the equation somewhat by assuming  a worst-case
scenario,  where the soil  1s completely dry (Pa equals PT) and where  the
concentration at the surface  (C2)  equals 0,  meaning any Increase 1n C2 would
effectively reduce  the driving force behind the vapor flux and,  thus, reduce
the vapor  flux  from the soil surface.  Fanner et al. called this equation the
Assessment Application (41):

                                J  -  D,PT4/3Cs/L                       (Eq. 20)

Appl 1 cablll ty—
     The Fanner  Model  provides an estimate of Individual compound emissions.
The Intended applicability  of the Fanner Model 1s quantification of
steady-state volatile  chemical fluxes from hazardous waste landfills.  This
model does not  account for  convectlve transport due to biogas generation and
                                      106

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1s not applicable to municipal landfills or other landfills containing gas
generating wastes.  Use of the Fanner Model  assumes  the transport of a
volatile compound through the soil cover layer Is controlled by a molecular
diffusion process.

L1m1tat1ons--
     The Fanner Model assumes that the soil/waste below the soil  cover layer
1s saturated with constituent 1.  This assumption tends to overestimate the
emissions by not accounting for the true concentration  gradient below the soil
cover.  Additionally, the Fanner Model does not account for the emissions
associated with atmospheric/meteorological  effects such as barometric pressure
fluctuations.  Also, at high concentrations (greater than  5 percent by
volume), the diffusion process creates Its  own convectlve  sweep or apparent
velocity within the landfill.  This convectlve mechanism Is not accounted for
by the Farmer Model (44).  These latter two limitations are likely to result
1n underestimates of landfill emission rates.

Shen Model--
     Shen modified the Farmer Model (45,46,47) to determine a vapor emission
rate, as opposed to the vapor flux rate, and to enable  calculation of the
volatilization of specific components of the complete waste mixture.  This
modification assumes Raoult's Law applies.   Sh»n multiplied the Farmer
equation by the exposed contaminated surface area and by the weight fraction
of the component in the mixture.  The modified equation 1s (45):

                             E, - D^AfP/'3) Uf,                    (Eq. 21)

     where     E, • emission rate of the component 1  (g/sec);
               0, - diffusion coefficient of component  1n  air  (cm2/sec);
               C, • saturation vapor concentration of component 1  (ug/cm3);
               A  - exposed area (cm2);
               Pt - total  soil  porosity  (dimensionless);
               L  • effective depth of the  soil cover (cm); and
             W/W « weight faction of component 1  in  the waste (g/g).
                                      107

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     The model assumes completely dry soil and zero concentration of
volatilizing material at the soil surface, a worst-case scenario considered
appropriate for cap design and most analyses for volatilization release from
landfill wastes.  This assumption should be used 1n all cases except where
cover soils can be shown to have significant soil moisture.  In these
Instances, the soil air-filled porosity should be substituted Into the
equation for the total porosity by replacing Pt4/3 with Pa10/3/PT2-

Appl 1 cabin ty«
     The Shen Model differs from the Farmer Model In that 1t relates emissions
to the waste composition with a weight factor (w1) and multiplication of the
flux by the landfill area.  Like the Fanner Model, the Intended applicability
is quantification of steady-state volatile chemical emission rates from
hazardous waste landfills.  This model does not account for convective
transport due to biogas generation and is not applicable to municipal
landfills or other landfills containing gas generating wastes.  In the use of
the Shen Model, it Is assumed that the relatively toxic properties of organic
waste placed In hazardous and Industrial waste landfills minimize gas
production due to blodegradation.

Limitations--
     The Shen Model does not account for the landfill  gas losses in leachate
systems, run off, or soils.  But here again, due to the Inert properties of
the volatile constituents, this accountability Is considered by Dr. Shen to be
minute.  The Shen Model also assumes that the soil Is  completely dry with no
Internal gas generation.  However, the Shen Model can  be modified to account
for biogas generation with a multiplicative factor of  6.  This assumption
would tend to overestimate emissions by not accounting for actual wet soil
conditions below the soil cover layer.  As with the Farmer Model, the Shen
Model  does not account for emissions due to meteorological fluctuations (e.g.,
barometric pressure pumping).

     Another limitation of the Shen Model 1s the Incorporation of Raoult's Law
to relate the waste composition to emission rate.  Raoult's Law Is applicable
only to waste saturated with constituent 1 and Ideal solutions.   Application
                                     108

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of the Shen Model to wastes containing dilute concentrations of the
constituent 1 Is likely to result In an overestimate of emission rate.

Thlbodeaux a Model-
     The Thlbodeaux a Model (43,48) was developed by Thlbodeaux to estimate
the emissions of volatile constituents due to Interphase vapor transport from
landfills with no Internal gas generation.  The model Is derived from Pick's
Law of steady state diffusion.  Molecular diffusion Is the controlling and
only transport mechanism addressed by the Thlbodeaux a Model for the movement
of volatile constituents toward the soil/air Interface and then to the
overlying air.  To describe this mechanism, the two-resistance theory 1s used
to describe the two-film resistance 1n which the movement of chemical
constituents 1s limited by their ability to diffuse through the soil and after
migration from the surface, through the air.

     The model assumes that a pure component 1 exerts Its pure component vapor
pressure under the earth, subject to normal geophysical and meteorological
factors.  Thlbodeaux defines an overall mass transfer coefficient to describe
vapor movement which 1s hindered by both the resistance due to soil
characteristics and diffusion resistances at the air Interface.

                              E, - %  (0,-C,,) A                     (Eq. 22}

                              Ei  '  E.oii +  Eair/soii                     (E<1- 23)

     where     1K, -  overall  soil phase mass-transfer coefficient  (cm/sec);
               Cn -  concentration  of  1 above  the soil/air  Interface (g/cm3);
                C, « concentration  of 1  In the sand-filled  chamber pore spaces
                     (9/cm3);
               E1 - rate of vapor movement within the soil  phase (g/sec); and
                A • landfill surface area (cm2).
                            LSOll
«VC,)A                      (Eq.  24)
                                      109

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     where     \ - effective dlffusivity of constituent 1  within the pore
                     spaces  (cm/sec);
                 L - depth of the soil fill cover (cm); and
                C, - concentration of 1 at the air/soil Interface (g/cm3).
                                        t (C,-CU) A
                                                    (Eq.  25)
     where     3D, • gas phase mass-transfer coefficient using the equation
                     developed by MacKay and Natsugu (m/hr).
      3D, - 0.0292 Vx°'78 Lx-°'n  Sc-°'67
                                                                   (Eq. 26)
     where
- wind speed measured at 10 m (m/hr);
• length of the ground emission source in the direction of
  the wind  (m); and
• Schmidt number for the gas.
     Overall mass-transfer coefficient:
                                                                     (Eq. 27)
     where
                     tortuosity, taken to be 3
                     porosity of the cover material
Applicability--
     Llke the Fanner and Shen models, the Intended application of the
Thibodeaux a Model 1s a hazardous waste landfill.  This model does not account
for convective transport due to internal gas generation typically present in
municipal landfills.

Umitatlons--
     The Thibodeaux a Model does not account for the possible emissions due to
barometric pressure fluctuations or Internal gas generation.  In addition, the
                                      110

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Thlbodeaux a Model does not account for the convectlve sweep of a volatile
constituent caused by high concentrations greater than 5 percent by volume.  A
number of factors, such as waste composition, mult1component systems, and
biological or chemical reactions, greatly Increase the uncertainty in the use
of the two-resistance theory.

Logarithm Gradient Model--
     The Logarithm Gradient Model (43) 1s the modern day Interpretation of the
Fanner Model developed to address volatile constituent emission rates for
landfill concentrations greater than 5 percent by volume.  In general, this
model takes Into account both the diffusive mechanism as described by Pick's
Law and the convectlve mechanism due to the sweep or apparent velocity which
diffusion can create with high concentrations.

     The Logarithm Gradient Model is (43):

                                     Ln  p—M  A                  (Eq. 28)

     where      E, - emission rate (g/sec);
                DE - effective diffusion coefficient (cm2/sec);
                PT • total  pressure below the cover layer (mm Hg);
                 M  - mole weight of constituent (g/mol);
                 R  - molar gas constant (cm3 mm Hg/mol  °K);
                 T  - absolute temperature (°K);
                 L  - length of soil cover (cm);
                P, • partial  pressure at the air-soil  surface (mm Hg);
               P,* * partial  pressure of the volatilizing material  in soil  gas
                     at the bottom of the soil depth (mm Hg); and
                 A • landfill surface area (cm2).

Appl 1 cabili ty-
     This model can generally be applied to landfill situations where
molecular diffusion 1s the controlling vapor transport mechanism.  The model
accounts for the apparent velocities associated with high volatile
                                      111

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concentrations, but does not account for the convectlve sweep movement
associated with co-disposal (biogenic gas production) practices.

Limitations--
     The limitations Indicated for both the Fanner Model and the Shen model
apply to this model.  However, the Logarithm Gradient Model accounts for
convectlve transport resulting from the diffusion of highly volatile
constituents (greater than 5 percent by volume).

RTI Closed Landfill Model-
     The Research Triangle Institute (RTI) closed landfill model (43,47)
accounts for emissions via two mechanisms: diffusion through the soil cap and
convectlve loss from barometric pumping through passive landfill vents.  The
model Is based on the Fanner Model (above) which was modified to account for
convectlve losses due to barometric pumping and the decline in emission rate
over time.

     The total Instantaneous emission rate 1s a function of the total Initial
emission rate at the time of landfill closure which 1s the sum of the
instantaneous emissions associated with diffusion through the cap and
barometric pumping.
                                 *
                                E, - £„ + E21                        (Eq.  29)
                *
     where     E1   • total  Initial  emission  rate  at  the  time  of closure
                     (9/sec);
               En *  emissions associated with diffusion through the cap
                     (g/sec);  and
               E21 *  emissions associated with barometric pumping (g/sec).

     The equations for estimating En and E21 are  present below.
                                                                         30)
                                     112

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     where
     where
     where
 A •  landfill surface area (cm2);
D, -  vapor diffusion coefficient In air (cro2/sec);
PA «  soil cap a1r-f1lled porosity (cm3/cm3);
PT •  total porosity of the soil cap (cm3/cm3);
C, •  concentration of constituent In the vapor space  beneath
      the cap (g/cra3);
C, •  concentration of constituent In the air above  the  cap
      (g/cm3) assumed to be 0;  and
 L  - cap thickness (cm).
                                       Q Ct A
                                                      (Eq. 31)
      flow rate of gas through the vent (cm3/cm2-sec);
      concentration of constituent 1n the gas within the
      landfill (g/cm3);  and
      landfill surface area (cm2).
                -[hAEfw
                               -1
(At A)
(Eq. 32)
     (cm);
  h - thickness of waste bed within landfill
Efw  •  air porosity  fraction  of fixed wastes;
 Pr - reference barometric pressure (mm Hg);
 P1 « final barometric pressure (mm ug);
 Tr • reference landfill  temperature (°C);
 Tj • final landfill  temperature (°C);  and
 At - time Interval over which change in pressure  and/or
      temperature occurred  (sec).
The total Instantaneous  emission  rate  at  any  time  1s  then computed via an
exponential decay  function:
                                          *
                           E,(t) - 31.56 E<  exp(-Xt)                  (Eq. 33)
                                      113

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     where    E,(t)- total time-dependent emission rate (mg/yr);
                E, - Initial emission rate, at time of landfill closure
                     (g/sec);
                 t - time since landfill closure (mo); and
                 A • decay constant (mo"1)  « 2.63 x  106  E,*/^; and
               N01  • total mass of the constituent 1n the landfill (g).
The average emission rate from a closed, vented landfill over the time since
landfill closure 1s given by the following expression:

                      EAi(t) - t^ 1 [1-exp (-Xt)]               (Eq. 34)
     where  EA1(t)  - average emission rate over the time since landfill
                     closure (mg/yr);
                 t - time since landfill closure (mo);
               •  \ - decay constant (mo"1);  and
                 *
                E, - Initial emission rate at time of landfill closure
                     (g/sec).

     The RTI closed landfill model assumes that no blodegradatlon occurs and
that the landfill 1s passively vented to the atmosphere.  Transport of the
constituent in moving water 1s assumed not to occur.

Applicability--
     The RTI Model estimates the time-dependent behavior of emissions from
landfills.  RTI modified the Farmer Model to account for the convective loses
from barometric pumping through vents.  In addition, the RTI Model was
designed to account for the decline in the emission rate from closed landfills
over an extended period of time.  The time dependency was Incorporated simply
by adding an exponential decay function.  The decay constant was taken as the
ratio of the emission rate at the time of landfill  closure to the total mass
of the constituent in the landfill.
                                      114

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L1m1tat1ons--
     The RTI Model does not Include convectlve or purging action associated
with blogas production commonly found at municipal solid waste landfills.  It
assumes, as did the Shen and Fanner models, that the toxic properties of the
waste will Inhibit biological processes and, thus, prevent blogas generation.
Furthermore, the liquid waste which contains the volatile constituent 1 1s
assumed to be bound 1n the fixed waste within the landfill cell.  No
experimental or field verification has taken place.

4.4.2  Emission Models for Closed Landfills with Internal Gas Generation

(Thlbodeaux) Convective "Add On" Model-
     The Convective "Add On" Model was developed by Thlbodeaux to account for
both the diffusion and convectlve mechanisms present 1n landfills at which
co-disposal of municipal solid waste and hazardous organic waste has been
practiced.  The model describes the migration of a chemical constituent 1 due
to the convectlve gas sweep of biological gas production within the soil cover
layer.  As the apparent velocity, Vy, of the constituent, approaches zero, the
model reduces to the diffusion controlled Farmer Model  described above.

     The Convectlve "Add On" Model 1s (43):

                             Vv (CrC )
                     E1 ' [expVv)-13 + V yc 1 A               <*• 35>
     where      E{ - rate of vapor movement within  the  soil  phase (g/sec);
                Vy - mean gas velocity in pore  spaces  (cm/sec);
                C1 - concentration of 1 in sand chamber filled pore spaces
                     (9/cm3);
                C, • concentration of 1  at the  air-soil  Interface (g/cm3);
                 L • depth of fill cover (cm);
                DE • effective dlffusivlty of 1 within the soil  pore space
                     (cmz/sec);  and
                 A - landfill surface area (cm2).

                                      115

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Appl1cabillty--
     The Convectlve "Add On" Model can be used to estimate volatile emissions
from landfills with Internal gas generation.  This model accounts for both
diffusion and convectlve transfer.  However, the transfer due to net upward
gas flow greatly overshadows the diffusion transfer mechanism (44).  This
deduction 1s based, In part, on laboratory experiments of simulated gas flow
through a soil cover.                                                       •

L1m1tat1ons--
     A major limitation of this model 1s the required Input of mean gas
velocity through the soil cover.  The limitations applied to the Farmer and
Shen Models apply to this model as well.  However, the "Add On" Model does
account for biogas convection.

Thlbodeaux b Model--
     The Thlbodeaux b Model (43,48) Includes emissions due to barometric
pressure pumping.  The model accounts for the air emissions resulting from
concentration gradients (diffusion), biogas generation sweeps (convection),
and barometric pressure pumping (convection) (49).  The barometric pressure
fluctuations create a pressure gradient within the landfill cell, pumping
vapors to the atmosphere.

     The Thlbodeaux b Model Incorporates Darcy's Law to characterize the
laminar flow of gases flowing through porous media due to pressure gradients.
The gas flow velocity within the landfill  cell  can be estimated as:

                       V  -  (kpg/uL)(P-/>) -  (Kg/L)(P-*)                 (Eq.  36)

     where       V • velocity;
                 k - specific permeability of covering material  in Darcys or
                     cm2;
                 u • viscosity of gas;
                 p » density of gas;
                 L - soil cover thickness;
                                     116

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                 P - landfill  cell  pressure;
                 * - barometric pressure;
                 g - acceleration of gravity; and
                 K • permeability (cm/sec).
     The Thibodeaux b Model  1s (43):
                       OF
               ^  EI - r  ci   ^^   A                          (Eq-37)
     where R „ J.V                                                   (Eq. 38)
                  (P-*)                                             (Eq. 39)
               E, -  emission rate  (g/sec);
               C, -  concentration  of  1  1n the sand chamber filled pore spaces
                     (9/cm3);   .
               V  -  superficial  velocity through the soil cover layer
                     (cm/sec);
               k  «  permeability jf soil cover layer material  (cm2 cp/sec
                     atm);
               P  -  landfill cell  pressure  (atm);
               u  -  landfill cell  gas viscosity (cp);
               K  -  atmospheric  pressure (atm);
               L  •  depth of soil  cover layer (cm);
               DE -  effective dlffuslvlty of 1 within the air-filled soil
                     pore space (cm2/sec); and
               A  - landfill  surface area (cm2).

Appl 1 cabH1 ty--
     The Thibodeaux b Model can be  applied to situations where molecular
diffusion, convection, and barometric  pressure fluctuations are to be
expected.  Efforts by Springer Indicate  that the annual barometric pressure
                                     117

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fluctuation does not average out to one and, therefore, should be considered.
Furthermore, Springer observed through computer simulations of flux with
benzene that barometric pressure fluctuation only slightly Influenced the flux
rate at co-disposal facilities, and greatly Influenced the flux rate at
hazardous waste landfills where no Internal gas generation Is expected.

Limitations--
     The limitations observed in Thibodeaux's Convectlve "Add On" Model
applied to this model with the exception of barometric pressure fluctuations.
Springer's observations Indicate that the Thibodeaux b Model 1s applicable to
landfills with no internal gas generation (49).

Exact Model--
     The Exact Model, (43) developed by Thibodeaux,  Is a steady state model
which accounts for diffusion due to concentration gradients, the convective
velocity created by highly volatile compounds, and convection due to biogas
generation (50).  Application of the model requires an iterative procedure,
since the flux term, J1, appears on both sides of the equation.  The Logarithm
Gradient Model discussed above Is used to calculate the initial estimation of
the flux to start the Iterative calculation.  Since It 1s a steady-state
model, the flux 1s not given as a function of time and the concentration of
constituent 1 is assumed to be constant within the landfill cell.
     The Exact Model 1s (43):
                VP.M.
                  A A
                  RT
    1 -
+   C  LVPTD,
                                               (Eq. 40)
     where
               V  -

               MA"
               PT-
               1  -
               D  -
volatile chemical flux (g/cmz-sec);
apparent biogas velocity (cm3/cm2-sec);
vapor pressure of chemical  A (atm);
molecular weight of chemical A (g/mole);
atmospheric pressure (atm);
soil Jayer thickness (cm);
effective diffusion coefficient (cm2/sec);
                                     118

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          ^..,-Al    ..   ,„,
            :<  EN -  enhancement factor from experimental  data;
              DA1 •   diffusion coefficient of chemical  A In air;
                e •  porosity of soil layer;
               e, «  air-filled porosity of soil  layer;
                R -  molar gas constant; and
                T •  absolute temperature (*K).
Applicability—
     The Intended applicability of this model  1s  municipal  landfills with
Internal gas generation.  This model  can be used  to estimate the flux of a
volatile constituent 1 from closed landfills due  to both diffusion and
convective transport mechanisms.  However,  this model  can only be used for
landfills with an internal gas velocity greater than zero.

Limitations--
     When the model predictions were  compared to  the experimental data   s
developed by Thlbodeaux, large discrepancies were observed.   The experimental
emission rates were higher than the model  predictions,  and Thlbodeaux
attributes this deviation to surface  diffusion which occurs in parallel with
pore diffusion and, in general, enhances the total  diffusion rate.

     Thlbodeaux Incorporates the enhancement factor, EN, in the Exact Model to
account for the discrepancies observed between the effective diffusivity
(obtained by laboratory experiments)  and the Millington-Qulrk diffusivity.
Therefore, one major limitation of Thibodeaux's Exact Model  1s the
availability and accuracy of the enhancement factor.  Another limitation of
Thibodeaux's Exact Model 1s that the  value of the apparent gas velocity, V,
needs to be known.  In order to apply Thibodeaux's Exact Model, the
enhancement factor needs to be experimentally obtained for the specific
constituent, soil type, soil cover depth,  gas type, gas velocity, and gas
humidity.
                                      119

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     Thibodeaux's Exact Model may be useful  1n estimating the order of
magnitude value of the emission flux If the  soil  cover depth 1s less than 10
cm.  The enhancement factor for a shallow soil cover (I.e.,  7.62 cm) ranges
from 1.58 to 4.93 compared to the range of 5.54 to 17.2 for  a deep soil cover
layer (I.e., 38.1 cm).

4.4.3  Emission Models for Open Landfills

Arnold's Open Landfill Model--
     The Arnold Open Landfill Model (43) provides an estimate of the
cumulative vapor release from the surface of open landfills  as a function of
time.  Arnold's Open Landfill Model applies  Pick's Second Law of unsteady-
state diffusion to describe the diffusion process from a liquid surface at
which the concentration of volatilizing liquid remains constant.  The model
assumes that the air space above the liquid  surface is at a  constant pressure
and convective forces are absent.

     In applying Pick's 'Second Law, Arnold incorporated a correction factor
for Pick's Second Law to account for the displacement of the air (or Inert gas
medium) by the volatilizing constituent.  This correction factor is a function
of the equilibrium vapor pressure of the constituent.  Values of Pick's
correction factor, Pv, are plotted against equivalent vapor  pressure in Pigure
21.

     The Arnold Open Landfill Model is (43):

                                                                    (Eq.  41)
                                     120

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       0.2-
                     20
100
                     Equilibrium Vapor Pressure, %
Reference: Shen, T.T., "Estimating Hazardous Air Emissions from Disposal Sites." Pollution
          Engineering. August, 1981.
      Figure 21.  Pick's correction  factor,  Fv, plotted against equivalent
                      vapor  pressure,  Ce.
                                       121

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       where     V° -  volume of vapor released at  ambient pressure and
                       temperature (cm3);
                    *
                   y » equilibrium mole fraction of the volatilizing component
                       1n the gas phase at the liquid-gas Interface;
                   A - area of the liquid surface (cm);
                  D1 • d1ffus1v1ty of volatilizing  component 1n air (cm2/sec);
                   t - time (sec);
                  Fv - Pick's Law correction factor; and
                   * - 3.1416

  Applicability--
       The Arnold Open Landfill  Model  Is applicable to  open landfills and dumps
  where emissions are due to volatilization at the  landfill surface.

  Limitatlons--
       The model assumes that emissions do not occur due  to biogas production or
  barometric pumping.  The model also does not account  for the effects of wind
'  speed which would tend to increase the emission rate.  Finally,  the model
  assumes a constant waste source, whereas,  a  surface crust may form as volatile
% constituents are lost from the surface soil.  This crust may then act similar
  to a landfill cover.

  Shen's Open Landfill Model--
       Shen's Open Landfill Model (43) provides the average volumetric emission
  rate of the volatile constituent from open landfill surfaces.  Shen modified
  the Arnold Open Landfill Model to account for the convection due to wind
  speed.  Shen took the time derivative of the Arnold Model and changed the time
  function, t, 1n the model to a position  function.  This position function is
  related to the length of the open dump and the wind speed.

       The Shen Open Landfill  Model  is (43):

                           dV
                                                                      (Eq.  42
                           dt         ....-_                          i
                               avg
                                       122

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                                                    3
                         - average emission rate (cm /sec);
                  vg
     where     y, -  equilibrium mole fraction;
               UL  • width of open landfill (cm);
               D,  • diffusion coefficient (cm2/sec);
                U  • wind speed (cm/sec);
               Fv  - Pick's law correction factor;
               LL  - length of open landfill (cm);  and
                x  - 3.1416

     The model has also been presented as Ziegler's modification of Arnold
as (45,50):
                         4Y - 2 CeW (DLv/*FY)1/2Wi                   (Eq. 43)
                         dt

     where     dY  -emission rate;
               dt
               W  - width of landfill;
               L  « longest dimension of the landfill;
               v  -wind speed;
               Hi  - weight fraction of a specific  compound in the waste;
               Ce  - equilibrium vapor concentration;
               D   - diffusion coefficient; and
               FY  - correction factor.

     The emission rate can Increase with increasing wind speed; however, the
dilution fraction also Increases.  The net effect of wind speed on ambient
concentration, therefore, becomes compensative and  depends on receptor
location.

Appl1cabllity--
     The Shen Open Landfill Model 1s applicable to  open landfills where
emissions are due to volatilization at the landfill surface.  It appears that
this model Is useful as a screening process to examine whether volatilization
will be significant for a given contaminant (46).
                                      123

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Umitatlons--
     The model does not provide for biogas generation or barometric pumping.
The model also does not provide for the formation of a weathered surface which
would tend to reduce emissions similar to a closed landfill cover.

RTI Open Landfill Model--
     Research Triangle Institute (RTI) modified the Shen Open Landfill Model
by Introducing the mole fraction of the constituent to account for more than
one volatile constituent 1n the liquid.  The RTI Open Landfill Model, shown
below,  uses  the  Ideal gas  law to  convert  the  volumetric emission of the
Shen Open Landfill Model and provide an average mass emission rate.(40,41)
     The RTI Open Landfill Model 1s (43):
                              2PM.Y,* W,
                                 1_ 3   L
     where     E, • average mass emission rate of component 1  (g/sec);
               P  * ambient pressure (mm Hg);
               M1 - molecular weight of component 1;
                *
               Y, • equilibrium mole fraction of component 1;
               WL « width of open landfill;
               D, - d1ffus1v1ty of component 1 In air (cm2/sec);
               LL - length of open landfill  (cm);
               U  • wind speed (cm/sec); and
               Fv « Pick's Law correction factor.

Appl 1 cabill ty~
     The RTI Open Landfill Model 1s applicable to open landfills where
emissions are due to volatilization at the landfill  surface.

Limitations--  The model does not account for biogas production, barometric
pumping, or formation of a surface crust.

                                      124

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-4.4.4  Emission Models for Landtreatment

  RTI Land Treatment Model-
       Research Triangle Institute (RTI) has developed a model  (42,43) for
  estimating emissions from land treatment areas.   The model  1s comprised of two
  equations; one for short time (Immediately after application  or tilling) and
  one for longer times.  The RTI land treatment equations are based on the
  premise that emissions are limited by vapor diffusion through the soil.  The
  model accounts for the removal of organic material  from the land treatment
  area by both biological degradation and air emissions.

       The expression for the Instantaneous emission  rate for short time periods
 • Immediately following Initial waste deposition 1s given by:

                          H.	L
                          La   Ia__  .  I_L_ 1/2  rt/t h             (Eq. 45)
       where      E -  emission rate of constituent (g/cm2-sec);
                 M0 -  area loading of constituent (g/cm2);
                  1 -  depth of waste in open landfill  (cm);
                 ea •  volume fraction of air-filled voids  In the soil
                       (dimensionless);
                 Kq -  ratio of gas-phase constituent to total  constituent in
                       solid waste (dimensionless);
                 Kg -  gas-phase mass transfer coefficient  (cm/s);
                  t •  time after waste application to the  landfill site (sec);
                 De -  effective diffusion coefficient of constituent 1n the
                       solid waste (cm2/sec);  and
                 tb -  time constant for biological decay (I.e.,  time required
                       for 63.2% of constituent to be degraded.
                                        125

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     For longer times after application or tilling,  when most of the
constituent 1s not present 1n the soil, the short-term equation will over
estimate air emissions.  Under these conditions,  the following equation 1s
applicable:
            E.      o             ex            J        e-Vtb    (E«.  W)
     where     E -   emission rate a long time after application or tilling
                     (g/cm2-sec);  (all  other parameters are the  same  as
                     presented above).

Applicabillty--
     The RTI Land Treatment Model  1s applicable to sites  where liquid or
semi-liquid waste 1s applied to the soil  surface.   The model  assumes  that
emissions from the surface are limited  by diffusion of vapors through the pore
space of the soil/waste mixture.   The model  accounts for  removal of organic
material from the soil/waste mixture by both biological degradation and  air
emission.

Limitations--
     The model Is not applicable to wastes which are easily biodegraded,  or to
sites with highly porous soils which allow easy vertical  migration  of the
liquid waste.  The model does not  account for  losses to these or other
pathways.

Thibodeaux-Hwang Model--
     Thibodeaux and Hwang developed a model  for determining volatile  emissions
from land treatment operations (49,51,52). The liquid being  land-treated is
assumed to soak Into the soil, coating  the pore walls.  The liquid  then
evaporates from the pore walls and diffuses through the soil  pores  to the
soil/air Interface.  After a short period of time,  a dry  zone develops at the
soil surface, with a wet zone below. Over time, the thickness of the dry zone
Increases while the thickness of the wet  zone  decreases.
                                     126

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The rate of emission can be determined by:(51)
where
      •<  [h 2 .2 De, t A (hD-hs)C<0 1/21
         L s            M               -I
                                                                (Eq.  47)
                                   Mo
       'ig
                                 As  f(y
                                                    1o
                                                                   .  48)
 A -
A, -

C1g •

C10 •
De1 •

Dw1 -
H
hs -
M10-
  t -
  y •

 Z  -
                surface area over which waste 1s applied  (cm2);
                Interfacial area per unit volume of soil  for  the oily
                waste, (cm2/cm3);
                effective wet zone pore space concentration of component
                1  (9/cm3);
                concentration of component 1 in oil (g/cm3);
                effective d1ffus1v1ty of component 1 1n the air-filled
                soil pore spaces (cm2/s);
                effective  diffusivity of compound  1  1n  the oil (cm2/s);
                flux of component 1 from the soil surface (g/cmz-sec);
                (hp2 +  hph$-2hs2)/6 accounts for  the lengthening dry zone;
                Henry's Law constant 1n concentration  form (cm3  oil/cm3
                air);
                depth of soil contaminated or wetted with landtreated
                waste (cm);
                depth of subsurface Injection,  if applicable  (cm);
                Initial mass of component 1 Incorporated  Into the zone
                (hp-hs),  (g);
                time after application  (sec);
                height of wetted soil remaining after  partial drying
                (cm); and
                oil layer diffusion length (cm).
                                 127

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 Appl1cab1l1ty--
      The Thlbodeaux-Hwang land treatment Model Is applicable to determining
 volatile emissions from landfarming of liquid wastes, Including oily wastes.

      The model  assumes that the soil column 1s Isothermal, liquid movement
 does not occur  by capillary action, adsorption to soil particles does  not
 occur,  and biochemical oxidation does not occur (49).  All of these factors
 would tend to reduce the emission rate.

 Limitatlons--
      The model  1s not applicable to wastes which are easily biodegraded, or to
 sites with highly porous soils which allow easy vertical migration of  the
 liquid waste.  The model  does  not account for losses to these or other
 pathways.

 4.4.5  Fugitive Dust

      Fugitive dust at hazardous waste sites (airborne wastes or contaminated
 soils)  most commonly results from wind erosion of the wastes or vehicular
 travel  over unpaved contaminated roads.  The U.S. EPA has developed equations
 to  estimate fugitive dust emissions arising from vehicle travel on unpaved
 roads (AP-42).   The U.S.  Soil  Conservation Service (SCS) has developed a model
 for predicting  fugitive dust emissions resulting from wind erosion.

      The SCS model  takes Into  account such factors as surface soil moisture
 content,  roughness,  and cloddiness, type and amount of vegetative cover,
 wind velocity and the amount of soil surface exposed to the eroding wind
 force.   The SCS equation can be expressed as:

                            E - f(r,C',K',L',V)                     (Eq. 49)

.where     E  •  potential  annual  average wind erosion soil loss;
           T  -  soil  credibility Index;
           C'  •  climatic factor;
           K'  •  soil  ridge roughness factor;
                                      128

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          L' - field length along the prevailing wind direction;  and
          V  - vegetative cover factor.

     The SCS wind equation computes total  fugitive dust emissions due to  wind
erosion which result from the combination  of surface creep,  saltation,  and
suspension.  If only the fraction of soil  loss that 1s suspendable and
trans-portable over significant distances  by wind Is desired,  the wind
equation must be adjusted (reduced) to reflect emissions from only this
phenomenon.  The SCS wind erosion equation 1s not reliable when altered to
estimate short-term emissions.  The nodel  1s designed to estimate annual
erosion losses only.

     The U.S. EPA has developed the following equations which  Can be used  to
estimate fugitive dust emissions resulting from vehicular travel  on
contaminated unpaved roads (53):
              EyT.R(5.9,

or 1n metric form:
                                                                                 4
                           /_s WSj>\/W_\0.7/w\0.5  f?65-           (Eq.  51)
                           U2M48A2.7/    U/     V  365
     where     E^  -  emission factor for vehicular traffic;
                 k - 0.45 - particle size multiplier for particles <10um
                     (i.e., particles that may remain suspended once they
                     become airborne and which can be inhaled Into the
                     respiratory system);
                 s - silt content of road surface material;
                Sp • mean vehicle speed;
                 W • mean vehicle weight;
                 w • mean number of wheels; and
                Dp • number of days with at least 0.254mm (0.01 Inch) of
             ;        precipitation per year.
                                      129

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     To estimate fugitive emissions due to vehicle travel for a given time
period, the emission factor, EVT defined above, Is multiplied by the  vehicle
miles traveled during that time period.  Maximum release conditions  may be
estimated by using a small value of Dp In the model  to reflect assumed
drought conditions.  Average emissions can be estimated by using annual
average value for Dp.

Appl 1 cabin ty-
     The AP-42 dust model 1s only applicable to dust resulting from vehicular
traffic.  The SCS model 1s applicable for wind-blown dust.

Limitations--
     The SCS model, as presented, does not provide sufficient detail for
application.

4.4.6  Additional Models

     Additional models Identified but not Included here are: Hwang's
modification of Farmer, (51,54) RTI Open Dump Model, (42) Hartley Method,
(36,55) Hamaker Method, (55) and Dow Method (55).   The latter three equations
were developed for volatilization of pesticides applied soil.

4.4.7  Non-Aerated Lagoons

Mackay and Leinonen Dynamic Two-Film Model--
     This dynamic model (56,57) best serves those  Instances Involving Isolated
disposal of a given quantity of waste, as opposed  to the steady-state scenario
offered by the other models.  Laboratory validation of this model was reported
(57).

     This model assumes that nearly stagnant films of well mixed bulk air and
water systems occur on both sides of the liquid/air Interface.

                       HI  - *,i (C, - P/H,)                          (Eq. 52)
                                     130

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'where     N,   - mass  flux  rate  (mol/m2-hr)
           K1L • overall nass transfer coefficient (m/hr)
           C,   • concentration of 1 (mol/m3)
           P,   - equilibrium partial pressure of 1 In the vapor (atm)
           H,   - Henry's Law constant for 1 (atm-m3/mo1)

 Appl 1 cabin ty-
      The model offers an  alternative to the steady-state scenario.   However,
 Wetherold (36) reports that despite Its theoretical validity, the model  1s
 difficult to  apply to the "real world."  The Input parameters are difficult to
 determine or  find in available  literature.  And, this  model  best applies to
 the emissions of  single compounds.

 Limitations--
      The model fails to provide for white  caps, thermoclines, eddy  diffusion
 and other similar phenomena,  tending to under-predict  emissions when these
 conditions occur  at the lagoon.

 Thibodeaux, Parker and Heck Model--
      This model  (52), which can be applied to both non-aerated and  aerated
 lagoons, evolved  from basic accepted theories of mass  transport.   It 1s  used
 to determine  emission rates of  individual  compounds, assuming that  the
 concentration of  each compound  remains constant in the aqueous phase (it does
 not interact  with the other compounds present).  It also assumes that the
 influx of the compound 1s steady, that its biodegradation  rate is  steady, and
 that the lagoon surface can be  clearly separated Into  either quiescent (non-
 aerated) or turbulent (aerated) zones.

      To use the equation,  four  mass transfer coefficients  must be  determined
 from Impartial relationships.
                            q, - M^ (X,  - X,*)                       (Eq. 53)     ^
                                      131

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For each volatile component 1:
                                    t      t
                                   k1    HkJ
                                             + A,,)                   (Eq.  54)

                                                                     {Eq'  55)
                             n
                            *1     Kl    "Kg
     where     q,  - flux of component 1 from the lagoon surface (g/cm2-sec);
               M,  - molecular weight of component 1 (g/g-mol);
               Klt  - overall liquid-phase mass transfer coefficient for
                     component 1 (mol/cm2-s);

               X,  - mole fraction of component 1 1n the aqueous phase (this
                     must be measured); and

               X,* • mole fraction of component 1 1n equilibrium with the mole
                     fraction of -1 in air, (Y1t  where 1f Y,  1s  assumed to be
                     negligible, X,*  can equal  0);

          Kj , k? -  overall liquid-phase mass transfer coefficient for
                     aerated non-aerated zones of a lagoon,  respectively
                     (mol/cm2-s); and

          At,  A,,  •    surface areas of aerated and unaerated zones,
                     respectively (cm);

          K j, k j»  Individual  liquid phase mass transfer coefficients for
                     the aerated and  unaerated zones, respectively (mol/cm-s);
          K  , K" -  Individual  gas phase mass transfer coefficients for the
                     aerated and unaerated zones, respectively (mol/cm-s); and
                 H - Henry's Law constant In mole fraction form (y » Hx).
                                     132

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Appllcabinty--
     The Thtbodeaux, Parker, and Heck model  1s applicable to aerated,  non-
aerated, and combined lagoons.  The model  assumes  steady-state conditions and,
therefore, Is applicable to undisturbed lagoons.   The model  Is probably not
applicable to disturbed (disturbed sludge) conditions.

Limitations—
     The accuracy of this model has not been verified as  of  1982.   Wetherold
(36) expressed some skepticism regarding the accuracy or  availability of some
parameters necessary for the calculation of the mass transfer coefficients.
Also, the model requires additional development to satisfy the need for a
predictive model capable of predicting total VOC emissions from- a  lagoon
containing a complex mixture of compounds (36).

     One way to deal with this, as suggested by OeWolf (52),  1s to sum up the
emissions estimated for several classes of compounds by selecting  a
representative compound from each class.  Acknowledging this selection as
"arbitrary", DeWolf provides some suggestions, noting that some compounds are
more likely to be encountered and those 1n mid-molecular  weight range of 4 to
8 carbons are "likely to dominate 1n frequency of  occurrence".  He suggests:

          Class                          Compound
          Paraffins                       Hexane
          Oleflns                         Butene
          Aromatlcs                       Toluene
          Halogenated hydrocarbons        Methylene chloride
          Oxygenated hydrocarbons         Acetone
Smith, Bomberger, and Haynes Model--
     The Smith et al. model (36) Is applicable to emissions prediction for
highly volatile compounds in a lagoon setting.  The  model  1s not applicable to
low and Intermediate volatility compounds.   Also, liquid phase resistance
should be the controlling resistance.
                                      133

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      The volatilization rate 1s expressed as a first-order kinetic equation.
                                                                      (Eq. 58)
                                             env
.where     E - mass emission rate per unit volume  (Ibs/gal-day);

       (K*)env-  volatilization rate constant for compound a 1n the environment
                (day'1);
                                                                *
           c -  concentration of compound a (Ibs/gal);

      Ka      •  ratio of volatilization constants  of compounds a and oxygen as
      K*
        lab      K lab measured In laboratory (dimensionless);  and

:     (K')env »  oxygen reaeration rate 1n the environment (day"1).

 Applicability—
      The model is applicable to volatilization  of high  volatility compounds
 from non-aerated waste disposal lagoons.

 Li'nitations--
      The model is limited in that 1t 1s designed  to predict emission rates of
 highly volatile Individual  compounds and It may be  difficult  to apply to
 complex  multicomponent wastes.   The model  Is not  appropriate  for estimating
 emissions of low or Intermediate volatility compounds.   Also,  Wetherold (1982)
 notes that determining the  ratio of volatilization  constants  of a compound
 (Ka/K')  is  expensive in the  laboratory;  attempts to estimate this  ratio simply
 using diffusion coefficient valves Increase the model's  overall  uncertainty.

 Shen Model--
      The Shen Model (47,58)  presents an empirical equation for determining
 volatile emissions from lagoons.  The Shen Model  1s (47):

                                      134

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and,
ERp, - 18 x 10
                                         '6
                                                                     (Eq.  59)
     where    ERP1 - emission rate potential of compound 1 (g/sec);
                 A  « lagoon surface area (cm2);
                C, - concentration of compound 1  1n lagoon (mg/1); and
               KL, • liquid-phase mass transfer coefficient of compound  i  (g
                     mol/cmz-sec).
'3
'0-5
                *-20
- 4.45 x 10'  (M,)'-  (1.024)*-2  (U)
                                                    °'67    '0'85
                            (H)
                                                                   (Eq. 60)
     where     M, - molecular weight of compound 1 (g/mole);
                t - lagoon surface temperature (oc);
                U - surface velocity • 0.035 wind speed (cm/sec); and
                H - average liquid depth of the lagoon (meter).

Applicability—
     The Shen Model 1s applicable as a screening technology to estimate
volatile emission rates from lagoons.  It appears, from Shen's discussion,
that the model assumes the lagoon Is a dilute water solution, although this  is
not explicitly stated.  Shen Indicates that the model should only be used when
"emission rates and risks are clearly acceptable or unacceptable. "(47)

Limitations--
     The model should be limited to use as a screening technology.
RTI Model -
     The RTI Model 1s a simple volatile constituent mass transfer model  (42):
      E, - K,A C,
                                                                     (Eq. 61)
                                      135

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      where     E1 -  air emissions for component 1  from the liquid surface
                      (g/sec);
                 K1 - overall mass transfer coefficient  for component 1
                      (m/sec);
                  A - liquid surface area (m2); and
                 Ct « concentration of component  1  In  the liquid phase (g/m3).

      The calculation of the mass transfer coefficient (K{)  will  depend on
 whether the lagoon 1s quiescent, turbulent,  a  combination of quiescent and
 turbulent, or has an oil film.  In addition, the equation can be adjusted  to
 account for losses due to biodegradation.  Several  methods for calculation of
 KL  are given In the listed reference  as  well as  examples  for  applying  the
                                                                »
 model to specific site types.

 Applicability--
      The RTI Model Is applicable to assessing  volatile  emissions from aerated
 and non-aerated lagoons.  The model Is applicable to  quiescent and turbulent
 lagoons and can be adjusted to Include biodegradation,  although the toxic
•mature of most waste lagoons will limit biological  activity.   The model Is
-applicable to both undisturbed and disturbed site conditions.

 Limitations--
      The model 1s not applicable to lagoons with a  surface crust.  While the
 calculation of the mass transfer coefficient Includes wind speed for quiescent
 lagoons, the turbulent lagoon calculations appear to  consider wind speed to
 have negligible affect on the emission rate.

 4.4.8  Aerated Lagoons

 Thibodeaux, Parker, and Heck Model--
      This model 1s described 1n 4.4.7.

 RTI Model-
      This model Is described in 4.4.7,  and can be adjusted for aeration.
                                      136

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                                   SECTION 5
                                 CASE STUDIES

      Section 5 1s a collection of five case studies that demonstrate the
protocol described 1n this manual for developing BEEs.  The purpose of this
section 1s to document different experiences regarding site Investigation and
characterization and to demonstrate the protocol for developing BEEs as
applied to these case studies.  The sites selected represent different regions
of the country, different types and distributions of waste, varying levels of
air emissions potential, and varying levels  of historical air pathway analyses
(APA) performed 1n support of the Remedial  Investigation/Feasibility Study
(RI/FS) process.

     Only the first case study demonstrates  application of the complete
protocol.  The protocol was Implemented only partially at the other sites.
The assessment technologies used (or not used) 1n these case studies do not
necessarily represent the best or most technically suitable assessment
technologies.  Many factors Influenced the decision-making process concerning
the development of BEEs leading to air pathway evaluations.  Also, the work at
these sites was conducted without the benefit of a formalized protocol for
designing APA programs and developing BEEs.

5.1  CASE STUDY 1:  PETROLEUM WASTE LANDFILL/LAGOON

     Case Study 1 1s a disposal area for wastes from a defunct refinery.

5.1.1     Site History

     The petroleum waste site resulted from  years of dumping bottom sludge
from refinery vessels and tanks at a disposal  area located adjacent to the
refinery.  The on-site disposal activity was performed as general  refinery
upkeep and was typical of the oil industry at that time.
                                     137

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     This small refinery was located 1n Southern California between the
foothills of a mountain range and a small  community.   The refinery dumped Its
wastes on site from about 1930 to 1950.  In 1952,  the refinery was dismantled
except for an old garage and several tanks.  Since 1953,  the site has been a
crude oil pumping station.  No known dumping has resulted from the pumping
station operation; therefore, all waste dates back over 35 years.  At present,
the property 1s separated from an elementary school  and a number of residences
by a fence and a drainage channel.  The site 1s  shown In  Figure 22.

     The refinery dumped most of Its sludge 1n a landfill on the western edge
of the property.  The landfill covered approximately one  acre of surface area
and was bermed at the middle at some unknown time, thereby separating the
landfill at the north end from a lagoon at the south end.  The landfill is
believed to have resulted from dumping soil Into the landfill to solidify the
liquid waste.  Investigations of the site  disclosed that  the entire
landfill/lagoon contained roughly 11,100 cubic yards of waste to a depth of
                                                                        *i
about 6 feet.  The waste was an oily sludge, with an odor and appearance
typical of refinery wastes.

     The site 1s subject to hot summers and mild winters.  Precipitation is
approximately 20 Inches per year, occurring p, .dominantly during the winter
months.  During site work, winds generally were  light and easterly or
northeasterly during cooler periods.  During warmer periods, onshore sea
breezes yielded moderate breezes from the  west and southwest.  The residential
neighborhood was downwind of the lagoon and landfill  most of the time.

5.1.2     Ob.iectives

     The objectives of the site work, from an air pathway perspective, were
several-fold: provide estimates of the undisturbed and disturbed site
emissions; to use BEEs to develop a mitigation plan;  and  to conduct ambient
monitoring during the remedial investigation and mitigation to ensure worker
and community protection through the setting of  appropriate action levels.
                                      138

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 N
 +   30-foot Meteorological Tower



 A   10-foot Meteorological Tower



^^ Suspected Disposal Areas, 1-8





    0  tOO  200  300 400  500
           FEET
                Figure 22.  Location  of suspected disposal  areas.
                                       139

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Table 14 summarizes the activities conducted at the site to address the air
pathway.  These activities are described below.

5.1.3     Scoping

     In late 1980, the owner sought regulatory agency approval  to remove the
waste and apply It to site roads.  California's Regional Water Quality Control
Board denied the request after two sets of samples, sent to two Independent
laboratories, disclosed high lead concentrations In the waste.   The owner then
sought a more thorough environmental evaluation of the site and
recommendations for remediation.
                                                              *
     The Initial task In completing the scoping phase of the site
characterization was a review of existing data.  Information was collected
from the owner's site files, from files at a similarly operated refinery, from
public agencies, and from available references.  The collected data were
reviewed to provide a working'knowledge of the site history, conditions, and
environmental setting.  Essentially no activities had been conducted to
determine waste volume, environmental Impacts, emissions characteristics, or
waste existence and type in other suspected disposal areas.

     The site Investigation was Initiated by a site Inspection.  The
inspection served to familiarize the crew with the site, to locate special
features, and to assist in the development of appropriate sampling methods.
This undertaking Identified two types of wastes: a tar-like waste and a
granular waste that gave off fumes and white vapors when It came in contact
with water. The granular waste caused eye Irritation and hindered breathing.
Based on this site scoping, the potential for volatile air emissions during
site mitigation was deemed to be high and further site characterization
activities were initiated.
                                      140

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                 TABLE 14.  APA ACTIVITIES CONDUCTED AT THE SITE
 APA Objectives

 Determine the baseline  and disturbed emissions for the site using direct
 emission measurement  technologies.  Protect on-s1te workers and the public
 from air emissions during the  Investigation by using air monitoring and action
 levels  to stop  site work.


? Scoping

 The lagoon and  landfill were determined to contain petroleum waste that had a
 moderately high volatile organic air emissions potential.  Partlculate
 emission potential from the sludge/tar-like solid waste was considered to be
 low.


 Screening Measurements

 The site was surveyed using real-time Instruments (Indirect technology) for
 "indicator compounds on  a grid  system.  Soil samples were collected for head
 % space analyses  to assess air emissions potential (direct technology).  These
 data were used  to design the In-depth measurement strategy.

 *;
 In-Depth Measurements
-**%     *-   - ^ T- • III • I • I

 The In-depth emission measurements Included:

      •    Undisturbed baseline emission measurements using the surface
           emission Isolation flux chamber;

      •    Disturbed baseline emission measurements using the downhole emission
           chamber; and

      •    Air monitoring for worker and public protection.

 These data were used  to develop undisturbed and disturbed site BEEs.


 Mitigation

 Undisturbed and disturbed BEEs were used to develop a remedial alternative
 that Included excavation and removal of the waste and air emissions control
 technologies.
                                       141

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 5.1.4  Overview of Fieldwork for Site Characterization

      An undisturbed emission survey (see  5.1.5) was completed  to  assess the
 atmospheric Impacts of volatilized compounds under prevailing  site conditions.
 The emission survey used Indirect real-time Instrument measurement techniques.
 Knowledge of the type of waste Indicated  that total hydrocarbons  and  benzene,
 as representative of aromatic species,  were good  Indicator compounds  for
 volatile emissions from the petroleum waste.  It  was also possible that sulfur
 dioxide (S02)  could be  an air contaminant from the waste.  Thus, total
 hydrocarbons,  benzene,  and S02 were selected as the Indicator compounds.
 Other compounds may have been equally well suited for use as Indicators,  but
 the compounds  selected proved to be adequate.  Testing for these  compounds
 showed low emissions (less than  three times background levels)"of total
 hydrocarbons,  benzene,  and S02.  This result was obtained by comparing  on-site
 emission rate  data to background or off-site data.  It was concluded  that no
 significant atmospheric Impacts  existed on or off site for undisturbed  site
 conditions.

      To assess the potential impacts  of air emissions of the combined site
 during remediation and to provide adequate monitoring for on-site personnel
 and nearby residences,  a monitoring program was conducted that  included:
 constant meteorological monitoring at two stations; monitoring  for emissions
rfrom waste disturbance activities at  the  property boundary between the  waste
 and the nearby residences; and surveying  of corehole borings.

      Two meteorological towers (see Figure 22) were used to collect continuous
 data.  A 33-foot tower equipped  with  meteorological instrumentation collected
 the primary meteorological site  data  during the field activity.   In addition,
 a 10-foot tower provided micro-meteorological wind speed and wind direction
 data.  The towers were positioned upwind  and downwind of the landfill and
 lagoon.  Meteorological data were used  in receptor modeling, in conjunction
 with the measured emission rate  data,  for planning remedial options.

      Additional waste characterization  efforts were performed.  Five  core
 holes were drilled through the waste  and  into the soils below  the waste to
                                      142

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permit sampling of the waste and soils and examination of waste and soil
stratification and physical properties.  They also provided a means for
measuring volatile species emissions as a function of depth In the waste.
Wastes were found to be only 5 or 6 feet deep over the 50,000 square-foot pit
area, for a total of approximately 11,100 cubic yards of wastes 1n the
landfill and lagoon.  Hastes were generally soft and semi-fluid 1n the lagoon
and hard or soil/waste mixtures In the landfill.  The waste had a pH below
2.0, contained varying levels of trace metals (Including high concentrations
of lead 1n some samples), and had a very high percentage of organic material.
Soils below the wastes were predominantly alluvial gravels mixed with sand and
silt.  The soils rapidly buffered acidic waste leachate.  Trace metals were
found in varying concentrations and no apparent trend existed with depth.  The
underlying soils had been Impacted by low levels of hydrocarbons originating
in the waste pit.

     In addition to the air-related work described above, extensive work was
undertaken to assess the Impact of the site on local ground water.  Also,
eight small areas suspected of being former waste disposal areas were
Investigated.

     The site Inspection data were reviewed and a subsequent site
Investigation plan was developed.  This Included an undisturbed emission
survey, air monitoring on-s1te and at the fence!ine during drilling and
sampling of wastes in the landfill and lagoon, and an emissions survey under
disturbed conditions to estimate the potential for emissions during possible
future disturbance of the wastes during an excavation activity.

5.1.5  Undisturbed Emissions Survey

     Both screening and In-depth measurements were performed.
Screening Measurements--
     A survey of the undisturbed surface emissions  was  conducted.   First,  the
main waste piUdisppsal areaowas surveyed and a map was prepared with a grid
                                     143

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 system overlying the waste area to provide location reference.  An emissions
 survey was  performed which consisted of a real-time Instrument survey (an
 Indirect measurement screening technology) for Indicator species at randomly
 selected grid  points mapped over the landfill and lagoon.  This survey
 provided general data on the level of gas concentrations from the landfill and
 lagoon, Identified potential areas of higher concentrations, documented
 background  conditions (I.e., gas species concentration background levels), and
 provided Input Into the safety program, ensuring adequate worker/operator
 protection.  This screening technology was selected because 1t was a quick and
 Inexpensive way to survey the site for areas of high air emissions potential.
 These data  could then be used to design the in-depth measurement approach.

     During the emission screening, portable, real-time monitors were used to
 determine sulfur dioxide (S02), total hydrocarbon compounds (THC), and
 aromatic compounds (benzene).  THC measurements were made with an organic
 vapor analyzer (OVA).  S02 measurements were made with an electrochemical  cell
 instrument.  The HNU analyzer was used to detect aromatic species reported as
 benzene.  S02, THC, and benzene,  as well as surface and air temperature, were
 measured at 27 grid node points under quiescent conditions.  The portable
 analyzers provided rapid feedback, but could not differentiate between various
 hydrocarbon or sulfur species.

;     For this  site, benzene, S02,  and THC were used as Indicators of air
 emissions.  Benzene Is a carcinogenic contaminant representative of aromatic
 compounds.  Sulfur dioxide was a possible Inorganic air contaminant on site.
 Total hydrocarbons were monitored for an Indication of total organic air
 emissions.

 In-Depth Measurements-
     After  completion of the screening measurements, in-depth measurements
 were conducted to quantitate the gas emissions from the undisturbed site for
 risk assessment purposes and to aid in siting drilling locations.  The need
 for this type  of sampling was determined before any screening measurements
 were performed, based on the waste type and the proximity of receptors  (i.e.,
 the suspected  large volume of highly volatile wastes was considered likely to
                                      144

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 cause significant air Impacts during any remedial  waste removal  or disturbance
 activities).  Direct emission measurements  were  performed  using  an emission
 Isolation flux chamber.  This 1n-depth technology  was  selected because 1t Is
 Ideally suited to obtain emission rates from homogenous area sources.   The
 flux chamber Is relatively easy to use and  multiple measurements (I.e., 8 to
 10) can be obtained 1n one day.  Gas samples collected from the  flux chamber
 outlet line were analyzed using real-time analyzers.   Samples also were
 collected in gas canisters for detailed hydrocarbon speciation 1n an off-site
.laboratory.

      The site was divided into zones of high and low emissions potential  based
 on plotted results from the real-time instrument survey.   Locations for in-
 depth measurements were randomly selected from grid cells  in these different
 zones.  Based on the results of the real-time Instrument survey,  nine  flux
 chamber measurements were performed to assess the  undisturbed emission from
 the main landfill/lagoon.  The flux chamber was  constructed and  operated as
.described in Section 4.  Measurements at  a,given grid  point were typically
 made over a 40-minute time period.

      Chemical measurements performed on the air  leaving the emission chamber
 included:

           Continuous determination of S02 (InterScan);
      •    Continuous determination of THC (OVA);
      •    Continuous determination of benzene (HNU); and
           Grab sampling for organic speciation (Photovac 1010).

 Undisturbed Emission Survey Results--
      A total of 27 grid nodes were sampled,  including  sampling at five
 background locations (upwind of each block),  five  duplicate sample points,  and
 sampling at one control point location at three  different  times  of the day
 (morning, noon, and afternoon).  The control  point was  one of the grid points
 that was regularly sampled to establish an  estimate of  the temporal
 variability In emissions at the site.
                                      145

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     Very low gas concentrations were observed over the exposed waste.  Most
of the screening measurements showed background levels at the locations
sampled for S02,  THC,  and benzene as shown  In  Table 15.   Moderately low levels
of undisturbed emissions were observed over exposed waste In the lagoon and
the landfill.  Table 16 provides undisturbed site emissions data.

     The results of the screening and 1n-depth emissions testing showed that:

     •    The emissions were highest 1n the landfill and lagoon where wastes
          were exposed (especially where natural  disturbances occurred; I.e.,
          cracking of surface, waste seeps, etc.);

     •    Control point sampling at various times of the day ("same location)
          Indicated a large temporal variation in emissions due primarily to
          solar surface heating;

          Areas surrounding the combined site or 1n overburden on top of the
          waste material showed background  levels of emission; and

          Volatile emission rates from the  combined site (landfill and lagoon)
          were low for S02 and benzene under undisturbed conditions.   For
          steady-state conditions:  S02 emission  rates ranged from background
          to 5.6 ug/m2 minute"1; THC emission rates ranged from background to
          120 ug/m2,  minute"1; and benzene from background to 470 ug/m2,
          minute"1.  Emissions did  show a high dependence on  diurnal
          temperature fluctuations with more emissions observed during the
          hottest periods, as expected.  The field photovac analytical
          capability provided limited hydrocarbon speciation data that helped
          direct more detailed hydrocarbon  sampling and analysis.  The
          photovac data were not used to determine emission estimates.

5.1.6  Disturbed Emissions Survey

     Both screening and in-depth measurements were performed.
                                      146

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       TABLE 15.   SUMMARY OF  SCREENING MEASUREMENTS OF UNDISTURBED WASTE


                  	Range  of Values	

 Number of          SO., (mm)         THC  loom)             Benzene  (pom)
Measurements      Peak   Average     Peak  Average         Peak       Average


    41            0.005   0.005      2-4a      2-4'      0.01-0.80b  0.01-0.70b
a  Differences probably due to  Instrument drift.

b  Background levels only detected at 30 of 41 points.
                                     147

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      TABLE 16.-  CASE STUDY 1: SUMMARY OF UNDISTURBED SITE EMISSIONS DATA


 Lagoon                  S02                  THC*                Benzene6
Location
(Surface)            (mg/m2, rain'1)        (ug/m2, mln"1)         (ug/m2,  mln'1)


   II                    0.14                  1.8                    4.7
   12                    0.14               120                    470
   #3                    0.14                  7.3                   43
   #4                    0.14                44                      1.8
   15                    5.6                   7.3                  _U	
a As determined by portable FID (OVA).

b As determined by portable PID (HNu).
Average                   1.2                 36                     98
Landfill
Location
#1
n
Average
0.14
U_
0.77
7.3
2i_
18
3.6
1^
3.6
                                      148

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Screening Measurements--
     Samples of  soil/waste were collected during drilling at each sampling
point as part of the screening survey.  Screening for volatile organic
compounds (VOCs) in these samples was performed at the field site with a
Photovac 1010 portable photoionization gas chromatograph (GC).  This GC has
part-per-billion (ppb) level sensitivity for mi Hi liter volumes of air.  Soil
and waste samples were collected (2 to 3 grams) and stored in 40 ml VOA vials
with Teflon\ SEPA.  The vials were equilibrated in a 30*C water bath for 30
minutes prior to the head space analysis for VOCs.  This sampling procedure is
considered a direct measurement screening-technology.

     During disturbance activities, fenceline monitoring for S02 and benzene
was conducted using portable real-time instruments.  Also meteorological
conditions were  monitored during all work disturbing the site.  Action levels
were established to require cessation of site activities if exceedances were
noted (none occurred) to protect the local community.

     Downwind and border monitoring consisted of three activities:

          S02 and THC were monitored immediately downwind of the disturbance
          activity;

     •    S02 and THC were monitored at a mobile unit approximately 40 feet
          downwind of the Initial disturbance activities; and

          S02 and benzene were monitored at a mobile unit at the.downwind
          fenceline between the drilling operation and the nearby residences.

Standard monitoring procedures (see Volume IV of this series of manuals) were
used in operating the border and downwind stations.  Air analyzers were
operated according to written quality control protocols and continuous data
printouts were collected using strip chart recorders.  The monitoring stations
were positioned each day based on wind direction data from the meteorological
stations.
                                      149

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In-Depth Measurements--
     Downhole emission measurements at various depths 1n the waste were
conducted during drilling activities to determine an emissions "profile" In
the waste.  These data were used to characterize the waste properties and to
predict potential gas emission from the wastes 1f they were excavated.

     Downhole emissions measurements were performed using the direct emissions
measurement technique (I.e. downhole flux chamber).  This technique 1s
considered an 1n-depth measurement technology and was applicable for the
landfill and the lagoon.  The plexlglas chamber had an exposed surface area of
0.00318 m2.   The chamber Input and output lines  were 40  feet long,
facilitating flux measurement to 30 feet below land surface.
                                                              »

     Five locations for drilling were selected as part of the solid waste
Investigation.  They are shown 1n Figure 23.   They were representative of
waste bodies and were equally spaced across the waste areas.  Hydrocarbon
samples were collected in 2.8-liter stainless steel canisters.  After
collection, the canisters were shipped to an off-site laboratory for analysis.

     A total of 18 downhole emission measurements were performed and realtime
data for S02, THC,  and benzene were collected at each point using  the real-
time analyzers.  Canister samples were collected at six locations  (at various
depths within the five core holes) for speciation analyses.  Canister samples
were not collected at all sampling locations in an effort to conserve project
resources.  The Indicator compounds were used to represent air emissions
potential in the absence of the canister samples.
                                      150

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              Figure 23.   Location of waste soil  coreholes.
                                   151

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 Disturbed Emission Survey Results--
      The results of air monitoring conducted during drilling  are  summarized in
 Table 17.  The results of border and  Immediate downwind monitoring for
 disturbed site activities Indicated no  significant Impact  from  fugitive
 emissions downwind from the site (northeast) boring activities.   Even though
 the disturbed waste had a high emissions  potential, small  amounts of waste
 were exposed 1n the drilling operations following the conservative operating
 procedure.  The border station was positioned on the west  border  to ensure
 neighborhood safety.  This location also  provided valuable onsite safety
 Information for site operations personnel.

      The results of the downhole emissions survey Included peak and steady-
 state emissions for S02 and THC  at the  given depth.  Benzene data were  not
.collected due to the lack of an extractive pump in that analyzer  that could
 pull  the sample through the long sampling lines.  The steady-state values are
 more representative of the level of emissions expected Involving  a disturbance
 of the waste (I.e., removal).  Data results are presented  1n  Table 18 to
 illustrate the S02 and THC emissions observed as a function of the  type of
 waste/soil.  This format Illustrates  the  relative emissions characteristics of
 S02  and  THC per depth  in the cores as well as the emission tendencies of the
 waste/soil.  A comparison of peak to  steady-state emission values is used to
 identify emission sources in the waste  pit (I.e., limit of vertical
.contamination).

      Volatile emission rates from the site under disturbed conditions were
 higher than the undisturbed site and demonstrated potential for volatile
 emissions during waste disturbance activities.  The S02 emission  rates  under
 disturbed conditions ranged from background (1.6 EE4 ug/m2, minute'1) to 1.1.
 EE6 ug/mz,  minute'1, and the THC emission  rates ranged from 3.8  EE3 ug/m2,
 minute"1 to 3.8  EE6  ug/m2, minute"1.  The  results of the hydrocarbon speciation
 analyses Indicated the following hydrocarbon composition:
                                      152

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                 TABLE 17.  DOWNWIND/BORDER MONITORING RESULTS
Location
West Border
(Fence)
Core S-l
Downwind
40 m
Core S-2
West Border
(Fence)
Core S-2
West Border
(Fence)
Core S-3
West Border
(Fence)
Core N-l
West Border
(Fence)
Core N-2
Date
08/02/83
08/02/83
08/02/83
08/03/83
08/03/83
08/03/83
08/05/83
08/05/83
08/08/83
08/08/83
08/09/83
08/09/83
Species
Benzene*
S02b
Benzene
S02
Benzene
S02
Benzene
S02
Benzene
S02
High Leveld
(ppmv)
0.12C
Background
Background
Background
Background
Background
0.35
0.12
0.12C
Background
0.16°
Background
Duration
Elevated
Background


<5 minutes


*  Benzene Instrument (HNU) background typically 0.1 ppmv.
                                      - •


b  S02 Instrument (InterScan Analyzer)  background typically 0.05 ppmv.



c  Reading attributed to Instrument drift.



d  Background refers to Instrument reading  1n "clean" air.
                                      153

-------An error occurred while trying to OCR this image.

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          Hydrocarbon Class
Average %
 Ranoe %a
          Alkanes
          Alkenes
          Aromatics
          Oxygenates
          Halogenated
          Sulfonated
          Unidentified
"5 cores, 6 canister samples
  79.0
  15.0
   4.2
   0.62
   1.2
   NO
   2.0
  68 - 87
0.87 -
2.4  -
0.15 -
0.091-
    ND
0.42 -
21
8.1
1.5
3.3
6.6
These data show that most of the air emissions were alkane species and of no
significant concern regarding toxicity.  The aromatic fraction was, as
expected, around 5 percent, and was composed of numerous compounds.

5.1.7  Development of BEEs

     Calculation of baseline emission estimates (BEEs) can be developed from
either ambient concentration data (indirect techniques) or from emission irate
measurement data (direct techniques).  BEEs can be calculated for each
contaminant species detected or for a group Table 18 of contaminant species.
BEEs obtained from direct measurement techniques which provide rate data
(i.e., mass per unit time per given surface area) are preferable.  The BEE is
normalized for the area of the source and has units of mass of contaminant or
group of contaminants per time.

     BEEs can be calculated from individual emission sources and summed for
sites containing multiple emission sources (operable units), such as a lagoon
and a landfill with each source characterized by different air emission rates
and contaminant species.

     The calculation of an undisturbed emission estimate for this site
Included the following considerations.  The site consisted of a waste area
containing a landfill in the northern portion and a lagoon 1n the southern
portion, separated by a berm.  Each portion of the site was evaluated
separately.  Undisturbed emission factors for each of the two operable units
were calculated separately and then averaged to provide an overall site
                                      155

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emission estimate.  The undisturbed emission rates for the lagoon and the
landfill, and the combined site emission estimate calculations are presented
below.

     The undisturbed BEE for the lagoon (average) was calculated for S02 and
THC.  The surface emission Isolation flux chamber survey results from five
single measurements were averaged by species and multiplied by the lagoon
surface area to determine the unit BEE.

    Lagoon BEE$0  - (I.2ug/m2-m1n)(6860 m2) -  8.2 x  103 ug/m1n of S02
    Lagoon BEETHC -  (36 ug/m2-m1n)(6860 m2) - 2.5  x 10s ug/m1n of THC
Similarly, the BEE for the landfill operable unit (average) was calculated for
S02 and THC.   The emission Isolation flux chamber survey results were averaged
for each species and multiplied by the surface area of the landfill to
determine the unit's BEE.

   Landfill BEE$0  - (0.77 ug/m2-m1n)(7240 m2) »   5.6 x  103 ug/m1n of SO
   Landfill BEETHC - (18 ug/m2-min)(7240 m2)  -  1.3 x  10s  ug/m1n of THC
     The overall site BEE (for S02 and THC)  can  be  obtained by summing the
respective unit BEEs by species.

     Calculation of emission estimates for disturbed site conditions can be
performed from either air monitoring data (concentration measurements) during
waste disturbances or from direct emission rate measurement data.
Concentration values can be expressed as a concentration (ppm-v) for each
species, as a ratio of the species concentration to the total concentration
from all species, or as a percentage value for the species of Interest over
the total concentration contributed from all other species.  The disturbed
site emission flux data has the units of mass per time per unit area.
                                      156

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     The emission  estimate  1s calculated by multiplying the average measured
emission rate  by the  total  surface area of disturbed material.  This  results
In a single value  of  mass per unit time which provides a relative estimate of
the rate of air emissions from the source.  Emission estimates can be
calculated for a site with  either Individual sources or with multiple sources.
These operable units  often  are Investigated and remediated Independently.
Emission estimates for a combined site can be calculated by using the highest
disturbed emission estimates for each source and summing the emission per time
for each source.

     Summaries of  the average disturbed emissions flux for both units of the
Case Study 1 site  are presented below:
                                                              *

          Landfill
               S02  -  9.2 x 102  (ug/m2-min)
               THC - 1.7  x 103 (ug/mz-m1n)

          Laooon
               S02  -  2.9 x 103 (ug/m2-m1n)
               THC - 6.4  x 103 (ug/m2-m1n)

     These data can be used 1n conjunction with estimates of exposed  disturbed
waste to predict air  Impacts from various waste disturbance and treatment
technologies.

     Examole

     Excavation of the landfill would typically expose 50 m2 of waste at a
     time.  The estimate of THC air emissions from the site activity  would be:

             THC (landfill) - 1.7 x 103 (ug/m2, minute'1)  x 50m2
                            • 8.5 x 10s (ug/min)

Depth-specific Information could be used to provide area and depth-specific
emission estimates as needed.
                                      157

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5.1.8  Summary

     The Case Study 1 Investigation was generally a thorough,  well  documented
study that fully addressed the air pathway for volatile contaminants.  The
study followed closely the steps outlined 1n this manual's protocol and all
objectives were met.  Furthermore, site personnel report that  the knowledge of
the potential for emissions, ultimately resulted In a safer and more cost-
effective remediation of the site.  BEEs were used 1n risk assessment and in
designing removal plans.  Air emission control technologies were selected
based on the BEEs.

5.2  CASE STUDY 2;  BRUIN LAGOON

     Case Study 2 1s a disposal lagoon that received various wastes from a
mineral oil refinery.  This site was under remediation 1n 1984 when subsurface
gases were unexpectedly released during cleanup.  Work was halted and the
remedial design was reassessed.  A second Remedial  Investigation/Feasibility
Study (RI/FS) was then performed.  This case study focuses on  the APA
conducted during this second RI/FS (see Table 19).

5.2.1  Site History

     Bruin Lagoon 1s located about 45 miles north of Pittsburgh, In Bruin
Borough of Butler County, Pennsylvania.  The 4-acre site 1s situated along the
western bank of Bear Creek's South Branch, approximately 7 miles upstream of
the creek's confluence with the Allegheny River.  Part of the  site lies within
the creek's 100-year floodplain.  To the west, the site 1s bordered by private
homes and State Route 268.  Bruin Borough's main residential and commercial
areas are within five blocks of the site and more than 30 residences are
within 500 feet of the lagoon.  To the south Is an abandoned refinery, which
is the source of the wastes deposited in the lagoon.  Also, adjacent to the
site are two ponds and a small stream that drain into Bear Creek.
                                      158

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         TABLE 19.   APA ACTIVITIES CONDUCTED AT THE CASE STUDY 12  SITE


APA Objectives

Assess the extent and composition of subsurface gas pockets.  Monitor the
ambient air for health and safety reasons.


Scoping

Initially, the lagoon was determined to contain wastes that had minimal
potential for volatile or participate matter emissions (first RI/FS).  The
second RI/FS did assume that volatile emissions from subsurface gas pockets
were likely.


Screening Measurements

A variety of portable, real-time analyzers and detector tubes were used to
monitor the ambient air during drilling activities.   Monitoring took place at
the site perimeter and in the ambient breathing zone near the drill rig.  Soil
samples were collected and the emissions from the samples were scanned.  The
screening data were used to design the in-depth measurement strategy.


In-Deoth Measurements

The in-depth emission measurements Involved collecting and analyzing grab
samples of gas from boring/wells whenever the ambient breathing zone
monitoring showed elevated concentrations significantly over background
levels. However, these data were not used to develop undisturbed and disturbed
site BEEs.
Mitigation

The disturbed waste emissions data were used in the development of the
remedial action plan.  Although disturbed emission rates were not calculated,
knowledge of areas considered to be "hot spots" were used to conduct site
operations in a way that prevented major releases of air toxics to the air.
The remedial alternative Included gas monitoring during  on-site stabilization
and neutralization of the unstabilized sludge and collecting, venting, and
treating as necessary.
                                     159

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     Currently 1n remediation, Bruin Lagoon 1s an unllned earthen diked lagoon
that has been partially covered with 9300 cubic yards of stabilized soil/
sludge mixture treated during the first attempt at remediation.   Beneath this
material 1s approximately 17,200 cubic yards of unstab111zed sludge/tar, with
up-welling of the waste 1n a number of areas.  The sludge/tar contains
sulfurlc acid and heavy metals, along with other contaminants.  The lagoon
area of the site Is generally level and lacks vegetation.  A cross-sectional
view of the site Is shown 1n Figure 24.

     Bruin 011 Company, producer of white (mineral)  oil, began disposing of
Its wastes at the lagoon In the 1930s.  This continued for more  than 40 years.
Materials discarded there Included:
                                                              *
     •    Residues scraped from crude oil storage tanks;
     •    Used bauxite, charcoal filtering agents, and bone powder;
          011s not meeting specification;
     •    Coal fines;
          Lime;
          Spent alkali; and
     •    Boiler house coal and ashes.

     The lagoon attracted national attention 1n 1968 when about  3,000 gallons
of acidic sludge spilled Into the South Branch of Bear Creek through a breach
in the dike.  In the Allegheny River, roughly 4 million fish died and many
downstream communities temporarily lost their water supplies. The spill was
addressed, but the remedial investigation of the site didn't begin until 1981.

     The abandoned refinery and the lagoon were owned by AH & RS Coal Company,
which underwent bankruptcy proceeding in 1986.
                                      160

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 5.2.2  Objectives

      The objectives of the site work,  from an air pathway perspective, were
 two-fold:  to monitor the ambient air for health and safety reasons; and to
 assess the extent and composition of subsurface gas  pockets.   To meet the
 latter objective, sampling and analysis of vapors contained 1n the shallow
 wells were performed to:  Identify the composition and extent of gases trapped
 under the site; determine their regeneration rates;  and assess the potential
 for their release Into the atmosphere during remedial  construction work.

 5.2.3  Scoping

      The existing data were reviewed to provide a working knowledge of the
?.site history, conditions, and environmental setting.  Based on this review, no
 specific potential emission characterization was called for in the first
 RI/FS.  After unexpected emissions were encountered  when drilling through the
 bottom of the lagoon during remediation, the second  RI/FS did address the air
 pathway to a greater extent.

 5.2.4  Overview of Fieldwork For Site Characterization

      EPA contractors began what would become the first RI/FS at Bruin Lagoon
 in July 1981.  Air monitoring during this remedial investigation failed to
 find detectable levels of organics, sulfur dioxide (S02),  hydrogen sulfide
 (H2S), hydrogen chloride (HC1),  or hydrogen cyanide  (HCN)  in  ambient air at
 the site.  Although one well boring showed organic vapors during drilling
^operations, the levels were not detectable at the ambient breathing zone.
 Significantly, no borings through the open lagoon were performed in this
 initial effort.

      With the RI/FS completion in January 1982, EPA  and the Pennsylvania
 Department of Environmental Resources (PADER) selected a remedial, alternative
 that Included sludge stabilization, dike reinforcement, debris removal, and
 construction of a multi-layer cap to cover the lagoon.  Design kicked off in
 September 1982 and cleanup actually started in August 1983.
                                       162

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     The project proceeded until Nay 4, 1984, when hazardous gas and acid mist
escaped from an unanticipated crust, thought to be the bottom of the lagoon,
that was broken during mitigation.  These organic vapors and sulfur dioxide or
hydrogen sulflde reached the ambient breathing zone but were not detectable at
the site perimeter.  Gas sampling was performed for worker and public
protection.  Gas samples from beneath the crust revealed high concentrations
of carbon dioxide, hydrogen sulflde, and sulfuric add mist.  Consequently,
EPA suspended cleanup activities and Immediately launched 1n emergency
response, which Included some removal, covering the lagoon with stabilized
sludge, Installing 13 shallow gas monitoring wells, and collecting and
analyzing additional sludge and soil samples.

     The site remained in the emergency mode until September 1984.  The second
RI/FS was Initiated the following January.  Air monitoring conducted
throughout this RI Included:

     •    Health and safety;
     •    Site perimeter;
     •    Ambient breathing zone;
     •    Downhole concentration sampling and analysis; and
     •    Sample screening.

     Conclusions drawn from a review of all  of these activities (the two RI/FS
endeavors and the emergency action) Included Identification of a "hot spot" in
the unstabilized portion of the lagoon that  contained carbon dioxide, hydrogen
sulfide, sulfur dioxide and methane at levels deserving attention during
remediation.  The RI/FS concluded, however,  that subsurface gases were not
present throughout the site.  To address the "hot spot" the remedial
alternative selected in September 1986 Included gas monitoring, venting, and
treating during excavation, followed by post-closure monitoring.
                                     163

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5.2.5  Undisturbed Emissions Survey

     Based on the available documentation, no screening or 1n-depth mea-
surements were made to assess the undisturbed emission at the site.  Since the
site contains heavy metals and 1s unvegetated, an evaluation of the entrained
partlculate matter from the site would have been advisable, and some screening
measurements for particulates and Inorganic gases may have been warranted.
Some air monitoring was performed Immediately prior to site disturbances.
These limited data do address, undisturbed emissions.

5.2.6  Disturbed Emissions Survey

     Both screening (air monitoring and sample headspace) and in-depth (soil
vapor well) measurement techniques were used to assess the emissions during
site disturbances such as drilling.  The following discussions are largely
taken from the second RI/FS prepared for the Bruin Lagoon site (59).

Screening Measurements--
     The following air monitoring equipment was available on site during all
drilling activities:

          HNU photoionization detect>r (PID) with 11.7 and 10.2 eV probes;
          OVA (organic vapor analyzer) flame ionization detector (FID);
          H2S portable gas monitor;
     •    S02 portable gas monitor;
          H2S monitor alarms;
     •    Explos1meter/oxygen monitor; and
          Detector tubes S02,  H2S,  H2S04, 02,  C02, natural gas.

     Based on gases detected in past site work, portable direct reading real-
time Instrumentation was primarily used for gas characterization and health
and safety purposes.  Detector tubes were used for screening of possible
instrumentation interferences, confirmation of direct reading concentrations,
and analysis of gases not detected on available instrumentation.
                                      164

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     The direct reading monitoring Instruments determined to be most effective
for monitoring drilling operations were the HNU PID (11.7 eV), H2S portable
gas monitor, H2S monitor alarms, and S02 portable gas monitor.  The HNU PID
was selected over the OVA FID due to the sensitivity of this Instrument to
hydrogen sulflde gas.  The HNU PID could detect both hydrogen sulfide gas and
organic vapors.  This selection was made because of past historical data
demonstrating possible H2S gas release.

     Periodic monitoring of ambient air at the site perimeter was routinely
performed during drilling operations.  Also, 1f ambient breathing zone
concentrations Indicated possible gas releases, perimeter monitoring was
Immediately Initiated.  Seventeen monitoring locations were established along
the site fence line at intervals of approximately 150 feet and'marked with
stakes.  Figure 25 shows the perimeter monitoring locations.  Perimeter
monitoring was conducted with the H2S and  S02 portable gas monitors  and the
HNU PID.

     During all drilling operations, the H2S and S02 portable gas monitor,  H2S
monitor alarms, explosimeter/oxygen monitors, and HNU PID were used for
characterization of the ambient breathing zone.  Background levels  were
determined prior to starting the drilling.

     Portable Instrument readings provided continuous,  real-time monitoring of
each split spoon and drilling depth to determine at what depth,  if any, gas
releases occurred.  Each split spoon and core sample was scanned with Figure
25 all direct reading instrumentation immediately after collection.  Samples
showing positive readings were usually selected for chemical analysis.

In-Depth Measurements--
     If ambient breathing zone monitoring  showed elevated concentrations
significantly above background levels, a grab sample of the gas  present in the
boring/well was collected for analysis.   These grab samples  were analyzed to
characterize the emitted gases.   Grab samples were  collected from a point
approximately 3 feet below the ground surface by Inserting tubing Into  the
                                      165

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boring/well and pumping the gas Into an air bag collector.  The bag sample was
then sealed and analyzed on-s1te using available Instrumentation and detector
tubes.

Disturbed Emission Survey Results—
     The following results are taken from the second RI/FS prepared for the
Bruin Lagoon site (59).

   ••  A1r monitoring conducted during the 1981 remedial Investigation of Bruin
Lagoon revealed no detectable levels of organ1cs, S02,  H2S, HC1, or HCN  1n  the
ambient air at the site.  Organic vapors were detected within one well boring
during drilling operations; however, no detectable levels were found in the
ambient breathing zone at this location.  It should be noted tfiat no borings
were constructed through the open lagoon during the Initial RI and,  as a
result, the gases trapped below the crust were not encountered.

     Background air monitoring performed during field work in June 1984 showed
no detectable levels of H2S or methane.   Air samples  collected from the  soil
boring Indicated the presence of H2S,  C02, methane, and aromatic hydrocarbons.
S02 was not detected in the downhole samples.   H2S was present  in the  soil  gas
on the average at about 300 to 400 ppm; Initial concentrations were greater by
an order of magnitude or more.

     Low levels of organic vapors, sulfur dioxide and hydrogen sulfide were
released Into the ambient breathing zone when the subsurface of the site was
disturbed by drilling operations.  S02 concentrations were observed as high as
50 ppmv but typically were found at 0.5 to 18 ppmv in the breathing zone
during drilling operations.  H2S concentrations were  lower with high
concentrations observed at 14 ppmv with typical concentrations of 1  to 10
ppmv.  However, concentrations of these gases were not detectable at  the site
perimeter.

     The analytical  results for the subsurface gas samples collected  from the
13 shallow wells Installed during the 1984 emergency  action showed various
concentrations of volatile organics, S02,  H2S04, and methane 1n the wells.
                                      167

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Methane was observed in all the wells ranging from 2.6 to 4,400 ppm.  These
concentrations showed good correlation with the organic CH4  levels  measured 1n
the field by the OVA.  Analysis of carbon tube samples collected for each well
showed no detectable volatile organic compounds.  Sulfur dioxide was found to
be present 1n 11 of the 13 wells, with four wells having S02 concentrations
greater than 100 ppm.

     The results of the 1984 sampling of subsurface gases at the Bruin Lagoon
site showed elevated levels of S02.   The presence of H2S04 mist was limited to
three wells (A-8, A-10, and A-13).  Additionally, reactions  and gas releases
occurred during the Installation of each of these wells.  Elevated levels of
S02 also were detected in well  A-2.   These wells are all  located within  50
feet of one another, and, as a result, the data suggest that this area of the
site 1s a "hot spot" with respect to potentially harmful trapped subsurface
gases.  Additional sampling one year later confirmed the presence of a "hot
spot" area located in the central part of the site.

5.2.7  Development of BEEs

     No baseline emission estimates or disturbed emission estimates were
generated.  It was noted, however, that remediation may result In the release
of pockets of hazardous gases trapped below a crust at the bottom of the
lagoon.  BEEs would allow performance of risk assessments for various release
and meteorological scenarios at receptor points of Interest.

     Given the available data, the best method for determining BEEs for this
site would be to take the existing ambient air monitoring data and back-
calculate an emission rate using an air dispersion model.  This Is done by
setting up the model's run conditions to match those at the site as closely as
possible, and then varying the source term to find an emission rate that
produces downwind concentrations equal to those actually measured.  Using the
respective air monitoring data sets, this procedure could be used for both
undisturbed and disturbed conditions.  However, the accuracy of this procedure
is limited by the amount and representativeness of the available air  -
monitoring data.          ,          •
                                      168

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  5.2.8  Summary

       The  Case Study 2 Investigation points up the need to consider potential
  emissions from the disturbed  site before any remedial actions are undertaken.
  Here,  no  soil borings through the open lagoon were performed during the first
  RI/FS.  The  initial  failure to do so, or to even consider potential air
..emissions at this  site,  resulted in the need for a second RI/FS and associated
 : schedule  delays and extra  expenses.  The study did not closely conform to the
  steps outlined in  the protocol of this manual.  No undisturbed emission
  measurements were  performed (beyond some background air monitoring) and no
  emission  rate data were  collected.
                                                                *
       The  best technology for  screening particulate matter (PM) emissions at
  this  site would have been  to  collect upwind/downwind samples on filters using
 .high-volume  sampling pumps (hi-vols).  The total particulate matter present in
  the air would be determined by dividing the filter weight gain by the volume
 ;of air sampled.  Analysis  of  the filter catch for selected metal species would
  assist in assessing the  health Impacts from undisturbed emissions.  A less
  acceptable alternative would  have been to measure the ambient particulate
 -matter loadings using a  portable particulate matter analyzer.  The activities
  conducted, however,  provided  valuable data that were very useful in the
  design, selection,  and implementation of the remedial alternative.

  5.3   CASE STUDY 3:   LOWRY  LANDFILL

       Case Study 3  is an  active municipal landfill that formerly also accepted
  liquid  and solid industrial wastes and domestic sewage sludge.  This case
'.study focuses on APA activities conducted at the site (see Table 20).

  5.3.1   Site  History

       The  Lowry Landfill  is co-owned by the City and County of Denver,
  Colorado.  It opened for business as a municipal landfill in 1965.  The site
  is located about 20 miles  southeast of Denver and two miles east of the City
                                       169

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          TABLE 20.  APA ACTIVITIES CONDUCTED AT THE CASE STUDY 13 SITE


  APA Objectives

  A soil  gas  study was  conducted to locate waste pits, determine the extent of
  off-site subsurface gas migration, and determine the waste pit contribution to
  such migration.   An air monitoring program was conducted to measure ambient
  air pollutants during Installation of monitoring wells 1n the waste pits.


  Scoping

  The landfill  was determined to contain both hazardous and municipal wastes.
  The generation of off-gases from the wastes was considered to be a hgih
  probability.


  Screening Measurements

  The ambient air  was monitored upwind and downwind of the site during
  monitoring  well  Installation.  Samples were collected using a variety of
  adsorption  media.   Soil samples were collected and the emissions from the
  samples were  scanned.


  In-Depth Measurements

  The in-depth  emission measurements Involved collection of soil gas samples at
  a large number of points  using vapor monitoring wells for deep sampUgn and
  ground  probes for shallow sampling.  However, these data were not used to
  develop undisturbed and disturbed site BEEs.


  Mitigation

  Migration plans  have  not  yet been prepared.  The site 1s currently under study
  to further  understand the air emissions potential from the site.  These study
  activites Include air monitoring at nearby receptors of concern  (e.g.,
:; community school).
€
                                       170

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of Aurora, 1n Arapahoe County.  The site covers approximately 480 acres.  The
surrounding area was mostly undeveloped when the landfill was established, but
1s growing rapidly today.  (Proximity of the closest residence was not given
1n the Remedial Investigation (RI) report.

     From 1965 until the advent of the Resource Conservation and Recovery Act
(RCRA) In 1980, the facility accepted municipal refuse, liquid and solid
Industrial waste (some of which was hazardous), and domestic sewage sludge.
The landfill handled these wastes by excavating pits, filling them three-
quarters with liquids and then covering the waste with refuse until a mound
several feet above the land surface was created.  Landfills were dug
repeatedly, sometimes Into old, filled landfills.  The landfills at the south
end of the facility were covered with as much as 30 to 60 feet of refuse.

     In 1975, Continental Oil Company contracted with site owners to set up
and run an oil sludge disposal operation in the southeastern portion of the
site.  This operation and the acceptance of Industrial waste stopped with RCRA
1n 1980.  At that time, the City and County of Denver hired a private firm to
manage the site as a municipal waste facility only.  This contractor, Waste
Management, Inc., formed a subsidiary which opened a hazardous waste disposal
facility just north of Lowry.  This facility was closed In 1982.

     In the early 1980s, Lowry Landfill began to be closely scrutinized by a
number of public agencies due to odor problems and other concerns.  These
first cursory looks focused primarily on the groundwater contamination
pathway, studying only shallow groundwater.  Not all landfills were located or
confirmed.  Initial Investigations disclosed that records of types and
locations of waste were incomplete and inaccurate.  Also, no measures had been
taken to prevent leachate or seepage from these pits.

     Among the 60 pits Identified through aerial photographs, it was estimated
that roughly 100 million gallons of liquid wastes were disposed on-site over
15 years.  Wastes Identified Include:  acid and alkaline sludges; caustics and
solids; brines, Including plating wastes and other water-based sludges;
organics, both natural and synthetic,  such as petroleum-based oils, grease,
                                     171

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and chlorinated solvents and sludges; watersoluble oils;  municipal  sewage
sludge; Tow-level radioactive wastes; pesticide wastes;  asbestos; and metallic
wastes.

     EPA did not become Intimately Involved at the site  until  about 1981 when
Lowry was first considered as a candidate for the NPL.   In 1984,  Lowry was
placed on the NPL and formal Investigations were Initiated.

5.3.2  Objectives

     At the Lowry site, a soil gas study and an air quality Investigation were
performed as part of the RI.  The soil gas study was conducted to help locate
the waste pits, to determine the extent of any off-site  subsurface migration,
and to determine the waste pit contribution to such migration. The air
quality Investigation was conducted to measure contaminants in the ambient air
during Installation of monitoring wells in the waste pits.

5.3.3  Scoping

     Existing data were collected and reviewed to provide a working knowledge
of the site history, conditions, and environmental  setting.  A topographic map
of the site and Its environs was developed from aerial photos. Surveying was
performed to map sampling locations and determine the relative coordinates and
elevation of each location.

5.3.4  Overview of Fieldwork For Site Characterization

     The purpose of the first phase, of a two-phase remedial Investigation,
was to characterize the site geology and climate; Identify the location and
contents of all landfills; characterize the extent of contamination, Including
air and soil gas; and Identify data gaps to be filled in  during rememdial
Investigation Phase II.

     Investigatory work into some of the landfills was thwarted by three piles
of vehicle tires, two piles of roughly 2 million tires each and one pile of up
                                      172

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to 8 million tires.  Findings disclosed that soil gas, air, groundwater,
surface water, and soil all were contaminated and that some migration was
occurring.  To detect air contamination, contractors sampled upwind and
downwind of the site, and 50 feet downwind from the five waste pit wells
shortly after Installation (to demonstrate a worst-case emissions scenario).
The results showed that air quality was degraded as 1t crossed the site from
south to north (the direction of the prevailing wind).  Volatile organic
compounds (VOCs) were detected at 0.020 to 16 parts per billion (ppb) higher
in the downwind samples relative to the upwind samples.

     Separately, samples for soil gas emissions were taken from the landfills,
from gas well points and probes, and from 10 gas sampling wells installed
around the site perimeter by the contracted facility operator In 1981.  The
results disclosed 19 VOCs, found in ranges of 37 to 160,000 ppb, and verified
that contaminated soil gas was migrating off-site in the vicinity of one of
the perimeter wells.

     A complete meteorological monitoring station has been operating at Lowry
since April 21, 1985.  It measures wind speed and direction, temperature,
relative humidity, barometric pressure, and precipitation on a 10-meter tower.
Measurements are taken by a Climatronics Electronic Weather Station (EWS)
connected to a Campbell Scientific CR21 data logger.  The data are read
periodically into a mainframe DEC-10 computer.

5.3.5  Undisturbed Emissions Survey

     No screening or In-depth measurements were made to assess the undisturbed
emissions at the site.  However, the Phase I RI report (60) does recommend
that ambient air and meteorological monitoring be performed in the planned
Phase II work to collect background data.  Based on the types of waste present
and the presence of contaminated soil gas, screening measurements (at a
minimum) would have been warranted for this site during Phase I activities.
                                      173

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5.3.6  Disturbed Emissions Survey

     Both screening (headspace sampling and upwind/downwind air monitoring)
and In-depth (soil vapor wells) Measurement technologies were used to assess
the air pathway.

Screening Measurements-
     Split spoon samples collected during drilling activities were retrieved
and opened, then the air space above the samples  was  scanned using an HNU
portable organic vapor analyzer.

     The ambient air was monitored over a 12-day  period  during Installation  of
monitoring wells 1n the waste pits.  The monitoring took pi ace"in November and
December of 1985 during which there was some snow cover; therefore,  the
results do not equal a worst-case scenario.  Samples  were collected upwind and
downwind of the site and 50 feet downwind of the  waste pit well Installations.
A controlled release of waste pit well  gas was  permitted to help predict
                                                                        1
ambient air Impacts associated with remediation of the waste pits.  Samples
were collected by concentrating air on  carbon molecular  sieves (CMS),
polyurethane foam, Tenax, and glass fiber filters.  The  sampling methods are
listed in Table 21.

In-Depth Measurements--
     Soil gas samples were collected from a number of locations, Including 10
existing soil vapor wells around the perimeter  of the facility and wells
installed at four locations in suspected waste  pits.  The wells at the waste
pits were drilled to within 2 feet of the water table.   Ground probes also
were driven Into the waste pits at the  same four  locations to measure the gas
emanating from the waste pits and municipal refuse and reaching the near-
surface.  Three more ground probes were Installed at  areas without underlying
waste pits.
                                     174

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       Samples were collected from all  locations  using  a pump to transfer gas to
 , a tedlar bag within a rigid-wall container.   Sample gas was extracted at
  roughly 1 L/m1n for 4 to 5 minutes.   The perimeter soil  vapor wells required
  purging (three well volumes) before  sample collection; the other sampling
  points had free-flowing gas.

       Samples were analyzed for priority pollutants by GC/MS using EPA Method
  624 at an off-site location.

  Disturbed Emission Survey Results—
       A large data base was developed during  this  program and 1s summarized
  here.
                                                                •

       The upwind/downwind sampling Indicated  that  the  site 1s a VOC emissions
  source.  Total VOCs on-site were 54  ppb higher  than upwind values, and
  downwind concentrations were 25 ppb  higher than upwind values.  Downwind
  concentrations of acetone, carbon dlsulflde, and  toluene were 3 to 10 times
  the upwind values.  During the controlled release,  these compounds were found
  at 8 to 100 times the upwind values.   Other  compounds, such as 1,1,1-
  trichloroethane, benzene, and TCE also were  found at  elevated (4 to 20 times)
  levels downwind.  These emissions could be expected to be greatly higher
  during non-winter weather conditions.

       The upwind/downwind sampling showed particulate  matter emissions to be a
  problem at the site.  The upwind values averaged  187  ug/m3 and the downwind
  samples averaged 325 ug/m3 with a range of 112  to 643  ug/m3.  The  average
^downwind total solid participates (TSP) exceeded  the  Primary TSP National
* Ambient Air Quality Standard of 260  ug/m3.

       Nineteen hazardous volatile organic compounds were detected 1n soil gas
  samples emanating from waste pit liquid.  These compounds were similar to
  those found 1n the liquid samples.  Concentrations ranged from 460 to 291,000.
  ppb.  Nineteen volatile organic compounds were  found  In the refuse gas
  samples, 1n ranges of 37 to 160,000  ppb.  Compounds were nearly Identical to
  those found In gas samples above waste pit liquids except that the
                                        17&

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 concentration of compounds above these liquids was two to five tiroes greater
 than  In the overlying refuse and six tines greater than In refuse with no
 underlying pits.   It Is reasonable to conclude that the liquids and refuse are
 contributing to gas contamination.

      The results of perimeter well gas sampling Indicate that subsurface
, contaminant migration has occurred at Hell GPM-3 and possibly at GPM-7.
.Thirteen hazardous substances were detected In gases at Well GMP-3, near waste
 pits and refuse disposal areas.  Substances Included volatile organics at
 ranges of 9 to 1,200 ppb.

 5.3.7  Development of BEEs

      No baseline emission estimates for either the undisturbed or disturbed
 wastes were generated, though sufficient data exist to estimate a disturbed
.BEE.  Given the available data, the best method for determining BEEs for this
.site would be to take the existing ambient air monitoring data and back-
^calculate an emission rate using an air dispersion model.  This Is done by
:,setting up the model's run conditions to natch those at the site as closely as
 possible, and then varying the source term to find an emission rate that
 produces downwind concentrations equal to those actually measured.  Using the
 respective air monitoring data sets, this procedure could be applied to both
 undisturbed and disturbed conditions.

 5.3.8  Summary

      The Case Study 3 investigation did not closely conform to the protocol
 steps outlined In this manual.  No undisturbed emission measurements were
 performed and no emission rate data were collected.  While substantial data
 were collected, scheduling the air monitoring during cold temperatures and
 snow cover conditions limited the data's applicability.

      The best technology for screening undisturbed emissions at this site
 would be to:  1) perform ambient air monitoring around the perimeter of the
 facility to determine the magnitude of baseline emissions from the site and to
                                       177

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  verify If any adverse health or safety risks are present; and 2)  survey the
...site using a portable analyzer and windscreen to delineate any localized
  emission "hot spots."  The results of these screening studies would need to be
  Interpreted to determine 1f any further undisturbed emission measurements were
  warranted.

  5.4  CASE STUDY 4;  WESTERN PROCESSING LANDFILL

       Case Study 4 1s a former Industrial waste processing and recycling
  facility.

  5.4.1  Site History
                                                                *
       The 13-acre Western Processing site Is situated In the Green River Valley
  between Seattle and Tacoma, five miles Inland from Puget Sound.   The  site was
  used for agricultural purposes until  1951 when 1t was leased to the Department
  of Defense.  An anti-aircraft artillery base operated there until the lease
  expired in 1960.  The owner opted for a cash settlement and left  in place the
  Installation's buildings and on-site drainage system that linked  Its
  facilities to a septic tank, a tile subsurface drain field, a 500-gallon
  chlorlnation tank and a ditch leading to Mill Creek which runs along  the
  site's western border.

       Western Processing, a waste recycling operation, purchased the site  in
  1960 and claimed to have reclaimed or recycled millions of gallons of liquid
  waste and thousands of tons of solid waste before it was shut down in 1982.
f The wastes handled Included:  animal  blood, brewer's yeast, chrome baths,
  corrosive liquids, crank case oil, flue dust, lead, pickle liquor, plating
  bath solutions, solvents and paints,  and zinc skimmings.  These wastes were
  handled, stored, or disposed of in storage lagoons (acid/caustic/cyanide
  wastes), a fertilizer plant, a solvent recovery plant, bulk storage tanks,
  cooling water lagoons, a chlorine gas tank storage house, a laboratory,
  naphtha storage tanks, a SB-gallon drum storage area, and piles of flue dust.
  By the late 1970s, the below-ground surface Impoundments had been filled  and
  were being used to store waste material.
                                       178

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       The site Is located In an Industrial  area.  A barbed wire  fence  separates
  the site from a bicycle and jogging trail, which follows a  railroad right-of-
  way.  This Is the nearest community exposure to the site.   Trail  users
  reported seeing hoses draped over the  fence discharging Into  a  ditch  along the
  railroad tracks that feeds Into Hill Creek, prior to the closure  of the
:-  recycling plant (61).  The site 1s shown  1n Figure 26.

  5.4.2  Objectives

       The Remedial Investigation/Feasibility Study (RI/FS) process did not
  address the air pathway for contaminant transport to any meaningful extent.
  Therefore, no objectives were set or met.

  5.4.3  Overview of Fleldwork for Site  Characterization

•v-     State and local  Inspections of Western Processing or Its vicinity date
i*back to 1977.   These were Initially concerned about the quality of water *fn
5Mill Creek.   In 1982, EPA determined that  the company's management practices
,  were resulting 1n the release of priority  pollutants and other  contaminants to
  the environment.

       A remedial  investigation Initiated in the fall of 1982 led to emergency
  and Interim remedial  site activities In April 1983.  These  Included removal of
  some liquids,  solids, and drums,  and reorganization of concrete blocks from
  five surface Impoundments to create a  large diked area where excavated
  materials were then placed.   The excavated materials contained  solvents, paint
  sludge,  and some  heavy metals.   Also,  buried storage tanks  and  drums  were
  encountered during this activity.   Later in the fall, the state of Washington
  led an effort  to  prevent storm water infiltration and runoff, which Included
  further excavation and berming  as  well as paving of the reaction  pond.
                                       179

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RADIAN
C«•»0•*TIOM
                SANITARY

                DRAIN FIELD

                DISCHARGE LINE
                                          WESTERN PROCESSING
                                                                     /  =
                                                                     I! :

                                                                     III
                                                                    RAILROAD

                                                                     /  :
                                                                 DITCH I
                                                                      *  I
                                                                      1  'I
                    Figure 26.  Western processing site.
                                     180

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      A Phase I surface cleanup, funded by the potentially responsible parties,
 started with release of a remedial action plan (62) In July 1984.  In that
 plan, 1t was clear that air emissions work had been United.  The report noted
 the northerly direction of winds would primarily deposit any contaminants
 stirred up or blown off waste piles In or near Puget Sound.  The report cited
 a 1982 air analysis that showed only trace amounts of trlchloroethene,
.toluene, xylene, and tetrachloroethene.  The low levels and high volatility of
 these compounds, coupled with wide atmospheric dispersal, were thought to
 create only limited effects on receptors during past operations.  "Although
 past releases Into the atmosphere may have been greater than observed 1n the
 1982 samples and undoubtedly Included partlculate matter and contaminants.
 Other than volatile organics, this pathway 1s not believed to have been
 significant."

      That the air pathway was overlooked to some extent during the RI/FS stage
 Is apparent.  However, Phase II remediation work began in 1987 to remove
 shallow wastes at the site, and a comprehensive air monitoring program was
^initiated.  This program Is outlined below (as described in Lepic and Foster
 (63).)

    An air monitoring program was Implemented to ensure adequate protection of
 both the field team and the surrounding community.   Work area monitoring was
 conducted to identify action levels where personnel protection levels must be
 upgraded.  Continuous upwind and downwind perimeter monitoring was conducted.

    Direct reading, real-time Instruments were used to determine total gases
 and vapors, cyanide, gamma radiation and combustible gas; partlculate
 concentrations also were measured.  The field Instrumentation used at Western
 Processing included:

         OVA 128: total organic vapors;
         HNU PI 101: .total  organic vapors;
         Hand-held aerosol  monitor (HAM):  total  particulates;
         Gastech CGI: combustible gases;
         Ludlum 19: gamma radiation;
                                      181

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        Monltox Compur 4100:  cyanide;
        Draeger pump and colorimetrlc detector tubes:  cyanide and methane;
        H1-volume air samplers: suspended particulates;  and
   •    Recording meteorological station: wind direction and speed.

   A1r was monitored regularly at 16 fixed locations around the site perimeter
to detect any possible off-site migration of airborne contaminants.  In
addition, monitoring was conducted at each sample location to determine
adequate protection levels and to ensure worker safety.   These monitoring
procedures are described below:

        Borehole and excavation site monitoring:  an OVA, HNU and HAM were used
        to monitor the breathing zone at the drill  rig and backhoe during the
        subsurface exploration and sampling activities.   A cyanide detector
        and combustible gas Indicator were used regularly; and

        Drum, tank and utility monitoring: an OVA and HNU, radiation detector,
                                                                        *v-
        combustible gas Indicator and cyanide monitor were used to test the
        atmosphere within containers for flammable vapors.

5.4.4  Scoping

   Collection and review of the existing data were performed.  Based on this
data review, no need for an air pathway analysis was perceived.

5.4.5  Undisturbed Emissions Survey

   No screening or In-depth measurements were made to assess the undisturbed
emissions at the site.  Table 22 lists some of the contamination found at the
site.  Based on the very high concentrations of heavy metals (e.g., lead at
31,000 ppm) found 1n the surface soil, an evaluation of the entrained
participate matter from the site would have been advisable, and some screening
measurements were warranted.
                                      182

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TABLE 22. MAXIMUM AND AVERAGE CONCENTRATIONS IN SOIL FOR SELECTED CONTAMINANTS
Contaminant
Chromium
Z1nc
Arsenic
Antimony
. Lead
Cyanide
Phenol
Aldrin
Dieldrln
PCB-1248
Hexachloroethane
Phenanthrene
Pyrene
"1 , 1 , 1-Trichloroethane
^Methyl ene Chloride
Toluene
Trlchloroethene
Maximum
Surface
5,300
81,000
38
98
31,000
15
19.0
0
0.145
3.30
5,090
20,000
16,000
0
0.130
0
0.037
Cone, (com)
Subsurface
7,600
40,500
102
130
141,000
179
65.0
2.86
3.34
19.6
*
1,80
62.4
11.0
174
49
394
580
Average*
Cone, (ppm)
594
2,580
3.28
8.59
5,450
11.2
1.65
0.006
0.007
0.341
0.0192
720
184
2.87
1.49
6.44
19.3
* Based on geometric averaging approach.
                                     183

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  5.4.6   Disturbed Emissions  Survey
              '  >
      No screening or in-depth measurements were made to assess the disturbed
  emissions  at the site.   Based on the very high concentrations of organic
  compounds  1n the subsoil, an evaluation of the emission potential would have
  been advisable.

  5.4.7   Development of BEEs

      No baseline emission estimates for either the undisturbed "or disturbed
  wastes  were  generated.   Given the available data, the best method for
  determining  BEEs for this site would be to take the existing ambient air
  monitoring data  (discussed  below) and back-calculate an emission rate using an
 fair dispersion model.  This 1s done by setting up the model's run conditions
  to match those at the site  as closely as possible, and then varying the source
  term to find an  emission rate that produces downwind concentrations equal to
  those actually measured.  Using the respective air monitoring data sets, this      M
  procedure could  be applied  to both undisturbed and disturbed conditions.           ™

  5.4.8   Summary

      The best  technology for screening undisturbed particulate matter
 •^emissions at this site would have been to collect upwind/downwind samples on
  filters using  high-volume sampling pumps (hl-vols).  The total particulate
  matter  present in the air would be determined by dividing the filter weight
  gain by the  volume of air sampled.  Analysis of the filter catch for selected
fmetal species  would assist  in assessing the health Impacts from undisturbed
  emissions.   A  less acceptable alternative would have been to measure the
  ambient particulate matter  loadings using a portable particulate matter
  analyzer.

      Screening VOC emissions also would have been advisable, based on the
  waste composition data.  The best technology for screening undisturbed VOC         ^
  emissions at this site would have been to:  1) perform ambient air monitoring      I
  around  the perimeter of  the facility to determine the magnitude of baseline
                                       184

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emissions from the site and to verify 1f any adverse health or safety risks
were present; and 2) survey the site using a portable analyzer and windscreen
to delineate any localized emission "hot spots."  The results of these
screening studies would need to be Interpreted to determine 1f further
undisturbed emission measurements were warranted.

     The best technology for assessing disturbed VOC emissions would have been
to expose representative areas of waste using a backhoe (or drill rig), and to
measure emission rates using the flux chamber technique.  The best technology
for assessing partlculate matter emissions would have been to use hi-vol
samplers arrayed downwind (I.e., transect technique) to capture emissions
during site disturbances.
                                                               •
5.5  CASE STUDY 5:  OUTBOARD MARINE CORP. LAGOON/LANDFILL

     Case Study 5 1s a manufacturing site where harbor sediments and nearby
land are contaminated with PCBs.

5.5.1  Site History  .

     Outboard Marine Corp. (OMC) sits on the west shore of Lake Michigan, 37
miles north of Chicago and 10 miles south of the Wisconsin border.  This
hazardous waste site evolved from an outboard motor manufacturer that used
PCBs in die cast machines from the early 1950s to the early 1970s.

     Over the years, the facility discharge created three areas of contami-
nation (see Figure 27).  The first is Waukegan Harbor,  a 37-acre Irregularly
shaped harbor feeding Into Lake Michigan.  The operation also led to
contamination of "North Ditch," a small  tributary that  drains surface water
runoff Into Lake Michigan.  A nine-acre  parking lot north of the plant was
Identified as another area of significant PCB contamination.
                                     185

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RADIAN
                      EAST-WEST PORTION
                      OF NORTH DITCH
NORTH SHORE
SANITARY
DISTRICT
                                      PARKING
                                      LOT
                                      AREA
            OUTBOARD MARINE CORP.
            JOHNSON OUTBOARDS DIV.
            PLANT NO. 2
                            OMC CORPORATE
                            HEADQUARTERS
                            OFFICES
         NEW
         DIE
         CAST
         COMPLEX
                             JOHNSON OUTBOARDS
                             PLANT NO. 1
         \
                   Figure 27.  Hap of Case Study  5  site.
                                       186

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      Concerns about possible receptors of site contamination  Included the
 harbor's biological community and fish 1n Lake Michigan.   The City of
 Waukegan, population 67,653 1n 1980,  Is nearby,  but  the harbor area 1s zoned
 Industrial.  The 15 businesses 1n the Immediate harbor area that employ about
 3,500 people were the Immediate concern.  Also,  the  local  Port Harbor received
 heavy recreational use and long-term plans Included  development of the Upper
 Harbor.  Potentially, people 1n a variety of locations could  be exposed to the
.contamination via direct contact, fish consumption or possible drinking water
 contamination.

      OMC purchased roughly 9 million  pounds of PCBs  from Monsanto Co.  over a
 20-year period beginning in the early 1950s.   OMC used the PCBs as hydraulic
 fluids 1n die casting machines and related equipment.  This equipment leaked
 routinely and the fluids ran from the plant floor Into floor  drains that
 discharged Into Waukegan Harbor and North Ditch.  EPA estimated that as much
 as 20 percent of the PCBs purchased could have been  discharged.

•     It was not until 1975 that the Illinois  Environmental Protection Agency
.(IEPA) discovered the high levels of  PCBs in  soils and harbor sediments near
 CMC's plant.  This discovery was triggered by a  1971 EPA study that showed PCB
 concentrations in Lake Michigan fish.   In 1976,  the  EPA began to regulate PCB
 disposal.  At that time, OMC began to sample  Its outfalls  and then sealed two
 outfalls leading to North Ditch, pursuant to  a joint Administrative
 Enforcement Order by EPA and IEPA (64).   OMC  later declined to Immediately
 remove sediments contaminated with PCBs,  as demanded by EPA.   When clean-up
 negotiations among EPA,  IEPA,  and OMC failed,  legal  actions were filed.   These
 legal  actions were still pending in early 1988.  Superfund money for this site
 became available in 1983.

 5.5.2   Objectives

      The objective of the APA for this site was to model the  exposure  of
 downwind receptors to PCBs during baseline  conditions.
                                      187

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5.5.3  Scoping •

     Existing data were collected and reviewed to provide a working knowledge
of the site history, conditions, and environmental  setting.  No Information
was uncovered that Indicated a need to modify the air pathway analysis
objectives.

5.5.4  Overview of Fleldwork for Site Characterization

     Discovery steps through site characterization led to the conclusion that
PCB concentrations were significant and that PCB release to the surrounding
environment could follow a number of pathways.

Waukegan Harbor--
     EPA contractors estimated that 1n Slip Number 3  1n the harbor about 7,200
cubic yards of muck, varying in thickness from 2 to 5 feet, was contaminated
by about 167,200 pounds of PCBs.  Concentrations typically exceeded 500 ppm.
Another 3,700 cubic yards of sand and silt (about 7 feet thick) were
contaminated by about 138,000 pounds of PCBs.  In one localized area near a
former OMC outfall, concentrations exceeded 10,000 ppm.

     In the upper harbor about 35,700 :ub1c yards of  muck, 1 to 5 feet thick,
were contaminated with approximately 5,000 pounds of  PCBs.  Concentrations
here typically were 50 to 500 ppm.

North Ditch-                                                            '
     Contractors broke the North Ditch Into three areas for study.  In the
"crescent ditch," about 28,900 cubic yards of soil, roughly 25 feet thick,
were contaminated by about 403,700 pounds of PCBs,  creating concentrations
ranging from 5,000 to 38,000 ppm.  Another 2,300 cubic yards of soil 3 feet
thick north of the die storage area were contaminated by an estimated 200
pounds of PCBs.  Concentrations here typically were about 200 ppm.
                                      188

-------
      The  "oval  lagoon,"  about 27 feet deep, contained about 14,600 cubic yards
 of soil contaminated by  about 85,500 pounds of PCBs 1n the top 5 feet.
 Concentrations  within those 5 feet were about 26,000 ppm; no data were
 available for below 5 feet.

      In the main part of North Ditch, about 25,000 cubic yards of soil about
 25 feet thick were contaminated by at least 4,300 pounds of PCBs.
 Concentrations  In 200 feet of 
-------
5.5.6  Disturbed Emissions Survey

     No field measurements or modeling estimates were made to assess the
emissions during site disturbances.  It would be advisable to conduct a
laboratory or field study to determine the degree to which volatilization will
Increase during dredging or other site remediation work.   The emission
estimates could then be used as Inputs to dispersion models to assess the
Impact on downwind receptors.

5.5.7  Development of BEEs

     As discussed above, undisturbed (baseline)  emission  estimates were
                                                               »
developed for two of the three operable units at the site.  These estimates
were 12 to 40 Ib. PCB/year and 15 Ib. PCB/year.   No disturbed emission
estimates were developed.  If emission rate data were available for waste in
the disturbed state (e.g., flux chamber test data), then  disturbed emission
estimates should have been developed using the same modeling approach used to
develop the BEEs.

5.5.8  Summary

     The air pathway for contaminant transport was assessed at this site for
undisturbed conditions using modeling techniques.  This was a valid, cost-
effective option, given the logistical problems of making direct field
measurements at this site and the low probability of detecting PCBs in the
ambient air downwind of the site.

     The best technology for assessing the disturbed PCB  emissions would have
been to dredge up representative contaminated material and directly measure
emissions with a flux chamber.  As an alternative, this approach could be
modified to perform the work in a laboratory setting.
                                      190

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                                   SECTION 6
                                   REFERENCES

 1.   NUS  Corporation.   Procedures  for Conducting A1r Pathway Analyses  for
     Superfund Applications  -  Volume 1, Application of A1r Pathway Analyses
     for  Superfund  Activities.   EPA Draft Manual, December 1988.

 2.   Radian Corporation.   Estimation of Air Emissions From Clean-up Activities
     at Superfund Sites.   EPA  Interim Final Manual, January 1989.

 3.   NUS  Corporation.   Procedures  for Conducting A1r Pathway Analyses  for
     Superfund Applications  -  Volume IV, Procedures for Dispersion Modeling
     and  Air Monitoring for  Superfund Air Pathway Analysis.  EPA Draft Manual,
     December 1988.

 4.   Camp, Dresser  and  McKee,  Inc.  Guidance Document for Cleanup of Surface
.    Impoundment Sites.  Prepared  for U.S. Environmental Protection Agency,
     June 1985.

 5.   Hwang, S.T.  Model  Prediction of Volatile Emissions.  Environmental
     Progress, Vol. 4,  No. 2,  May  1985.

 6.   Shen, T.T.  Air Pollution Assessment of Toxic Emissions from Hazardous
     Waste Lagoons  and  Landfills.  Environmental International, Vol. II,  pp.
     71-76, 1985.

 7.   Shen, T.T.  Air Quality Assessment for Land Disposal of Industrial
     Wastes.  Environmental Management, Vol. 6, No. 4, pp. 297-305, 1982.

 8.   Shen, T.T.  Estimating Air  Emissions from Disposal Sites.  Pollution
     Engineering, 13(8), pp. 31-34, 1981.

 9.   Shen, T.T. and G.H. Sewell.  Air Pollution Problems of Uncontrolled
     Hazardous Waste Sites.  Civil Engineering for Practicing and Design
     Engineers, 3(3):241-252,  1984.
                                      191

-------
10.  Balfour, W.D. and C.E. Schmidt.   Sampling Approaches for Measuring
     Emission Rates from Hazardous Haste Disposal  Facilities.  Presented at
     the 77th Annual APCA Meeting, June 1984.

11.  Storm, O.L. Hazardous Materials  Common to Specific Industries.  In:
     Handbook of Industrial Waste Compositions in  California.  Cal. DHS 1978.

12.  Radian Corporation.  Air Quality Engineering  Manual  for Hazardous Waste
     Site Mitigation Activities,  Revision 2.  Air  Quality Engineering and
     Technology, Department of Environmental Protection,  Division of
     Environmental Quality CN027, 1987.
                                                              *
13.  CDM Federal Programs Corp.  Data Quality Objectives  for Remedial Response
     ctiviteis.  EPA 540/G-87-004, U.S. Environmental  Protection Agency,
     Washington, DC, 1987.

14.  U.S. Environmental Protection Agency.   Interim Guidellens and
     Specifications for Preparing Quality Assurance Project Plans.  QAMS-
     005/08. Office of Monitoring Systems and Quality  Assurance, Office of
     Research and Development, Washington,  DC,  1980.

15.  KapUn, E.J., A.J. Kurtz, and M. Rahlmi.   VOC Sampling for Emission Rate
     Determination and Ambient Air Quality on an Inactive Landfill.  Presented
     at New England Section, Air Pollution Control Association,  Fall 1986
     Conference, Worcester, MA, October 6-7, 1986. 27  pp.

16.  South Coast Air Quality Managmente District.   Landfill Gas Emissions:
     Report of the Task Force, El Monte, CA, 1982.

17.  Wood, J.A., and M.L. Porter.  Hazardous Pollutants in Class II Landfills.
     South Coast Air Quality Management District,  El Monte, CA,  1986.
                                     192

-------
  18.   Eklund,  B.H., U.D. Balfour,  and C.E.  Schmidt.  Measurement of Fugitive
       Volatile Organic Emission Rates.   Environmental  Progress,  4(3):199-202,
       1985.

  19.   Balfour, H.D., B.M. Eklund,  and S.J.  Williamson.  Measurement of Volatile
       Organic  Emissions from Subsurface Contaminants.  Radian  Corporation,
       Austin,  TX,  1985. 20 pp.

  20.   Dupont,  R.R.  Measurement of Volatile Hazardous  Organic  Emissions.
       Journal  of the A1r Pollution Control  Association, 37(3):168-176, 1987.

  21.   Balfour, W.D., R.G. Wetherold,  and D.L.  Lewis. Evaluation  of Air
       Emissions from Hazardous  Waste  Treatment, Storage,  and Dis'posal
       Facilities.  EPA 600/2-85/057,   U.S. Environmental Protection Agency,
       Cincinnati,  OH, 1984.  2 vol.

  22.   Eklund,  B.M., M.R. Kienbusch, D.  Ranum,  and T. Harrison.   Development of
>.      a Sampling Method for Measuring VOC Emissions from  Surface Impoundments.
       Radian Corporation, Austin,  TX, no date. 7 pp.

  23.   Keinbusch, M.R.  Measurement of Gaseous  Emission Rates from Land Surfaces
       using  an Emission Flux Chamber:  Users Guide, EPA Contract 68-02-3889,
       Radian Corporation, Austin,  TX, 1986.

  24.   Cowherd, C.  Measurement of Particulate Emissions from Hazardous  Waste
       Disposal Sites.  For presentation at: 78th Annual Meeting, A1r Pollution
       Control  Association,  Detroit, MI,  June 16-21, 1985.

"  25.   Astle, A.D., R.A. Duffee,  and A.R. Stankunas.  Estimating  Vapor  and Odor
       Emission Rates from Hazardous Waste Sites.  In:  National  Conference  on
       Management of Uncontrolled Hazardous  Waste Sites, U.S. Environmental
       Protection Agency, et  al., Washington, D.C., 1982.  pp.  326-330.

  26.   Eklund,  B. Detection  of Hydrocarbons  1n  Groundwater by Analysis  of
       Shallow  Soil Gas/Vapor.   Radian Corporation, Austin, TX, 1985.   78  pp.
                                       193

-------
27.  Devitt, D.A., R.B. Evans, U.A. Jury, T.H. Starks, B. Eklund, and A.
     Gholson.  Soil Gas Sensing for Detection and Mapping of Volatile
     Organics.  National Hater Hell Association.  1987.

28.  Kerfoot, H.B. Soil-Gas Measurement for Detection of Groundwater
     Contamination by Volatile Organic Compounds.  Environmental Science and
     Technology, 21(10):1022-1024, 1987.

29.  Schmidt, C.E., R. Vandervort, and W.D. Balfour.   Technical Approach and
     Sampling Techniques Used to Detect and Map Subsurface Hydrocarbon
     Contamination.  For presentation at the 79th Annual Meeting, A1r
     Pollution Control Association, Minneapolis, MN,  1986.  31 *pp.

30.  Schmidt, C.E., and W.D. Balfour.  Direct Gas Emission Measurement
     Techniques and the Utilization of Emissions Data from Hazardous Waste
     Sites.  Reprinted from:  National Conference on  Environmental Engineering
     Proceedings, Environmental Engineering Division, ASCE, 1983.  8 pp.

31.  Balfour, W.D., C.E. Schmidt, and B.M. Eklund. Sampling Approaches for
     the Measurement of Volatile Compounds at Hazardous Waste Sites.  Journal
     u/ Hazardous Material 14 (1987) 135-148.

32.  EPA Reference Methods, Environment Reporter, December 5, 1980.

33.  Radian Corporation.  Review of Soil Gas Sampling Techniques.  Austin, TX,
     1983.  26 pp.

34.  L.J. Thibodeaux, D.G. Parker, and H.H. Heck.  Measurement of Volatile
     Chemical Emissions from Wastewater Basins.  U.S. EPA, Hazardous Waste
     EngineerinResearch Laboratory, EPA/600/5-2-82/095.  Cincinnati, OH  1982.

35.  C.Cowherd, K.Axetell, C.M. Guenther, and G.A. Jutze.  Development of
     Emission Factors for Fugitive Dust Sources.  EPA  450/3-74-037.  U.S.
     EPA, Cincinnati, OH  1974.
                                      194

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36.  Hetherold, R.G., and O.A. Oubose.  A Review of Selected Theoretical
     Models for Estimating and Describing Atmospheric Emissions from Waste
     Disposal Operations.  EPA Contract 68-03-3038, U.S. Environmental
     Protection Agency, Office of Research and Development, Industrial
     Environmental Research Laboratory, Cincinnati, OH, 1982.  73 pp.

37.  EspUn, G.J.  Boundary Layer Emission Monitoring.  JAPCA Vol. 38, No. 9,
     1158-1161 September 1988.

38.  U.S. Environmental Protection Agency.  Guideline on Air Quality Models
     (Revised).  Office of Air Quality Planning and Standards, PB86-245248.
     Research Triangle Park, NC  July 1986.

39.  Baker, L.W., and K.P. MacKay. Screening Models for Estimating Toxic Air
     Pollution Near a Hazardous Waste Landfill.  Journal of the Air Pollution
     Control Association, 35(11):1190-1195, 1985.

40.  Farmer, W.J., M.S. Yang, J. Letey, W.F. Spencer, and M.H. Roulier.  Land
     Disposal of Hexachlorobenzene Wastes: Controlling Vapor Movement in
     Soils. In: Land Disposal of Hazardous Wastes. Proceedings of the Fourth
     Annual Research Symposium, U.S. Environmental Protection Agency,
     Municipal Environmental Research Laboratory, San Antonio, TX, March 6, 7,
     and 8, 1978. pp. 182-190.

41.  Farmer, W.J., M.S. Yang, J. Letey, and W.F. Spencer.  Land Disposal t)f
     Hexachlorobenzene Wastes:  Controlling Vapor Movement in Soil.
     EPA-600/2-80-119, U.S. Environmental Protection Agency, Office of
     Research and Development, Municipal  Environmental Research Laboratory,
     Cincinnati, OH, 1980.  69 pp.

42.  U.S. Environmental Protection Agency.  Hazardous Waste, Treatment,
     Storage and Disposal Facilities (TSDF) — Air Emission Models.  Draft
     Report, Office of Air Quality Planning and Standards,  Research Triangle
     Park, NC, 1987.  pp. 6-1 to 6-16.
                                      195

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 43.   Radian Corporation.   Survey and  Assessment of Air  Emission  Modeling
      Techniques for Landfills.   Draft Final  Report.   EPA  Contract  68-01-7287,
      U.S.  Environmental  Protection  Agency, Washington,  D.C.,  1988.   115 pp.

 44.   Springer,  C.,  K.T.  Valsaraj, and L.J. Thlbodeaux.  In  Site  Methods to
      Control  Emissions from Surface Impoundments and  Landfills.  Journal of
      the Air Pollution COntrol  Association,  36(12): 1371-1374, 1986.

 45.   Shen, T.T.  Estimating Hazardous Air Emissions from  Disposal  Sites.
      Pollution  Engineering, 13(8):31-34, 1981.

 46.   Shen, T.T.  Air Quality Assessment for  Land Disposal of  Industrial
;.     Wastes.  Environmental Management, 6(4):297-305, 1982.South Coast Air
      Quality Management District.   Landfill  Gas Emissions:  Report  of the Task
      Force, El  Monte, CA,  1982.

 47.   Shen, T.T., and G.H.  Sewell.   Air Pollution Problems of  Uncontrolled
      Hazardous  Waste Sites. Civil Engineering for Practicing  and Design
      Engineers, 3(3):241-252, 1984.

 48.   Farlno,  W., P. Spawn, M. Oaslnski, and  B. Murphy.  Review of  Landfill
      AERR  Models.  In: Evaluation and Selection of Models for Estimating Air
      Emissions  from Hazardous Waste Treatment, Storage, and Disposal
      Facilities.  Revised  Draft Ftnal  Report. Contract  No.  68-02-3168, U.S.
;      Environmental  Agency, Office of  Solid Waste, Land  Disposal  Branch, 1983.
      pp. 5-1  -  5-13.

 49.   Thlbodeaux, L.J., and S.T.  Hwang.  Landfarming of  Petroleum Wastes -
      Modeling the Air Emission Problem.  Environmental  Progress, l(l):42-46,
      1982.

 50.   Shen, T.T.  Air Pollution Assessment of Toxic Emissions  from  Hazardous
      Waste Lagoons and Landfills.   Environment International, ll(l):71-76,
      1985.
                                      196

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51.  Hwang, S.T. Toxic  Emissions from Land Disposal Facilities. Environmental
     Progress,  l(l):46-52,  1982.

52.  DeWolf, G.B., and  R.G. HethereId.  Protocols for Calculating VOC
     Emissions  from Land Applications Using Emission Models.  Radian
     Corporation, Austin, TX, EPA Contract No. 68-02-3850, U.S. Environmental
     Protection Agency, Research Triangle Park, NC, 1984.  28 pp.

53.  U.S. EPA AP-42: Compilation of Air Pollutant Emission Factors, Fourth
     Edition.  USEPA/OAQPS  RTP, NC  September 1985.

54.  Hwang, S.T.  Estimating and Field-Validating Hazardous Air Emissions from
     Land Disposal Facilities. In: Third Pacific Chemical Engineering
     Conference, Seoul, Korea, 1983. pp. 338-343.

55.  Thomas, R.G. Volatilization from Soil.  In: Handbook of Chemical Property
     Estimation Methods, U.J. Lyman, W.F. Reehl, and D.H. Rosenblatt, eds.
     McGraw-Hill, New York, NY, 1982.  pp. 16.1 - 16.50.

56.  Mackay, D., and P.J. Leinonen.  Rate of Evaporation of Low-Solubility
     Contaminants from Water Bodies to Atmosphere.  Environmental Science and
     Technology, 9(13): 1178-1180, 1975.

57.  Mackay, D., and A.T.K. Yeun.  Mass Transfer Coefficient Correlations for
     Volatilization of Organic Solutes from Water.  Environmental Science and
     Technology, 17(4):211-217, 1983.

58.  Shen, T.T. Hazardous Air Emissions from Industrial  Waste Treatment
     Facilities.  In:  Industrial Waste:  Proceedings of the Fourteenth
     Mid-Atlantic Conference, June 27-29, 1982, J.E. Alleman and J.T.
     Kavanagh, eds., Ann Arbor Science, Ann Arbor, MI, 1982.  pp. 361-372.

59.  Record of Decision, Remedial Alternative Selection, Bruin Lagoon Site,
     Bruin Borough, PA.  September 29, 1986.
                                      197

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60.  CH2M Hill.  Phase I Remedial  Investigation,  Lowry Landfill, Vols. I and
     II. EPA No 38.8LOS.3 Milwaukee, HI.  September 2, 1986.

61.  CH2MH111.  Final Remedial  Investigation Data Report:  Western
     Processing. RA-WA-37-OL16-1, Kent, HA.  December 17, 1984.

62.  Dames and Noore and Landau Associates Western Processing Technical Basis
     for Remedial Action Plan, Phase II.  October 3, 1984.

63.  Leplc, K.A. and A.R. Foster.  Superfund 1987: Proceedings of the Eighth
     National Conference.  Washington, DC. November 16-18, 1987.

64.  U.S. Environmental Protection Agency. Superfund Record of Decision:
     Outboard Marine Corp. Site, IL.  EPA/ROD/R05-84/007, Washington, DC,
     1984.
                                      198

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      APPENDIX A
ANNOTATED BILIOGRAPHY

-------
                                  APPENDIX A

                            ANNOTATED BIBLIOGRAPHY


  I.      Adams, D.F.  Sulfur Gas Emissions from Flue  Gas  Desulfurization
          Sludge Ponds.  Journal  of the A1r Pollution  Control  Association,
          29(9):963968, 1979.

               This article describes an enclosure  used  to measure natural
               sulfur species emissions.  This  article was used to assist In
               the development of the Radian surface flux  chamber.


 II.      Aim, R.R., C.P. Hanauska, K.A. Olson,  and M.T. Pike. The Use of
          Stabilized Aqueous Foams to Suppress  Hazardous Vapors. -- A Study of
          Factors Influencing Performance. In:  Superfund '87:  Proceedings of
          the 8th National Conference,  The Hazardous Materials Control
          Research Institute, Washington, D.C.,  November 16-18, 1987. pp. 480-
          484.

               This article presents results from laboratory and field testing
               of 3M vapor suppression  foams.   Field testing was performed on
               excavated material using a direct emissions approach:  surface
               emissions Isolation flux chamber.


III.      Aim, R.R., K.A. Olson,  and R.C. Peterson. Using  Foam to Maintain Air
          Quality During Remediation of Hazardous Waste Sites. Presented at
          the A1r Pollution Control Association's 80th Annual  Meeting and
          Exhibition, New York, NY, June 21-26,  1987.  17 pp.

               This paper Is not useful for determining  emission measurements
               or estimating techniques.  It also 1s not useful as a case
               study.  It provides some data on the effectiveness of foams
               from laboratory tests and Radian testing  of 3M foam, using a
               surface isolation flux chamber.


 IV.      Aim, R.R., K.A. Olson,  and E.A. Reiner. Stabilized Foam: A New
          Technology for Vapor Suppression of Hazardous Materials. Presented
          at the International Congress on Hazardous Materials Management,
          Chattanooga, TN, June 8-12, 1987.  13 pp.

               This paper is not useful for determining methods of emission
               measurement or estimating, or as a case study.   It provides
               data on the effectiveness of vapor suppression foam from
               laboratory tests using a "Radian-style" flux chamber and GC.
               The paper includes few details and references Radian field
              'testing of 3M foams.

-------
    V.      Asolan, M.F., and M.J. Barboza.   A Practical  Methodology for
            Designing and Conducting Ambient A1r Monitoring at Hazardous Waste
            Facilities.  For Presentation at the 79th Annual  Meeting of the Air
            Pollution Control Association, Minneapolis, MN, 1986.   16 pp.

                 This paper presents an approach for designing ambient air
                 monitoring programs, including a decision tree.   The emphasis
                 Is placed on establishing program objectives, Including why
                 sampling 1s performed, for  who, and what 1s  to be sampled.  The
                 approach 1s Intended for use for project planning rather than
                 project execution.


   VI.      Astle, A.D., R.A. Ouffee, and A.R.  Stankunas.   Estimating Vapor and
            Odor Emission Rates from Hazardous  Waste Sites.  In:   National
            Conference on Management of Uncontrolled Hazardous Waste Sites, U.S.
            Environmental Protection Agency, et al.,  Washington, D.C., 1982.
            pp. 326-330.
                                                                «
                 This article discusses sampling and evaluation of emissions for
                 odor.  The sampling tunnel  may have some usefulness for
                 investigating volatile emission rates versus wind speed;
                 however, the technique would require development  and testing.


?VII.      Baker, L.W., and K.P. tockay. Screening Models for Estimating Toxic
-           Air Pollution Near a Hazardous Waste Landfill. Journal  of the Air
            Pollution Control Association, 35(11):1190-1195,  1985.

                 Baker and Mackay evaluate performance of four air dispersion
                 models to calculate the ambient air concentration of vinyl
                 chloride versus measured concentration downwind of a landfill.
                 The vinyl chloride emission rate was calculated using Shen's
                 modification of Farmer's gas migration equation.   The air
                 dispersion models used are  a ground level point source model,
                 two virtual point source mdoels,  and a simple box model.

  VIII.      Balfour, W.D., R.G. Wetherold, and  D.L.  Lewis. Evaluation of Air
            Emissions from Hazardous Waste Treatment,  Storage, and Disposal
            Facilities. EPA 600/2-85/057, U.S.  Environmental  Protection Agency,
            Cincinnati, OH, 1984. 2 vol.

:'                 Emission rates based on direct and indirect  emission
                 measurements were compared  to  emission rates calculated from
                 predictive models.  Emission rate measurement techniques were
                 also compared against each  other.   Emission  measurement
                 techniques include surface  Isolation flux chamber,  vent
                 sampling, concentration profile,  transect, and mass balance.
                 Predictive models Include the  Thibodeaux,  Parker,  and Heck
                 Models (non-aerated surface impound), the Thibodeaux-Hwang
                 Model (land treatment), and an API  model  (tanks).   Details for
                 each measurement technique  and model  are  provided.

-------
 IX.      Balfour, W.D., C.E. Schmidt, and B.M.  Eklund.   Sampling Approaches
          for the Measurement of Volatile Compounds at Hazardous Waste Sites.
          Radian Corporation, Austin, TX, no date.  29 pp.

               Sampling techniques for measuring volatile emission rates and
               for measuring soil gas concentrations are discussed.  Emission
               rate techniques Included are emission Isolation flux chamber,
               vent sampling, concentration profile, transect, and mass
               balance.  Soil gas concentration  techniques are headspace
               analysis of soil cores, soil gas  probes (ground probe), and
               passive samplers.

               Each approach Is described, and the  applicable equations are
               presented.


  X.      Balfour, W.D., and C.E. Schmidt.  Sampling Approaches for Measuring
          Emission Rates from Hazardous Waste Disposal Facilities.  Radian
          Corporation, Austin, TX, 1984.  13 pp.

               Balfour and Schmidt present five  sampling approaches for
               measuring volatile emissions:  surface emission Isolation flux
               chamber, vent sampling, concentration-profile, transect
               technique, and mass balance.  A comparison of the applicability    ^
               of each technique to various TSDF sites or units 1s given.         fl


 XI.      Balfour, W.D., B.M. Eklund, and S.J. Williamson.  Measurement of
          Volatile Organic Emissions from Subsurface Contaminants.  Radian
          Corporation, Austin, TX, 1985. 20 pp.

               This paper presents results of field rcaasurement performed with
               the surface emission Isolation flux  chamber.  It also evaluates
               the effect of six operating variables on  measured emission rate
               and appropriateness of statistical sampling procedure for area
               sources, and provides an analysis of variability 1n the method.

XII.      Banerjee, P., and D.fl. Homer. The Impacts of Using Assumed Versus
          Site-Specific Values 1n Determining Fate  and Transport. In:
          Superfund'87: Proceedings of the 8th National  Conference, The
          Hazardous Control Research Institute,  Washington, D.C., November 16-
          18, 1987. pp. 126-128.

               This article does not discuss emission rate measurement;
               rather, It emphasizes the Importance of the need to obtain
               site-specific data rather then assumed or literature-derived
               values as Inputs to risk assessment.


XIII.     Berrafato, L.R., and R.A. Wadden.  Predicted vs. Measured Air           V
          Emissions of Volatile Organlcs from a  Simulated Hazardous Waste
          Lagoon.  In:  Toxic Hazardous Wastes,  Proceedings of the 18th Mid-
          Atlantlc Hazardous Waste Conference, Chem. Ind. Inst. Toxicol.,
          Research Triangle Park, NC, 1986.  pp. 515-525.

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               Evaporation of toluene and chlorobenzene from a simulated
               lagoon was measured based on the liquid concentration of these
               chemicals In the lagoon.  The evaporation rate was compared to
               a predictive model similar to the Mackay-Lelnonen Model.  The
               results showed the model may be useful for order of magnitude
               estimates.


XIV.      Bllsky, I.L.  Air Pollution Aspects of Hazardous Waste Disposal In
          Texas. Environmental Progress, 5(2):123-129, 1986.

               This article examines the Texas administrative review process
               for proposed hazardous waste disposal facilities.  A case study
               of a waste disposal facility application 1s reviewed.


XV.       Blasko, M.J., B.F. Cockroft, W.C. Smith, and P.P. O'Hara.  Design of
          Remedial Measures and Waste Removal Program, Lackawanna Refuse
          Superfund Site. In: Superfund '87: Proceedings  of the 8th National
          Conference, The Hazardous Control Research Institute, Washington,
          D.C., November 16-18, 1987.  pp. 367-370.

               This article discusses the development of the design and con-
               struction bid package for the remedial measures and removal
               program.  No Information on emissions data 1s given.  The RI
               report would have to be reviewed directly to see if a case
               study exists.


XVI.      Breton, M., T. Nunno, P. Spawn, W. Far1no, and R. Mclnnes.
          Evaluation and Selection of Models for Estimating Air Emissions from
          Hazardous Haste Treatment, Storage, and Disposal Facilities.  EPA-
          450/8-34-020, U.S. Environmental Protection Agency, Office of Air
          Quality Planning and Standards, Emission Standards and Engineering
          Division, Research Triangle Park, NC, 1984.  157 pp.

               Mathematical models describing the release rate of volatile air
               emissions from hazardous waste treatment, storage, and disposal
               facilities were compiled and reviewed.  Mathematical modeling
               techniques which predict volatile air emission release rates
               from landfills, landfarms, surface Impoundments, storage tanks,
               wastewater treatment processes, and drum handling and storage
               facilities were assessed.  Existing field test validation
               efforts were also reviewed.  Models reviewed include:  landfill
               -- Farmer Model, Shen modification of Farmer Model, Thibodeaux
               a Model, Thibodeaux Convective "Add On" Model, Thibodeaux b
               Model, and Shen's Open Dump Model; land treatment --
               Thlbodeaux-Hwang Model and Hartley Model; lagoons -- Mackay and
               Leinonen Model, Mackay and Wolkoff Model, Thibodeaux, Parker
               and Heck model, Shen Model, Smith Model, and McCord Model.

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XVII.     Caputb, Jr., K., and R.L. Bittle.  Case History:  A Superfund
          Cleanup 1n Central Pennsylvania.  In:  Hazardous and Toxic Wastes:
          Technology, Management and Health Effects,  S.K. Majumdar and E.W.
          Miller, eds.  Pennsylvania Academy of Science,  Easton, PA, 1984.
          pp. 228-241.

               This chapter Is not relevant to the current project; no
               emission measurements are reported.  Caputo and Bittle describe
               the general details of an emergency cleanup at an Industrial
               site.


XVIII.    Caravanos, J., and T.T. Shen. The Effect of Wind Speed on the
          Emission Rates of Volatile .Chemicals from Open  Hazardous Waste Dump
          Sites.  Source unknown.

               This article presents a modified diffusion equation (Shen
               Model), which Includes wind speed as a variable.  Experimental
               data are presented for benzene, carbon tetrachlorlde, and
               trlchloroethylene applied to soil, which approximate a spill.
               The equation also could be applied to waste exposed at surface.


XIX.      Cassis, J.A., E.P. Kunce, and T.A. Pederson. Remedial Action at
          Uncontrolled Hazardous Waste Sites:  Problems and Solutions.  In:       M
          Hazardous Waste Management for the 1980s, T.L.  Sweeney, H.G. Bhatt,     V
          R.M. Sykes, and O.J. Sproul, eds.  Ann Arbor Science, Ann Arbor, MI,    ^
          1982.  pp.241-264.

               This chapter Is not relevant to this program.  The authors
               describe a remedial action plan for the Pollution Abatement
               Services Oswego Site in Oswego, New York.


XX.       Cimorel!i, A.J.  Palmerton Zinc National Priorities List Site:
          Atmospheric Deposition Analysis of Cadmium, Zinc, Lead and Copper in
          the Vicinity of the New Jersey Zinc Palmerton Facility. U.S.
          Environmental Protection Agency Region III  Air  Management Division,
          1986.  93 pp.

               Cimorelli discusses heavy metal deposition from stack
               emissions.  Meteorological data are used to Identify areas of
               high deposition, to design a soil sampling program.


XXI.      Countess, R.J., R. Brewer, and R.J. Gordon.  Sampling Airborne Toxic
          Organics by Remote Control.  Presented at the 78th Annual Meeting of
          the Air Pollution Control Association, Detroit, MI, 1985.  16 pp.

               This paper describes a radio-controlled air sampler, which         •
               would be useful as a sampling method.                               ™

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  XXII.      Cowherd, C. Measurement of Particulate  Emissions  from Hazardous
            Waste Disposal Sites.   For presentation at:  78th  Annual  Meeting,  Air
            Pollution Control  Association, Detroit,  MI,  June  16-21,  1985.

                 Article describes the MRI wind tunnel and  exposure  profiling
                 techniques for participate  emissions rate  measurement.  The  MRI
                 wind tunnel Is a  portable wind tunnel which  can  be  used for
                 direct emissions  measurement.   The exposure  profiling technique
                 1s used for Indirect emissions measurement and Is similar to
                 the transect  technique.


~XXIIi;    Cox,  R.D., K.J. Baughman, and R.F,  Earp.  A  Generalized  Screening
            and Analysis Procedure for Organic  Emissions from Hazardous  Waste
            Disposal Sites.  In:  Proceedings of the 3rd National  Conference  and
            Exhibition on Management of Uncontrolled Waste  Sites,  Washington,
            D.C., 1982.

                 The authors describe a technique developed by Radian
                 Corporation for analysis of gas, liquid, and solid
                 environmental samples. The technique uses gas chromatography
                 with flame ionization, photoionization  and Hall  electrolytic
                 conductivity  detectors, as  well as  mass spectrometry.


*,XXIV.      DeWolf, 6.B., and  R.6. Wetherold.   Protocols for  Calculating VOC
j,           Emissions from Surface Impoundments Using Emission Models:
            Technical Note. Radian Corporation, Austin,  TX,  EPA  Contract  No.
            68-02-3850, U.S. Environmental Protection Agency,  Research Triangle
            Park, NC, 1984. 34 pp.

                 DeWolf and Wethrrold present the Thibodeaux  models  for  aerated
                 and nonaerated steady-state Impounds and the Mackay and
                 Lelnonen Model for unsteady-state  Impounds.   Input  variables
                 are defined,  sources of these  variables are  suggested,  and
                 approximate precision levels for the variables are  given.
                 Physical property Inputs are discussed  and methods  for  their
                 estimation are given,  along with selected  values  for  some
                 materials.


•XXV.       DeWolf, G.B., and  R.G. Wetherold.   Protocols for  Calculating VOC
-            Emissions from Land Applications Using  Emission Models.  Radian
            Corporation,  Austin, TX,  EPA Contract No. 68-02-3850,  U.S.
            Environmental Protection  Agency, Research Triangle Park, NC, 1984.
            28  pp.

                 The authors present  the Thibodeaux-Hwang Model for  land
                 treatment and the Farmer Model  for  landfills.  Input  variables
                 are defined,  sources of the variables are  suggested,  and
                 approximate precision levels for the variables are  given.
                 Physical property inputs are discussed  and methods  for  their
                 estimation are given,  along with selected  values  for  some
                 materials.

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XXVI.     Dupont, R.R. A Flux Chamber/Solid Sorbent Monitoring System for Use
          1n Hazardous Organic Emission Measurements from Land Treatment
          Facilities.  Presented at the 79th Annual Meeting of the Air
          Pollution Control Association, Minneapolis, MN, 1986.  15 pp.

               This paper reports on testing of the emission Isolation flux
               chamber with Tenax\ tubes as the sampling media.


XXVII.    Dupont, R.R. A Flux Chamber/Sorbent Tube Monitoring System for
          Hazardous Organic Emission Measurements from Land Treatment
          Facilities.  In:  192nd National Meeting, American Chemical Society,
          Division of Environmental Chemistry, 26(2):394-397, 1986.

               This 1s not useful for a case study; the technology 1s already
               known.  The article reports that testing of the emission Isola-
               tion flux chamber with Tenax\ tubes for sample collection was
               effective for measuring specific volatile species under both
               laboratory and field conditions.


XXVIII.   Dupont, R.R.  Measurement of Volatile Hazardous Organic Emissions.
          Journal of the A1r Pollution Control Association, 37(3):168-176,
          1987.

               An emissions Isolation flux chamber was laboratory tested In
               combination with Tenax\ and charcoal tube sampling to determine
               the recovery efficiencies for selected organics.  The testing
               validates the use of a "Radian-style" flux chamber.  Testing
               Included the use of flow rates significantly below the standard
               protocol.


XXIX.     Eklund, B.M., U.D. Balfour, and C.E. Schmidt.  Measurement of
          Fugitive Volatile Organic Emission Rates.  Environmental Progress,
          4(3):199202, 1985.

               This article describes the design and operation of a "Radian-
               style" emission Isolation flux chamber.  It also provides
               limited data from several projects, which can be used as
               emission measurement case studies.

XXX.      Eklund, B. Detection of Hydrocarbons in Groundwater by Analysis of
          Shallow Soil Gas/Vapor.  Radian Corporation, Austin, TX, 1985.  78
          pp.

               This report describes five methods of measuring soil vapor
               concentrations:  surface flux chamber, soil probe, downhole
               flux chamber, accumulator, and soil coring.  All five methods
               would be useful for data collection for direct measurement
               -and/or predictive modeling.

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XXXI.     Eklund, B.M., W.D. Balfour, and C.E. Schmidt.  Measurement of
          Fugitive Volatile Organic Compound Emission Rates with an Emission
          Isolation Flux Chamber.  For presentation at:  AIChE Summer National
          Meeting, Philadelphia, PA, 1984.  8 pp.

               The authors present the procedures for using the surface
               emission Isolation flux chamber for direct emission rate
               measurement.  Also presented are the results of measurements at
               two spill sites, three landfills, several surface Impounds, a
               landfarm, and a remedial action.


XXXII.    Eklund,,B.M., M.R. Klenbusch, D. Ranum, and T. Harrison.
          Development of a Sampling Method for Measuring VOC Emissions from
          Surface Impoundments.  Radian Corporation, Austin, TX, no date. 7
          pp.
               This paper describes the development program for evaluating and
               modifying the design and operation of the surface Isolation
               flux chamber for use on surface Impounds.


XXXIII.   Enfield, C.G., R.F. Carsel, S.Z. Cohen, T. Phan, and D.M. Walters.
          Approximating Pollutant Transport to Ground Hater.  Ground Water,
          20(6): 711-722, 1982.

               This article does not provide Information on emission rate
               determination.  It present three transport models for
               evaluating the movement of organic chemicals through the soil
               to the groundwater.  The models Include losses due to
               degradation and sorptlon.  Field data are compared to the
               models.

XXXIV.    Engineering Science, Inc. Determination of Air Toxic Emissions from
          Non-Traditional Sources In the Puget Sound Region.  EPA 910/9-86-
          148, U.S. Environmental Protection Agency, Region X and Puget Sound
          Air Pollution Control Agency, Seattle, WA, 1986.  108 pp.

               This report develops emission estimates for several selected
               sources in the Puget Sound Region Including POTWs, Industrial
               wastewater treatment plants, Superfund sites, municipal land-
               fills, and TSDFs.  Emissions are based on theoretical
               equations.  The report contains some useful examples of
               theoretical equation applications.  The report may also provide
               case study site information.
XXXV.     Farino, W., P. Spawn, M. Jasinski, and B. Murphy.  Review of
          Landfill AERR Models.  In: Evaluation and Selection of Models for
          Estimating Air Emissions from Hazardous Waste Treatment, Storage,
          and Disposal Facilities. Revised Draft Final Report. Contract No.
          68-02-3168, U.S. Environmental Agency, Office of Solid Waste, Land
          Disposal Branch, 1983. pp. 5-1 - 5-13.

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               This section describes six predictive models that estimate
               volatile emissions:  Fanner,  Shen's modification of Fanner,
               Thlbodeaux (three variations),  and Shen's Open Dump.  The first
               five models are based primarily on gas diffusion through the
               landfill cover.
XXXVI.    Farmer, W.J., M.S. Yang, J. Letey,  W.F.  Spencer,  and M.H. Rouller.
          Land Disposal of Hexachlorobenzene  Wastes:  Controlling Vapor
          Movement 1n Soils. In: Land Disposal  of Hazardous Wastes.
          Proceedings of the Fourth Annual  Research Symposium, U.S.
          Environmental Protection Agency,  Municipal  Environmental Research
          Laboratory, San Antonio, TX, March  6, 7, and 8,  1978. pp. 182-190.

               Farmer presents a predictive equation for determining
               hexachlorobenzene vapor diffusion through a soil cover.
               Volatilization through soil, water, and polyethylene film was
               studied In laboratory simulations.   The predictive equation
               should be applicable to other  waste types.


XXXVII.   Farmer, W.J., M.S. Yang, J. Letey,  and W.F. Spencer.  Land Disposal
          of Hexachlorobenzene Wastes:  Controlling Vapor  Movement 1n Soil.
          EPA-600/280-119, U.S. Environmental Protection Agency, Office of
          Research and Development, Municipal Environmental Research
          Laboratory, Cincinnati, OH, 1980.  69 pp.

               The volatilization fluxes of hexachlorobenzene through a
               covering of soil, water, and polyethylene film were simulated
               In the laboratory.  Volatilization through  soil was directly
               related to soil porosity.  Fanner develops  a diffusion equation
               for determining flux rates through the soil  covering.


XXXVIII.  Glllesple, D.P., F.J. Schauf, and J.J. Walsh. Remedial Actions at
          Uncontrolled Hazardous Waste Sites, Survey and Case Study Investiga-
          tion.  In:  Proceedings of the Second National Symposium on Aquifer
          Restoration and Ground Water Monitoring, National Water Well
          Association, Worthlngton, OH, 1982.  pp. 369-374.

               This paper 1s not useful.  It  discusses how nearly half of all
               remedial actions completed by  1980 were Ineffective at cleaning
               up the sites.
XXXIX.    Gravltz, N. Derivation and Implementation of Air Criteria During
          Hazardous Waste Site Cleanups. Journal  of the A1r Pollution Control
          Association, 35(7):753-758, 1985.

               This article presents an approach  for developing fenceline air
               monitoring criteria to protect community health.  The approach
              ?1s dependent on developing acceptable community exposure
               levels, and back calculating  the fenceline concentration by
               assuming Gaussian wind dispersion.  The method does not require
               emissions measurement.

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XL.        Greenberg,  H.  A Review of: 1) A Technical Approach for Sampling and
           Analysis  of VOCs at Hazardous Waste Sites and 2) Some Case Studies
           In  New Hampshire.  Presented before the Fall Meeting, Air Pollution
           Control Association New England Section, Conference on A1r Toxics,
           Worcester,  MA, October 6-7, 1986.  30 pp.

               This document contains overhead slides for a conference
               presentation on  sampling VOCs in ambient air at landfills.
               Case studies are not worked up as emission estimates.


XLI.       Hanisch,  R.C., and M.A. McDevitt.  Protocols for Sampling and
           Analysis  of Surface Impoundments and Land Treatment/Disposal Sites
           for VOCs.   EPA Contract No. 68-02-3850, U.S. Environmental
           Protection  Agency, Office of Air Quality Planning and Standards,
           Research  Triangle Park, NC, 1984.  88 pp.

               The  report  gives detailed description for analysis of volatile
               organics by Radian gas chromatography with multiple detectors
               (GC/MD) system and gas chromatography with mass spectrometry
               (GS/MS) system.  The report gives a brief discussion of predic-
               tive emission models and lists Inputs to models, but does not
               present models.  A description of a statistical approach to
               collecting  sufficient samples for representativeness 1s
               Included.                 -   .


XLII.      Helsing,  L.D., M.P. Morningstar, J.B. Berkowitz, and T.T. Shen. Risk
           Analysis  of Pollutants at Hazardous Waste Sites: Integration Across
           Media  Is  the Key.  In: Superfund '87: Proceedings  of the 8th
           National  Conference,  The Hazardous Control Research Institute,
           Washington, O.C.,  November 16-18, 1987.  pp. 471-475.

               This paper  describes the types of pollutants frequently found
               at hazardous  waste sites and how they can be transferred from
               one media to  another.  This paper describes how all media need
           *    to be  taken Into account when performing risk analysis.  No
               Information on emission rate determination is provided.


XLIII.     Hwang, S.T. Measuring Rates of Volatile Emissions from Non-Point
           Source Hazardous Waste Facilities.  Presented at the 75th Annual
           Meeting of  the Air Pollution Control Association, New Orleans, LA,
           1982.  22 pp.

               This paper  presents Concentration Profile, Plume Mapping (tran-
               sect), and  Upwind/Downwind models for Indirectly measuring
               emission rates.


XLIV.     Hwang, S.T. Toxi^Emissions from Land Disposal  Facilities. Environ-
          mental Progress, rl(l):46-52, 1982.

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               Hwang gives theoretical equations for emission rate estimates
               from surface Impoundments (natural surface and aerated), land-
               fills (based on soil diffusion), and land treatment (oily
               wastes).  The equations require knowledge of waste and site
               characteristics to determine variables and coefficients.  All
               equations would be difficult to apply for a complex waste,
               requiring computer calculation.  The equations can be applied
               more easily to a single component waste, or Its primary compo-
               nents.


XLV.      Hwang, S.T. Comparison of Model Predicted Volatile Emission Rates
          Versus Results of Field Measurements at Hazardous Waste Sites.
          Presented at:  American Institute of.Chemical Engineers, National
          Meeting, Summer 1984.  American Institute of Chemical Engineers, New
          York, NY.  18 pp.

               Paper presents a comparison of measured and estimated emission
               rates based on field sampling results and theoretical models.
               Measurements were performed at landfills, surface Impounds, and
               land treatment facilities.  Field sampling techniques used were
               concentration profile, transect, and surface emission Isolation
               flux chamber.  The predicted emission rates were generally
               within the confidence Intervals of the measured emission rates,
               although the author Indicates that more study 1s required to
               validate the models.  The specific models used are referenced
               but not discussed.


XLVI.     Hwang, S.T.  Estimating and Field-Validating Hazardous Air Emissions
          from Land Disposal Facilities. In: Third Pacific Chemical
          Engineering Conference, Seoul, Korea, 1983. pp. 338-343.

               Models for estimating volatile emissions are reviewed,
               Including Shen's modification of Farmer's equation (landfill),
               the  Thlbodeaux-Hwang equation (land treatment) and surface
               Impound equation.  Predicted versus measured emissions
               (concentration profile and upwind/downwind techniques) are
               compared, but limited data are given.


XLVII.    Hwang, S.T.  Model Prediction of Volatile Emissions. Environmental
          Progress 4(2):141-144, 1985.

               Hwang presents a comparison of measured and predicted emission
               rates.  Measurement techniques Include transect and
               concentration profile techniques.  Isolation flux chambers and
               upwind/downwind are also discussed.  The article contains
               limited data from potential case studies.


XLVIII.   ICF,^Incorporated.. The RCRA Risk-Cost Analysis Model Phase III
          Report Appendices. Submitted to the Office of Solid Waste, Economic
          Analysis Branch, U.S. Environmental Protection Agency, 1982.
          Appendix E, 31 pp.

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                 Appendix E describes natural chemical, physical, and biological
                 processes that  reduce the concentration of chemicals 1n  the
                 environment.  These processes are the basis for deriving
                 surface and groundwater decay rates for the chemicals  Included
                 1n the RCRA Risk-Cost Analysis Model.  Important for baseline
                 emission rate estimates Is the discussion on volatilization
                 from water.


 XLIX.      Jubach, R.W., R.R. Stoner, T.F. laccarlno, and D.R. Smiley.   An
            Atmospheric Field Program Conducted at a Hazardous Waste Site.
1            Presented at the 78th Annual Meeting of the Air Pollution Control
            Association, Detroit, MI, 1985.  14 pp.

                 This study characterizes the atmospheric dispersion at a
                 hazardous waste site from ground level release.  The study
                 consists of releasing a tracer gas and measuring the concentra-
                 tion with two sampling arrays (I.e., transect techniques).
                 Measuring the of actual waste releases are not Included.
                 Downwind data could be useful as a theoretical case study.


•L.         Kaplin, E.J., A.J. Kurtz, and M. Rahimi.  VOC Sampling for  Emission
t.           Rate  Determination and Ambient A1r Quality on an Inactive Landfill.
»           Presented at New England Section, Air Pollution Control Association,
            Fall  1986 Conference, Worcester, MA, October 6-7, 1986. 27  pp.

                 This paper describes sampling performed at an Inactive landfill
                 in New York (a  municipal waste landfill containing Industrial
                 waste). Sampling included ambient air, emission flux chamber
                 (crude), crevices, and vent, sampled with Tenax, PUF/GFF, mylar
                 bags,  Impingers, and high volume samplers with GFF.  Flux
                 measurements Included both covered and uncovered areas.  Data
                 are somewhat limited, but this study may be useful as  a  case
                 study.


 LI.        Karably,  L.S.,  and K.B. Babcock. Effects of Environmental Variables
            on Soil  Gas  Surveys. In: Superfund '87: Proceedings  of the 8th
            National  Conference, The Hazardous Control Research Institute,
            Washington,  D.C., November 16-18, 1987.  pp. 97-100.

                 This may be useful as a case study if sufficient soil data are
                 available.  Soil gas was measured at 40 locations and over time
                 at a fire fighting training area.  This paper reports how
                 environmental conditions (principally weather) affected
                 results.   Limited analytical data are presented.


 LII.       KaHml,  A.A.,  W.J. Fanner, and M.M. Cliath.  Vapor-phase Diffusion
            of Benzene in Soil.-,-Journal of Environmental  Quality, 16(l):38-43,
            1987.

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               The authors use Farmer's diffusion model  and laboratory testing
               method to determine benzene emission rates through soil (I.e.,
               landfill emissions).  The effects of soil bulk density and
               moisture content are Investigated.


 LIII.    Kelnbusch, N.R.  Measurement of Gaseous Emission Rates from Land
          Surfaces using an Emission Flux Chamber:  Users Guide, EPA Contract
          68-02-3889, Radian Corporation, Austin, TX,  1986.

               This document Includes a detailed description for using the
               emission Isolation flux chamber,  Including design of sampling
               program, QA/QC, data reduction,  and examples.


LIV.      Kerfoot, H.B. Soil-Gas Measurement for Detection of Groundwater
          Contamination by Volatile Organic Compounds.   Environmental Science
          and Technology, 21(10):1022-1024, 1987.
                                                               *
               This article describes sampling  using a ground probe system for
               soil gas.  Soil gas data are correlated with groundwater data
               showing good correlation.  Soil  gas data  are correlated with
               soil probe depth below ground surface,  also showing good
               correlation.  Ground water was at shallow depth 1n this study
               (3-4m).  Data could be used as a case study If additional soil
               characteristics data are available.                       .


LV.       Kerfoot, H.B., and P.B. Durgln. Soil-Gas Surveying for Subsurface
          Organic Contamination: Active and Passive Techniques. In: Superfund
          '87: Proceedings  of the 8th National  Conference, The Hazardous
          Control Research Institute, ^'shington, D.C.,  November 16-18, 1987.
          pp. 523-524.

               This article provides an overview of considerations 1n
               designing a soil-gas survey.  It does not provide Information
               on sampling techniques for air pathway  assessment.


LVI.      Lepic, K.A., and A.R. Foster.  Remediation at  a Major Superfund
          Site: Western Processing -- Kent, Washington.   In: Superfund '87:
          Proceedings  of the 8th National Conference, The Hazardous Control
          Research Institute, Washington, D.C.,  November 16-18, 1987.  pp. 78-
          84.

               This article summarizes a remedial Investigation conducted at a
               Western Processing site.  Continuous upwind and downwind air
               monitoring was conducted, as well as some location-specific
               sampling.  It may be useful as a case study.  No data on air
               monitoring are presented; the author would have to be
               contacted.

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L
LVII.     Lewis* R.G., 8.E. Martin, D.L. Sgontz, and J.E. Howes.  Measurement
          of Fugitive Atmospheric Emissions of Polychlorlnated Blphenyls from
          Hazardous Waste Landfills.  Environmental Science and Technology,
          19(10):986-991, 1985.

               This article describes air sampling for PCBs at three
               uncontrolled landfills and one controlled landfill.  Emission
               rates were not calculated.  The data set may be usable for
               calculating emission rates.  Sampling was performed using low-
               volume and high-volume samplers and PUF cartridges.


LVIII.    Mackay, D.M., P.V. Roberts, and J.A. Cherry.  Transport of Organic
          Contaminants 1n Groundwater.  Environmental Science and Technology,
          19(5): 384-392, 1986.

               This article describes the mechanisms Involved in the transport
               of organic chemical contaminants in ground water, Including
               advection, dispersion, sorption and transformation.


LIX.      Mackay, D., and P.O. Lelnonen.  Rate of Evaporation of Low-
          Solubility Contaminants from Water Bodies to Atmosphere.
          Environmental Science and Technology, 9(13): 1178-1180, 1975.

               The authors present predict models (Mackay and Lelnonen) for
               emission rates from aqueous systems.  Equations are presented
               for both steady and unsteady state systems.


LX.       Mackay, D., and A.T.K. Yeun.  Mass Transfer Coefficient Correlations
          for Volatilization of Organic Solutes from Water.  Environmental
          Science and Technology, i7(4):211-217, 1983.

               Volatilization rates of organic compounds in water were
               measured In a wind-wave tank for compounds of varying Henry's
               Law Constants.  The data yielded correlations for liquid and
               vapro-phase transfer coefficients as a function of windspeed,
               and showed that interactions did not occur when mixtures of
               compounds volatilized simultaneously.


LXI.      Marquardt, G.D.  Toxic Air Quality Investigation at a Hazardous
          Waste Site.  In: Superfund '87: Proceedings  of the 8th National
          Conference, The Hazardous Control Research Institute, Washington,
          O.C., November 16-18, 1987.  pp. 284-295.

               This article does not provide data for baseline conditions.
               However, It may be useful as a case study.  Sampling was per-
               formed upwind, on site, and downwind during field Investigation
               (drilling) and during a controlled release from a gas well.
               Sampling techniques could be used for Indirect measurement of
               baseline emissions; techniques Include Tenax\, carbon molecular
               sieve, high-volume participate sampler, and PUF.

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 LXII.      Meegoda, N.J., and P.  Ratnaweera. A New Method  to  Characterize
           Contaminated Soils. In:  Superfund '87: Proceedings  of the 8th
           National Conference, The Hazardous Control  Research  Institute,
           Washington, D.C., November 16-18, 1987.  pp. 385-389.

                This paper 1s not related  to emission  rate determination; it
                presents an electrical  method to determine engineering
                characteristics of  soil.


 LXIII.     Miller, G.C., V.R. Herbert,  and R.G. Zepp.  Chemistry  and
           Photochemistry of Low-Volatility Organic Chemicals on  Environmental
           Surfaces.  Environmental  Science and Technology, 21 (12):1164-1167,
           1987.

                This article discusses  factors affecting the  transformation,
                mobility, and fate  of xenobiotic chemicals (specifically
                dioxins and PAHs).   Emphasis is placed on  discussing effects on
                and near the soil surface  and factors  that affect the rate of
                photolysis.


 LXIV.      Panaro, J.M. A1r Monitoring  and Data Interpretation  During Remedial
           Action at a Hazardous  Waste  Site.  In:  Hazardous  Wastes  and
       .  -  Environmental.Emergencies: Management, Prevention, Cleanup, Control,
           Hazardous Materials Control  Research Institute, Houston,  TX, 1984.
           pp.160-164.

                Panaro describes  the air monitoring program employed during
                Initial remedial  measures  at a chemical recycling plant.  He
                does not address  emission  estimates.


IXV.       Polcyn, A.J., and H.E. Hesketh.  A Review of Current Sampling and
           Analytical Methods for Assessing Toxic and  Hazardous Organic
           Emissions from Stationary Sources.  Journal of  the A1r Pollution
           Control Association, 35(1):54-60, 1985.

v               This article is a brief review of sampling methods (i.e.,
                sample collection media) and analytical methods.   The methods
                are summarized in tables,  and give references for detailed
                descriptions. The  article does not discuss measurement
                techniques (i.e., sampling design) or  modeling.


 LXVI.      Qulmby, J.M., R.W. Cibulskis, and M. Gruenfeld.  Evaluation and Use
           of a Portable Gas Chromatograph for Monitoring  Hazardous  Waste
           Sites.  Source unknown.

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                 This paper evaluates the use of the  Century Systems Organic
                 Vapor Analyzer Model OVA-128 which Is  a portable gas
                 chromatograph with a fume 1on1zat1on detector (GC-FID).  The
                 paper addresses Instrument operating performance, QA/QC
                 consideration, operational difficulties and recommended field
                 uses.  Instruments can be used to perform field screening of
                 ambient air, as well as other uses.


  LXVII.    Radian Corporation.  Review of Soil  Gas Sampling Techniques.
            Austin, TX, 1983.  26 pp.

"'-                Report presents the results of a literature review to Identify
                 techniques applicable to soil  gas sampling and measurement.


  LXVIII.    Radian Corporation.  3M Foam Evaluation for Vapor Mitigation:
            Technical Memorandum.  Sacramento,  CA, 1986.   95 pp.
                                                                *

                 The effectiveness of temporary and stabilized foam for control-
                 ling VOC emissions from petroleum refinery waste was tested.
                 Testing was performed using the surface emission Isolation flux
                 chamber.


*, LXIX.     Radian Corporation. vA1r'Qua*l1ty Engineering Manual  for Hazardous
''           Waste Site Mitigation Activities,  Revision  No.  2.   Sacramento, CA,
            1987.  291 pp.

                 This guidance document provides general  Information for
                 designing and reviewing air monitoring programs  for hazardous
                 waste site remedial  programs.   An overview of New Jersey's
                 agency Involvement 1n the remedial process Is given.   Sampling
                 and analysis methods are discussed 1n  detail.


  LXX.       Radian Corporation.  Ambient A1r Monitoring at  Hazardous Waste and
            Superfund Sites, Revision No.  2.   Sacramento, CA,  1987.   389 pp.

                 This guidance document provides Information for  reviewing air
                 quality engineering  activities  for hazardous  waste site
                 remediation programs.   It also  provides  an overview of the
                 phases of the hazardous site  remediation process and the  role
                 of New Jersey's agencies In  the process.   Descriptions are
                 given for types of waste sites,  potential  air contaminants, and
                 basic remedial processes.


  LXXI.      Radian Corporation.  Survey and Assessment  of Air  Emission Modeling
            Techniques for Landfills.   Draft  Final Report.   EPA Contract 68-01-
            7287, U.S. Environmental  Protection  Agency, Washington,  D.C.,  1988.
            115 pp.

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                Article reviews  theoretical models for landfill  air emissions
                Including:   Farmer Hodel, Shen Model, Thibodeaux a  Model,
                TMbodeaux  Logrithmic Gradient Model, RTI Closed Landfill
                Model,  Thibodeaux Convectlve  "Add On" Model, Thibodeaux b
                Model,  Thibodeaux Exact Model, Arnold's Open Landfill  Model,
                Shen's  Open Landfill Model, and RTI Open Landfill Model.


 LXXII.     Saeger,  M.L., and E.E. Rlckman, Jr. Final Report: Ambient A1r
           Monitoring at Hazardous Waste Treatment, Storage, and Disposal
           Facilities,  Phase I.  EPA Project Number 68-02-4326, U.S.
           Environmental Protection Agency, Emissions Standards  and Engineering
           Division,  Office of Air Quality Planning and Standards,  Research
           Triangle Park, NC, 1968.

                The authors contacted several state and federal  regulatory
                agencies and treatment, storage and disposal facilities (TSDFs)
                to  determine the air monitoring requirements for TSDFs. Few  of
                the states  contacted had established requirements,  and there
                was no  consistency among states.  The program was of a limited
                scope and was intended to determine if a study should  be
                conducted to assess the feasibility of conducting air
                monitoring  programs at TSDFs.


 LXXIII.  ,  Schmidt, 
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                This article presents an RI/FS/RM case  study where an air
                pathways assessment was performed at  a  hazardous waste site.
                Both baseline and disturbed site air  emissions were measured
                and reported.


 LXXVI.     Schmidt, C.E., and M.VI. Eltgroth.  Off-Site  Assessment of A1r
           Emissions from Hazardous Waste Disposal  Facilities.  Reprinted from:
           Management of Uncontrolled Hazardous  Waste Sites,  Hazardous
           Materials Control Research Institute,  Silver Spring,  MD,  1983.14 pp.

                Field data and modeling (Lugranglan model) were used to
                estimate downwind air concentrations  of contaminants using
                measured disturbed site emissions data.  Modeled data were
                compared to measured data.


 LXXVII.    Schmidt, C.E., and W.O. Balfour.   Direct Gas Emission*Measurement
           Techniques and the Utilization of Emissions  Data  from Hazardous
           Waste Sites.   Reprinted from:  National  Conference on Environmental
           Engineering Proceedings, Environmental  Engineering Division,  ASCE,
           1983.  8 pp.

                This article describes direct emissions measurement  techniques
e               and discusses "various applications of/these  techniques to waste
r               management.  Techniques Included  are  surface and downhole
                Isolation flux chambers, ground  probes, and  soil  vapor
                monitoring wells.


 LXXVIII.   Schmidt, C.E., R. Vandervort, and  W.D.  Balfour.   Technical  Approach
           and Sampling  Techniques Used to Detect and Map Subsurface
           Hydrocarbon Contamination.   For presentation at the 79th  Annual
           Meeting, Air  Pollution Control  Association,  Minneapolis,  MN,  1986.
           31  pp.

                This paper presents a case study  where  several  direct air emis-
                sions measurement techniques  were used  to detect emissions from
                a gasoline plume  on groundwater about 90 feet below  the land
                surface.
 LXXIX.     Shen,  T.T.,  and  T.  J.  Tofflemire.  Air Pollution Aspects  of Land
           Disposal  of  Toxic Waste.   In: National Conference  on Hazardous
           Material  Risk Assessment,  Disposal and Management, Miami  Beach,  FL,
           April  25-27,  1979.  pp.  153-159.

               This paper  provides a general discussion of the air  pollution
               dangers Inherent  1n landfill Ing Industrial waste, especially
               co-disposal with  municipal waste.  Volatilization processes are
               discussed.  Also  discussed are methods for reducing  the rate of
               volatile loss.

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LXXX.     Shen, T.T.  Estimating Hazardous Air Emissions from Disposal Sites.
          Pollution Engineering, 13(8):31-34,  1981.

               This article presents Shen's modification of Fanner's equation
               for the diffusion of volatlles  from a landfill, and Zlegler's
               modification of Arnold's equation for open dumps (also referred
               to as Shen's open dump equation).  A table of diffusion
               coefficients for selected compounds 1s given.  Two example
               calculations for PCB emission are also given.


LXXXI.    Shen, T.T., and G.H. Sewell.  Air Pollution Problems of Uncontrolled
          Hazardous Waste Sites. Civil Engineering for Practicing and Design
          Engineers, 3(3):241-252, 1984.

               Shen and Sewell provide three theoretical equations for
               predicting emission rates (Shen landfill  model, Shen landfarm
               model, Shen lagoon model) for volatlles and one for dust.  The
               equations require some field data about soil, waste
               characteristics, site size, etc., but no direct or Indirect
               measurement of emissions.  The  equations should be used with
               caution, and some spec1esspec1f1c coefficients may be difficult
               to determine or Infer.

LXXXII.   Shen, T.T.  A1r Pollution Assessment of Toxic Emissions from            ^
       ••'  Hazardous Waste Lagoons and Landfills.  Environment International,      V
          11(1):71-76, 1985.

               Shen briefly discusses the available methods for determining
               emission rates and their drawbacks.   He does not provide
               technical detail for the use of methods,  but Includes Isolation
               flux chamber, transect, concentration profile, and predictive
               models.


LXXXIII.  Shen, T.T.  Air Quality Assessment for Land Disposal of Industrial
          Wastes.  Environmental Management, 6(4):297-305, 1982.

               Shen presents a models for predicting emission rates from land-
               fills (Shen modification of Fanner),  dumps (Arnold Model) and
               lagoons based on the diffusion  theory.  Shen also presents data
               on the comparison of predicted  versus measured ambient concen-
               tration of PCBs at a New York landfill.  This article may be
               useful as a case study.


LXXXIV.   Shen, T.T. Hazardous Air Emissions from Industrial Waste Treatment
          Facilities.  In:  Industrial Waste:   Proceedings of the Fourteenth
          Mid-Atlantic Conference, June 27-29, 1982, J.E. Alleman and J.T.        *
          Kavanagh, eds., Ann Arbor Science, Ann Arbor,  MI, 1982.  pp. 361-       fl
          372.                                                                    ™
               Shen presents predictive models for dust and volatile organics
               emissions from lagoons (Shen Model), and discusses the fate of
               volatile emissions in the environment in general  terms.

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LXXXV.    Sherman, S., W. Dickens, and H. Cole. Analysis Methods and Quality
          Assurance Documentation of Certain Volatile Organic Compounds at
          Lower. Detection Limits. In: Superfund '87: Proceedings  of the 8th
          National Conference, The Hazardous Control Research Institute,
          Washington, D.C., November 16-18, 1987.  pp. 280-283.

               This paper Is not useful.  It discusses modification of EPA
               Method 624 to allow lower detection limits for groundwater
               analysis.


LXXXVI.   Sklpa, K.J., D.F. Ellas, and J.D. Gram.  Monitoring and Evaluating
          Multiple Source Emissions at Hazardous Waste Sites.  Presented at
          the 78th Annual Meeting of the Air Pollution Control Association,
          Detroit, MI, 1985.  11 pp.

               This paper discusses, in a generic form, the 1ss*ues to be con-
               sidered In selecting monitoring and modeling approaches to
               assess the air Impacts from a hazardous waste site.


LXXXVII.  Smith, P.G., and S.L. Jensen. Assessing the Validity of Field
          Screening of Soil Samples for Preliminary Determination of
          Hydrocarbon Contamination. In: Superfund '87: Proceedings  of the
          8th National Conference, The Hazardous Control Research Institute,
          Washington, D.C., November 16-18, 1987.  pp. 101-103.

               This paper compares results from vapor screening of samples in
               the field using portable analyzers (FID and PID) to results
               from laboratory TPH analyses.  Comparison of the results showed
               poor correlation Indicating the field screening of vapors
               should not be used as the sole criteria for selecting samples
               for analysis.


LXXXVIII. South Coast Air Quality Management District.  Landfill Gas
          Emissions: Report of the Task Force, El Monte, CA, 1982.

               This report describes task force activities, Including sampling
               of emissions at several landfills in the South Coast Air
               Quality Management District.  Data presented are very limited;
               sampling methods were headspace over landfill, shallow ground
               probe, and vent sampling.  Site-specific sampling results could
               possibly be worked up as a case study.
LXXXIX.   Springer, C., K.T. Valsaraj,  and L.J.  Thibodeaux.   In Situ Methods
          to Control Emissions from Surface Impoundments  and Landfills.
          Journal of the Air Pollution  Control Association,  36(12):1371-1374,
          1986.

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               This article discusses various control  measures to reduce air
               emissions from landfills and lagoons.   Included are air-
               supported structures, floating objects, shape modification,
               aerodynamic redesign, oil and surfactant covers, and synthetic
               membrane covers.  The effectiveness and other considerations
               for use of each method are discussed in general.


XC.       St. Clalr, A.E., and K.T. Ajmera. Remedial Action at Uncontrolled
          Hazardous Waste Sites. Environmental Progress, 3(3):188-193, 1984.

               This paper describes the feasibility study approach used to
               develop and select a cost-effective remedial action alternative
               for the McColl Superfund site In Fullerton, California.  Data
               from the McColl remedial investigation, not presented in this
               paper, can be used as a case study of baseline emission rate
               determination.


XCI.      Thibodeaux, L.J., and S.T. Hwang.  Landfarming of Petroleum Wastes -
          - Modeling the Air Emission Problem.  Environmental Progress,
          l(l):42-46, 1982.

               This article reviews volatilization from land farming of
               petroleum wastes, discusses distribution of oil waste in the       ^
               soil, and presents a gradlentless diffusion model for     .         M
               estimating emissions (Thibodeaux-Hwang  Model).  The article        ^
               also gives predicted versus measured emission rates for
               Deldrln.


XCI I.     Thomas, R.G.  Volatilization from Soil.  In: Handbook of Chemical
          Property Estimation Methods, W.J. Lyman, W.F. Reehl, and D.H. Rosen-
          blatt, eds. McGraw-Hill, New York, NY, 1982. pp. 16.1 - 16.50.

               This chapter presents a discussion of the theory of volatiliza-
               tion of organics from soil.  Thomas presents five models for
               calculating volatile loss from the soil.  The models are:
               Hartley Model; Hamaker Model; Meyer, Letey, and Farmer Model;
               Jury, Grover, Spencer, and Farmer Model; and Dow Methods.  This
               work is based on pesticides applied to  soil.  A decision tree
               indicating which models apply for varying conditions is
               Included.  The models could be applied  to sites with known
               contaminants.


XCIII.    Thomas, R.G.  Volatilization from Water.  In:  Handbook of Chemical
          Property Estimation Methods:  Environmental  Behavior of Organic Com-
          pounds, W.O. Lyman, W.F. Reehl, and D.H. Rosenblatt, eds., McGraw-
          Hill, New York, NY, 1982.  pp. 15-1 to 15-34.                           A

               Chapter describes the volatilization process from water.           ^
               Various methods for estimating volatilization rates are
               discussed.  The Mackay and Leinonen model and others are
               presented.

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XCIV.     Thome!oe, S.  Summary of Reports Prepared for the Development of
          Air Emission Standards for Hazardous Waste Treatment, Storage, and
          Disposal Facilities. U.S. Environmental Protection Agency, Office of
          A1r Quality Planning and Standards, Emission Standards and
          Engineering Division, Chemicals and Petroleum Branch, Research
          Triangle Park, NC, 1987.

               This report contains annotated bibliographies and contacts for
               several studies and reports.  Most are directly applicable to
               treatment, storage, and disposal facilities, but some may
               provide sampling techniques applicable to uncontrolled sites.


XCV.      Tucker, W.A., and L.H. Nelken.  Diffusion Coefficients 1n Air and
          Water.  In:  Handbook of Chemical Property Estimation Methods:
          Environmental Behavior of Organic Compounds, W.J. Lyman, W.F. Reehl,
          and D.H. Rosenblatt, eds. McGraw-Hill, NY, 1982.  pp.-17-1 to 17-25.

               Chapter discusses molecular diffusion 1n air and water.
               Methods are not useful for estimating dispersion in air.
               Methods may be relevant to uncontrolled sites (i.e., within
               lagoon or landfill), however, factors such as wind mixing
               (lagoons) or soil gas flow (landfills) may outweigh molecular
               diffusion.


 XCVI.    U.S. Environmental Protection Agency. Letter from J.R.  Farmer,
          Director, Emission Standards and Engineering Division,  to D. Kolar,
          Environmental Counsel, Browning Ferris Industries, dated October 30,
          1987, regarding EPA's Investigation of techniques  for controlling
          air emissions from municipal landfill facilities.

               The U.S. EPA sent a questionnaire to Browning Ferris Industries
               requesting Information on their landfills.  The results, des-
               cribed in this memorandum, do not provide Information for base-
               line emissions.


XCVII.    U.S. Environmental Protection Agency.  Material on RCRA Facility
          Investigation Guidance (RFI) provided by the U.S. Environmental
          Protection Agency, Office of Air Quality Planning and Standards, to
          Radian Corporation, Sacramento, CA, December 1987.

               The material provided Includes a Section 12 on Air, Case Study
               14: Use of Air Monitoring Data and Dispersion Modeling to
               Determine Contaminant Concentrations Down-Wind of a Land
               Disposal Facility, and Case Study 15: Use of Meteorological
               Data to Design an Air Monitoring Network.  This material
               provides a recommended strategy for characterizing releases to
               the air. .A1r monitoring and modeling are discussed in general
               form.  The Field Methods section provides considerable
               Information on available sampling media and appropriate species
               applications.

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XCVIII.   U.S. Environmental Protection Agency.  RCRA Facility Investigation
          (RFI) Guidance, Volume III, Section 12, A1r and Surface Water
          Releases.  OSWER Directive 9502.00-6C, Office of Solid Waste, 1987.

               Provide recommended strategy for characterizing releases to
               air, which Includes characterizing the source and the
               environmental setting for removal actions at RCRA facilities.


XCIX.     U.S. Environmental Protection Agency.  Superfund Exposure Assessment
          Hanual.  OSWER Directive 9285.5-1, Office of Solid Waste and
          Emergency Response, Washington, D.C.

               Section 2.3 of this manual presents eight equations for
               predicting short-term and long-term emission rates for
               landfills with and without Internal gas generation, lagoons,
               landfarms, spills and leaks.  Both participates-and volatile
               emissions are discussed.  Equations and discussions are given
               for determining Input variables.


C.        U.S. Environmental Protection Agency.  Hazardous Waste Treatment,
          Storage and Disposal Facilities (TSDF) --Air Emission Models.  EPA-
          450/3-87-026, Office of Air and Radiation, Office of Air Quality
          Planning and Standards, Research Triangle Park, NC, 1987.

               Analytical models are presented for estimating air emissions
               from hazardous waste treatment, storage, and disposal
               facilities (TSDF).  Air emission models have been developed for
               aerated and nonaerated surface Impoundments, land treatment
               facilities, landfills, and wasteplles (RTI models).  Emission
               model predictions are compared to available field data.  This
               report also Includes emission factors for transfer, storage,
               and handling operations at TSDFs.  The models have been
               assembled Into a spreadsheet that 1s Included In this report as
               floppy diskette for use on a microcomputer.  Appendices Include
               a list of  physical-chemical properties for approximately 700
               compounds and a comprehensive source 11st of pertinent
               literature In addition to that cited in the report.


CI.       Vandervort, R., C.E. Schmidt, and W.D. Balfour.  Surface and Subsur-
          face Gas/Vapor Monitoring Techniques Applied to Environmental
          Contamination Caused by Petroleum Products and Processing Wastes.
          Radian Corporation, Sacramento, CA.  12 pp.

               This paper discusses the application of surface and subsurface
               emission rates and vapor concentration measurements for
               Investigating petroleum leaks and hazardous waste site
              ; Investigations.

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CII.      Vaught, C.C. A Basic Programming Technique for the Estimation of VOC
          Emissions from Hazardous Waste Treatment, Storage, and Disposal
          Facilities.  Presented at the 78th Annual Meeting of the A1r
          Pollution Control Association, Detroit, HI, June 16-21, 1985.  9 p.

               This paper describes a BASIC program for use on microcomputer.
               The program uses unspecified predictive models to estimate
               emission rates for surface Impounds, landfills, land treatment,
               and storage tanks.  The program Includes a chemical library of
               required model variables which are accessed by use of CAS num-
               bers, as well as estimation programs for filling data gaps, and
               adjustments for site- specific temperature conditions.  The
             .  program was developed in 1985 and may have been updated.


CIII.     Vogel, G.A.  Air Emission Control at Hazardous Waste Management
          Facilities. Journal of the Air Pollution Control Association, 35(5):
          558-566, 1985.

               This article 1s not related to emissions measurement.  It
               Identifies a method to control toxic air emissions from tanks,
               lagoons, landfills, land treatment facilities, and waste piles.
               Control cost information is also Included.


CIV.      Walker, "K.A. Air Emissions from Hazardous Waste Treatment, Storage
          and Disposal.  Presented at the 77th Annual Meeting of the Air
          Pollution Control Association, San Francisco, CA, 1984.  14 pp.

               Summarizes OSW's work which is presented In detail by Balfour,
               Wetherold, and Lewis (1984) included elsewhere is this biblio-
               graphy.  Volatile air emissions at TSDFs were compared for
               measured versus predictive models.


CV.       Weston, R.F. Performance of Remedial Response Activities at Uncon-
          trolled Hazardous Waste Sites (REMII):  Draft Remedial
          Investigation/ Feasibility Study Report for the Bruin Lagoon Site,
          Bruin Borough, Pennsylvania.  U.S. EPA Contract No. 68-01-6939, U.S.
          Environmental Protection Agency, 1986.

               This report presents the results of the remedial investigation
               performed at a refinery waste lagoon located 45 miles north of
               Pittsburg in Bruin Borough, Butler County, Pennsylvania.  Air
               pathway analyses were performed for determining the health and
               safety requirements for workers and nearby residences during
               excavation of the lagoon.  Also, sampling and analysis of sub-
               surface soil gas from wells located in the lagoon were
               performed to determine the soil gas composition, regeneration
               rates, extent of trapped soil gas within the lagoon and to
               assist in the assessment of the potential for the release of
               soil gas into the atmosphere during future excavation.

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«
CVI.      Wetherold, R.G., and D.A. Dubose.  A Review of Selected Theoretical
          Models for Estimating and Describing Atmospheric Emissions from
          Waste Disposal Operations.  EPA Contract 68-03-3038, U.S.
          Environmental Protection Agency, Office of Research and Development,
          Industrial Environmental Research Laboratory,  Cincinnati, OH, 1982.
          73 pp.

               This report presents models for determining emissions from
               landfills, land treatment, lagoons, waste piles, and tanks.
               Models Include both predictive models and Indirect measurement
               techniques.  Estimates of model precision and accuracy, and
               potential sources for model variables are Included.  Models
               Included are:  Hartley Model; Thibodeaux-Hwang Model; Farmer
               Model; Smith, Bomberger, Haynes Model, Mackay and Leinonen
               Model; Thibodeaux Concentration Profile;  and Thibodeaux,
               Parker, and Heck Model.


CVII.     Wetherold, R.G., B.M. Eklund, and T.P.  Nelson. A Case Study of
          Direct Control of Emissions from a Surface Impoundment. In:
          Proceedings of the llth Annual Research Symposium on Incineration
          and Treatment of Hazardous Waste, Annual Solid Waste Research
          Symposium, U.S. Environmental Protection Agency, Cincinnati, OH,
          1985. pp. 85-92.

               Testing was performed to determine the effectiveness of an         £
               Inflated flexible dome enclosure in controlling VOC emissions      ^j
               from an aerated wastewater lagoon.  Effectiveness was Investi-
               gated by performing a mass balance of VOCs around the system.
               The article Is not directly applicable to baseline emission
               estimates.


          Wood, J.A., and M.L. Porter.  Hazardous Pollutants in Class II Land-
          fills. South Coast Air Quality Management District, El Monte, CA,
          1986.

               This report describes sampling for air toxics at several Class
               II landfills.  Landfill gas sampling was  performed at 20 sites
               from vents (when present) and headspace over the site.  Ambient
               air sampling was performed at five sites.  Air toxics were
               detected even though the species cannot be legally disposed of
               at Class II landfills.

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             APPENDIX  B

   CHEMICAL AND  PHYSICAL PROPERTIES
AFFECTING BASELINE EMISSION ESTIMATES

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  CHEMICAL AND PHYSICAL PROPERTIES OF THE WASTE MATERIAL  AFFECTING EMISSIONS
       Property
                     Effect
Saturation Concentration
Diffusion Coefficient
Molecular Weight
Partial Pressure of
Constituents
Weight Fraction
Combination of Constituents
Concentration of Waste
Henry's Law Constant
The waste will  tend to reach equilibrium with
the soil vapor.  If sufficient waste 1s
present, the equilibrium concentration within
the air-filled  voids of the soil  matrix will
reach saturation.   Because the rate of
emission to the atmosphere 1s directly
proportional tot he soil vapor concentration,
the emission rate will increase as saturation
concentration Increases.

Compounds with  high overall diffusion
coefficients will  be emitted at higher rates
than those with lower diffusion coefficients
via Increased transport, on a relative basis.
The overall diffusion coefficient may be
comprised of diffusion through the soil-water
Interface, soil-air Interface, soil, water,
air, and soil vapor.

Lower molecular weight compounds typically
have higher volatilization and diffusion
coefficients.  Other compound characteristics
may predominate.  Molecular weight is used to
determine diffusion rates in some predictive
models.

High partial pressure Increases the emission
rate of a species by increasing Its soil
vapor concentration.

An effect similar to partial pressure, it is
used as an input to some predictive models.
Not as Important as Henry's Law constant.

This increases  the complexity of the
emissions process and determines the emission
rate.  It may change over time as more
volatile species are lost.

Increasing waste concentration Increases the
emission rate for dilute wastes by Increasing
the vapor pressure and, therefore, vapor
concentration.

This is used to determine diffusion
coefficients.  A high Henry's Law constant
produces a higher diffusion rate.
                                                                  (Continued)

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       Property
Porosity
Adsorption/Absorption
Properties of Soil
Soil Moisture
Wick Effect
Particle Size Distribution
Organic Content of Soil
Microbial Activity
                     Effect
One of the controlling factors for diffusion
through the soil.  Emission rates typically
Increase with Increasing soil porosity.
Total porosity, I.e., dry soil, may represent
worst-case conditions for predictive models.
Air-filled porosity nay be more a realistic
parameter for many sites.

Soil with high sorptlon properties will
reduce the vapor density of the sorped
compounds and, therefore, the emission rate.
The effect may be minimal where high waste
concentrations saturate the sorption sites.
The effect may be reversed causing increased
emissions.

Its effect varies.  High moisture will reduce
the air-filled porosity, with pores being
filled under worst-case conditions and,
therefore, should reduce the emission rate.
Moisture may be preferentially adsorped by
the soil, releasing volatiles and Increasing
the emission rate.  Drying of soil may
Increase available sorptlon sites.  Moisture
is required for the wick effect.

Soil moisture may draw waste constituents to
the surface through the soil pores.  This
process can increase the concentration of the
constituents at the surface and, therefore,
Increase the emission rate.

This affects the total soil porosity and soil
pore continuity.  Increased soil pore
continuity Increases the emission rate.  A
higher percent of fines will typically
Increase particulate emissions.

High organic content will Increase the
sorptive characteristics of the soil and
reduce the emission rate.  High organic
content also will increase microbial action.

Its effect varies.  It may reduce the
emission rate by biological reduction of the
waste present.  It also may increase the
emission rate due to gas formation which
carries volatile species to surface.
                                                                  (Continued)

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       Property
                     Effect
Depth of Landfill Cover
Compaction of Landfill'Cover
Ground Cover
Size of Landfill/Lagoon
Amount of Exposed Waste
Water Depth 1n Lagoon
Aeration of Lagoons
Temperature
Wind
Emission rates decrease with Increasing depth
(thickness) of cover as the diffusion path
Increases.  For an open dump or landfill, the
cover thickness 1s zero.

Increasing compaction reduces the soil
porosity and disrupts continuity of the soil
pores, thereby, reducing the emission rate.

Soil cover, typically vegetation, will reduce
particulate emissions by reducing the
erodablHty of the soil.  It also will help
hold soil moisture, which reduces the air-
filled porosity and reduces volatile
emissions.

The emission rate is directly proportional to
the size of the landfill or lagoon.

Emission will Increase when waste is exposed
at the surface, both due to volatilization
and wind erosion.

Water overlying waste will act as a cover.
Diffusion through water may control the
emission rate.

Aeration increases emission of volatile and
particulates with increasing volume of air
used and/or agitation.  The effect 1s due to
air stripping of volatiles and bulk transport
of liquid particles.

Increasing temperature Increases the
volatilization rate for organic species and,
therefore, the emission rate.  Increasing
temperature reduces soil moisture, increasing
air-filled porosity and the emission rate.

Wind removes the volatilized compound
concentration in the boundary layer over the
site, maintaining the driving force for
volatilization.  Increasing wind speed
reduces the boundary layer over the site.
Wind causes turbulence within the boundary
layer, providing the driving force for
surface soil/waste erosion and increasing
particulate emission rate.
                                                                  (Continued)

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       Property                                       Effect


Cloud Cover                      Increased cloud cover reduces solar heating
                                 of the surface and, therefore, the
                                 volatilization rate from surface.  It also
                                 affects wind stability.

Precipitation                    Emissions are reduced by reducing the air-
                                 filled soil  porosity.  It may Increase
                                 landfill emission by displacing soil  vapor
                                 from soil voids.  It may Increase surface
                                 water and air emissions  by floating waste
                                 constituents to the surface.  Precipitation
                                 Increases agitation of the lagoon surface,
                                 potentially  increasing emissions, but it also
                                 increases water depth over waste in the
                                 lagoon.

Humidity                         Increasing partial  pressure of water  vapor in
                                 air reduces  the capacity for some types of
                                 volatilized  material. It may reduce  air-
                                 filled soil  porosity.

Barometric Pressure              Changing barometric pressures cause bulk flow
                                 of soil vapor into/out of soil.  The  overall
                                 net effect is to Increase the emission rate.
                                 The effect Increases with frequency and scale
                                 of barometric changes.

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     U.S. Environmental Protection Agency
     MD-10
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     Volume No.

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