&EPA
United States
Environmental Protection
Agency
Office of Research and
Development
Washington DC 20460
EPA/600/R-98/OZO
February 1998
Monitoring and
Assessment of In-Situ
Biocontainment of
Petroleum Contaminated
Ground-Water Plumes
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EPA/600/R-98/020
February! 998
Monitoring and Assessment of
In-Situ Biooontainment of
Petroleum Contaminated
Ground-Water Plumes
by
R. Ryan Dupont
Darwin L. Sorensen, Marian Kemblowski
Mark Bertleson, Dietrick McGinnis, Idris Kami), Yang Ma
Utah Water Research Laboratory, Utah State University
Logan, Utah 84322-8200
Cooperative Agreement No. CR 818835-01
Project Officer
Charlita Rosal
Characterization and Monitoring Branch
Environmental Sciences Division
Las Vegas, Nevada 89193-3478
Prepared for
National Exposure Research Laboratory
Office Of Research And Development
U. S. Environmental Protection Agency
Research Triangle Park, North Carolina 27711
Printed on Recycled Paper
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Notice
The information in this document has been funded wholly or in part by the United States Environmental Protection
Agency under CR 818835-01 to the Utah Water Research Laboratory, Utah State University. It has been subjected to
the Agency's peer and administrative review, and it has been approved for publication as an EPA document. Mention
of trade names or commercial products does not constitute endorsement or recommendation for use.
Abstract
This two-year field research project was conducted to assess the potential for natural attenuation of gasoline
contaminated groundwater plumes at two underground storage tank (UST) sites in northern Utah. An evaluation of
rapid site assessment techniques for plume delineation and subsurface site characterization was carried out using
cone penetrometer and ambient temperature headspace (ATH) analysis techniques. An approach was developed for
the collection and evaluation of initial site contaminant soil concentration and routine ground-water quality monitoring
data for the determination of the efficacy of in situ biocontainment and "stabilization" of fuel-impacted groundwater
plumes to provide guidance regarding implementation of an intrinsic remediation, monitoring-only alternative at UST,
sites. A screening-level Natural Attenuation Decision Support System (NADSS) was developed to provide guidance
to regulatory personnel on data collection, data reduction, data interpretation, and decision-making efforts to evaluate
the nature and potential extent of intrinsic plume bioattenuation taking place under a given set of site conditions. This
screening-level NADSS is described in detail, and IBM PC compatible software is provided in a companion EPA
document: A Screening Level Natural Attenuation Decision Support System for the Assessment of Biocontainment
of Hydrocarbon Contaminated Plumes. Data collected from the two field sites are presented and evaluated in detail in
the report, and the rate and extent of the natural attenuation of ground-water plumes at these two sites are quantified.
This report was submitted in fulfillment of CR 818835-01 by Utah Water Research Laboratory, Utah State University,
under the sponsorship of the U.S. Environmental Protection Agency. This report covers a period from September 24,
1991, to August 15,1995, and work was completed as of January 15,1995.
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Contents
Page
Notice '. ...ii
Abstract ii
Tables vi
Figures viii
Abbreviations and Symbols xiii
Acknowledgments xiv
Chapter 1 Introduction 1-1
General Problem Statement , 1-1
Objectives , 1-3
Chapter 2 Conclusions 2-1
Site Assessment Techniques 2-1
Cone Penetrometer Testing (CPT). Techniques 2-1
Ambient Temperature Headspace Measurements 2J1
Field Versus Laboratory Generated Data 2-1
Site-Specific Intrinsic Remediation Mechanisms 2-2
Hill AFB Site 2-2
Layton Site , 2-3
Overall Methodology 2-4
Improvements in Field Screening/Plume Delineation 2-4
Implementation of the Intrinsic Remediation Protocol 2-4
Utility of the Fate-and-Transport Modeling Approach : 2-4
Chapters Recommendations , 3-1
Site Assessment Techniques 3-1
Cone Penetrometer Testing (CPT) Techniques 3-1
Ambient Temperature Headspace Measurements 3-1
Field Versus Laboratory Generated Data 3-1
Site-Specific Intrinsic Remediation Mechanisms 3-1
Hill AFB Site 3-1
Layton Site 3-2
• Chapter 4 Materials and Methods 4-1
Research Approach 4-1
Site Selection 4-2
Field Methods...... 4-3
Conceptual Approach to Process Monitoring 4-3
Site Assessment/Characterization Phase 4-5
Contaminant Plume Delineation 4-5
Soil-Gas Sampling 4-5
Soil Sampling 4-5
Water Sampling 4-6
Ambient Temperature Headspace Technique 4-6
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Contents (Cont'd)
• Site Hydrogeology 4-8
Process Monitoring Phase 4-8
Analytical Methods 4-8
Assessment of Intrinsic Remediation 4-11
Determination of Steady-State Plume Conditions 4-11
Contaminant Centerline, Concentrations 4-12
Dissolved Contaminant Plume Mass and Center of Mass Calculations 4-12
Estimation of Contaminant Degradation Rates 4-16
Dissolved Plume Mass Changes Over Time 4-16
Plume Centerline Concentration Data 4-16
Calibration of Analytical Fate and Transport Ground-Water Model 4-19
Estimation of Source Mass/Lifetime 4-19
Predicting Long-Term Behavior of Plume 4-21
Decision Making Regarding Intrinsic Remediation 4-24
Long-Term Monitoring Program for Site..... 4-25
Potential Aquifer Assimilative Capacity 4-27
Dissolved Oxygen 4-27
Nitrate 4-29
Iron/Manganese 4-30
Sulfate 4-31
Methanogenic Systems '. 4-31
Fate-and-Transport Modeling '. 4-32
Model Overview and Description 4-33
Model Input Requirements 4-34
Pore Water Velocity 4-34
Dispersivity 4-34
Sorption Coefficient/Retardation Factor -..4-34
Model Calibration 4-34
Use of the Model in Intrinsic Remediation Assessment '. ..4-36
Chapters Results and Discussion - Site Assessment and Monitoring Techniques -• 5-1
Cone Penetrometer Techniques 5-1
Original Hill AFB Conceptual Site Model 5-1
Revised Hill AFB Conceptual Site Model 5-2
Ambient Temperature Headspace Measurements 5-7
Theory of Measurement Technique 5-7
Previous Studies 5-13
Field Versus Laboratory Generated Data 5-15
Chapters Results and Discussion - Site 1 - Building 1141 Site, HAFB, Utah 6-1
Site Description and Site History... 6-1
Geologic Setting 6-1
Previous Site Activities , 6-1
UWRL Site Activities 6-3
Determination of Steady-State Plume Conditions 6-3
Contaminant Centerline Concentrations 6-3
Dissolved Contaminant Plume Mass and Center of Mass Calculations 6-4
Estimation of Contaminant Degradation Rate 6-7
Dissolved Plume Mass Changes Over Time 6-7
Plume Centerline Concentration Data 6-16
Estimation of Source Mass/Lifetime 6-16
Predicting Long-Term Behavior of Plume 6-16
Decision Making Regarding Intrinsic Remediation 6-16
Impacted Receptors 6-16
Potential Aquifer Assimilative Capacity 6-16
IV
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Contents (Cont'd)
Long-Term Site Monitoring Program : 6-17
Summary of Intrinsic Remediation Evaluation at the Hill Site 6-18
Chapter? Results and Discussion - Site 2 Elaine Jensen RV Site, Layton, Utah .' 7-1
Site Description and Site History 7-1
Geologic Setting 7-1
Previous Site Activities..... 7-1
UWRL Site Activities 7-3
Determination of Steady-State Plume Conditions 7-6
Contaminant Centerline 'Concentrations 7-6
Dissolved Contaminant Plume Mass and Center of Mass Calculations 7-7
, Estimation of Contaminant Degradation Rate 7-13
Plume Centerline Concentration Data 7-13
Ground-Water Model Calibration 7-18
Hydraulic and Chemical Model Input Parameters 7-18
Source Area Dimensions 7-19
Simulation Times ....7-19
Model Calibration Results ..7-20
Estimation of Source Mass/Lifetime 7-20
Mass Based on Soil Core Data 7-20
Mass Based on Residual Product Estimate 7-21
Contaminant Mass Lifetime 7-25
Predicting Long-Term Behavior of Plume 7-28
Decision Making Regarding Intrinsic Remediation 7-28
Impacted Receptors 7-31
Potential Aquifer Assimilative Capacity 7-31
Long-Term Monitoring Program for Site 7-32
Summary of Intrinsic Remediation Evaluation at the Layton Site 7-32
Chapters References 8-1
Chapter 9 Bibliography 9-1
Appendix A Cone Penetrometer QA/QC Procedures Implemented by Terra Technologies--
Southwest, Inc., at the Hill And Layton Field Sites.. A-1
Appendix B Detailed Analytical Methods for Ambient Headspace Measurements B-1
B-1 UWRL Procedure ....„ B-1
B-2 Lab-ln-A-Bag (LIB) Procedure (In-Situ, Inc., 1991) B-2
Appendix C Thiessen Polygon Method for Assignment of Areas to Ground-Water Monitoring
Points for Plume Mass Estimates ; C-1
Appendix D Ground-Water Slug Test Data and Conductivity/Ground-Water Velocity Calculations from the
Layton and Hill AFB, Utah Field Sites, April 8 to 10,1992 D-1
Appendix E Raw Data for Field ATH Versus Laboratory TPH Data Comparison ; E-1
Appendix F Summarized BTEX, Naphthalene, and TPH Ground-Water Concentration Data Used for Plume
Centerline and Mass Calculations for the Hill AFB Site ' F-1 .
Appendix G BTEX, Naphthalene, and TPH Ground-Water Dissolved Plume Mass and Mass Center
Calculations for the Hill AFB Site.... , G-1
Appendix H Dissolved Oxygen Concentrations Measured in Ground-Water Monitoring Wells and
Sampling Points During the Study at the Hill AFB Site .' H-1
Appendix I • Summarized BTEX, Naphthalene, and TPH Ground-Water Concentration Data Used for
Plume Centerline and Mass Calculations for the Layton Site 1-1
Appendix J BTEX, Naphthalene, and TPH Ground-Water Dissolved Plume Mass and Mass Center
Calculations for the Layton Site J-1
Appendix K Dissolved Oxygen Concentrations Measured in Ground-Water Monitoring Wells and
Sampling Points During the Study at the Layton Site .' K-1
Appendix L Laboratory Nitrate, Sulfate, Iron, and Manganese Data for Ground-Water Samples
Collected from the Hill and Layton Field Sites L-1
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Tables
Table
Page
4-1.
4-2.
4-3.
4-4.
4-5.
4-6.
4-7.
5-1.
5-2.
6-1.
6-2.
6-3.
6-4.
7-1.
7-2.
Analyses Conducted on Reconnaissance Samples Collected During the Site Assessment/
Characterization Phase 4"6
Analyses Conducted on Samples Collected During the Installation of Soil-Gas and
Ground-Water Monitoring Points 4-8
' Analyses Conducted on Ground-Water and Soil-Gas Samples Collected During the Process
Monitoring Phase of the Project 4'9
Analytical Methods Used for Ground-Water, Soil-Gas, and Soil Core Samples Collected
During the Study
.4-10
Changes In Contaminant Mass and Mass Center Coordinates Possible for a Contaminant Plume,
and the Corresponding Interpretation of These Changes Relative to Plume Mobility and Persistence 4-15
Potential Hydrocarbon Assimilative Capacity Relationships for Electron Acceptors of Importance
at UST Sites ;.: 4'33
Input Data and Estimated Sorption Coefficients/Retardation Factors Used for Model Input at the
Field Sites Investigated In this Study •
,.4-35
Field Versus Laboratory Total Hydrocarbon Results from the Hill AFB, UT, Field Site Collected
July and December 1992
.5-16
Field Versus Laboratory Total Hydrocarbon Results from the Layton, UT, Field Site Collected
July and December 1992
,.5-17
Summary Total Mass and Center of Mass Coordinate Data for BTEX, Naphthalene and TPH
Estimated from Data Collected at the Hill AFB Site from March 1992 to January 1994 6-8
Contaminant Center of Mass Velocities and Degradation Rates Based on Ground-Water Data
Collected at the Hill AFB Site from March 1992 to January 1994 6-12
Potential Ground-Water Aquifer Assimilative Capacity at the Hill AFB Site Based on Ground-Water
Data Collected from March 1992 to January 1994 6-17
Proposed Long-Term Sampling Schemes for Annual Compliance and Process Monitoring at the
Hill AFB Site , 6'17
,.7-5
Summary of Well Completions and Measured Water Levels at the Layton, UT, Field Site
Summary Total Mass and Center of Mass Coordinate Data for BTEX, Naphthalene, and TPH
Estimated from Data Collected at the Layton Site from July 1992 to February 1995 7-9
VI
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Tables (Cont'd)
7-3. Contaminant Center of Mass Velocities Based on Ground-Water Data Collected at the Layton Site
From July 1992 to February 1995 '. 7-14
7-4. Summary of Contaminant Degradation Rates Estimated From Time-Averaged Centerline
Concentrations Measured at the Layton Site From July 1992 To February 1995 Corrected for
Contaminant Retarded Velocity 7-17
7-5. Summary of Ground-Water Head Gradient, Ground-Water Flow Direction, and Pore Water
Velocity Results for the Layton Site Collected During this Study 7-18
7-6. Input Data and Estimated Sorption Coefficients/Retardation Factors Used for Model Input at the
Layton Field Site 7-19
7-7. Summary of Model Calibration Results for BTEX Centerline Concentrations Measured at the
Layton Site in March 1993, and Time-Averaged Naphthalene Centerline Concentration Data 7-21
7-8. Summary of Average Contaminant Concentration, Estimated Total Residual Soil Mass, and
Dissolved Plume Mass in February 1995 Measured at the Layton Site ...7-22
7-9. Summary of Estimated Total Residual Contaminant Mass Based on Residual Product Volume
Estimates, and Dissolved Plume Mass in February 1995, Measured at the Layton Site 7-27
7-10. Summary of Estimated Residual Contaminant Mass Lifetime Based on Model Calibrated
Degradation Rates Determined for the Layton Site 7-27
7-11. Summary of Estimated Time to Reach MCL Levels within the Contaminant Plume at the Layton Site
for BTEX, Naphthalene and TPH Compounds Based on Field Calibrated Fate-and-Transport
Model Results : 7-28
7-12. Potential Aquifer Assimilative Capacity at the Layton Site Based on Ground-Water Data Collected
from March 1992 to January 1994, 7-32
7-13. Proposed Long-Term Sampling Schemes for Compliance and Intrinsic Process Monitoring at the
Layton Site.. 7-33
VII
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Figures
Figure
Page
4-1. Conceptual model of the distribution of contaminants released from a leaking UST into the
subsurface environment 4-3
4-2. The Intrinsic Remediation Assessment Approach developed and applied in this field study to
identify and quantify intrinsic remediation processes taking place at a given field site 4-11
4-3. Plume contaminant centerline concentration profiles during the growth (Time 1 to 2), steady-state
(Time 2 to 3), and receding periods (Time 3 to 4) of a contaminant release 4-12
4-4. Decision logic in response to outcome from analysis of steady-state plume conditions 4-13
4-5. An example of Thiessen area boundaries identified for the Hill AFB site in: a) June 1993, and b)
January 1994. Note the consistent outer plume boundary and the variable internal area
distribution between sampling times 4-14
4-6. Decision logic in evaluating contaminant degradation rates 4-17
4-7. Time course of ethylbenzene dissolved plume mass data collected from the Hill AFB, UT, site from
March 1992 to January 1994 4-18
4-8. Time course of natural log transformed total petroleum hydrocarbon dissolved plume mass data
collected from the Hill AFB, UT, site from March 1992 to January 1994 4-18
4-9. p-xylene concentration data collected from the Layton, UT, site in January 1994. a) p-xylene
concentration versus distance downgradient from the source area; b) Natural log transformed
p-xylene concentration versus time of travel downgradient from the source area 4-20
4-10. Calibration of fate-and-transport model using field-determined p-xylene concentration data collected
from the Layton, UT, site in January 1994 4-21
4-11. Decision logic in evaluating contaminant source mass and source lifetime 4-22
4-12. Configuration of soil cores and associated geometry used for calculation of average borehole
contaminant concentrations as input to total mass estimates 4-23
4-13. Decision logic in evaluating long-term behavior of contaminant plume 4-24
4-14. Predicted impact on plume centerline p-xylene concentrations 5 and 20 years after 100 percent
source removal based on a field data calibrated fate-and-transport model for the Layton, UT, site 4-25
4-15. Decision logic in evaluating applicability of intrinsic remediation plume management approach for
a given site 4-26
4-16. Requisite components of a long-term monitoring strategy applied at an intrinsic remediation site 4-28
viii
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Figures (Cont'd)
4-17.
5-1.
5-2.
5-3.
5-4.
5-5.
5-6.
5-7.
5-8.
5-9.
5-10.
5-11.
5-12.
5-13.
5-14.
5-15.
6-1.
6-2.
6-3.
6-4.
Ground-water monitoring network applied at an intrinsic remediation site for both compliance
and-intrinsic remediation process monitoring 4-28
Schematic of a typical CRT operation collecting soil resistance data for textural analysis below
the ground-water table •
..5-2
Graphical presentation of CRT data collected during initial site investigation activities from the
Hill AFB site 5'3
Tabular CRT data collected from the Hill AFB site showing soil textural interpretation from the CRT
log presented in Figure 5-2 5-4
Conceptual site model for ground-water contaminant plume at the Hill AFB site based on conventional
site data collected during the period from 1989 to 1991 (Engineering Science, 1991) 5-5
Ground-water elevation data collected from the Hill AFB site on April 23, 1991, showing westerly
ground-water flow across the site (Engineering Science, 1991)
.5-6
Ground-water piezometer and monitoring well locations placed throughout the Hill AFB site in
July 1992 -. • 5-8
Initial ground-water plume hydrocarbon data developed from field screening headspace analyses
conducted at the Hill AFB site, July 1992 5-9
Ground-water elevation map generated from CRT installed monitoring probes at the Hill AFB
site in July 1992 5-10
Textural map for soils at the ground-water table generated from CRT data collected at the
Hill AFB site in July 1992 '• 5-11
Relationship between laboratory- and field-determined ground-water TPH concentrations for
Hill AFB for data collected July and December 1992 5-18
Normalized residuals for Hill AFB data shown in Figure 5-10 5-18
Relationship between laboratory- and field-determined ground-water TPH concentrations for
Layton for data collected July and December 1992
.5-19
Normalized residuals for Layton data shown in Figure 5-12 ' 5-19
Relationship between laboratory- and field-determined ground-water TPH concentrations for
the combined Hill AFB and Layton data collected July and December 1992 5-20
Normalized residuals for the combined Hill and Layton data shown in Figure 5-14 5-20
Site map for Hill AFB, UT, Site 1141 (Engineering Science, 1991) 6-2
Combined BTEX plume centerline concentration data collected from Hill AFB, UT, Site 1141 from
July 1992 to January 1994 ,
.6-5
Expanded concentration scale for combined BTEX plume centerline concentration data presented
in Figure 6-2 6'5
TPH plume centerline concentration data collected from Hill AFB, UT, Site 1141 from July 1992 to
January 1994
.6-6
IX
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Figures (Cont'd)
6-5.
6-6.
6-7.
6-8.
6-9.
6-10.
6-11.
6-12.
6-13.
6-14.
6-15.
6-16.
6-17.
6-18.
6-19.
6-20.
7-1.
7-2.
7-3.
7-4.
7-5.
Expanded concentration scale forTPH plume centerline concentration data presented in Figure 6-4 6-6
Outer plume boundary used for Hill AFB site plume total mass and mass center calculations.
Thfessen areas for the July 1993 sampling event are shown 6-7
Time course of total dissolved plume mass estimates for BTEX and naphthalene contaminants
at the Hill AFB site over the course of the study 6-8
Time course of total dissolved plume mass estimates for TPH at the Hill AFB site over the course
of the study : 6-9
Center of mass positions for benzene at the Hill AFB site during the study 6-9
Center of mass positions for toluene at the Hill AFB site during the study 6-10
Center of mass positions for ethylbenzene at the Hill AFB site during the study 6-10
Center of mass positions for p-xylene at the Hill AFB site during the study 6-11
Center of mass positions for naphthalene at the Hill AFB site during the study ,..6-11
Center of mass positions for TPH at the Hill AFB site during the study 6-12
Zero order regression for changes in dissolved benzene mass in the ground-water plume at the
Hill AFB site overtime 6-13
Zero order regression for changes in dissolved toluene mass in the ground-water plume at the
Hill AFB site overtime 6-13
Zero order regression for changes in dissolved ethylbenzene mass in the ground-water plume
at the Hill AFB site overtime 6-14
Zero order regression for changes in dissolved p-xylene mass in the ground-water plume at the
Hill AFB site overtime 6-14
First order regression for changes in dissolved naphthalene mass in the ground-water plume at the
Hill AFB site overtime 6-15
Ffrst order regression for changes in dissolved TPH mass in the ground-water plume at the
Hill AFB site overtime 6-15
Map for Elaine Jensen RV, Layton, UT, site (Wasatch Geotechnical, 1991).
.7-2
Conceptual site map for Elaine Jensen RV, Layton, UT. Soil and ground-water contamination based
on field and laboratory soil, soil-gas, and ground-water data available 1990 to 1991 (Wasatch
Geotechnical, 1991) 7-4
Soil textural profile observed at the ground-water table from CPT data collected at the Layton, UT, site
in July 1992 7-5
Fine-grained soil profile observed at the Layton, UT, site at the 12 to 16 ft depth from CPT data
collected in July 1992 7-6
Combined BTEX plume centerline concentration data collected at the Layton, UT, site from
July 1992 to February 1995 7-7
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Figures (Cont'd)
7-6.
7-7.
7-8.
7-9.
7-10.
7-11.
7-12.
7-13.
7-14.
7-15.
7-16.
7-17.
7-18.
7-19.
7-20.
7-21.
7-22.
7-23.
7-24.
7-25.
7-26.
7-27.
TPH plume centerline concentration data collected at the Layton, UT, site from July 19.92 to
February 1995 7-8
Outer plume boundary used for Layton site plume total mass and mass center calculations. Thiessen
areas for the July 1993 sampling event are shown 7-8
Time course of total dissolved plume mass estimates for BTEX and naphthalene contaminants at
the Layton site during the study... '.
.7-9
Time course of total dissolved plume mass estimates for TPH at the Layton site during the study 7-10
Center of mass positions for benzene at the Layton site during the study 7-10
Center of mass positions for toluene at the Layton site during the study 7-11
Center of mass positions for ethylbenzene at the Layton site during the study 7-11
Center of mass positions for p-xylene at the Layton site during the study 7-12
Center of mass positions for naphthalene at the Layton site during the study 7-12
Center of mass positions for TPH at the Layton site during the study 7-13
Time-averaged dissolved plume centerline concentrations for benzene and toluene measured at
the Layton site during the study • 7-14
Time-averaged dissolved plume centerline concentrations for ethylbenzene and p-xylene measured
at the Layton site during the study 7-15
Time-averaged dissolved plume centerline concentrations for naphthalene measured at the
Layton site during the study 7-15
Time-averaged dissolved plume centerline concentrations for combined BTEX components
measured at the Layton site during the study 7-16
Time-averaged dissolved plume centerline concentrations for TPH measured at the Layton site
during the study • 7-16
Natural log transformed, time-averaged p-xylene plume centerline concentrations versus
contaminant travel time from the source area measured at the Layton site during the study.
.7-17
Dissolved TPH concentrations in transverse transect of plume at the Layton site measured from
July 1992 to February 1995 = 7-20
Results of benzene plume centerline calibration at the Layton site using data collected in March 1993...,..7-23
Results of toluene plume centerline calibration at the Layton site using data collected in March 1993 7-23
Results of ethylbenzene plume centerline calibration at the Layton site using data collected in
March 1993 '. • 7"24
Results of p-xylene plume centerline calibration at the Layton site using data collected in March 1993 7-24
Results of naphthalene plume centerline calibration at the Layton site using project time-averaged
concentration data for transect beginning at MLP-05 7-25
XI
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Figures (Cont'd)
7-28. Estimated extent of residual contamination at the Layton site based on ground-water concentration
data collected in February 1995 7-26
7-29. Predicted impact on plume centerline benzene concentrations 5 and 10 years after 100 percent
source removal based on the field data calibrated fate-and-transport model for the Layton site ;....7-29
7-30. Predicted impact on plume centerline benzene concentrations 10 and 18 years after 100 percent
source removal based on the field data calibrated fate-and-transport model for the Layton site 7-29
7-31 Predicted impact on plume centerline toluene concentrations 2, 3.25, and 5 years after 100 percent
source removal based on the field data calibrated fate-and-transport model for the Layton site 7-30
7-32. Predicted impact on plume centerline ethylbenzene concentrations 5, 7.5, and 10 years after
100 percent source removal based on the field data calibrated fate-and-transport model for the
Layton site 7-30
7-33. Predicted impact on plume centerline p-xylene concentrations 1.5 d, and 0.5 and 5 years after
100 percent source removal based on the field data calibrated fate-and-transport model for the
Layton site 7-31
xii
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Abbreviations and Symbols
ADE
ATH
BTEX
CEC
CPT
DDW
DEQ
EQL
FID
GC
HAFB
HC(s)
1C
ICP
LIB
MSE
OVM
PID
MCL
NADSS
TCD
IDS
UST
UWRL
VOA
SYMBOLS
H
Kd
Advection-dispersion equation
Ambient Temperature Headspace technique
Benzene, toluene, ethylbenzene, xylenes
Cation exchange capacity
Cone penetrometer testing
Distilled deionized water
Department of Environmental Quality
Environmental Quality Laboratory, UWRL
Flame ionization detector
Gas chromatography
Hill Air Force Base, Utah
Hydrocarbon(s)
Ion chromatography
Inductively coupled plasma arc spectrophotometer
Lab-ln-A-Bag ATH method
Mean square error
Organic vapor monitor
Photoionization detector
Maximum contaminant level
Natural Attenuation Decision Support System
Thermal conductivity detector
Total dissolved solids
Underground storage tank
Utah Water Research Laboratory
Volatile organic analysis
Henry's law constant
Soil/water partitioning coefficient
XIII
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Acknowledgments
The project team gratefully acknowledges the support and encouragement of the Hill Air Force Base (Hill AFB)
Environmental Management staff and the owner of the Layton, Utah, site, Mr. Jay Dansie, during the entire duration of
the project. Both owners provided background data and logistic support for their sites, making the field work both
possible and enjoyable, even on late January evenings.
A great deal of support was also provided'by the Utah Water Research Laboratory (UWRL) in the form of student
stipends, contract and budget support, logistic support, and moral support. UWRL Environmental Quality Laboratory
(EQL) technicians Van Lu Zhai and Hong Shang, and numerous graduate and undergraduate students in the Civil and
Environmental Engineering Department and Department of Chemistry and Biochemistry at Utah State University,
provided field and data reduction support leading up to the final products.
Finally, EPA CRD-Las Vegas scientists, Iris Goodman and Charlita Rosal, should be acknowledged for their efforts in
initiating this project and in supporting the UWRL in carrying out this research.
XIV
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Chapter 1
introduction
General Problem Statement
Potential groundwater quality impacts from leaking
underground petroleum storage tanks are a significant
environmental concern due to the sheer number of
such tanks (-1.2 million (NWWA, 1985; U.S. EPA
1984a, 1986a)) and the extent of possible
environmental contamination when they leak. Hinchee
et al. (1987) estimated that 130,000 gallons of
groundwater, 2,300 yd3 soil, and 800 yd3 of soil vapor
could be contaminated from 1,000 gallons of gasoline.
Compounding the problem is the fact that many tanks
have reached or exceeded their design life; many are
not adequately protected against corrosion; and many
do not have adequate overfill and spill containment
systems.
Many of these petroleum storage tanks are currently
being removed and replaced or upgraded to eliminate
the source of possible petroleum contamination to
underlying aquifers. However, there remains a large
number of sites with groundwater contamination above
existing water quality limits (300,000 confirmed releases
as of June 1995, with an additional 100,000 releases
expected by 2000 (e.g., Hal White, U.S. EPA, Office of
Underground Storage Tanks (OUST), personal
communication, 1995)). While contamination from
petroleum storage tank releases can have a significant
impact on public health and the environment, active
remediation of each of these contaminated sites
represents a significant resource burden to the
independent tank owners, the petroleum industry, and
the public. Historically, however, expectations of having
to apply active remediation at all sites has generally not
allowed focusing resources on those sites which
represent the greatest threat to public health and the
environment.
When released into the subsurface environment,
gasoline distributes among the soil, gas, and water
phases that make up this environment. As the gasoline
moves through the unsaturated zone, it leaves behind
vapors containing volatile gasoline components and
residual liquid hydrocarbons retained within the soil
matrix. A large fraction of gasoline components are
water soluble and migrate to underlying groundwater
with infiltrating water. Plumes of groundwater
hydrocarbon contamination spread within the soil
environment by groundwater advection and diffusion.
These contaminants are generally not conservative, but
are degraded and transformed through a variety of biotic
and abiotic processes which actively take place in the
subsurface environment (Dragun, 1988; Lyman et al.,
1991; U.S. EPA, 1991). Many gasoline components are
biodegradable, and a primary mechanism for their
transformation in the subsurface is via biodegradation.
During biodegradation, these components provide a
carbon and energy source for the growth of soil
microorganisms, resulting in a demand for terminal
electron acceptors that are necessary if energy is to be
extracted from these hydrocarbon contaminants. These
biodegradation reactions take place under a variety of
soil pH and oxidation reduction potential (redox)
conditions and involve various terminal electron
acceptors (oxygen, nitrate, manganese, iron, sulfate,
carbon dioxide, carbon). Also, these reactions take
place at various rates, each affecting, to a different
degree, the ultimate migration and effective
containment of contamination in both the unsaturated
and saturated zones.
Due to dispersion and diffusion, concentrations of
contaminants are relatively low near the fringes of the
plume. Slow advective rates and low contaminant
concentrations near the plume boundaries provide an
opportunity for microbial communities to become
enriched with contaminant degraders. This enrichment
results in microbial populations capable of decomposing
the advancing plume. If biodegradation of the
contaminant proceeds at a rate greater than or equal to
the rate of advance of the contaminant front, the plume
will be effectively contained, and it can eventually be
completely remediated if the source of contamination is
removed.
This biocontainment proceeds at a rate limited by the
overall limiting reaction, e.g., oxygen transfer to the
plume, contaminant solubilization, nutrient availability,
etc. It can be hypothesized then, that under certain
1-1
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conditions, intrinsic biodegradation processes can
prevent significant migration of contaminants away from
the source of contamination, i.e., degradation rate ^
transport rate away from source. Once the source of
contamination is removed, e.g., following tank
repair/removal, intrinsic biodegradation mechanisms may
eventually result in complete contaminant removal from
the affected soil/groundwater.
The only costs associated with site clean-up under
these intrinsic biocontainment conditions are related to
costs for source removal and for the necessary, ongoing
monitoring of contaminant distribution and movement
over the lifetime of the dissolved contaminant plume.
This low-cost management option is attractive to both
the regulatory and regulated communities. It becomes
necessary, however, to quantitatively describe such
degradation reactions unambiguously so that reliance
on passive methods can be assured for long-term
contaminant control and protection of public health and
the environment. Without reliable containment
information, contamination may continue to spread,
worsening existing conditions, posing increased public
health risk, and increasing final cleanup costs.
Knowledge of intrinsic degradation process rates for
contaminants at fuel release sites has been limited. This
lack of information has been primarily due to the lack of
standard, well-tested methodologies for the monitoring
and quantification of in situ degradation rates in
subsurface soil and groundwater environments. To
obtain this type of information, chemical/biological
parameters in an aquifer and the overlying vadose zone
Indicative of in-situ biodegradation processes taking
place in these environments must be well understood
and documented. Once this is accomplished, routine
measurements of these parameters, or a subset of
these parameters, would allow identification of
conditions under which in-situ biodegradation could be
relied upon to provide natural attenuation of a
contaminant plume. These measurements would also
provide a methodology for monitoring the progress of
contaminant degradation in response to efforts to
enhance intrinsic plume biocontainment.
Ideally, measurements to identify hydrocarbon
contaminated groundwater conditions that would result
in effective plume biocontainment, and measurements
used to monitor the progress of these biodegradation
reactions, would be made on-site using simple and low-
cost methods. This would allow inexpensive
determinations to be made rapidly and routinely at many
locations throughout a site, without the need for costly
and delayed laboratory support. This would facilitate
sound environmental management of the many
thousands of leaking underground storage tank sites
that exist throughout the country.
Although this simple field-based approach is not entirely
feasible, rapid field measurements, supported by
inexpensive laboratory determinations of critical ground-
water quality variables, provide sufficient information to
assess the potential for in-situ biocontainment of a
groundwater plume. This also allows the monitoring of
the progress of these attenuation reactions over time.
This project involved the evaluation of simple on-site
instruments (headspace hydrocarbon analyzer, pH
meter, dissolved oxygen (DO) meter, commercially
available chemical kits for analysis of alkalinity, Fe2+,
Mn2+, SO42', and NOg in groundwater, and a hand-held
O2/CO2/total hydrocarbon meter for gas analysis. These
on-site measurements were supported by laboratory
analyses (Fe2+, Mn2+, SO42, and NOi in groundwater)
to evaluate the effectiveness of field screening
measurements. These measurements were made to
quantitatively describe significant bioprocesses
controlling the fate and movement of dissolved
hydrocarbon plumes at a site. The total suite of water
quality data could not be reliably determined from field
analyses. However, a combination of field-determined
parameter values (headspace hydrocarbon analysis, pH,
alkalinity and DO in groundwater and an O2/CO2/total
hydrocarbon analysis for the soil gas) and laboratory-
determined properties (Fe2+, Mn2+, SO42", and NO^ in
groundwater) were found to be a low-cost approach to
quantitatively describe intrinsic remediation reactions
occurring at the two study sites. With these low-cost,
routine measurements, it is hoped that more frequent
data can be obtained, to allow improved, more cost-
effective, protective management of UST sites.
Environmental hazards from leaking underground
storage tanks are significant. Active, intensive
remediation of all of the estimated 300,000 to 400,000
potential sites is neither technically practical, nor
economically feasible. The dilemma facing the
regulatory community is the requirement to protect
public health and environmental quality with limited
manpower and a shrinking resource base. The goal of
this project was to identify and validate field monitoring,
data reduction, and reporting techniques that can be
utilized to rapidly and conclusively demonstrate the
existence of intrinsic biodegradation reactions at leaking
UST sites. With this demonstration of natural
containment of a hydrocarbon plume, rational decisions
can be made regarding the need for active remediation
to ensure protection of public health and the
environment. Based on an evaluation of field and
laboratory water-quality and soil-core measurements,
and companion modeling results, recommendations
regarding the selection of process variables, monitoring
procedures, and data reduction and reporting methods
needed at hydrocarbon contaminated sites to document
intrinsic bioremediation of groundwater plumes have
been made.
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These recommendations form the foundations of a
screening-level Natural Attenuation Decision Support
System (NADSS) described in a companion document,
A Screening Level Natural Attenuation Decision
Support System for the Assessment of Biocontainment
of Hydrocarbon Contaminated Plumes. In this decision
support system, site-specific soil, site, and contaminant
characteristics are utilized to aid site remediation
personnel in: 1) the design of data-gathering programs,
2) the analysis, verification, and interpretation of field
data, 3) the use of a screening-level contaminant fate
and transport model, 4) the assessment of the impact of
source removal on accelerating overall plume
stabilization and site remediation, 5) the determination of
the reliability of intrinsic biocontainment for site
management to assure the protection of public health
and the environment, and 6) the need for further
evaluation of natural attenuation mechanisms occurring
at a particular site through long-term monitoring and
advanced-level natural attenuation modeling.
Objectives
This work was conducted because of the need for
prudent investment of environmental cleanup funds,
because of the containment/treatment potential of
intrinsic biodegradation processes occurring at fuel
contamination sites, and because of the perceived need
for a standard methodology for developing and
interpreting site characterization data to quantify these
intrinsic biodegradation reactions. Specific objectives of
this research project were to:
1.
2.
4.
Assess intrinsic biodegradation reactions
occurring at two well-defined fuel spill sites.
Assess and select practical field sampling and
analytical methods which best quantify the
observed biodegradation reactions. This
assessment was based on a comparison of field
methods with rigorous laboratory analyses. It
was also used to identify which parameters are
best quantified with standard laboratory
techniques.
Develop a data reduction and analysis
methodology that could be used to quantify
intrinsic remediation processes occurring at a
UST site based on field and laboratory-
determined soil and groundwater quality data.
Develop a screening-level decision support
system which would guide site managers
through the site assessment and
biocontainment prediction process to determine
whether an intrinsic remediation approach is
protective, or whether a more aggressive
corrective action approach is required at a given
site.
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Chapter 2
Conclusions
The research was conducted in four phases. The first
was a site assessment/characterization phase in which
contaminant distribution and site hydraulic
characteristics were determined using field and
laboratory methods. The second phase involved
process monitoring, in which field and laboratory
analyses were used to monitor ground-water and soil
gas characteristics that reflected in-situ biodegradation
reactions taking place throughout the field sites. The
third phase was the reduction of field data to yield
quantitative estimates of plume mass, plume migration,
and source lifetime. The final phase involved the use of
a three-dimensional analytical model to provide in-situ
biodegradation process verification and long-term
predictions of the fate of the plumes as they were
attenuated by natural biodegradation reactions. Based
on the results of the study, the following conclusions
can be made for each phase of investigation.
Site Assessment Techniques
Cone Penetrometer Testing (CPT)
Techniques
1. Results from the Hill Air Force Base (AFB) site
indicate that conventional site assessment
techniques based on small numbers of large
diameter ground-water monitoring wells and
limited soil core and shallow soil gas survey data
can be severely limited in their ability to provide a
detailed understanding of subsurface soil
conditions at a site.
2. The CPT techniques used in this study allowed
the delineation of subsurface conditions that
greatly impacted local ground-water flow and
contaminant transport below the Hill AFB site.
This resulted in a significant modification to the
conceptual model of contaminant distribution
and migration observed at the site.
3. The CPT approach, coupled with placement of
small diameter ground-water monitoring probes
and field ambient temperature headspace (ATH)
measurements, enabled the collection of cost-
effective data for accurate plume delineation on
nearly a real-time basis.
Ambient Temperature Headspace
Measurements
1. Literature findings suggest that for
reproducible, temperature-insensitive ATH
measurements, headspace-to-liquid volume
ratios should be as high as possible without
compromising contaminant sensitivity. Values
between 10:1 and 20:1 should be sufficient to
yield robust measurements, with acceptably low
method detection limits.
2. The use of a detector that provides a linear
response to organics over a wide range of
contaminant concentrations is critical in
obtaining representative ATH measurements.
The flame ionization detector (FID) has this
characteristic (Perry, 1981), and is generally
preferred over photoionization detector (PID)
systems which are more sensitive to moisture
and have a narrower linear range than the FID
(U.S. EPA, 1990b; Holbrook, 1987).
3. The use of ATH methods must be based on a
general knowledge of the nature of the
contamination being screened for. For a given
contaminant distribution, the ATH method
provides consistent and representative
indications of the level of contamination in a
given sample. However, when contaminant
composition varies significantly between sites or
within a given site, this contaminant level/ATH
relationship begins to lose its validity.
Field Versus Laboratory
Generated Data
1. The data obtained for the Hill AFB and Layton
sites support the findings of Bobbins et al.
(1989) which suggest that, for a given
distribution of contamination, field ATH
measurements provide a consistent and
representative indication of the level of
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contamination in a given sample. Based on a
comparison of data from each of the field sites,
specific laboratory versus field concentrations
relationships were site dependent.
2. Field ATH measurements appeared more
sensitive to the contaminant distribution found
at the Layton site (where a hydrocarbon sheen
on a number of ground-water samples was
observed) compared to that observed at the Hill
AFB site. This was based on the slope of the
laboratory purge and trap versus field ATH
ground-water concentration relationships
observed at each site. The slope of this
relationship was less than one at the Hill AFB
site, while it was nearly two at the Layton site.
3. The field ATH measurement method appears,
as expected from theory, to be more sensitive in
field situations with free product or high levels of
residual saturation than at those sites where
weathered fuel contamination exists.
4. Based on the combined data set's normalized
residuals, it was shown that the combined
regression loses its accuracy at high ground-
water concentrations. This suggests that site-
specific relationships between laboratory and
field hydrocarbon measurements will be more
valid than general relationships developed from
a range of site conditions.
5. Field ATH measurements can be used to
effectively guide initial ground-water quality
investigations and to optimize ground-water
monitoring probe and monitoring well placement
for long-term site monitoring. However, field
screening data should not be used as a
substitute for laboratory-determined ground-
water hydrocarbon data.
Site-Specific Intrinsic Remediation
Mechanisms
The intrinsic remediation evaluation protocol developed
in this study was used to evaluate the potential for plume
containment and to quantify intrinsic attenuation
mechanisms taking place at the two field sites. This
seven-step protocol involved: 1) determining whether a
plume has reached steady-state conditions; 2)
quantifying contaminant degradation rates; 3) estimating
the mass of contaminant remaining in the source area; 4)
estimating the length of time the source area will
continue to act as a. source of ground-water
contamination; 5) predicting the long-term behavior of
the plume; 6) making decisions regarding the
acceptability of an intrinsic remediation management
approach at a given site; and 7) developing a long-term
monitoring strategy for compliance and intrinsic
remediation process monitoring. Based on the
application of this protocol to the two field sites
investigated in this study, the following conclusions can
be reached.
Hill AFB Site
1. A centerline concentration profile analysis of
spegific compound and total petroleum
hydrocarbon (TPH) plumes existing at the Hill
AFB site indicated that a significant decline in all
contaminant concentrations took place within
the dissolved plume over the course of the
study.
2. Dissolved contaminant mass data also showed a
significant decline in plume mass for all specific
compounds and TPH by the end of the two-year
study. Center of mass calculations indicated a
movement of all mass centers 17 to 106 ft
downgradient of the source area. This
suggested that the plume was responding to a
pulse source with contaminant attenuation.
3. Dissolved plume mass changes over time were
used to estimate zero and first order
degradation rates for benzene, toluene,
ethylbenzene, and xylene (BTEX),
naphthalene, and TPH contaminants.
4. The BTEX components followed zero order
degradation with rates ranging from 0.06 g/d for
ethylbenzene and p-xylene to approximately
0.1 g/d for benzene and toluene. Naphthalene
and TPH followed first order kinetics with rates of
approximately 0.03 and 0.009/d, respectively.
5. Based on the dissolved contaminant masses
evident in the plume at the end of the study
period, the lifetime of the BTEX compounds
within the plume was short (less than two
weeks). Approximately 270 days was predicted
for 99.9 percent naphthalene removal. More
than two years was estimated for the same
removal efficiency of TPH components under
existing site conditions.
6. The decision to apply intrinsic remediation at this
site is warranted based on: 1) the contaminant
degradation rates and plume attenuation
observed; 2) the lack of an impacted
downgradient receptor; and 3) the potential
aquifer assimilative capacity that is more than 90
times greater than that required for the
assimilation of the TPH and BTEX remaining in
the dissolved plume.
7. A long-term monitoring scheme for both
compliance and process monitoring purposes
• can be carried out using the existing monitoring
network. Annual monitoring until 1997 should
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provide adequate data to validate complete
plume assimilation to permit site closure.
Layton Site
Centerline concentration profile analysis of
specific compound and TPH plumes existing at
the Layton site indicated that, despite variations
in concentrations, the plume appeared to be at
steady-state conditions during the course of the
study and through February 1995.
Plume steady-state conditions were confirmed
using dissolved contaminant mass and center of
mass calculations. Center of mass data
indicated that only TPH showed any actual
downgradient movement, and its mass center
showed only a net movement of 10 ft over the
two-and-a-half year study period. These results
suggest that the Layton plume was acting as a
continuous source which was stabilized by
ongoing intrinsic attenuation mechanisms.
Changes in contaminant plume centerline
concentrations with distance from the source
area were used to estimate contaminant first
order .degradation rates for BTEX and
naphthalene. Contaminant retardation factors
were used to convert downgradient distances to
contaminant travel times so that these rates
could be expressed in the conventional units of
1/time.
The contaminant fate and transport model
described in this study was also used to
estimate contaminant degradation rates through
model calibration to measured field data. Field
data from March 1993 were used" for the BTEX
components to generate first order degradation
rates. These calibrated rates account for
dispersion, dilution, and site-specific sorption
and transport characteristics that control the
movement and degradation of contaminants at
the Layton site. Degradation rates generated
from the plume centerline concentration
method were statistically equivalent to those
developed from the model calibration effort at
the 95 percent confidence level.
Naphthalene concentrations, observed along
most of, the March 1993 plume centerline
transect, were above 1 mg/L and exceeded the
expected naphthalene aqueous equilibrium
concentration which was based on the known
composition of automotive gasoline.
Consequently, a time-averaged naphthalene
concentration was used for model calibration. A
portion of the naphthalene, transect, with time-
averaged concentrations below the known
equilibrium water concentration, was selected
for model calibration. This yielded a first order
naphthalene degradation rate that was
statistically equivalent to the rate generated from
the centerline concentration method.
6. Comparison of results from the centerline
concentration and model calibration methods for
degradation rate estimates for continuous
sources suggest that the simpler degradation
rate approach can be used to provide
representative contaminant degradation rates
when a plume has reached steady-state
conditions.
7. The soil-core data available from the Layton site
were limited and provided residual phase source
area mass values that were underestimated
based on masses dissolved in the ground-water
plume in February 1995. Residual product
volume estimates were based on gasoline
residual saturation values reported in the
literature for silty clay soils similar to those at the
Layton site.
8. From these residual mass estimates, the lifetime
of the total mass of BTEX and naphthalene at
the Layton site, based on reaching their
maximum contaminant level (MCL) values in the
plume, ranged from approximately 30 years for
toluene to over 100 years for ethylbenzene.
Due to MCL concerns for ethylbenzene, the
projected site management time frame without
source removal was approximately 100 years.
9. With 100 percent source removal, the required
site management time frame, based on the
ethylbenzene MCL, was reduced to
approximately 14 years. Under these site
conditions, however; benzene becomes the
contaminant with the greatest duration of
concern, requiring approximately 22 years to
reach its MCL value of 5 (ig/L.
10. The time to reach ground-water MCL values for
the BTEX components was also estimated using
the field calibrated fate-and-transport model.
Results from these simulations indicated that
site management would be controlled by the
benzene plume since it was projected to require
approximately 18 years to reach an MCL of 5
|u.g/L everywhere within the plume following 100
percent source removal or source depletion.
The time to reach the MCL values for ail other
components was projected to be seven-and-a-
half years or less.
11. The decision to apply only an intrinsic
remediation plume management approach at
the Layton site should be made with caution.
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Despite apparent plume stabilization and the
lack of an impacted downgradient receptor, low
contaminant degradation rates (approximately
one order of magnitude lower than at the Hill
AFB site), large residual masses of contaminant
within the source area and a marginal potential
aquifer assimilative capacity will require long-
term monitoring and site management estimated
to last more than 100 years.
12. Active source removal and residual mass
remediation are warranted at the Layton site to
accelerate the rate of contaminant removal from
the site and shorten the length of time required
for plume management.
13. A long-term monitoring scheme for both
compliance and process monitoring purposes
can be carried out using the existing monitoring
network. An annual monitoring frequency
should provide adequate data to validate plume
assimilation and to refine estimates of plume
lifetime and contaminant removal rates.
Overall Methodology
Improvements in Field
Screening/Plume Delineation
1. The combined CPT/ATH procedures used in
this field investigation for initial plume
delineation proved to be rapid and cost
effective. These procedures led to a
significantly improved understanding of
subsurface conditions at both of the field sites.
2. These procedures enabled the use of densely
spaced sampling networks that provided a
detailed picture of contaminant distribution at
these sites. This network spacing produced
detailed quantification of dissolved contaminant
mass and center of mass migration and allowed a
detailed assessment of contaminant
degradation and plume attenuation not possible
with a more conventional monitoring approach.
Implementation of the Intrinsic
Remediation Protocol
1. The intrinsic remediation protocol developed in
this study provides a logical, quantitative
approach for evaluating the presence and rates
of contaminant assimilation within an aquifer
system.
2. The protocol provides improvements over
conventional assessment methods for plume
containment through its use of multiple
approaches to evaluate intrinsic remediation
processes occurring under field conditions.
Plume centerline concentration analysis is used,
along with plume mass and center of mass
analysis, to incorporate the aerial aspects of
plume containment that have not normally been
incorporated into field evaluations of intrinsic
remediation processes.
Utility of the Fate-and-Transport
Modeling Approach
1. The modeling approach used to describe
intrinsic remediation processes occurring at the
two LIST field sites allowed the~ quantitative
assessment of contaminant migration and
degradation using data from the field screening
and plume delineation approaches developed
in this study.
2. The model was easy to implement in a
spreadsheet environment and appeared to
provide a quantitative description of
contaminant plume profiles that were observed
at the two distinctly different field sites evaluated
in this study. The model provided independent
verification of plume steady-state conditions and
allowed the rapid assessment of the impact of
various source removal options on the duration
of contaminant plumes produced from
hydrocarbon releases at these sites.
2-4
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Chapter 3
Recommendations
An evaluation of rapid site screening/plume delineation
techniques and a quantitative assessment of natural
attenuation mechanisms taking place at two field sites
were carried out in this study. Based on these results,
the following recommendations can be made regarding
site assessment/plume delineation and the evaluation of
intrinsic remediation mechanisms for plume containment
at UST sites.
Site Assessment Techniques
Cone Penetrometer Testing (CPT)
Techniques
Rapid plume delineation techniques (i.e., CPT,
Geoprobe) offer the complete elimination of soil cuttings
and large volumes of contaminated ground water that
are often costly and regulatorily challenging to manage.
This makes the screening techniques used in this study
ideal for application at many sites. Due to the
effectiveness of the CPT techniques used in this study
to accurately delineate localized site characteristics, it is
recommended that some form of rapid plume
delineation and field screening be implemented at most
UST sites. The importance of additional insights into
local ground-water flow conditions that can be provided
by these CPT techniques, as in the Hill AFB case, is
invaluable especially when considering an intrinsic re-
mediation management option at a site. Accurate and
representative plume delineation that can cost-
effectively be provided by these rapid plume delineation
techniques are essential if successful intrinsic
remediation monitoring and modeling are to occur.
Ambient Temperature Headspace
Measurements
1. Literature findings suggest that for reproducible,
temperature-insensitive ambient temperature
headspace (ATH) measurements, headspace-to-
liquid volume ratios should be as high as possible
without compromising contaminant sensitivity.
Values between 10:1 and 20:1 should be
sufficient to yield robust measurements, with
acceptable low method detection limits.
2. Use of a detector that provides a linear response
to organics over a wide range of contaminant
concentrations is critical in obtaining repre-
sentative ATH measurements. The flame
ionization detector (FID) has this characteristic
(Perry, 1981), and it is generally preferred over
photo iorjization drector (PID) systems which are
more sensitive to moisture and have a narrower
linear range than an FID (U.S. EPA, 1990b;
Holbrook, 1987).
3. The use of ATH methods must be based on a
general knowledge of the nature of the
contamination being screened for. For a given
contaminant distribution, the ATH method
provides consistent and representative
indications of the level of contamination in a given
sample. However, when contaminant composition
varies significantly between sites or within a given
site, this contaminant level/ATH relationship
begins to lose its validity.
Field Versus Laboratory Generated
Data
1. The primary use of field ATH measurements
appears to be in the initial site assessment phase,
which was done in this study, where rapid, semi-
quantitative results generated from the method
are used for detailed plume delineation efforts.
2. Once this initial screening is completed, it is
recommended that laboratory groundwater
hydrocarbon concentration analyses be con-
ducted to provide accurate ground-water quality
data for further site fate-and-transport and intrinsic
remediation evaluation.
Site-Specific Intrinsic Remediation
Mechanisms
Hill AFB Site
Based on the results of this research project, ample
evidence exists to suggest that intrinsic remediation
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processes have successfully attenuated petroleum con-
taminants released at the Hill AFB site. The following
recommendations for the site can be made based on
these findings.
1. An intrinsic remediation management approach
should be applied at this site. This approach
suggests that the monitoring of ongoing pro-
cesses should take place to ensure that aquifer
conditions which have resulted in plume
containment persist there over time.
2. Since the plume at the Hill AFB site appears to be
responding as a pulse source, site management
activities should focus on long-term monitoring.
An annual monitoring frequency is recommended,
with sample collection and analysis as presented
in Chapter 6.
3. Site closure actions should be initiated when this.
annual monitoring indicates that contaminant
assimilation (i.e., ground-water concentrations
below contaminant MCLs throughout the site) has
been accomplished. This process is projected to
be complete by 1997.
Layton Site
Based on the results of this research project, ample
evidence exists to suggest that intrinsic remediation
processes have successfully attenuated petroleum con-
taminants released at the Layton site. The following
recommendations for the site can be made based on
these findings.
1. An intrinsic remediation management approach
can be applied at this site. This approach is limited
by the mass of contaminant that remains at the
site, however. With the large mass of contaminant
remaining at the site, 30 to over 100 years was
projected before source depletion and site
restoration is complete if only accomplished by
intrinsic remediation processes.
Since the plume at the Layton site is reflective of a
continuous source, site management activities
should focus on source removal and long-term
monitoring. Source removal is prudent at this site
to reduce the length of time the aquifer remains
impacted. Monitoring of ongoing intrinsic
processes should take place to ensure that
aquifer conditions which have resulted in plume
containment persist there over time. If source
removal is not implemented, a three-to five-year
monitoring frequency is recommended. If source
removal activities are carried out, the time for site
restoration is expected to be significantly reduced
and a two- to three-year monitoring frequency is
recommended. Sample collection and analysis
should be carried out as described in Chapter 6.
The effectiveness of residual phase, source
removal at the Layton site should be investigated
over the near term using field scale treatability
assessments. Potentially applicable technologies
include bioventing for residual contamination at
and above the capillary fringe, and some form of air
injection ground-water treatment, i.e., air sparging
or preferably in-well aeration, for contaminant
removal in the saturated zone. Application of
these technologies for the removal of residual
mass can greatly reduce the time required for
plume management at the site. Application of
these technologies may also reduce the overall
site management costs if they can be
implemented in a cost-effective manner.
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Chapter 4
Materials and Methods
Research Approach
The research was conducted in four phases. The first
was a site assessment/characterization phase in which
contaminant distribution and site hydraulic
characteristics were determined using rapid field charac-
terization methods.. The second phase involved pro-
cess monitoring, in which field techniques were used to
monitor ground-water and soil-gas characteristics that
reflect in-situ biodegradation reactions taking place
throughout the field sites. The third phase was the re-
duction of field data to yield estimates of total dissolved
plume contaminant mass, center of mass, mass center
trajectory, contaminant degradation rates, and estimated
source lifetime. The final phase involved the use of a
three-dimensional analytical model to provide in-situ
biodegradation process verification and long-term pre-
dictions of the fate of the plume as attenuated by natural
biodegradation reactions. This research effort was car-
ried out by performing the following tasks.
1. Two field sites with known contamination from
gasoline storage tanks were selected. These
sites were former gasoline filling stations and were
• accessible to the research team. Both sites were
"aged" with "constant" source terms where it was
reasonable to hypothesize that natural
biodegradation reactions, and subsequent plume
containment, had developed and were quantifi-
able.
2. At both sites, single and multilevel ground-water
'. monitoring probes were placed within and around
the area of the contaminant plume. These wells
included upgradient "background" wel.ls, and
wells within the area of contamination, allowing the
definition of the boundaries of the plumes with
some certainty. A gradient of chemical and
biological conditions was observed throughout
each plume so that transformation/degradation
rates, mass transfer rates, etc., could be esti-
mated. Plume characterization was carried out
using cone penetrometry and 5/8-in diameter
piezometer ground-water sampling wells to rapidly
and inexpensively collect soil textural information
and ground-water data from sampling locations
throughout each plume. Following initial plume
characterization, multilevel monitoring points were
installed with three monitoring points placed within
a 15-in radius of each other. Soil samples were
collected from three locations within the vadose
zone and three locations within the saturated
zone during the construction of each well to pro-
vide soil core data for the initial site characteriza-
tion phase of the study. During long-term monitor-
ing, site characterization information was collected
using all of the ground-water sampling points.
Multilevel unsaturated zone sampling wells were
located throughout the site to allow monitoring of
biodegradation processes taking place within the
zone 'of contamination. Unsaturated zone
sampling probes were placed using three monitor-
ing positions per well, and were located based on
ground-water hydrocarbon concentrations mea-
sured throughout the site. An attempt was made
to provide a three-dimensional description of the
unsaturated zone lying above the contaminated
aquifer during the long-term monitoring phase of
the project using these sampling locations.
The following data were collected throughout the
site during the initial site characterization phase of
the project.
pH (soil & ground-water)
Oa (ground-water)
Fe2+, Mn2+ (ground-water) •
NOg, SC>42' (ground-water)
Aromatic hydrocarbons, TPH (soil, soil-gas, and
ground-water)
The following data were collected throughout the
site six times during the process monitoring phase
of the project.
pH (ground-water)
O2, CO2 (soil-gas)
C>2 (ground-water)
4-1
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Fe2+, Mn2+ (ground-water)
NOJ, SO42% Cl- (ground-water)
Aromatic hydrocarbons, TPH (soil-gas, and
ground-water)
Field data were reduced to generate estimates of
total dissolved mass of contaminant and the
migration of this contaminant mass using the
following techniques.
Total dissolved plume mass was estimated using
the Thiessen area method (Chow et al., 1988) to
assign a specific plume area to each ground-water
monitoring point. Total dissolved plume mass was
estimated for each sampling event used in the
study.
The center of the dissolved plume mass was
estimated by taking the first moment about a
defined axis at each site. The dissolved plume
center of mass (centroid) was determined for each
sampling event used in the study.
The movement of the plume centroid over time
was described based on the changes in its
absolute position. Contaminant plume velocities
were calculated between each sampling interval.
Contaminant degradation rates were estimated
based on the change in total dissolved plume
mass between each sampling interval.
Aquifer assimilation capacity was estimated based
on the change in terminal electron acceptor
concentration and mass within versus outside the
plume.
Finally, an analytical, three-dimensional ground-
water fate-and-transport model which accounts for
advection, dispersion, contaminant sorption, and
contaminant degradation was applied to both field
sites to validate the observation of intrinsic
biodegradation at these sites. The use of this
model involved the following steps.
Hydraulic properties for the aquifer were selected
based on measured field data and information
regarding the nature of soil below each site.
A source configuration was established for each
site. Model input variables for measured source
concentrations, contaminant properties, and time
since the release were varied to evaluate the
sensitivity of the model to these parameter values
and to determine those combinations of
parameters producing the best model fit of
centerline contaminant concentrations for a tester
data set.
• Once the model was calibrated to centerline
concentrations, the contaminant degradation
rates and source configurations were further
refined to calibrate the model to the measured
total dissolved contaminant mass for the tester
data set.
• With a degradation rate set to zero, the mass of
contaminant degraded over the calibrated lifetime
of the plume was determined by the difference
from the calibrated non-zero degradation rate
model results as an independent estimate of
contaminant assimilation rate in the plume.
• Finally, the effects of source removal on the
lifetime of the plume and the maximum plume
travel distance were assessed using the site-
specific, field-data calibrated model.
Site Selection
The major thrust of the research was to develop a
methodology that could be used to demonstrate bio-
containment of soluble hydrocarbon plumes under a
variety of hydrogeologic conditions. It is important that
the application of this methodology to hydrocarbon-
contaminated sites is simple and that the required
chemical, biological, and hydrogeological data are easy
to collect or estimate. In general, two types of contami-
nation scenarios could have been considered
depending on the behavior of the contamination
source. In one case, the source of contamination has
been exhausted. Here only a soluble plume persists
and, while it is being transported by ground-water, it is
subjected to a variety of degradation reactions (abiotic
degradation, aerobic and anaerobic degrada-
tion/transformation, sorption, etc.). A release of hydro-
carbon-contaminated water from a disposal pit where
little or no residual saturation persists within the vadose
zone is an example of such a case. In the second
scenario, the source of ground-water contamination
persists for a long period of time due to residual-phase
hydrocarbon existing in the subsurface either above or
below the ground-water table.
Conceptually, the first scenario is easier to investigate
than the second. To demonstrate that the soluble
plume is degrading, it is sufficient to monitor the
changes of the total mass of plume over time. If the data
indicate that the mass decreases with time at a significant
rate, and that hydrocarbon concentrations are reduced
below a level of concern, no additional analyses or
modeling are necessary. Although, from the conceptual
view point this is a simpler case, in reality such a
demonstration may prove difficult due to the problems
and costs associated with monitoring a traveling soluble
plume. In particular, it may be difficult to prove, without
proper controls, that the observed decrease in mass is
real and not due to the always present uncertainties
4-2
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related to ground-water monitoring systems. In addition,
this scenario is less important from a practical point of
view. After the source of contamination is removed, the
remaining soluble plume can be dealt with in a number of
ways, including removal by pump and treat techniques.
However, in many situations, it is prohibitively expensive
to remove. hydrocarbon-contaminated soil from the
vadose and saturated zones. Simple mass balance
calculations, as well as limited field data, indicate that if
this residual hydrocarbon is left in place it could serve as
a source of local ground-water contamination for
decades. It is therefore of utmost importance to be able
to estimate the long-term effects of residual saturation
on ground-water resources. For these reasons, this
research effort was focused on the evaluation of the fate
of soluble hydrocarbon plumes originating from
"continuous" sources. Both sites investigated were of
this "continuous" source-type at the initiation of the
study, although the complete dissolution of the mass in
the source area was observed at one site (i.e., a
"continuous" source becoming a "pulse" source for all
contaminants of concern) during the two-year study
period. The specific characteristics of each site are
described in Chapters 5 and 6 which follow.
Field Methods
Conceptual Approach to Process
Monitoring
The field investigation program reported here was
closely related to the data interpretation effort, keeping
in mind "that data were collected which were both
necessary and sufficient to analyze the behavior and
fate of the soluble hydrocarbon plumes under
investigation. In order to define what data were needed,
it was instructive to first analyze the processes involved
in a typical hydrocarbon release to the soil environment.
In a typical gasoline spill, a separate-phase product is
released and migrates in the subsurface toward the
water table as indicated in Figure 4-1. This movement is
driven by gravity and-capillary forces. After the product
reaches the capillary fringe, it spreads horizontally above
it and depresses the ground-water table. 'At this point,
the presence of the product is usually detected in
monitoring wells, and a product recovery effort is put into
place. As a result, some of the mobile product is
removed. However, a significant portion of the product
may remain in the unsaturated zone in the form of
residual saturation (discontinuous blobs of hydrocarbon
trapped in small pores and pore throats). The amount of
this residual phase depends on the soil type and the
presence of other phases; in dry sand the residual
saturation may be as low as three to 10 percent of the
pore space, while the residual saturation of hydrocarbon
trapped below'the water table may reach 50 percent of
the pore volume.
All of the residual phase cannot be practically removed
by pumping or soil flushing. The only practical way to
remove it is through subsurface air stripping, known
commonly as soil vapor extraction (SVE), through in-situ
Fumes
Continuous Phase
Residual Saturation
Dissolved Hydrocarbon
Figure 4-1. Conceptual model of the distribution of contaminants released from a leaking UST
into the subsurface environment.
4-3
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biodegradation via bioventing, or by physical removal of
the soil through excavation. SVE is ineffective in low
permeability soils and for low volatility compounds.
Neither SVE nor bioventing remove hydrocarbon
trapped below the water table, and soil excavation is
expensive and requires further treatment of the
excavated soil before final disposal. In cases where the
hydrocarbon cannot be efficiently removed from the
subsurface, the residual phase acts as a long-term
source of ground-water contamination due to slow
hydrocarbon dissolution into the aqueous phase. The
local rate of dissolution depends on two factors: (1) the
composition of the residual saturation and (2) the
ground-water velocity. The rate at which the source term
is diminished depends on the initial mass of
hydrocarbons present, and thus depends on the total
concentration of hydrocarbons in soil.
As the hydrocarbon plume is transported in ground-
water by advection and hydrodynamic dispersion, it
mixes .with the surrounding ground-water. If the
surrounding ground-water contains oxygen, and if there
are appropriate bacteria present in the subsurface, then
aerobic biodegradation will occur at the fringes of the
plume. The oxygen used in these biodegradation
reactions comes both from the ground-water and from
the vapor phase in the vadose zone via molecular
diffusion. If alternative metabolic processes are
important at the site, i.e., degradation under denitrifying,
sulfate reducing, iron reducing or methanogenic
conditions, then the availability of these terminal
electron acceptors to the indigenous microorganisms, in
addition to oxygen, dictates the overall rate and extent
of hydrocarbon degradation in the contaminated aquifer.
The overall rate of degradation will depend then on the
rate of mixing of hydrocarbons and terminal electron
acceptors in the ground-water.
It should be noted that the advective transport of
hydrocarbons in ground-water is retarded due to the
distribution of constituents between the aqueous and
soil phases. This retardation should enhance the mixing
process since the electron acceptors approaching the
hydrocarbon plume from the upstream direction will have
a velocity essentially that of the ground-water, which is
greater than that of the retarded hydrocarbon plume.
Fuel hydrocarbons from leaking storage tanks represent
potential sources of carbon and energy for soil
microorganisms. Given this potential, it is likely that a
community of microorganisms will develop in most
ground-water systems that will degrade dissolved
hydrocarbons where concentrations are not toxic and
requisite nutrients and electron acceptors are not
limiting overall metabolic reaction rates. It is possible
then, that microbial degradation of hydrocarbon
contaminants in ground-water and the vadose zone may
proceed fast enough to effectively stop the spread
and/or movement of the contaminant plume.
Respiratory metabolism will generally lead to much more
rapid transformation and mineralization of hydrocarbons
than will anaerobic, fermentative processes (Dragun,
1988; Downey et al., 1988). In areas of high
hydrocarbon concentration, one or more reactants
necessary for microbial .utilization and mineralization of
the hydrocarbons may become limiting. For respiratory
metabolism to proceed, the availability of respiratory
electron acceptors (e.g., O2, Mn4+, NOg, Fe3+, SO42-,
COs2") is critical. Nutrients (especially N and P) must also
be available to the microorganisms if their metabolism,
leading to hydrocarbon degradation, is to occur
unhindered.
Ground-water is often anaerobic due to the utilization of
oxygen in the decomposition of organic matter. This is
especially frequent when ground-water is contaminated
with petroleum hydrocarbons (Lovely et al. 1989). In
these situations, respiratory electron acceptors other
than oxygen may be used for hydrocarbon degradation.
Evidence of respiratory mineralization of hydrocarbons
in contaminated ground-water can be gathered by
monitoring changes in ground-water chemistry and-
overlying gases that reflect the utilization of respiratory
electron acceptors. For example, Lovely et al. (1989)
showed that Fe3+ reduction, evidenced by the
accumulation of the Fe2+, could be linked to the
microbial oxidation of petroleum aromatic compounds in
an anaerobic aquifer. Similarly, NOg or SC>42' reduction
and methanogenesis (COs2' reduction) supports
anaerobic microbial respiratory degradation of ground-
water contaminants (Lovely and Phillips, 1987b).
Observations of the changes in petroleum hydrocarbon
concentrations, the disappearance of Og, the
accumulation of CC>2, the accumulation of Fe2+, the
disappearance of SO42', and/or the accumulation of HgS
and CH4 in a hydrocarbon-contaminated aquifer system,
coupled with observations and modeling of ground-
water movement and contaminant plume migration, allow
calculations of mass balances for these materials. The
mass balance calculations then allow the quantitative
assessment of the rate of biodegradation of
hydrocarbon contaminants base.d on the rates of
change of electron acceptors and respiration products
observed at the field site.
In summary, there are two major hydrocarbon-producing
and hydrocarbon-degrading mechanisms which occur
within a contaminated ground-water plume, hydrocarbon
dissolution and respiratory microbial degradation. At
some point in time, these two processes reach steady-
state. This will happen when the rate of contaminant
dissolution is equal to the overall rate of contaminant
biodegradation. Under these conditions, contaminants
within the soluble hydrocarbon plume will reach a
steady-state distribution, i.e., the spatial hydrocarbon
concentration distribution will remain constant in time. It
should be noted that this conceptual model does not
4-4
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take into account the depletion of source mass over
time. However, the source depletion time scale may be
on the order of decades, while plume equilibrium is
expected to occur within months to several years from
the beginning of plume development.
Site Assessment/Characterization Phase
Reconnaissance sampling of ground-water was
conducted in the initial phase of the project to define the
spatial, three-dimensional distribution of the contami-
nated zone. In addition, characterization of site
hydrogeology was developed to define, as completely
as possible, the nature of ground-water flow and mixing
below each site.
Contaminant Plume Delineation
Initial saturated zone characterization was conducted
using cone penetrometry techniques (Blegen et al.,
1988; Smythe et al., 1988). All cone penetrometer work
was conducted by Terra Technologies (Houston, TX)
using field procedures and quality assurance/quality
control (QA/QC) methods specified in Appendix A
through a subcontract arrangement with the Utah Water
Research Laboratory (UWRL). Specific procedures and
data interpretation methods are provided in the paper by
Klopp et al. (1988), among others. In what is termed the
position mode, the point is continuously pushed
through the soil and resistance data are recorded with a
resolution of approximately 10 in. If the soil'texture
allows, once the tip reaches the desired depth and is
removed from the soil, temporary or permanent sampling
points can be placed in the remaining hole without the
expense and effort necessary for the placement of a
conventional sampling well. The placement of
temporary and permanent monitoring points at both field
sites was made possible using this method.
For initial plume delineation, samples drawn from the
5/8-in diameter temporary piezometer wells were
analyzed on-site using ambient temperature headspace
(ATH) analysis techniques. Duplicate ground-water
samples were collected, with headspace analyses being
run on one duplicate using field screening techniques.
The second sample was transported to the UWRL and
analyzed using laboratory purge-and-trap procedures:
This comparison allowed the evaluation of the
representativeness of field screening techniques for
hydrocarbon delineation during site screening activities.
Subsequent to initial site plume delineation, 44
permanent ground-water monitoring points were placed
throughout the plume at the Hill AFB site, while 21
permanent points were placed at the Layton, UT, field
site to provide point measurements of saturated zone
conditions upstream, within, and surrounding the
contaminant plume.
Aromatic hydrocarbon, boiling point splits and total
petroleum hydrocarbon measurements provided the
primary information regarding the spatial distribution and
composition of the soluble contaminant source term.
Associated soluble electron acceptors (O2, NOg,
SO42+), microbial respiration products (Fe2+, Mn2-*-), and
ground-water pH were also used to define reaction zone
boundaries of various types which have developed
within and surrounding the dissolved hydrocarbon
plumes. Table 4-1 summarizes the analyses that were
conducted. The geological/ hydrogeologic stratification
of the aquifer and vadose zone was also described,
based on cone penetrometer resistance and slug test
measurements.
Soil-Gas Sampling
Soil-gas samples from the vadose zone above the
contaminant plume at the study sites were collected with
push probes to aid in the delineation of areas of
biological activity. Soil-gas sampling techniques have
been used by a number of authors for the delineation of
subsurface contamination from both residual saturation
and ground-water plumes (Glaccum et al., 1983;
Kreamer, 1983; Schmidt and Balfour, 1983; Evans and
Schweitzer, 1984; Eklund, 1985; Morgan and Klingler,
1987; Zdeb, 1987) with varied success. Current
recommendations are to utilize soil-gas sampling with
care, especially if site surficial geology is not well
defined, and to obtain soil-gas samples as close to
suspected ground-water contamination as possible.
Soil-gas data were collected and analyzed on site for
total hydrocarbons, O2, and CO2 to provide support data
for site assessment samples. In addition, soil-gas Oa,
CO2, CH4) total hydrocarbon, aromatic hydrocarbon, and
boiling point split samples, collected via stainless steel
canisters, were analyzed using laboratory instruments to
assess the accuracy and representativeness of field
measurements for hydrocarbon, respiration product,
and reactant gas detection. These soil-gas data can
provide insights into the nature and extent of gas
production and utilization in the unsaturated zone. The
data also allow the estimation of O2 and CO2 flux into and
out of the contaminant plume to estimate in-situ
biodegradation rates (Dupont et al., 1991; Hinchee et
al., 1991). Soil-gas data provided rapid feedback
regarding general subsurface hydrocarbon and
bioprocess conditions. Data were also evaluated as to
their efficacy in identifying plume boundaries and in
detecting significant respiration reactions that were
occurring in the contaminant plume at the two field sites
investigated in this study.
Soil Sampling
A soil core sampling site was selected and named to
correspond with the nearest water sampling point (SS-
well name). The cone penetrometer truck was
maneuvered into position and a steel probe was used to
push a hole to the top of each sampling depth. The
probe was then removed from the hole and replaced
4-5
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Table 4-1. Analyses Conducted on Reconnaissance Samples Collected During the Site
Assessment/Characterization Phase
Sample Type Measurement
Ground-water O2
Fe2+, Mn2+
PH
Aromatic HCs*
Total HCs
Boiling point splits
Soil-gas O2
CO2
CH4
Aromatic HCs
Total HCs
Boiling point splits
Method
Membrane Probe
Colorimetry
Glass electrode
Lab GCf
Field/Lab GC
LabGC
O2 Meter
CO2 Meter
GC
LabGC
Field/Lab GC
LabGC
Purpose
Electron Acceptor
Electron Acceptor
CO2, Eh
Substrate
Substrate
Substrate
Electron acceptor
Mineralization product
Electron acceptor
Redox couple
Mineralization product
Redox couple
Substrate
Substrate
Substrate
*HCs = Hydrocarbons
tGC = Gas Chromatography
with a steel collar attached to an 18- to 30-in long section
of 1.5-in O.D. galvanized steel conduit. The conduit was
then pushed into the hole to the appropriate sampling
depth, filling the conduit with soil. The conduit was
pulled out of the hole, cut into 6-in long pieces, sealed
with aluminum foil and duct tape, and placed on ice for
transport to the UWRL Environmental Quality Laboratory
(EQL). Single sampling events varied in sampled depth
from 6 in to 2 ft depending upon soil conditions.
Samples were stored at the EQL in an anaerobic
chamber, filled with 8 percent hydrogen and 92 percent
nitrogen at 10°C to mimic subsurface conditions, prior to
analysis.
Water Sampling
Water samples were collected either with a hand
operated peristaltic pump or, for the conventional two- to
four-in monitoring wells existing at the field sites, using a
submersible centrifugal pump. All sampling equipment
was decontaminated with soap and water wash, a water
rinse, and a final distilled water rinse between sampling
locations. Three casing volumes were removed from the
monitoring wells and gravel points before sampling.
Samples were collected into two 140-mL syringes to
minimize loss of volatile compounds and to minimize
oxygenation of the sample. One syringe was used for
laboratory volatile organic analysis (VOA) samples and
on-site ATH analysis for volatile hydrocarbons. The
second syringe was used for ATH, nutrients, and metals
analyses. For metal and nutrient analysis, the
suspended solids in the sample were allowed to settle
up to one hour, then the sample was filtered through a
0.45-|j.m syringe filter and a 1-g C-18 sorbent filter to
remove dissolved organic materials. Samples for metal
analysis were preserved by field adjusting the pH to <
2.0 with several drops of a solution of 50 percent nitric
acid. The VOA and nutrient samples were transported in
coolers on ice and stored at less than or equal to 4°C
until the appropriate analyses were conducted.
The soil core, soil-gas, and ground-water samples were
analyzed for physical and chemical characteristics
important in fate-and-transport assessment as shown in
Table 4-2.
Ambient Temperature Headspace Technique
Traditionally, water and soil samples from a leaking LIST
site are taken to a laboratory for extraction of
hydrocarbons and chromatographic analysis of individual
hydrocarbon contaminants. Reliable field techniques are
desirable to supplement laboratory analyses because
they are inherently less expensive and faster than
conventional methods. A less expensive analysis will
allow more samples to be analyzed on a fixed budget for
4-6
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Table 4-2. Analyses Conducted on Samples Collected During the Installation of Soil-
Gas and Ground-water Monitoring Points
Sample Type
Measurement
Method
Purpose
Ground-water
Soil-Gas
02
Cl, S042-, HC03-,
co32-
PH
Aromatic HCsf
Total HCs
Boiling point splits
02
CO2
CH4
*IC = Ion chromatography
fHCs = Hydrocarbons
= Gas chromatography
Membrane Probe
Colorimetry
1C*
1C
Glass electrode
Lab GCt
LabGC
LabGC
O2 Meter
CO2 Meter
LabGC
Electron acceptor
Electron acceptor
Ionic strength/
electron acceptor
Electron acceptor
nutrient
C02, Eh
Substrate
Substrate
Substrate
Electron acceptor
Mineralization product
electron acceptor
redox couple
Mineralization product
redox couple
Aromatic HCs
Total HCs
Boiling point splits
Soil core Available Fe
Available Mn
Carbonate
Organic carbon
pH
Kjeldahl-N
Extractable P
Texture
Aromatic HCsf .
Total HCs
Boiling point splits
Lab GC
Field/Lab GC
Lab GC
Extraction/color
Extraction/AA
Inorganic Carbon
Acid chromate
Oxidation
1:1 /glass electrode
Digestion/distillation
Extraction/color
% sand/silt/clay
LabGC
LabGC
LabGC
Substrate
Substrate
Substrate
Electron acceptor
Electron acceptor
Source/sink of CO2
Substrate/absorption
Redox/metals activity
Nutrient
Nutrient
Sorption/hydraulics
Substrate
Substrate
Substrate
a more complete assessment of site conditions. Having
a rapid analysis on site can also reduce expensive down-
time of sampling and drilling equipment during plume
delineation.
In this project, several field ATH techniques for
determining hydrocarbon contamination of water and
soil were evaluated. These techniques used detector
response to headspace total hydrocarbons generated in
a polyethylene bag as the quantitation method for
contaminated soil and ground-water. One of these
techniques was developed for water samples at the
UWRL, while the other technique was developed for
water and soil samples and is commercially available as
Lab-ln-A-Bag (LIB) (In-Situ Inc., 1991). Per these
techniques, the sample was put into a polyethylene bag
and air was added to create a headspace above the
samples. When soil samples were being analyzed, water
was added to the sample before the headspace was
introduced. After contaminants were allowed to
equilibrate between or among phases, the headspace
was routed to a detector. Detailed procedures for both
ATH methods are provided in Appendix B.
A Summit Instruments SIP-1000 portable gas analyzer
with a flame ionization detector was used in this study for
field determinations of hydrocarbon headspace
concentrations. In this instrument, samples are routed
4-7
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to the detector through the line which carries air to the
detector. Since there is no GC column in this line, the
detector responds to the entire sample without
separation of individual compounds in the gas matrix.
One-quart Ziplock® polyethylene freezer bags were
typically used in field headspace measurements in this
study. The sample was introduced through the zipper
closure, and the bag was sealed so that headspace
gases were isolated within the bag and sample train.
One of the problems with these bags is that fatty acids
are incorporated into the bags as a slip agent to keep
them from sticking together (Gerber, personal
communication, 1994). Experience in the field has
shown that, on hot days, these fatty acids can interfere
with headspace analyses. The bags should be
refrigerated if the ambient temperature is more than 80°F
to minimize this interference.
Stock solutions for calibration standards for the field
methods were made by saturating tap water with the
contaminant of interest. The stock solutions were made
into calibration standards by serial dilution with distilled
deionized water (DDW) in syringes. Sixty-mL syringes
were used for the UWRL method, while 140-mL
syringes were used for the Lab-in-A-Bag ATH (LIB)
method.
Readings from samples and standards were taken
directly off the SIP-1000. The net detector response to
headspace gases was determined for each by
subtracting the background response from these
values. Net, background-corrected detector response
values were used for all further data analysis of ATH
samples.
These field ATH techniques are fundamentally different
from laboratory procedures in two important respects:
(1) the contaminants which reach the detector are in
equilibrium with the original sample matrix rather than
being a more complete extraction of that matrix; and, (2)
the hydrocarbon constituents are not separated from
one another before they arrive at the detector. In order
for the field techniques to be truly useful, TPH
determinations from laboratory and field techniques
must be well correlated. The field/laboratory
hydrocarbon concentration relationship determined in
this field study is presented and discussed in Chapter 5.
Site Hydrogeology
Characterization of site hydrogeologic conditions began
with a review of existing geologic and hydrogeologic
information available for the sites. The geologic data
related to the site subsurface structure and depositional
environment were reviewed and analyzed, along with
available regional and site-specific ground-water flow
data. This initial data review was followed by a more
detailed investigation of subsurface hydrogeologic
conditions using cone penetrometer techniques
described above.
In order to quantify advective and dispersive soluble
plume transport at the site, the average pore-water
velocity was determined. This required the estimation of
average hydraulic -gradient, average hydraulic
conductivity, and average porosity throughout the site.
The average hydraulic gradient was estimated using
ground-water table elevation data measured in the
ground-water monitoring wells. The hydraulic
conductivity was determined from multiple slug tests
conducted at various locations throughout each site
(U.S. EPA 1990a). Total and air-filled porosity
measurements were determined using bulk density and
soil moisture content data developed from the soil cores
collected during ground-water and soil-gas monitoring
well placement. This information is crucial to
understanding soluble plume dispersion and transport
at the field scale.
Finally, to evaluate the attenuation of soluble
hydrocarbons in the ground-water plume, organic
carbon normalized soil/water distribution coefficients,
KOC. were estimated for the range of soils represented in
the subsurface. Koc values were estimated using
organic matter content analyses of the soil cores and the
distribution coefficients available from literature sources
for the contaminants of concern.
Process Monitoring Phase
Once the ground-water and soil-gas monitoring wells
were placed throughout the site, they were used to
provide detailed information regarding the three-
dimensional characteristics of the contaminant plume
and the changes in its characteristics over time. The
initial process monitoring phase of the project consisted
of collecting ground-water and soil-gas samples from all
monitoring well points during months 10, 13, 16, 19,
and 23 of the study.
Aromatic hydrocarbon, boiling point splits, and total
petroleum hydrocarbon measurements in ground-water
and soil-gas samples collected during this phase of the
study (Table 4-3) provided the primary information
regarding the spatial distribution and composition of the
soluble contaminant source term and resulting dissolved
plume as they were affected by seasonal ground-water
table elevation, and temperature fluctuations.
Associated electron acceptors, microbial respiration
products, and other water quality parameters affecting
microbial reactions were also used to define reaction
zone stability over time (Table 4-3).
Analytical Methods
Table 4-4 provides a summary of parameters measured
and analytical methods used throughout the field study.
Procedures that are not common or standardized are
briefly described below.
4-8
-------
The bioavailability of Fe3+ and Mn4+ as electron
acceptors was determined during the site assessment/
characterization phase of the study. To determine the
concentration of amorphous Fe3+ that was available in
aquifer material, the method .of Lovely and Phillips
(1987a) was used. Ferrous iron present in aquifer
sediment samples (0.1 g) was extracted with 5 mL of
cold 0.5 M HCI. The extract was treated with ferrozine in
a buffer (50 nM HEPES, pH=7) prior to being filtered
through a 0.2-|j.m polycarbonate filter. The
concentration of Fe2+ in the extract was determined by
measuring the absorbance of the filtrate at 562 nm. This
method does not oxidize Fe2+ nor reduce Fe3+ (Lovely
and Phillips, 1986). The same procedure was repeated
with another aquifer sediment sample using 5 mL of
0.25 M hydroxylamine hydrochloride in 0.25 M HCI as
the extractant. Under acidic conditions, hydroxylamine
reduces Fe3+ to Fe2+. The amount of hydroxylamine-
reducible Fe3+ is calculated as the difference between
the Fe2+ measured in the hydroxylamine and HCI
extracts. This concentration of Fe3+ indicates the-
capacity of the aquifer material to provide Fe3+ as a
terminal electron acceptor. Lovely and Phillips (1987a) '
showed a strong correlation (r2 = 0.94) between the
extent of reduction of various synthetic Fe3+ forms with
hydroxylamine and the capacity of an Fe3+-reducing
acetate enrichment culture to reduce the Fe3+ forms.
This indicated the validity of the method for quantifying
electron acceptor in aquifer materials. Once initial site
characterization was completed, subsequent analyses
for iron consisted of analysis for reduced iron (Fe2+) only
in ground-water samples.
The concentration of amorphous Mn4+ that was
bioavailable as an electron acceptor was determined
using the method of Lovely and Phillips (1988). This
method involved dissolving the Mn4+ in a 0.1 g wet
aquifer sediment sample into a solution (5 mL) of 0.25 N
hydroxylamine hydrochloride in 0.25 N HCI. The
manganese content was then measured by atomic
absorption spectrophotometry with an acetylene flame.
Production of Mn2+ was determined by cold extraction of
a 0.1 g sample with 5 mL of 0.5 N HCI for 10 min. The
sample was then filtered using a 0.2-prn pore filter and
manganese concentration in the filtrate was analyzed as
noted above.
Table 4-3. Analyses Conducted on Ground-Water and Soil-Gas Samples Collected During the
Process Monitoring Phase of the Project
Sample Type
Ground-water
Soil-gas
Measurement
02
Fe2+, Mn2+
so42-
NOo
i n v-r g
pH
Aromatic HCsf
Total HCs
Boiling .point splits
02
CO2
Aromatic HCs
Total HCs
Boiling point splits
Method
Membrane probe
Colorimetry
1C*
1C
Glass electrode
Lab GO*
LabGC
Lab GC
O2 Meter
CO2 Meter
LabGC
Field/Lab GC
LabGC
Purpose
Electron acceptor
Electron acceptor
Electron acceptor
Electron acceptor
nutrient
CO2, Eh
Substrate
Substrate
Substrate
Electron acceptor
Mineralization product
electron acceptor
redox couple
Substrate
Substrate
Substrate
*IG = Ion chromatography
fHCs = Hydrocarbons
= Gas chromatography
4-9
-------
Table 4-4. Analytical Methods Used for Ground-Water, Soil-Gas, and Soil Core Samples
Collected During the Study
Sample Type
Measurement
Method Type
Reference Method
Ground-water
Soil-gas
Soil core
02
CH4
Mn2+
Major cations
Cl, S042-, HC03-
pH
Aromatic HCs#
Total HCs
Boiling point splits
02
CO2
02
CO2
CH4
Aromatic HCs
Total HCs
Boiling point splits
Available Fe
Available Mn
Carbonate
Organic carbon
PH
Kjeldahl-N
Extractable P
Texture
Aromatic HCs
Total HCs
Boiling point splits
Membrane Probe
Lab GCf
Colorimetry
Colorimetry
IC§
Glass electrode
LabGC
LabGC
LabGC
O2 Meter
CO2 Meter
LabGC
LabGC
LabGC
LabGC
LabGC
LabGC
Extraction/color
Extraction/AA
Inorganic Carbon
Acid chromate
oxidation
1:1/glass electrode
Digestion/distillation
Extraction/color
% sand/silt/clay
LabGC
LabGC
LabGC
4500-OG, APHA (1989)*
TOD*
Alltech column (36254L)
Lovely & Phillips (1987)*
Lovely & Phillips (1988)*
300.0, U.S. EPA (1989)
4500-H + B, APHA (1989)*
5030, Modified 8020
Using FID* & Petrocol
column, U.S. EPA(1986e)
Gastechtor
Model 3250X
TCD
Alltech column (36254L)
TCD
5030, Modified 8020
using FID & Petrocol
column, U.S. EPA (1986e)
Lovely'& Phillips (1987)*
Lovely & Phillips (1988)*
Nelson (1982)
Nelson & Sommers (1982)
4500-H+ B, APHA (1989)*
4500-Norg B, APHA (1989)*
Olsen & Sommers (1982)
Gee &Bauder (1986)
5030, Modified 8020
Using FID & Petrocol
Column, U.S. EPA (1986e)
'Method utilizing a Hach field kit
fGC * Gas Chromatography
$TCD = Thermal conductivity detector
§IC s* Ion Chromatography
#HCs =s Hydrocarbons
•FID = Flame ionization detector
4-10
-------
Assessment of Intrinsic Remediation
Intrinsic remediation assessment as used in this study,
and incorporated into the Natural Attenuation Decision
Support System (NADSS) accompanying this report,
involves a seven-step process outlined in Figure 4-2.
These steps include the following: 1) determining
whether steady-state plume conditions have developed
during the monitoring period; 2) estimating contaminant
degradation rates from plume centerline concentrations
or model calibration for tracer compounds versus
reactive compounds detected within the plume; 3)
estimating the source mass term; 4) estimating the
source lifetime based on degradation rates estimated in
Step 2; 5) predicting long-term plume behavior from a
calibrated fate-and-transport model with and without
source removal efforts implemented at the site; 6)
decision making regarding the use of intrinsic
remediation at a given site and the impact and desirability
of source removal there; and 7) developing a long-term
monitoring strategy if intrinsic remediation is selected as
the preferred alternative for plume management at a
given site. Each of these steps is discussed in more
detail below and highlighted in the site-specific results
presented in Chapters 6 and 7.
Determination of Steady-State
Plume Conditions
Verifying that steady-state conditions exist for a
contaminant plume at a given site is critical in
establishing that intrinsic remediation processes are
likely taking place there and are likely to provide
continued plume containment under current site
conditions. Steady-state plume conditions occur when
the rate of contaminant release from the source area is
equivalent to the rate of contaminant assimilation by
biotic and abiotic processes taking place within the
aquifer. These steady-state conditions can be identified
by observing the time course of contaminant
concentration at a specific ground-water monitoring
location. A more desirable approach is to investigate
contaminant concentration and contaminant mass
distribution throughout the entire plume. This latter
approach involves the collection of centerline
contaminant concentration data at various time intervals
to determine if the entire plume has reached steady-
state concentrations or through a determination of the
total integrated mass and center of mass of contaminant
within the delineated plume.
Intrinsic Remediation
Assessment Approach
1. Steady-State Plume
Conditions?
5. Long-Term Behavior
2. Estimate
Contaminant
Degradation Rate
3. Estimate Source
Mass
4. Estimate Source
Lifetime
6. Intrinsic
Remediation for Site?
7. Long-Term
Monitoring for Site
Figure 4-2. The Intrinsic Remediation Assessment Approach developed and applied in this field
study to identify and quantify intrinsic remediation processes taking place at a given field site.
4-11
-------
Contaminant Centerline Concentrations
Plume centerline concentrations which are consistent
from one sampling interval to the next are indicative of
steady-state plume conditions. Comparison of data from
specific sampling intervals should be done carefully,
however. The distribution of contaminant mass
between the vadose zone and ground-water can have a
significant impact on the mass of dissolved contaminant
In the ground-water plume at a given ground-water table
elevation. If ground-water table elevations fluctuate
widely, significantly different volumes of contaminated
soil can be below the ground-water table, producing
significantly different dissolved plumes from one
sampling time to the next. While these variations in
ground-water plume characteristics are important in
understanding the overall risk posed by a given site,
they tend to confuse the issue of steady-state plume
evaluation. It is recommended then that if ground-water
table fluctuations can be expected to produce highly
variable contaminant plume profiles on a seasonal basis,
the steady-state evaluation should be based on
comparison of data with comparable ground-water
elevation values. This is recommended although these
data sets may be six months to one year apart in time.
If comparable data sets are collected based on ground-
water elevation consideration, a plume centerline
response indicated in Figure 4-3 should result. Figure
4-3 shows ground-water plume centerline concentration
data collected at four distinct points in time. As indicated
In this figure, the BTEX plume is shown to be growing
between Times 1 and 2 (based on increased
concentrations over time at fixed sampling locations),
appears stable between Times 2 and 3 (based on
comparable plume centerline concentrations at these
two sampling intervals), and has decreased between
Times 3 and 4.
Figure 4-4 summarizes the logic involved in the
interpretation of contaminant centerline concentration
relationships observed for a given plume. If steady-state
or receding plume conditions are indicated based on
three to four sets of comparable monitoring data, the
plume can be considered to be stable under existing
aquifer conditions. The intrinsic remediation
management option should then be evaluated for the
site. If the plume is observed to be growing, either
monitoring should be continued, or aggressive
containment and source removal activities should be
carried out if a sensitive receptor has already been
impacted by ground-water contamination.
Dissolved Contaminant Plume Mass and
Center of Mass Calculations
A more rigorous evaluation of plume steady-state
conditions involves the estimation of the total dissolved
mass and the location of the centroid of this mass for the
entire plume. In order to develop an estimate of the
dissolved contaminant mass within the entire plume, an
aquifer volume associated with each monitoring point
must first be determined. Once an aquifer volume is
associated with each monitoring point, the product of
contaminant concentration and aquifer volume for each
monitoring point is summed to yield a total dissolved
mass for the plume.
BTEX - Time 2
Concentration
(mass/vol)
BTEX-Time 4-
BTEX - Time 3
Time or
Distance
BTEX - Time I
Figure 4-3. Plume contaminant centerline concentration profiles during the growth (Time 1 to
2), steady-state (Time 2 to 3), and receding periods (Time 3 to 4) of a contaminant release.
4-12
-------
1. Steady-State Plume
Conditions?
Plume Stable or
Shrinking
Plume Growing
Continue w/Protocol
Receptor Impacted?
No
Yes
Continue to Monitor
Active Source
Removal/Remediation
Figure 4-4.
conditions.
Decision logic in response to outcome from analysis of steady-state plume
Aquifer volume is determined from the product of the
aquifer porosity, the average aquifer thickness
(generally the length of the largest sampling interval
used within the monitoring network at a given'sampling
time), and a plume surface area associated with each
sampling point, the method used in this study to obtain
an estimate of sampling point areas is the Thiessen
polygon method. This method was developed in the
field of hydrology for use in estimating areas associated
with point rainfall measurements within rain gage
networks. The Thiessen method assumes that the
concentration measured at a given sampling point is
equal out to a distance halfway to the sampling points
located next to it in all directions. The relative weights
(areas) represented by each sampling point are
determined by the construction of a Thiessen polygon
network, the boundaries of which are formed by the
perpendicular bisectors of lines connecting adjacent
points (Chow et al., 1988). Appendix C provides a
summary with examples of the application of the
Thiessen polygon method for ground-water plume mass
estimates at the two sites under investigation in this
study.
The outer boundary of the Thiessen polygon network is
estimated based on the outermost well locations. It is
important to be consistent with boundary definition if
mass calculations for different sampling events are to be
compared. An example of the boundary area used for
the Hill AFB site is shown in Figure 4-5, which
summarizes the areas used for total mass and mass
center calculations for the June 1993 and January 1994
data sets. Consistent plume boundaries were used for
all data reduction and analyses conducted in this study.
Refer to Appendix C for a summary of plume areas used
in all mass/mass center calculations.
4-13
-------
a) Thiessen areas for June 1993.
b) Thiessen areas for January 1994.
Figure 4-5. An example of Thiessen area boundaries identified for the Hill AFB site in: a) June
1993, and b) January 1994. Note the consistent outer plume boundary and the variable internal
area distribution between sampling times.
4-14
-------
Once areas associated with each sampling point are
determined, a thickness of contamination must be
estimated so that contaminated volume and total mass
calculations can be carried out. The estimation of this
thickness is only important if "absolute" masses are de-
sired. Without an estimation of contaminant thickness,
mass per unit thickness (M/L) comparisons would result
in trends identical to those of "absolute" mass. In the
case of both the Hill AFB and Layton sites, the actual
thickness of contamination was estimated to be the
maximum depth of ground-water sampled by any well or
monitoring point at each site. This thickness ranged
from 1.1 to 6.1 ft at the Hill AFB site and from 9.3 to 12.8
ft at the Layton site.
In addition to estimating the total mass of a compound
within the dissolved plume at both sites at a given point
in time, the representative center point of the combined
plume mass can also be calculated. This representative
mass center is termed the centroid of the mass. It is cal-
culated by taking the first moment of inertia of the mass
at each sampling point within the contaminant plume'
about specified X and Y axes. The X and Y coordinates
of the centroid of the total mass identify that position
which yields a moment of inertia for the total mass
equivalent to that of the sum of the individual moments
of the masses estimated for each of the sampling points.
Mathematically this can be expressed as follows for the
center of mass X and Y coordinates, respectively:
(4-1)
Y = j=l
(4-2)
(massi)
These center of mass (CoM) calculations are critical for
tracking and interpreting the movement of
contaminants, reactants, and products within the con-
taminant plume over time. The calculations can be used
to assess the status of the plume and interpret its migra-
tion pattern over time (Table 4-5). They can also be
used to estimate constituent migration velocities during
plume development so that effective retardation factors
and plume attenuation can be estimated based on
known aquifer pore water velocities. CoM calculations
were carried out for all contaminants, terminal electron
acceptors (TEAs), and products of interest at the field
sites investigated in this study. Results of both total
mass and CoM calculations are summarized in detail in
Chapters 5 and 6.
If plume centerline analysis and CoM calculations sug-
gest that the plume is growing over time, steady-state
conditions have not been reached. Either ongoing
monitoring should take place to ensure future attenua-
tion of the plume, or active source removal and/or site
remediation should occur if a sensitive receptor is, or will
be,- impacted in the near term. If the contaminant plume
is shown to have reached steady-state conditions, fur-
ther quantitation of the nature and extent of plume at-
tenuation taking place under site conditions is war-
ranted.
Table 4-5. Changes in Contaminant Mass and Mass Center Coordinates Possible for a
Contaminant Plume, and the Corresponding Interpretation of These Changes Relative to
Plume Mobility and Persistence
Contaminant Mass
Centroid of Mass
Interpretation
Increasing
Constant
Constant
Decreasing
Decreasing
Moving Downgradient
Moving Downgradient
Stable
Moving Downgradient
Moving Upgradient
Continuous source; unstable plume;
contaminant migration
Finite source; plume migration; minimal
natural attenuation
Continuous source; stable plume;
contaminant attenuation
Finite source; plume migration;
contaminant attenuation
Finite source; plume attenuation; rapid
contaminant attenuation; optimal
intrinsic bioremediation
4-15
-------
Estimation of Contaminant
Degradation Rates
Estimation of contaminant degradation rates can be
carried out using either plume dissolved contaminant
mass data, if a declining mass of contaminant is
observed over time in the plume, or from plume
contaminant ground-water concentration data if the
source is found to produce steady-state dissolved mass
in the plume over time. If steady-state mass is indicated,
degradation rates for the contaminants can be estimated
directly from centerline concentration data or through
the calibration of a contaminant fate-and-transport model
to field data observed throughout the contaminant
plume. Figure 4-6 presents the logic associated with the
estimation of field determined degradation rates and
suggests that if aquifer flow data are available, the use of
a fate-and-transport model accounting for advection,
dispersion, sorption, and degradation is preferred over
the use of plume centerline concentration data alone. In
addition, the use of less degradable "plume resident
tracer" compounds in the calibration process is desirable
for the calibration of the transport component of the fate-
and-transport model if data for these tracer compounds
are available. The use of the less degradable tracers
allows flow calibration without complications from
species degradation.
Dissolved Plume Mass Changes Over Time
As indicated in Table 4-5, when the total mass of
contaminant in the dissolved plume is shown to be
decreasing over time, a finite source is suggested and
both the position and concentration profile for the plume
would not be expected to be in a steady state. The
source is behaving as a pulse source and to estimate the
degradation rate of contaminants within the plume
resulting from this pulse source, analysis of the changes
in dissolved plume mass over time should be used.
A classical approach to the evaluation of contaminant
degradation rates in biological systems is to analyze the
time course of changes in contaminant concentration or
mass and investigate the relationship between
concentration or mass versus reaction time using zero or
first order reaction rate laws. Zero order reactions are
described by a contaminant reaction rate independent
of contaminant mass, i.e., a constant degradation rate
overtime, on
dM/dt = -k0
(4-3)
where k0 = the zero order degradation rate constant,
mass/time. The integrated form of this equation is
shown in Equation 4-4:
(4-4)
where M = contaminant mass at time t, mass; and M0 =
the initial contaminant mass at time t = 0, mass. If the
reaction taking place is governed by a zero order
degradation rate law, a plot of contaminant mass versus
time produces a linear relationship, the slope of which
equals -k0, and whose intercept value should equal M0.
First order reactions are described by a contaminant
reaction rate which is dependent on contaminant
concentration or mass, i.e., a degradation rate changing
over time, or:
dM/dt = -k-i M
(4-5)
where ki = the first degradation rate constant, 1/time.
The integrated form of this equation is shown in
Equation 4-6:
M = M0e~klt (4-6)
A plot of contaminant mass versus time produces a non-
linear relationship that can be linearized by plotting the
natural log of contaminant mass versus time. The slope
of this linearized relationship is equal to -k-|.
Figures 4-7 and 4-8 show total dissolved plume mass
data for ethylbenzene and total petroleum hydrocarbons
(TPH) collected from the Hill AFB, UT, field site showing
both zero order and first order mass reduction over time,
respectively. Time was calculated in these figures based
on the cumulative time between sampling events, with
August 1992 being the t = 0 point in these figures.
As indicated in Figure 4-7, a plot of ethylbenzene mass
versus time produced a linear relationship, the slope of
which was significant based on an alpha value of 0.05
(95 percent confidence level), resulting in a zero order
mass degradation rate of 0.063 g/d. The natural log
transformed data for TPH mass linearizes its relationship
with time as indicated in Figure 4-8, and produces a
significant regression based on an alpha value of 0.05
(95 percent confidence level). The first order TPH
degradation rate determined from this analysis from the
Hill AFB site is 0.009/d.
Plume Centerline Concentration Data
If the dissolved plume mass does not change
.significantly over time, a continuous source is indicated
(Table 4-5), and analysis of steady-state dissolved plume
concentration data can be carried out. Using the data
reduction approach described above for dissolved
plume mass, contaminant concentration data can be
analyzed using zero order reactions with Equation 4-7:
dC/dt = -k0
(4-7)
where ko = the zero degradation rate constant,
mass/volume/time. The integrated form of this equation
is shown in Equation 4-8:
C = C0 -k01
(4-8)
4-16
-------
2. Estimate
Contaminant
Degradation Rate
Dissolved Plume Mass
Changes Over Time
Declining Mass
Steady-State Mass
Plume Contracting
Steady-State Plume -
Ground Water Flow
Data Available?
Estimate Mass
Degradation Rate
Equations 4-3 or 4-4
Yes
No
Calibrate Fate-
and-Transport
Model
Use Plume Centerline
Data
Equations 4-8 or 4-10.
Figure 4-6. Decision logic in evaluating contaminant degradation rates.
4-17
-------
O)
35
301
25
20'
CO
b 151
CD
| 10-
CD
y = -0.06 x + 31.5, r2 = 0.9668
p = 0.003
JCL
0 100 200 300 400
Time (days)
500
600
Figure 4-7. Time course of ethylbenzene dissolved plume mass data collected from the Hill AFB,
UT, site from March 1992 to January 1994.
1 5
o
CO
5 4
x
Q_ ~
t=. 3
y = -0.009X + 8.6, r2 = 0.9102
p = 0.0117
100 200 300 400
Time (days)
500
600
Figure 4-8. Time course of natural log transformed total petroleum hydrocarbon dissolved plume
mass data collected from the Hill AFB, UT, site from March 1992 to January 1994.
4-18
-------
where C = contaminant concentration at time t,
mass/volume; and C0 = the. initial contaminant
concentration at time t = 0, mass/volume. A plot of
contaminant concentration versus time produces a linear
relationship, the slope of which equals -k0, and whose
intercept value should equal C0.
First order reactions using contaminant concentration
data are written as:
dC/dt=-k1 C
(4-9)
where k-j = the first degradation rate constant, 1/time.
The integrated form of this equation is shown in
Equation 4-10:
C =
(4-10)
A plot of the natural log of contaminant concentration
versus time is linear when first order degradation is
taking place, with the slope of this linearized relationship
equal to -k-|.
Figure 4-9 shows a typical data set collected from the
Layton, UT, field site. These data represent centerline
p-xylene plume concentrations measured at the site in
January 1994. Figure 4-9a shows a plot of p-xylene
concentration versus distance downgradient from the
source area. These data are non-linear, and Figure 4-9b
shows the natural log transformation of concentration
versus time of travel downgradient. Time of travel was
calculated based on the distance to a given monitoring
point from the source area, divided by the average pore
water velocity measured at the Layton site, 0.037 ft/d.
This pore water velocity was based on hydraulic
conductivity and hydraulic gradient data collected there
during the study. As indicated in Figure 4-9b, the
natural log transformed data are linearized and provide a
significant regression based on an alpha value of 0.05
(95 percent confidence level). The first order p-xylene
degradation rate, determined from this analysis of the
January 1994 field data at the Layton site, is 0.0016/d.
Calibration of Analytical Fate-and-Transport
Ground-Water Model
As indicated above, to obtain the best estimate of
contaminant degradation rates when a continuous
source scenario is observed at a site, calibration of fate-
and-transport models to measured field data is desirable.
These models integrate transport, retardation, and
degradation using site-specific contaminant and aquifer
properties. This was the case for the Layton field site
investigated in this study, and Figure 4-10 shows a plot
of the calibrated p-xylene data for Layton using an
analytical, three-dimensional model described later in
this chapter. As indicated in Figure 4-10, using a fate-
and-transport model accounting for flow and
contaminant sorption characteristics, in addition to
degradation, yields a "dilution-corrected" degradation
rate for p-xylene approximately five times lower than that
estimated from analysis of centerline concentration data
which did not account for advection and dispersion of p-
xylene within the aquifer. Details of this analytical fate-
and-transport model and its use in the assessment of
intrinsic remediation reactions at UST sites are described
later in this chapter.
Estimation of Source Mass/Lifetime
With an estimation of the rate of contaminant
degradation taking place at a site, management
decisions regarding the appropriateness of source
removal actions and the effect of such actions on the
projected lifetime of contamination at the site can be
made. The logic associated with source mass and
lifetime determinations is shown in Figure 4-11.. If a
pulse source exists at a site, little residual contaminant
mass exists in the original source area. Calculations
described above for the total dissolved mass existing
within the plume allow a determination of the lifetime of
the plume as follows for a zero order and first order
degradation rate, respectively:
Plume Lifetimezero =
(Last Dissolved Plume Mass)/ko
Plume
= -ln(M/M0)/k-|
(4-11)
(4-12)
where ko in Equation 4-11 has units of mass/time; and M
in Equation 4-12 represents the final mass to be
reached at the end of the calculated plume lifetime.
If a continuous source is found at a given site,
contaminant mass within the source area continues to
release mass to the ground-water, maintaining the
contaminant plume that has developed over time. To
arrive at an estimate of the potential lifetime of the
plume, an estimate of contaminant both above and
below the ground-water table must be made. These
estimates should be based on soil core samples
collected within the source area. This total mass
estimate requires that the soil volume associated with
each soil core be defined using a method such as the
Thiessen polygon method that was described above.
Once concentration and associated soil volume data are
compiled, the estimation of total contaminant mass is
based on the average borehole concentrations and
volume averaged summation of masses from each core.
Figure 4-12 indicates the configuration of soil cores and
associated geometry used in the following equations for
average borehole concentration, Cave, and total
contaminant mass, My, estimates in a source area:
4-19
-------
20
40 60 80 100 120 140 160
Downgradient Distance (ft)
a) p-xylene concentration versus distance downgradient from the source area
g>8
c
§5
04
CD o.
C 3
D
y = -0.0016x + 7.85, r2 = 0.7975
p = 0.0413
0 500 1000 1500 2000 2500 3000 3500 4000
Plume Travel Time (d)
b) Natural log transformed p-xylene concentration versus time of travel downgradient from the source area.
Figure 4-9. p-xylene concentration data collected from the Layton, UT, site in January 1994. a)
p-xylene concentration versus distance downgradient from the source area; b) Natural log
transformed p-xylene concentration versus time of travel downgradient from the source area.
4-20
-------
_0>
"5
T3
3
O
O
•d)
4000
3500
3000
2500
2000
1500
1000
500
• 0
\
Simulation Paramters: .
Degradation rate = 0.00033/d,
R = 5.97, t = 20 yr
• Field Measured Data
----- Predicted Data
:$-=•
-+-
20 40 60 80 100 120 140
Downgradient Distance from Source Area (ft)
160
180
200
Figure 4-10. Calibration of fate-and-transport model using field-determined p-xylene
concentration data collected from the Layton, UT, site in January 1994.
-ave.j
(4-13)
where C^ j = soil contaminant concentration in core j at
depth i in the core, mass contaminant/mass soil; hj, j =
core j interval thickness at depth i, length; and n = total
number of soil cores collected at the site.
(4-14)
where Aj = Thiessen area associated with core j, length2.
It should be noted that the denominator of Equation 4-
13 is the thickness of vadose zone contamination less
an uncontaminated surface layer for mass above the
ground-water table. For saturated zone mass
determinations, this denominator is the thickness of
contaminated soil below the ground-water table. Also,
total mass calculations provided in Equation 4-14 should
be carried out separately for mass above and below the
ground-water table so that a picture of the vertical
distribution of contaminant mass can be developed. .
Once the total mass of contamination is estimated above
and below the ground-water table, estimates for the total
lifetime of the plume can be made. For a continuous
source, the plume lifetime is the sum of the lifetime of
the dissolved plume mass plus the mass remaining in
the source area. If the mass removal rate is assumed to
be the contaminant degradation rate determined above,
then the total plume lifetime, Tcontjnuous> can be
estimated as:
Tcontinuous, zero =(MassV + MassSz + MD)/ko (4-15)
Tcontinuous, first =- ln[M/(Massv + MassSZ + Mrj)^ (4-16)
for zero and first order degradation rate relationships,
respectively, where Massy - contaminant mass in the
vadose zone, mass; Masssz = contaminant mass in the
saturated zone, mass; and Masso = contaminant mass in
the dissolved plume, mass.
Predicting Long-Term Behavior of Plume
The long-term behavior of a contaminant plume is
impacted both by the characteristics of the source--
affecting the duration of the release of contaminant into
the aquifer-and by the characteristics of the aquifer itself
affecting the transport and degradation of contaminant
once it is released from the source area. Figure 4-13
presents the decision logic related to long-term source
behavior, identifying differences in analysis of the plume .
based on whether it is considered a pulse or continuous
source.
If the plume can be considered a pulse source, no
residual source area exists, and the long-term behavior
of the plume is related to the projected life-time of the
plume based on calculations presented above.
If the site is shown to contain a significant source area,
producing a "continuous source" plume, long-term
plume behavior can be evaluated based on various
4-21
-------
3. Estimate Source
Mass
4. Estimate Source
Lifetime
Estimate Last
Dissolved Mass
Value
Estimate Mass Above
GW Table
Lifetime Based on
Degradation
Rate of Last
Dissolved Mass
Estimate-Mass Below
GW Table
Lifetime Based on Total
Mass at Site
Figure 4-11. Decision logic in evaluating contaminant source mass and source lifetime.
4-22
-------
Top of the
contaminated
zone
Q
Soil core
Vadose
Zone
Water Table
IB] Saturated
Zone
Figure 4-12. Configuration of soil cores and associated geometry used for calculation of
average borehole contaminant concentrations as input to total mass estimates.
source removal scenarios. If no source removal is to be
carried out, a worst-case scenario develops in terms of
the length of time the plume will persist. Under these
conditions, the plume lifetime is predicted based on the
sum of vadose zone, saturated zone, and dissolved
plume masses. If contaminant source removal is being
considered, the lifetime of the plume is controlled by the
nature and extent of source removal taking place at the
site. For example, if a significant mass of contaminant
exists above the ground-water table, i.e., Massy is large
relative to Mass-f, an analysis of the effect of vadose
zone source removal on the lifetime of the plume can be
made using Equations 4-17 or 4-18.
In these equations, p = 'decimal percent removal of
vadose zone contamination. Various removal scenarios
can be carried out to evaluate the impact of these
removal actions on the plume lifetime using this general
approach. If 100 percent vadose and saturated zone
source removal is assumed, the continuous source
plume lifetime equation reduces to that of the pulse
source as shown in Equation 4-11.
Once source removal strategies are investigated, the
complete long-term behavior of the contaminant plume
can be predicted. This is done by the superposition of a
continuous source, with a source concentration equal to
the negative of the initial concentration, on top of the
steady-state plume concentration profile. The1 time
when this simulation begins is at a point in time, T,
corresponding to the time of source removal, or the time
at which natural source depletion is projected to occur.
Both the steady-state plume and the imaginary -Co
plume are then projected forward in time to time t + T and
t, respectively, to yield a synthesized plume that reflects
the effect of source removal on the overall plume
footprint at the site.
1 continuous.zero ~
1-p) (Massv + Masssz + MassD)
E
(4-17)
-In
' continuous, first '—
M
(Massv +Masssz + MassD)
'
(4-18)
4-23
-------
5. Long-Term Behavior I
Plume Type?
Pulse
Continuous
.Dissolved Mass
Degradation
Without Source
Removal
With Source Removal
Total Mass
Degradation
Vadose Zone Source
Removal
Vadose and Saturated
Zone Source Removal
Figure 4-13. Decision logic in evaluating long-term behavior of contaminant plume.
For example, assume that a steady-state plume is
observed 20 years after an original source release. If it is
desired to predict the effect of source removal on this
steady-state plume five years after source removal, the
Steady-state contaminant plume at Year 25 for a Co
source concentration is modified by the addition of Year
5 modeling results for the -Co contaminant plume. This
modification accounts for five years of plume transport
and degradation without contaminant release from the
source area. Results of this example source removal
scenario are shown in Figure 4-14, and indicate, that
with complete source removal, significant reductions in
ground-water concentrations are predicted to occur.
Within 20 years following 100 percent source removal,
p-xylene ground-water concentrations are predicted to
be less than 150 iig/L, nearly 100 times lower than the
xylene MCL of 10,000 tig/L, within 80 ft of the source
location at the Layton site.
Similar scenarios could be carried out for various source
removal efficiencies, affecting the point in time in the
future when source depletion occurs and the -Co plume
approach becomes applicable. It is important to note
that the steady-state contaminant plume profile
represents the highest downgradient concentration
profile that would be expected at a site. The
concentrations at a given point in space will decrease
over time following source removal activities if the plume
is at steady-state, and if all other site conditions remain
the same over time.
Decision Making Regarding Intrinsic
Remediation
The analyses described above provide a basis for
making a decision regarding the applicability of an
intrinsic remediation approach for a given site. Figure 4-
15 provides a summary of the logic necessary to
complete the decision making process based on the
potential success of intrinsic attenuation reactions
providing plume containment and control, and on the
impact the plume has on downgradient receptors.
The focus of the previous discussion has been on
quantifying the transport and degradation of
contaminants of interest taking place under actual site
conditions. Additional supporting evidence for
verification that degradation reactions are biologically
mediated can be provided through an analysis of the
changes in background electron acceptor mass
compared to that within the plume itself. If contaminant
4-24
-------
c 4,000
5 3,500 -
£ 3,000 -I
o
" 2,500 -
_CD .
I clj 2,000 -
§ ' 1,500 -
o
Simulation Parameters:
Degradation rate = 0.00033/d,
R = 5.97, t = 25 & 40 yr
1 Predicted Data No
Source Removal
Predicted @ t = 25 yr; 5
yr After 100 Percent
Source Removal
• Predicted @ t = 40 yr; 20
yr After 100 Percent
Source Removal
"k-
4-
20
40 60 80 100 120 140 . 160
Downgradient Distance from Source Area (ft)
180
200
Figure 4-14. Predicted impact on plume centerline p-xylene concentrations 5 and 20 years after
100 percent source removal based on a field data calibrated fate-and-transport model for the
Layton, UT, site.
biodegradation is taking place, indigenous organisms
will utilize electron acceptors (O2, NOg, Mn4+, Fe3+,
SC>42', CO2) at a rate and to an extent that should
correspond to contaminant loss observed at the site.
The stoichiometry associated with microbial metabolism
known to occur under various electron acceptor
conditions allows a determination of the potential
contaminant assimilative capacity of background ground-
water moving into the source area and available in the
solid phase within the plume itself. If this theoretical
assimilative capacity is equal to or greater than the level
of contamination observed at the site, biological intrinsic
remediation processes can be, expected to play a major
role in contaminant attenuation. If this theoretical
assimilative capacity is limited, some source removal
and/or active site remediation action is likely warranted.
A detailed discussion of procedures that can be used to
estimate this theoretical assimilative capacity is provided
in a later section of this chapter.
The final questions that must be answered regarding
application of an intrinsic remediation management
approach at a site are: whether or not a sensitive
receptor is being impacted now or in the future when the
plume is projected to reach steady-state conditions; and
whether or not the projected lifetime of the plume is
acceptable to the owner/operator, regulatory agencies,
and other interested parties. In general, if an existing or
projected receptor impact exists, active source removal
and/or plume control/remediation may be required. The
issue of plume lifetime tends to be a more complicated
one. If significant contaminant mass remains in the
source area of a site, the resulting plume may persist for
decades. If remediation goals are established with
shorter timeframes, i.e., for property transfer reasons,
etc., this assimilation time will likely not be acceptable,
and active remediation may be required.
Long-Term Monitoring Program for Site
If an intrinsic remediation plume management approach
is selected for a given site, the last step in the
assessment process is the development of a long-term
monitoring strategy for the site. Figure 4-16 shows that
the requirements of the monitoring strategy are twofold,
namely, for compliance monitoring purposes, as well as
for intrinsic remediation process monitoring.
A compliance monitoring program is established to
provide data to the regulatory agency to confirm that
plume containment and risk management continue to
take place at the site. Compliance monitoring normally
involves the use of an upgradient, background
monitoring well, two to three monitoring wells within the
contaminant plume, and two to three downgradient
compliance wells used to detect contaminant migration
toward potential receptors. Ground-water elevation,
contaminant concentration, and minimal ground-water
quality data (pH, temperature, total dissolved solids) are
generally required to be reported from these monitoring
wells.
4-25
-------
(,. Intrinsic
Remediation for
Site?
Impacted Receptors
Now or When
Plume Reaches
Steady-State?
No
Yes
Evidence of TEA
Pool Sufficient for
Plume
Containment?
Apply Active
Remediation
Plume Lifetime
within Acceptable
Limits?
Apply Active
Remediation
Select Intrinsic
Remediation Plume
Management
Option
Apply Active
Remediation
Figure 4-15. Decision logic in evaluating applicability of intrinsic remediation plume
management approach for a given site.
4-26
-------
The information generated for compliance monitoring
purposes is necessary, but not sufficient for intrinsic
remediation process monitoring. Additional monitoring
locations and analyte data 'should be collected for
process monitoring purposes. Figure 4-17 shows a
typical monitoring well network that is appropriate for
both initial intrinsic remediation evaluation and long-term
compliance and intrinsic remediation process
monitoring. The.analytes that would typically be
measured in addition to those used'for compliance
monitoring include: terminal electron acceptors (O2,
NOg, SO42-); product (Mn2+, Fe2+, CH4) formed during
contaminant biodegradation; and water quality
characteristics (alkalinity and oxidation/reduction
potential) which are indicative of biological processes
taking place within a contaminated aquifer. With this
network established and additional process monitoring
data collected, the conceptual model of the site and.
model calibration results can be continuously updated to
provide'ongoing refinements to source lifetime
predictions.
Finally, the frequency of ground-water monitoring is
established as part of the long-term monitoring plan.
Compliance monitoring schedules generally require
quarterly to annual sampling. Under most
circumstances, annual sampling is the shortest time
interval necessary for intrinsic remediation process
monitoring since low ground-water velocities observed
at most sites do not warrant more frequent sampling
intervals. At a site with a ground-water velocity of 0.04
ft/d (similar to the Layton site), unretarded ground-water
moves less than 15 ft a year. With a retarded velocity 1/3
to 1/6 that of ground-water (appropriate for benzene and
xylene, respectively), contaminant movement of less
than three to five ft would be expected over a one year
time period. With a monitoring grid spaced at 30-ft
intervals, a one-year change in plume position cannot be
detected. Again, the sampling interval should be
assessed on a site-specific basis. Generally an annual to
biannual sampling schedule should be sufficient to
assure that adequate data are collected, while
minimizing the sampling and analysis burden at intrinsic
remediation sites.
Potential Aquifer Assimilative Capacity
Contaminant degradation by microorganisms takes place
when the contaminant serves either as a primary energy
source (electron donor) or are fortuitously metabolized
when other primary substrates are available to the
microorganisms (co-metabolism). In order for the
electron donors to be utilized by the indigenous
microbial community, compounds must also be available
which allow energy transfer by the microorganisms to
take place. These compounds are classified as electron
acceptors and are generally believed to be utilized in a
sequential fashion based on the relative energy yield to
the. microorganisms when energy production and
electron donor utilization is taking place. This sequence
of electron acceptor utilization is as follows: oxygen,
nitrate, manganese, iron, sulfate, carbon dioxide, and
organic carbon. Oxygen provides the greatest energy
yield and results in the broadest utilization of electron
.donors of all of the electron acceptors listed above.
Dominating electron acceptors and aquifer
oxidation/reduction potential (ORP) conditions change
as the plume moves downgradient from the source of
ground-water contamination. Near the source, oxygen
and nitrate are depleted, while high dissolved iron and
manganese concentrations are observed. Under these
highly reducing conditions, methanogenesis and sulfate
utilization are generally the primary reaction mechanisms
observed. Further downgradient from the source,
sulfate reduction gives way primarily to iron and
manganese metabolism. The system eventually
switches to nitrate-dominated metabolism, and ultimately
to areas away from the source that are once again
enriched in dissolved oxygen. The occurrence of
specific non-oxygen electron acceptor reaction zones is
dependent upon the pool of each electron acceptor
available in the aquifer and the nature of the electron
donor available to the microorganisms from the
contaminant release. In addition, the specific position of
each reaction zone and the location of the points of
transition from one dominant electron acceptor area to
the other is dependent upon the release rate of the
contaminants from the source, the nature of the
contaminants in terms of their rate of utilization under
specific electron acceptor conditions, and the rate of
ground-water migration below the site.
The nature of microbial processes taking place at
specific locations within an aquifer dictates the
predominant ground-water quality conditions and
specific dominant chemical species found there. It is
important then to review the characteristics of
metabolism under each electron acceptor condition.
Monitoring of these microbial processes forms the basis
for the detection and quantification of intrinsic
remediation reaction rates taking place in aquifer
systems and in estimating the potential assimilative
capacity of a given aquifer.
Dissolved Oxygen
Dissolved oxygen (DO) is the most energetically
favorable electron acceptor in respiratory metabolism.
The consumption of dissolved oxygen in an aquifer
indicates the activity of aerobic microorganisms and is a
primary indicator for the existence of biologically
mediated reactions at a contaminated site. In most
pristine aquifers, some oxygen exists (Major, 1988;
Manahan, 1990; Barcelona and Holm, 1991). In general,
there are no readily available non-biotic sources or sinks
for oxygen in aquifers. Oxygen, found in aquifers at a
maximum concentration of 8 to 10 mg/L, can be used
4-27
-------
7. Long-Term
Monitoring for Sfte
Compliance
Monitoring
Intrinsic Remediation
Monitoring
Update Source
Lifetime Predictions
Update Site
Conceptual Model
Update Model
Calibration
Figure 4-16. Requisite components of a long-term monitoring strategy applied at an intrinsic
remediation site.
X
Background
Well x
Ground-Water
Flow
X
X
X
O
x Driven Ground-Water Monitoring Points
o Conventional Ground-Water Monitoring Wells
Figure 4-17. Ground-water monitoring network applied at an intrinsic remediation site for both
compliance and intrinsic remediation process monitoring.
4-28
-------
quickly when an aquifer becomes contaminated, with
biodegradable organic material such as hydrocarbons
. (Major, 1988; Manahan, 1990).
The size and structure of a hydrocarbon compound
affect its aerobic degradation, rate. Compared to other
hydrocarbons, intermediate alkanes, CIQ to C24, are
considered the most unstable in aerobic environments.
Branched alkanes and aromatic compounds are found to
be more stable in aerobic environments. It has been
found that tertiary and quaternary carbon atomainterfere
with degradation processes, or in some instances, even
block degradation altogether (Atlas and Bartha, 1987) by
inhibiting (3-oxidation (Manahan, 1990).
The other terminal electron acceptors that can be used
by hydrocarbon degrading organisms, NOg, Mn4+, Fe3+,
SO42-, and CO2, require oxygen-free environments.
The presence of oxygen will generally inhibit the
utilization of the other terminal electron acceptors. In all
but subsurface plumes with very low concentrations of
hydrocarbons or well-oxygenated environments, the
rate of oxygen utilization will exceed oxygen inputs,
resulting in oxygen depletion and utilization of other
terminal electron acceptors within major portions of the
contaminant plume.
Quantitatively, the mass of oxygen depleted in the
degradation of hydrocarbon contaminants can be
estimated from the balanced equations for the
conversion of benzene (representative compound for
the aromatic hydrocarbons) and hexane (representative
compound for the .alkanes) to carbon dioxide and water
using oxygen as the electron acceptor. These balanced
equations can be written as follows:
C6H6 + 7.5O2 -> 6CO2 + 3H2O
C6H14 + 9.5O2 -> 6CO2 + 7H2O
(4-19)
(4-20)
These stoichiometric relationships indicate that 7.5 to
9.5 gmol of oxygen are required to oxidize 1 gmol of
hydrocarbon contaminant. This suggests that 3.1 ([7.5
x 32]/78) to 3.5 g ([9.5 x 32]/86) of oxygen will be
consumed per gram of hydrocarbon degraded. This
provides a conservative estimate of oxygen
consumption and expected hydrocarbon depletion
since it does not account for the carbon utilized in cell
mass production. The level of net cell mass would be
expected to be low due to infinite solids residence times
in the aquifer, and the low level of substrate available,
making endogenous respiration a significant reaction
under field aquifer conditions.
Nitrate
Nitrate can be utilized for both assimilatory and
dissimilatory metabolism. In either the presence or
absence of oxygen, a group of enzymes produced by a
variety of organisms can reduce nitrate to ammonia and
incorporate the ammonia into a variety of amino acids.
This assimilatory metabolism is suppressed in the
presence of large amounts of ammonia and by other
than neutral pHs (Atlas and Bartha, 1987). In the
absence of oxygen, nitrate can be used as a terminal
electron acceptor. Nitrate reduction produces a variety
of reduced nitrogen forms including: NO2~, NO, N2O,
and N2. As the nitrate is reduced, organic matter is
oxidized. In this case, the reduction of nitrate can lead to
the oxidation of hydrocarbons.
There are two types of dissimilatory nitrate reduction. In
the first type, nitrate ammonification, nitrate is reduced to
non-gaseous, water soluble products such as nitrite and
ammonia. Unlike assimilatory nitrate metabolism, this
process is not inhibited by increasing amounts of nitrite
or ammonia. Nitrate ammonification is common in
sewage treatment, stagnant water, and sediment.
Facultative organisms such as Alcaligenes, Escherichi,
Aeormonas, Enterobacter, Flavobacterium, and
Nocardia species utilize nitrate reduction to nitrite and
ammonia for dissimilatory metabolism (Brock and
Madigan, 1991).
The second type of nitrate reduction, denitrification, is
the reduction ,of nitrate to gaseous products. Nitrate
reducing bacteria such as Paracoccus denitrificans,
Thiobacillus denitrificans, and a variety of
pseudomonads are capable of this nitrate reduction
process (Brock and Madigan, 1991). Typically, a mixture
of nitrous oxide and nitrogen is produced. The actual
distribution of the oxidized product is dependent on
both the active microbial population and the
environment in which the reaction takes place:
Denitrification occurs under anaerobic conditions or in
aerobic environments with anaerobic microhabitats.
Dissimilatory nitrate reductase, the enzyme mediating
the first step in denitrification, is competitively inhibited
by oxygen, not inhibited by ammonia, and is particle
bound. Denitrification produces more reducing
equivalents than nitrate ammonification, making it the
more environmentally significant system.
The bulk of the literature describing the degradation of
hydrocarbons under denitrifying conditions has focused
on toluene and the xylenes. Zeyer et al. (1986)
described gaseous nitrogen products 'of the
degradation of xylene under denitrification conditions,
plus they calculated a first order rate of 0.45/day for the
degradation rate for xylene. Kuhn (1985) and Hutchins
(1991 a, b) found degradation rates were not the same
for the different xylene isomers. They found that o-
xylene degraded at a slower rate than p- or m-xylene.
Kuhn (1985) calculated rates for the faster degrading
xylenes to be 0.5/day, matching the degradation rates
Zeyer et al. (1986) observed for xylene under
denitrifying conditions.
4-29
-------
Benzene, toluene, and xylene (Major et al., 1988;
Hutchins, 1991 a, b) and some PAHs (Mihelcic and
Luthy, 1988a, b) have also been shown to degrade
under denitrifying conditions.
Quantitatively, the mass of nitrate depleted in the
degradation of hydrocarbon contaminants can be
estimated from the balanced equations for the
conversion of benzene (representative compound for
the aromatic hydrocarbons) to carbon dioxide and water
using nitrate as the electron acceptor. This balanced
equations can be written as follows:
+ 6H+ -» 6CO2 + 6H2O + 3N2
(4-21 )
It is evident then that 6 gmol of nitrate are required to
oxidize 1 gmoi of aromatic hydrocarbon contaminant.
This suggests that 1.07 g ([6 x 14]/78) of nitrate-
nitrogen will be consumed per gram of hydrocarbon
degraded. This provides a conservative estimate of
nitrate consumption and expected hydrocarbon
depletion since it does not account for the carbon
utilized in cell mass production. As indicated above,
however, the net production of cell mass would be
expected to be small, making the calculations only
slightly conservative in nature and acceptable for
degradation potential estimates used in this report.
Iron/Manganese
Ferrous iron and Mn2+ found in ground-water samples
may indicate the use of Fe3+ and Mn4+ as terminal
electron acceptors for respiratory metabolism. Both iron
and manganese are energetically favorable electron
acceptors in anoxic systems and can play a major role in
contaminant degradation when high oxygen demand in
Impacted aquifer systems exceeds the limited oxygen
supply normally delivered in ground-water systems. Iron
has been found to participate in the anaerobic
degradation of creosote (Lovely and Phillips, 1987b)
and crude oil (Lovely et al., 1 989).
The anaerobic degradation of hydrocarbons using iron
as a terminal electron acceptor may begin with
fermentative bacteria producing Fe(ll), CO2, and a sen'es
of organic intermediate products. These fermentative
products may then be mineralized by Fe(lll)-reducing
bacteria (Lovely and Phillips, 1988). The fermentative
step is not always necessary. Compounds that have
been mineralized in anoxic/Fe(lll) systems without a
fermentation step include toluene, benzoate, phenol,
and p-cresol (it is important to note that catechol can
reduce Fe(lll) in an abiotic reaction at the near neutral
pHs frequently encountered in ground-water) (Lovely et
al, 1989).
There are connections between the nitrogen and iron
systems. Nitrate reductase, the enzyme involved with
nitrate reduction to nitrite, can also reduce Fe(lll) (Brock
and Madigan, 1991). The first organism isolated that
could utilize Fe(lll) as a sole terminal electron acceptor,
GS-15 (Lovely and Phillips, 1988), can also utilize nitrate
as a terminal electron acceptor and is cultured with
nitrate (Lovely, 1991). Organisms capable of reducing
Fe(lll) are often also denitrifying organisms (Sorensen,
1982). Iron-reducing bacteria can also be cultured
aerobically, as in the case of Alteromonas putrefaciens.
Fe(lll)-reducing bacteria include both facultative and
obligate anaerobes (Lovely et al., 1989).
There is some evidence that Fe(lll) reduction can be the
predominant anaerobic system in the absence of
reducible nitrogen compounds (Lovely and Phillips,
1987b). However, there is some disagreement on the
role of ferric'iron as a terminal electron acceptor in
systems where sulfate reduction is possible. Although
the reduction to ferrous iron compared to sulfate
reduction is thermodynamically favorable, Beller et al.
(1992) reported that the microorganisms involved in
their study utilized sulfate as a terminal electron
acceptor. The amorphous ferric iron in the same system
served a more abiotic role, perhaps in removing
hydrogen sulfide from the system or serving as a
required nutrient. Haag et al. (1992) also found the
metabolism of toluene by sulfate reducers occurring in
the presence of ferric iron hydroxides. Sorensen (1982)
stated that there was no interaction between iron and
sulfate metabolism, and that both occurred
simultaneously. However, Lovely and Phillips (1987b)
found that the presence of amorphous ferrous iron
inhibited sulfate reduction as well as methanogenesis,
differing from the results of Beller et al. (1992), Haag et
al. (1992), and Sorensen (1982).
Fe(III) bioavailability is determined by its form.
Amorphous Fe(lll) oxyhydroxides are the preferred form
for the Fe(lll) reducing bacteria. Crystalline forms are
reduced much more slowly, if at all (Lovely and Phillips,
1987b). This need for amorphous iron can be a benefit
for in-situ remediation efforts. Clay will stabilize
amorphous iron (Lovely and Phillips, 1987b), creating a
reducible iron-rich environment for biodegradative
processes. From this amorphous iron, the bacteria will
form magnetite, tying up two-thirds of the available
oxidized iron in this unusable form. For each kilogram of
magnetite produced, 10 kilograms of biomass can be
produced (Frankel, 1987).
The rates of organic oxidation via iron reduction can
approach the rates of reaction, under aerobic processes.
The free energy change of acetate oxidation coupled to
Fe(III) or Mn(IV) reduction is near that of the oxygen
coupled reaction (Lovely and Phillips, 1988).
Manganese metabolism is less studied than iron
metabolism. Tetravalent manganese has been shown to
be reduced to divalent manganese as a terminal electron
acceptor (Lovely and Phillips, 1988; Lovely et al., 1989).
The same reaction has also been demonstrated to occur
4-30
-------
abiotically, resulting in the oxidation of organic
substances.
Quantitatively, the mass of dissolved iron produced in
the degradation of hydrocarbon contaminants can be
estimated from the balanced equations for the
conversion of benzene (representative compound for
the aromatic hydrocarbons) and hexane (representative
compound for the alkanes) to carbon dioxide and water
using Fe(lll) as the electron acceptor. These balanced
equations can be written as follows:
C6H6 + 30Fe(OH)3 + 60H+
6CO2 + 30Fe2+ + 78H2O
C6H14 + 38Fe(OH)3 + 76H+
6CO2 + 38Fe2+ + 102H2O
(4-22)
(4-23)
These stoichiometric relationships indicate that from 30
to 38 grrtol of dissolved iron are produced when 1 gmol
of hydrocarbon contaminant is oxidized using
amorphous iron as the terminal electron acceptor. This
suggests that 21.5 ([30 x 55.85]/78) to 24.7 grams ([38
x 55.85]/86) of dissolved iron will be produced per gram
of hydrocarbon degraded. This provides a conservative
estimate of dissolved iron production and expected
hydrocarbon depletion as discussed above since it does
not account for the small net mass of cell material
generated during iron metabolism.
Suit ate
In nature, sulfate reduction is both assirpilatory and
dissimilatory. For assimilatory metabolism,
microorganisms use sulfate to create cystiene,
methionine, and coenzymes. For dissimilatory sulfate
reduction, hydrogen sulfide is produced from suifate
reduction. This sulfate reduction reaction is carried out
by a number of obligate anaerobic organisms (Brock and
Madigan, 1991), usually in aquatic environments.
Hydrogen sulfide (H2S) is toxic to most organisms. In
assimilatory metabolism, sulfide is utilized at a rate fast
enough to prevent high concentrations of H2S from
occurring. For dissimilatory metabolism, released sulfide
has a number of possible fates. Sulfide reacts readily
with metals such as iron, forming iron sulfide, the black
color often found in anaerobic sediments, or it is
released as H2S gas. In aquatic environments, H2S finds
its way to the atmosphere due to its low water solubility.
The dissimilatory reduction of sulfate can occur.at a
variety of pH conditions, although the products can be
pH dependent. At pH values below 7, H2S is the major
product. At neutral pH, HS" is the main product. When
sulfate reduction is carried out at basic pHs, the sulfide
ion is the main product (Brock and Madigan, 1991).
It is interesting to note that molybdenum, present in
nitrate reductase (Brock and Madigan, 1991),
suppresses sulfate metabolism, while the presence of
sulfate inhibits methanogens (Winfrey and Ward, 1983).
To suppress methanogens, sulfate reducers out-
compete the methanogens for acetate and hydrogen.
As well as utilizing more complex substrates, the sulfate
reducers can maintain concentrations of 'acetate and
hydrogen too low for methanogens to utilize. Minor
methane production can occur in sulfate reducing
systems via the utilization of methylamines, a
noncompetitive substrate, by the methanogens (Lovely
and Phillips, 1987b).
Sulfate has been shown to be involved in the degrada-
tion of hydrocarbons, but higher rates of degradation
have been observed for sulfate-mediated degradation
of ha'logenated alkanes. Aeckersberg et al. (1991) ex-
perimented with a bacterium that could mineralize
saturated hydrocarbons in anoxic environments via sul-
fate reduction. Once isolated in the lab, the bacteria was
used to degrade hexadecane, n-dodecane, n-tetrade-
cane, n-pentadecane, n-heptadecane, n-octadecane,
n-eicosane, 1-hexadecane, 1-hexadecanol, and 2-
hexadecanol (Aeckersberg et al., 1991). Air of the
systems reduced sulfate to sulfide. Growth or sulfide
production by this organism has not been found using
saturated hydrocarbon substrates with less than a 12-
carbon chain.
Quantitatively, the mass of sulfate utilized in the
degradation of hydrocarbon contaminants can be
estimated from the balanced equations for the
conversion of benzene (representative compound for
the aromatic hydrocarbons) and hexane (representative
compound for the alkanes) to carbon dioxide and water
using sulfate as the electron acceptor. These balanced
equations can be written as follows:
C6H6 + 3.75SO42- + 7.5H+ -
6CO2 + 3.75H2S + 3H2O
C6H14 + 4.75SO42- + 9.5H+
6CO2 + 4.75H2S + 7H2O
(4-24)
(4-25)
These stoichiometric relationships indicate that 3.75 to
4.75 gmol of. sulfate are utilized when 1 gmol of
hydrocarbon contaminant is oxidized using the
dissolved sulfate as the terminal electron acceptor. This
suggests that 4.6 ([3.75 x 96]/78) to 5.3 g ([4.75 x
96]/86) of sulfate will be consumed per gram of
hydrocarbon degraded.
Methanogenic Systems
Methanogenic bacteria are a type of specialized
archaeobacteria that typically produce methane by
reducing carbon dioxide with electrons generated by
the oxidation of hydrogen. They exist as strict obligate
anaerobes. Methanogens require a redox potential
between -350 and -450 mV to be active (Atlas and
Bartha, 1987).
4-31
-------
Methanogenic systems in general are considered to
function orders of magnitude more slowly than aerobic
systems (Borden and Bedient, 1986). In addition, only
methanogenic systems, not methanogenic bacteria,
have been shown to degrade fuel hydrocarbons. The
participants in the degradation pathway are still relatively
unstudied, particularly the fermentative bacteria that
produce organic acids and other low molecular weight
organic compounds as substrates for the methanogens.
Methanogens are substrate specific, using simple
organic compounds such as methanol, formic acid,
acetic acid, and some inorganic substances such as
carbon dioxide, carbon monoxide, and diatomic
hydrogen as substrates (Grady and Lim, 1980). Due to
the small number of possible substrates they can utilize,
methanogenic bacteria function in a consortia involving
other microorganisms. These other microorganisms
include fermentative bacteria and facultative anaerobic
bacteria. The fermentative bacteria degrade the more
complex organic compounds such as carbohydrates and
proteins into substrates usable by the methanogens
(Atlas and Bartha, 1987). The facultative anaerobic
bacteria act as oxygen scavengers to maintain the
anaerobic environment (Grady and Lim, 1980).
The methanogenic consortia for degrading
hydrocarbons include fermentative organisms that
provide substrate for the methanogenic organisms,
possible through hydrogen-producing acetogens
(Grbic-Galic, 1986). Fermentative organisms, with the
methanogenic organisms suppressed, have been
shown to be capable of degrading toluene and
benzene. The reactions are both reductive and
oxldative, with the reductive reaction most probably
producing cyclohexane derivatives which have not yet
been isolated. The oxidative reaction uses oxygen from
water to produce phenol, p-cresol, and benzyl alcohol
(Grbic-Galic, 1986). These reactions could explain the
presence of ethylated and methylated phenols in
anaerobic subsurfaces contaminated with gasoline
(Rienhard et al., 1984). The absence of the reduced
products at these sites could be explained by the higher
vapor pressure of cyclohexane and some of its
methylated derivatives as compared to that of toluene or
benzene.
As with aerobic degradation, branched paraffinic
compounds are less degradable than unbranched
paraffinic compounds under methanogenic conditions
(Battersby and Wilson, 1989). Degradation of aromatic
compounds may be enhanced by the presence of
carboxyl or hydroxyl groups (Schink, 1984).
Schink's (1984), Battersby and Wilson's (1989), and
Grbic-Galic's (1986) experiments seem to compliment
one another. Toluene, xylene, and benzene do not
lead to methane production in some methanogenic
systems (Schink, 1984; Battersby and Wilson, 1989).
Schink (1984) also stated that although these
compounds were unsaturated, the rc-electron system
does not allow easy hydration of the double bonds.
Grbic-Galic (1986) stated that the fermentative bacteria in
the methanogenic consortium used in her experiments
could oxidize toluene and benzene into hydroxylated
products, perhaps more suitable for further degradation
by methanogenic bacteria.
Quantitatively, the mass of methane produced in the
degradation of hydrocarbon contaminants can be
estimated from the balanced equations for the
conversion of benzene (representative compound for
the aromatic hydrocarbons) and hexane (representative
compound for the alkanes) to carbon dioxide and
methane using the following balanced equations:
C6H6 + 4.5H2O -> 2.25CO2 + 3.75CH4
(4-26)
C6H14 + 2.5H2O -» 1.25CO2 + 4.75CH4 (4-27)
These stoichiometric relationships indicate that 3.75 to
4.75 gmol of methane are produced when 1 gmol of
hydrocarbon contaminant is metabolized under
methanogenic conditions. This suggests that 0.77
([3.75 x 16]/78) to 0.88 g ([4.75 x 16]/86) of methane will
be produced per gram of hydrocarbon degraded under
highly reducing conditions.
Table 4-6 summarizes the stoichiometry and mass
balance relationships that can be used to estimate the
potential aquifer assimilative capacity for a given aquifer
system. Negative values represent a utilization of
electron acceptors (i.e., oxygen utilization at the' rate of
7.5 gmol/gmol aromatic hydrocarbon), while positive
values reflect the production of species related to
electron acceptor use (i.e., Fe2+ production at the rate of
30 gmol/gmol aromatic hydrocarbon). The values
provided in the table are representative of aromatic and
aliphatic hydrocarbons expected at fuel contaminated
sites. The potential assimilative capacity, based on
measured electron acceptor concentrations and the
stoichiometric relationships given in Table 4-6, should
exceed the hydrocarbon concentrations measured at a
site to ensure that contaminant plume containment will
take place there.
Fate-and-Transport Modeling
The degradation rates of contaminants of concern in the
plumes at the two field sites investigated in this study
were independently estimated using a ground-water
fate-and-transport model describing the advection,
dispersion, and degradation of dissolved compounds
that take place within an aquifer system. The modeling
effort carried out in this study had four fundamental
4-32
-------
Table 4-6. Potential Hydrocarbon Assimilative Capacity Relationships for Electron Acceptors of
Importance at UST Sites
Electron
Acceptor
Oxygen
Nitrate
Iron (Fe2+)
Sulfate
Methane
Hydrocarbon
Type Degraded
Aromatic
Aliphatic
Aromatic
Aromatic
Aliphatic
Aromatic
Aliphatic
Aromatic
Aliphatic
Molar Relationship
(gmol/gmol HC Degraded)
-7.50
-9.50
-6.00
+30.00
+38.00
-3.75
-4.75
+3.75
+4.75
Mass Relationship
(g/g HC Degraded)
-3.10
-3.50
-1.07
+21.50
+24.70
-4.60
-5.30
+0.77
+0.88
objectives: 1) to provide independent verification and
support of apparent ground-water plume containment
(intrinsic remediation) observed at the field sites; 2) to
allow the evaluation of long-term plume behavior under
an intrinsic remediation management approach applied
at the sites; 3) to evaluate the impact of source removal
on long-term plume behavior and plume life-time; and 4)
to guide the development of a long-term monitoring
plan.
Model Overview and Description
An analytical solution for the advection-dispersion
equation, with degradation (Domenico, 1987), was
applied, along with site-specific physical/chemical input
parameters, in these modeling activities. Equation 4-28
is the form of the advection-dispersion equation (ADE)
which describes contaminant transport in three
dimensions. The first three terms of this equation
describe contaminant dispersion in the x, y, and z
directions; the fourth term describes contaminant
advection with the moving ground-water, while the last
term on the left side of Equation 4-28 is a generic kinetic
term used to simulate processes which result in the
degradation of the contaminant during migration.
The analytical solution for the ADE given in Equation 4-
28 for a continuous source is provided in Equation 4-29
(Domenico, 1987). In Equation 4-29, C(x,y,z,t) =
concentration at point x,y,z and time t, mass/volume; C0
= initial concentration, mass/volume; vr = retarded
ground-water velocity = v/R, L/time; v = ground-water
velocity, L/time; R = contaminant retardation factor,
unitless; A, = decay constant, 1/time; •
erfc
V
7 YV
\/
ly 2}
1
2(«Tx)2
\
/
erf
V •
(z + Z)
1
_2(azx)2
erf
x-vrt[
4haL\T
1 +
1 vr ;
-]
2(«LVrt)2
-ly
1
(z-Z)
1
:2(azx)2
X
,
(4-29)
4-33
-------
Model Input Requirements
Hydraulic and chemical properties affecting the transport
of contaminants within the subsurface, and which are
incorporated into the multidimensional transport model
given in Equation 4-29, include aquifer pore water
velocity and dispersivity and contaminant retardation.
The following sections describe methods used in the
determination of these parameters for input into the
modeling effort at the study sites.
Pore Water Velocity
Aquifer pore water velocities were calculated based on
measured values of hydraulic gradient and hydraulic
conductivity and estimated values of total aquifer
porosity using Darcy's Law (Equation 4-30).
(4-30)
Where K = hydraulic conductivity, length/time; 3H =
change in ground-water table elevation, length; 3L =
corresponding horizontal distance between head
measurements, length; and 0 = total porosity, unitless.
Hydraulic conductivity values were estimated at 1.5
ft/day for the Layton site, and 2.4 ft/d for the Hill AFB site
based on results of slug tests conducted in April 1992.
Total aquifer porosity was assumed to be 38 percent at
Layton, and 25 percent at the Hill site. Finally, average
hydraulic gradient values of 0.01 ft/ft and 0.029 ft/ft for
the Layton and Hill AFB sites, respectively, were used to
estimate average pore water velocities observed during
the study of approximately 0.037 and 0.28 ft/day for the
Layton and Hill AFB sites, respectively. Details of the
slug tests conducted at these sites, along with all
measured field hydraulic data, are provided in Appendix
D.
Dispersivity
Based on current practice in the field, a longitudinal
dispersivity of 0.1 times the plume length was used at
each site. Transverse dispersivity was assumed to be 20
times less than longitudinal dispersivity. Vertical
dispersivity was assumed to be negligible (0.001 m)
since the product released has a density less than that
of water. In addition, the vertical distribution of
contamination indicated by multi-level sampling probe
data did not suggest significant vertical dispersion at
either field site. The resultant longitudinal and
transverse dispersivity values used in all modeling
efforts for the Layton and Hill AFB sites were 14 and 0.7
ft, and 17 and 0.85 ft, respectively.
Sorption Coefficient/Retardation Factor
The term retardation factor defines the reduction in
contaminant velocity in an aquifer due to its sorption to
aquifer solids. It is the factor by which pore water velocity
is reduced to estimate contaminant velocity in ground-
water systems. The retardation factor is a function of the
soil/water partition coefficient of the compound, bulk
density, and porosity of the aquifer as defined by
Equation 4-31:
(4-31)
9
where R = retardation factor, unitless; pb = soil bulk
density, mass/volume; and Kd = soil/water partition
coefficient, volume/mass.
Soil textural information was collected for each site using
cone penetrometry techniques during the initial site
assessment phase of the study. Based on these
results, the soil texture at the ground-water table
throughout the Layton site was found to be clayey silt to
silty clay, while at the Hill AFB site the aquifer was
predominantly sandy to clayey silt. The soil bulk density
assumed for the Layton aquifer was 1.15 g/cm3, while for
the Hill AFB site, a bulk density value of 1.30 g/cm3 was
used in all modeling simulations.
Compound soil organic carbon normalized distribution
coefficients, Koc, available from the literature were used
to provide estimates of compound Kd values using the
relationship between K^ and Koc as follows:
oe
(4-32)
where fOc = weight percent organic carbon in the aquifer
material = 0.3 percent for the Layton site, and 0.25
percent for the Hill AFB site.
Using the input data listed above, results of Kd and R
calculations for the typical compounds of interest at both
fuel release sites (benzene, toluene, ethylbenzene,
xylene, and naphthalene) are summarized in Table 4-7.
These data were used as input for the fate-and-transport
modeling carried out in this study.
Model Calibration
Both statistical and visual methods were used to select a
number of model input values which best matched
contaminant ground-water, concentrations observed
over time at the two field sites. Model parameters that
were varied to fit the measured data included: elapsed
time since contaminant release and various contaminant
degradation rates. Model parameters that were held
constant during all calibration and model simulation runs
included: contaminant sorption coefficients, aquifer
pore water velocities and dispersivity values, source area
dimensions, and the initial source strength. With the
hydraulic parameters and source dimensions set for the
sites, the other variables were changed to produce the
4-34
-------
Table 4-7, Input Data and Estimated Sorption Coefficients/Retardation Factors Used for
Model Input at the Field Sites Investigated in This Study
Layton Site
Hill AFB Site
Compound
c* (mL/g)
Kd (mL/g)
R
•Compiled from U.S. EPA (1991), and API (1994)
Kd (mL/g)
R
Benzene
Toluene
Ethylbenzene
Xylenes
Naphthalene
190
380
680
720
1300
0.57
1.14
2.04
2.16 '
3.90
2.7
4.4
7.2
7.5
12.8
0.48
0.95
1.70
1.80
3.20
3.5
5,9
9.8
10.4
17.9
best fit of observed field data for contaminant plume
centerline concentrations observed at the sites in
January 1994.
The best fit model result was selected based on the
statistic, mean square error (MSE), which was
determined for the output of the fate-and-transport
model for a range of input parameters during a sensitivity
analysis phase of the modeling effort. The MSE was
used to determine goodness of fit of the model along
the centerline transect, of the plume. The MSE
represents the sum of the square of the difference
between the actual data points and model estimates,
normalized by the number of data points available for
model fit evaluation. The lower the value of the MSE,
the better the model predictions fit the observed data.
Equation 4-33 gives the mean square error.
(^(observed) ~^((predicted))
(4-33)
where Cj(0bserved) = observed (measured) concentration
at point i, mass/volume; Cj(predicted) = predicted
concentration at point i, mass/volume; and n = number
of observations available for model fit evaluation. Once
trends in MSE values were identified, continual
refinement of the modeling effort was carried out by
visual data fitting to further minimize the calculated MSE.
The following step-wise procedures were carried out
during model calibration efforts:
1. Hydraulic properties for the aquifer at each field
site were set constant at the values specified
above.
2. The source vertical dimension, Z, and the
simulated plume elevation, z, were set constant at
the following values based on the thickness of the
contaminated water column observed at each site:
Z = 10 ft at the Layton site and 5 ft at the Hill AFB
site; z = 1 ft for both sites.
3. The source lateral dimension, Y, and contaminant
site characteristics, R and Co, were set constant to
the values appropriate for each site.
4. A, and t were varied over ranges applicable for each
contaminant and for each site to evaluate the
sensitivity of model output to these parameter
values and to determine those combinations of
parameters producing the smallest MSE values.
5. For a given t value producing minimal MSE values,
A, values were selected which provided best fit
simulations of the January 1994 measured field
dissolved contaminant ground-water data.
6. Based on a A, = 0 versus calibrated A, degradation
rates, a determination was made regarding
evidence for biologically mediated contaminant
degradation based on significant differences
observed between these two simulation runs.
7. Finally, the effects of source removal on the
lifetime of the plume and the maximum plume
travel distance were assessed using the site-
specific, field-data calibrated model.
Details of the application of this fate-and-transport model
to each of the field sites investigated in this study are
provided in Chapters 6 and 7.
4-35
-------
Use of the Model in Intrinsic Remediation
Assessment
As indicated above, the use of this ground-water fate-
and-transport model is essential for the integration of
contaminant- and site-specific parameters that control
th@ overall fate of hazardous chemicals at a given site.
This model can be used to assess existing monitoring
data and to make determinations of both short- and long-
term behavior of a contaminant plume under existing site
conditions. It is also essential in providing quantitative
estimates of the impact of source removal or source
control on the ultimate size and duration of a
contaminant plume. The model can be used effectively
to evaluate the desirability and cost-effectiveness of
implementing source removal at a given site, but it is only
as good as the data put into it. The model will not
provide meaningful results if the required input data
cannot be reliably determined, or if dynamic flow and/or
source release conditions at the site do not justify the
use of this constant, plane source, one-dimensional
ground-water velocity model.
4-36
-------
Chapter 5
Results and Discussion - Site Assessment and
Monitoring Techniques
Cone Penetrometer Techniques
Cone penetrometer testing (CPT) was used at the field
sites for the development of soil textural information for
use as input to contaminant plume modeling. In
addition, CPT measurements were coupled to the
placement and sampling of small diameter ground-water
monitoring probes during initial plume delineation
activities. A cone penetrometer consists of a sampling
probe (cone) which has a point that is instrumented to
record the end bearing resistance forces that develop
on the tip of the probe versus those developed due to
side shear resistance when the point is pushed into a
soil matrix.
The relationship between bearing and shear resistance
is correlated with soil textural characteristics so that cost-
effective soil stratigraphic information can be collected
rapidly at a site without the extensive use of more
conventional soil investigation efforts of soil sample
collection, visual inspection, and interpretation above
ground. Soil coring, soil cuttings, and surface exposure
of subsurface materials are all eliminated by using CPT
techniques. The use of CPT systems is severely limited
at sites containing gravel and has a practical working
depth limit of 75 to 150 ft depending upon subsurface
conditions and the specific equipment being utilized. If
CPT can be used at a given site, however, it can provide
a great deal of subsurface geologic information rapidly
and inexpensively.
Figure 5-1 is a schematic of a typical CPT system with a
detail of the forces that develop during data collection.
Recent advances in the use of CPT for site assessment
activities have included the fabrication of sampling tips
that allow the collection of discrete water samples from
the cone while collecting resistance measurements
(Zemo et al., 1994) and the collection of electrical
conductivity data with CPT for the in-place detection of
hydrocarbon contamination in saturated, coarse-grained
soils (Strutynsky et al., 1991). Specific procedures and
data interpretation methods are summarized by Klopp et
al. (1988) among others.
The CPT unit utilized in this study was operated in what
is termed the "position" mode, where the cone is
continuously pushed through the soil while resistance
data were collected and reported with a resolution of
approximately 0.25 m (10 in). The units can also be
operated in the "time" mode where the cone is stopped
at a selected depth and the dissipation in pore water
pressure that develops initially due to displacement of
water by the advancing cone is monitored over time to
yield point measurements of aquifer permeability.
Finally, if the soil texture allows, as was the case in both
field sites investigated in this study, once the tip is
removed from the soil after cone measurements, a
temporary or permanent sampling point can be placed in
the open hole without the expense and effort required
for placement of a conventional sampling well. Figures
5-2 and 5-3 show examples of the typical data generated
from the CPT analysis carried out in this study.
Because of the "real-time" nature of data collection
using CPT measurement techniques, and because of
the nature of soils at the two field sites used in this
study, CPT soil texture determinations and placement
and sampling of small diameter ground-water monitoring
probes were used to.refine the conceptual site models .
that existed prior to this study. This application of CPT
data collection coupled to piezometer well placement is
appropriate for initial site investigation activities-at sites
where no prior data regarding ground-water plume
characterization are available. These techniques can
also be effectively applied at sites where existing data
are limited in scope and detail as was exemplified from
the results obtained from CPT and ground-water probe
data collected at the Hill AFB site.
Original Hill AFB Conceptual Site
Model
The CPT and initial ground-water probe contaminant
concentration data collected from the Hill AFB site
provide an excellent example of the desirability of
collecting well distributed, high-density site
5-1
-------
Figure 5-1. Schematic of a typical CPT operation collecting soil resistance data for textural
analysis below the ground-water table.
characterization data early in the site assessment
process so that subsequent sampling and corrective
action efforts are carried out in an optimal manner.
Details of the Hill AFB site are contained in Chapter 6, so
only selected information will be presented here to
illustrate the strength of the this non-conventional site
assessment approach.
The Hill AFB site was the location of a former 18,000-
gallon underground storage tank (UST) that was
excavated in 1989. At the time of excavation, holes
were observed in the tank and petroleum odors were
detected in the tank pit. Five conventional ground-water
monitoring wells were installed at the site and soil gas,
soil boring, and limited ground-water monitoring data
collected from the site from 1989 to 1991 led to the
conceptual site model shown in Figure 5-4. Ground-
water elevation data collected from the five monitoring
wells indicated a westerly flow through the site (Figure 5-
5), with limited site data suggesting a plume migrating to
the southwest (Figure 5-4). Initial site investigation
activities were used to verify this site model using CPT
measurements. In addition, an assessment was made of
the representativeness of ground-water probe sampling
and field ambient temperature headspace
determinations of contaminant concentrations relative to
known conditions at the site. This assessment was
carried out during initial site assessment efforts as if no
data were available from the site.
Revised Hill AFB Conceptual Site
Model
Soon after site investigation activities began, it became
apparent that the initial conceptual model of contaminant
distribution and plume migration at the Hill AFB site was
significantly flawed. Ground probe samples that were
collected near the source of contamination within the
plume boundaries displayed in Figure 5-4 did not show
any hydrocarbon levels above background
concentrations. A decision was made to attempt to find
the plume, and CPT analysis and ground-water
piezometer sampling was moved into the north and
northwest regions of the site.
5-2
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5-4
-------
1HUI l+IA-02
s
Si
OF
BEIX WATER
CCXTAIOUTIOM
SCAUEJ
Figure 5-4. Conceptual site model for ground-water contaminant plume at the Hill AFB site
based on conventional site data collected during the period from 1989 to 1991 (Engineering
Science, 1991).
5-5
-------
4511.65
SOLD
ELEVATIOH FEET
ABOVE UEWi
SEA LEVEL
auuof
GROUNOWATER
FLOW dRECnOH
OBUNCIATER ulalUUK
(BtWDJIATER-CtUffiEirT 0.03ft/FT
WUII4U-02
© 4586.62
\
Figure 5-5. Ground-water elevation data collected from the Hill AFB site on April 23, 1991,
showing westerly ground-water flow across the site (Engineering Science, 1991).
5-6
-------
Figure 5-6 indicates the ground-water piezometer
locations used throughout the Hill site. The
piezometers were installed in numerical order; it is
important to note the relative location and sequence of
monitoring points indicated on this figure. Field
hydrocarbon screening data collected from these
piezometers were successful in identifying .the true
northwesterly direction of the hydrocarbon plume
emanating from the source area at the Hill site. This is
indicated by the ground-water concentration data
determined from field screening ambient temperature
headspace measurements shown in Figure 5-7.
CPT measurements collected in this study also provided
insight into ground-water flow conditions existing below
the Hill site through detailed ground-water level data.
(Figure 5-8) and soil textural characteristics (Figure 5-9)
observed at the ground-water table. Figure 5-8 is a
detailed potentiometric map generated from CPT point
water elevation data and clearly shows a significant
northwesterly component to ground-water flow that was
not evident from the data available from the
conventional, five-well monitoring network. Figure 5-9 is
even more instructive in that it clearly indicates a
distribution of high and low permeability deposits that
correspond to what appears to be an old stream bed
resulting in channeling of the regional westerly flow to
the northwest direction beneath this UST site.
Similar plume delineation efforts carried out at the
Layton site confirmed the accuracy of its initial site
conceptual model. It is not known how widespread the
findings for the Hill AFB site are in terms of the
development of a less than complete picture of actual
plume distribution and transport using limited,
conventional site investigation data. It was found,
however, that the use of CPT methods facilitated the
rapid collection of soil textural information and the
placement and, sampling of ground-water probes. This
. yielded a much more comprehensive picture of both
structural and chemical features of the subsurface than
is possible using the soil core sampling and laboratory
handling and analysis procedures routinely applied at
UST sites. This added information is combined with the
complete elimination of soil cuttings and large volumes
of contaminated ground-water that are often costly and
regulatorily challenging to manage, making the
screening techniques used in this study ideal for
application at many sites. The importance of additional
insights into local ground-water flow conditions that can
be provided by these CPT techniques, as in the Hill AFB
case, is also unquestionable, especially when
considering an intrinsic remediation management option
at a site. Accurate and representative plume delineation
is essential if successful and effective intrinsic
remediation monitoring and modeling are to occur.
Ambient Temperature Headspace
Measurements
Theory of Measurement Technique
The distribution of compounds between water and air
and water and soil can be described at equilibrium by the
Henry's law constant (H) and soil water partitioning
coefficient (Kd), respectively. These coefficients are
generally assumed to be independent of concentration
for linear partitioning relationships, with all other factors
constant. In an air/water/soil system, partitioning
between soil and air can be deduced from H and Kd
using mass balance considerations. Values of the
partition coefficients depend on several factors
including: temperature, pressure, relative humidity,
solutes in the water, and soil characteristics (organic
carbon content, clay content, cation exchange capacity
(CEC), etc.). In order to obtain consistent results when
determining distribution coefficients, those factors
which influence interphase partitioning must be
controlled. Also, the relative amounts of the phases
need to be constant. As so many soil characteristics
affect contaminant distribution, distribution coefficient
results would also be expected to be a function of soil
type.
The relationships between sample concentration and
headspace analysis can be developed following the
logic of Bobbins et al. (1989) and In-Situ, Inc. (1991), by
describing the equilibrium distribution of a compound
between the headspace and water phases using the
Henry's law constant as follows:
H = Ca/Cw
(5-1)
where H = Henry's law constant, volumewater/volunieajr;
C = concentration of solute, mass/volume; a = air; and w
= water.
Mass balance requires that the mass of contaminant in
the system remains the same after equilibrium
partitioning, or:
Mwo = Mw + Ma
(5-2)
where M = mass; and o = original sample before adding
headspace.
This mass balance can be expanded to the following
form with solute mass expressed in terms of the product
of volume, V, and concentration, and with Henry's law
substituted for the equilibrium water concentration, Cw:
VwCwo = VwCa/H + VaCa
(5-3)
5-7
-------
180-
160-
140-
120-
Q) , ^ ,
B101
C
1
U 801
601
40-
20-
0 -
-20.
• Single Level
© Multilevel
© Monitoring Wells
19
•34
•43
•04
'02
•26
• 06
'03
•05
•28
©37
07 *09
'27
'13
'18
31
'32
'20
25
"42
4
01
-20 0
20
40 60 80 100
North Coordinates (ft)
120 140 160 180
Figure 5-6. Ground-water piezometer and monitoring well locations placed throughout the Hill
AFB site in July 1992.
5-8
-------
180'
160 -
Headspace Derived Ground Water
TPH Concentrations (|u.g/L)
01
• Single Level
© Multilevel
O Monitoring
-20
20
40
60 80 TOO
North Coordinates
-1—
120
140 160 180
Figure 5-7. Initial ground-water plume hydrocarbon data developed from field screening
headspace analyses conducted at the Hill AFB site, July 1992.
5-9
-------
HILL AFB - BLDG 1141 POTENTIOMETRIC MAP
180
160 -
14O -
120 -
1BO
1GO
HO
120
- 100
1
'•3
-20
-20
-20
O 20 4O 60 SO 100 120 1*O 1.60
North Coordinate (ft)
un, «r-«"8; 9round'water elevation map generated from CPT installed monitoring probes at the
Hill AFB site in July 1992.
5-10
-------
180-
• Single Level
© Multilevel
O Monitoring Wells
-20
-20
20
40 60 80 TOO 120
North Coordinates (ft)
140 160
180
Figure 5-9. Textural map for soils at the ground-water table generated from CPT data collected
at the Hill AFB site in July 1992.
5-11
-------
This relationship can be rearranged to an expression
where headspace concentration is linear with initial
sample concentration if the headspace to liquid volume
ratio and Henry's law constant are kept constant:
(5-4)
Henry's law constant depends on temperature and
matrix properties (Griffith et al., 1988; Bobbins et al.,
1989). Volume ratios, matrix properties, and
temperature ideally should be kept constant so that the
relationship between sample and air phase
concentration is the same among samples and
standards. This may not be easy to do as ambient
temperature can vary considerably at a site and
contaminants can significantly influence matrix
properties (Griffith et al., 1988). The effect of variations
in Henry's law constant can be mitigated somewhat if the
change in 1/H is small relative to Va/Vw. Larger air to
water volume ratios will also make the method less
sensitive to variations in Henry's law constant. However,
increasing Va/Vw will further dilute the contaminant and
decrease the sensitivity of the method to detect site
contamination. With the choice of a given set of
operating conditions comes a trade-off between
temperature sensitivity and the ability to measure low
contaminant concentrations.
For a linear response, detector response to a specific
compound in the headspace can be described by a
response factor as follows:
(5-5)
where D = detector response, mV; R = response factor,
mV/mass of compound; and i = a specific compound.
In a sample with multiple analytes, the concentration of
an individual compound can be written in terms of the
total analyte concentration.
(5-6)
where X| = mass fraction of total solutes represented by
component i in sample; and t = total.
If individual analyte concentrations are expressed as a
fraction of the total sample analyte concentration as
shown in Equation 5-4, and the result is used to
represent headspace concentration from Equation 5-5,
total detector response to all solutes is as follows:
I H( Vw J
(5-7)
where n = the total number of solutes in the sample.
Every term in the summation contains Ctwo. s° it can be
moved outside the summation to yield:
' - '•'two,
HJ Vw
(5-8)
If this summation is constant, detector response is linear
with the TPH (Ctwo) in the water sample. For the
summation to be constant with variations in Ctwo, the
relative distribution of contaminants (Xjs) should remain
constant. A sample richer in more volatile organics will
have a larger fraction of the organics partitioned into the
headspace and will produce a larger detector response
for the same level of total contamination than one
without high concentrations of volatile contaminants.
As indicated in Chapter 4, the equilibrium distribution of
a compound between the water and soil is described by
a soil/water partition coefficient as follows:
Kd = CS/C,
'W
(5-9)
where K^ = soil water partition .coefficient
(volumewater/massSOj|); and s = soil.
When water and headspace are added to a soil sample,
the following mass balance applies:
Mso = Ms + Mw + Ma
(5-10)
When solute masses are expressed in terms of
concentrations and Equations 5-1 and 5-9 are
substituted for the water and soil equilibrium
concentrations, respectively, the following equation
results:
WCSO = W KaCa/H + VwCa/H + VaCa
where W = weight of soil, mass.
(5-11)
This can be rearranged to yield an expression for the air
phase concentration which is a linear function of soil
sample concentration:
ca=-
csow
V
fWKd
H
V
V
(5-12)
This expression makes it possible to develop the
following relationship for soils in the same way that
Equation 5-8 was developed for water:
5-12
-------
CtsoW
V
w
n
£
i
Ry
i ^soi
WKdi
lHiVw
+
1
Hi
V
' V
a
W j
(5-13)
Detector response is linear with TPH (CtSo) if distribution
coefficients, mass, and volume ratios and distribution of
contaminants remain the same from one sample to the
next.
Previous Studies
Previous work with ATM analysis was conducted with
rigid sample containers (Holbrook, 1987; Bobbins et al.,
1987; Griffith et a|., 1988; Pavlostathis and Mathavan,
1992; Roe et al., 1989). This method for ATM analysis
commonly involves setting up air and water
compartments in a vial capped with a Teflon-lined septa.
After the analyte(s) equilibrate between/among the
compartments, a determination of the original sample
contamination is made by injecting some of the
headspace gas onto a GC for identification and
quantification of the constituents it contains.
Composition of the headspace is used to quantitate the
analyte in the unpartitioned aqueous or soil sample.
When rigid containers are sampled, the containers either
leak, which dilutes the headspace, or a vacuum is
created during sampling. The vacuum can slow the flow
of gases to, and decreases the response of, the
detector, and is highly undesirable.
In the Griffith et al. (1988) study, a methodology was
explored for analyzing benzene, toluene,
ethylbenzene, and xylene contamination in soil.
Analyses were made by injecting headspace gas onto a
portable GC with a packed column and FID. Standard
and sample systems were prepared in 40-mL volatile
organic analysis (VOA) vials. The standard systems were
composed of 30-mL liquid and 10-mL headspace
volumes. The soil systems were prepared by adding 2
to 4 g clean soil to the VOA vial, evacuating air from the
vial, spiking the vial with aqueous standard, adding an
amount of water such that the liquid to headspace ratio
was the same as the standard, and allowing enough air in
to bring the pressure to atmospheric. Loss of volatile
contaminant from the system was minimized by adding
ihe contaminant and water under a vacuum. This
method of introducing the contaminant does not
represent the situation of an actual field sample where
the contaminant must desorb from the soil in order to be
distributed among the compartments.
Soil contamination was estimated for a sample with all the
contaminant in the soil before partitioning. The
estimation was made by comparing headspace readings
to those of aqueous standards and assuming that the
contaminant was distributed entirely between the liquid
and headspace (complete extraction of the soil). A mass
balance allowed an estimation of the original,
unpartitioned soil concentration.
Systems were contaminated with toluene at seven soil
concentrations from 0.005 to 16 mg toluene/kg of soil
(Griffith et al., 1988). Measured soil concentration levels
produced extraction efficiencies with a mean percent
recovery across contamination levels of 93.6 percent
with a standard deviation of ± 27.7 percent. The
relationship between contamination level and percent
recovery appeared to be random, however.
Another set of systems evaluated by Griffith et al. (1988)
was contaminated with a mixture of equal amounts of
benzene, toluene, ethylbenzene, and xylene. Nine
concentration levels from 0.78 to 6.71 mg/kg of each
analyte were represented. Average recoveries of
benzene, toluene, ethylbenzene, and o-xylene were
96, 93, 99, and 114 percent, respectively.
The above tests were conducted with a very fine sand
fraction of a sandy soil with low organic carbon content.
One final test by Griffith et al. (1988) was used to
compare recoveries of the BTEX components from
seven sieved fractions of this soil. Soil grain size was
found to have no effect on recovery efficiency off the
sandy test soil for any of the compounds investigated.
Temperature effects were explored by analyzing the
headspace of toluene contaminated samples at different
temperatures. The response to toluene more than
doubled from 10 to 40 °C for samples with both 0.35 and
3.5 mg/L toluene aqueous concentrations. This
sensitivity to temperature was likely due to the large ratio
of liquid to headspace volume used in these systems
(approximately 3:1).
Roe et al. (1989) explored a similar technique for
analyzing BTEX in aqueous samples. Forty-mL VOA
vials were filled with samples or standards. The vials
were prepared for analysis by removing 10-mL of liquid
and allowing time for the analytes to equilibrate between
compartments. The headspace was injected onto a GC
with a capillary column and PID and FID in series. BTEX
components of samples were identified and quantitated
by comparison to standards.
In the Pavlostathis and Mathavan (1992) study,
soil/liquid/air systems were prepared in 8-mL amber vials
capped with Teflon faced septa. Trichloroethylene
(TCE) and toluene were injected into the systems and
allowed to equilibrate. Samples of the air and water
phases and a methanol extract of the soil phase were
injected into the purge chamber of a purge-and-trap
apparatus. The traps were desorbed onto a GC with an
electron capture detector (ECD) and a flame ionization
detector (FID) in series. Laboratory contaminated
systems were made with TCE and toluene, both
separately and together. Soil concentrations in these
systems of TCE and toluene were 1,015 and 600 |ag/g,
5-13
-------
respectively. A sample of the same soil which was
contaminated in the field was also analyzed in this way.
The field sample systems had methanol/water liquid
phases from 0 to 81 percent methanol. Dimensionless
Henry's law constants and soil/liquid partition
coefficients (K^) were calculated for laboratory and field
contaminated systems.
A comparison of the laboratory contaminated systems
showed that the presence of TCE decreased the Kj of
toluene by more than an order of magnitude.
Comparison of laboratory and field contaminated
samples showed that the Kd of toluene was also
concentration-dependent. This indicates that there are
possible matrix effects from other contaminants, and
partition coefficients might not be constant from sample
to sample even at a given field site. A constant partition
coefficient is one of the requirements for linearity in
Equations 5-8 and 5-13, and partition coefficient
variability can be a significant limitation to the general use
of ATH methods for soil and ground-water assessment
activities.
Holbrook (1987) described an investigation of an ATH
method for analyzing soils for volatile hydrocarbons. A
pint jar was filled halfway with soil and the top was sealed
with aluminum foil. After the system was agitated for 2
hours and equilibrated for an additional 2 hours, the foil
was pierced with the probe of a portable PID and a
reading was taken between 5 and 10 seconds afterward.
The PID was calibrated with a benzene standard and
results were reported as ppm benzene in the
headspace. Soils which had been spiked with gasoline
between 1 and 1,500 ppm were analyzed in this
manner. There was no response to unspiked soil and
some response to the 1 ppm soil. The response was
non-linear through the concentration range
investigated. Response began to decrease between
75 and 150 ppm and continued to drop with increasing
concentration. Readings were unstable at and above
300 ppm. This was explained as a quenching of the PID
at high vapor phase concentrations, a known
characteristic of PIDs.
ATH results using a PID detection system were
compared with SW 846 Method 8240 (U.S. EPA,
1986d) for samples from a leaking underground storage
site and a refinery landfarm. Method 8240 analyses
were used to quantify BTEX components from both
sites and naphthalene from the landfarm. When ATH
results were less than 30 ppm benzene, Method 8240
was non-detect for BTEX and naphthalene. When the
ATH results indicated more than 70 ppm benzene,
BTEX and naphthalene were detected in all samples
using Method 8240 procedures. The ATH method with
PID responds to any ionizable constituent in the
headspace, not just those reported in Method 8240
analysis, and consequently would be expected to be
more sensitive for samples containing constituents
detectable with a PID.
The procedure described in Robbins et al. (1989) is the
.closest to those utilized in this study. ATH systems
were set up in a quart-sized polyethylene bag. The bag
was penetrated and sealed to a tube and a three-way
valve. One port of the valve was connected to a portable
FID. The three-way valve routed air from the bag to the
FID in one position and from ambient air in the other
position. Compartment ratios were kept consistent
throughout the study, with a 100-mL aqueous
compartment and 25-g soil compartment. The air
compartment volume was consistent as bags were filled
with air to an average volume of 1391 mL (n=8, CV = 1.4
%). After the headspace was pumped into the bags with
a hand pump, the bags were agitated by hand in a water
bath until the headspace was routed to the detector for
analysis. The detector was calibrated with a methane
standard and ATH results were reported in ppm
methane.
Separate tests with equilibration times between 0.5 and
8 minutes and aqueous solutions of benzene, xylene, a
mixture of benzene and xylene, and a gasoline
contaminated ground-water sample, showed that the
system generally equilibrated within 4 minutes. The
benzene and gasoline contaminated soil samples
equilibrated within 30 seconds (Robbins et al., 1989).
ATH measurements were made of a single benzene
standard at temperatures between 11 and 41 °C. The
system was insensitive to these temperature
fluctuations within the precision of the test and can be
attributed to the relatively large headspace in this
system. The headspace-to-liquid-volume ratio of this
system is approximately 13:1, whereas the system in the
Griffith et al. (1988) study, which was much more
temperature-sensitive, had a headspace-to-liquid-
volume ratio of 1:3. This finding-strongly indicates that
for reproducible, temperature-insensitive ATH
measure-ments, headspace-to-liquid-volume ratios
should be as high as possible without compromising
contaminant sensitivity. Values between 10:1 and 20:1
should be sufficient to yield robust measurements, with
acceptable low method detection limits.
The importance of constant relative distribution of
analytes to the linearity of results with total contamination
was demonstrated by comparing ATH results of
aqueous benzene/xylene solutions with the same total
contamination and different ratios of constituents.
Response increased by a factor of 3 as benzene
increased from 0 to 100 percent of total contamination.
The relationship between contamination level and ATH
response was linear for the following cases (Robbins et
al., 1989).
5-14
-------
1. Aqueous benzene (n= 5, correlation coefficient =
0.997).
2. Aqueous xylene (n = 5, correlation coefficient =
0.999).
3. Dilutions of a gasoline contaminated ground-water
sample (n = 5, correlation coefficient = 0.997).
4. Benzene contaminated soil (n = 5, correlation
coefficient = 0.957).
5. Soil spiked .with gasoline (n = 6, correlation
coefficient = 0.989).
The ATH method was used at two LIST sites (a motor
pool and a service station) to measure contamination of
ground-water samples from monitoring wells. Duplicate
samples were analyzed in the laboratory for BTEX. The
laboratory analysis was done with a headspace
technique on a GC with a capillary column and PID and
FID detectors in series. Results of the two methods
were in different units but contours drawn from the total
BTEX, and ATH data had similar shapes. The log (total
BTEX) versus log ATH headspace relationship was linear
(n = 12, correlation coefficient = 0.945). ATH and
laboratory analyses were also compared for samples
collected from a bailer at various intervals during purging
of a monitoring well at these sites. Total BTEX and ATH
measurements decreased in a similar fashion during the
purging process. Finally, laboratory and ATH analyses
were compared at 10 depths of a soil core aUhe motor
pool site. The shape of the contamination profile was
similar between methods.
The results reported by Bobbins et al. (1989) support
the use of ATH methods for rapid site screening during
the initial site assessment phase when detailed plume
delineation is taking place. Their results provide strong
evidence that ATH methods can be used to quantify
general relationships of ground-water and soil
contamination that support more analytically rigorous
laboratory findings if ATH methods are carried out using
procedures that generally support the assumptions of
linearity. In general, the preferred methods for
conducting field ATH analyses include the use of:
1. Large headspace to aqueous volume ratios 10:1
, to 20:1 to minimize the effect of temperature
change on the distribution of contaminant
between the aqueous and air phases.
2. Use of a detector that provides a linear response
to organics over a wide range of contaminant
concentrations. The FID has this characteristic
(Perry, 1981) and is generally preferred over a PID
which is more sensitive to moisture and has a
narrower linear range than a FID (EPA, 1990b;
Holbrook, 1987).
3. The use of ATH methods must be based on a
general knowledge of the nature of the
contamination being screened for. As indicated in
the work by Bobbins et al. (1989), for a given
contaminant distribution the ATH method
provides consistent and representative
indications of the level of contamination in a given
sample. However, when contaminant composition
varies significantly between sites or within a given
site, this contaminant level/ATH relationship
begins to lose its validity.
Field Versus Laboratory Generated
Data
Two data sets (July and December 1992) were collected
in this study from each field site to evaluate the
representativeness of ATH field screening techniques,
and were compared to results from standard laboratory-
generated purge-and-trap hydrocarbon measurements.
Because no component speciation was carried out on
the headspace measured in the field, the comparison
between field and laboratory generated results was
based only on total hydrocarbon determinations using
serial dilutions of a gasoline saturated water standard in
the field and hexane equivalent concentrations for
laboratory results. Baw data for this comparison study
are included in Appendix E, while Tables 5-1 and 5-2
provide a quantitative summary of findings.
As indicated in Tables 5-1 and 5-2, the relationship
between field and laboratory determined ground-water
TPH results was quite variable, with the ratio of
field/laboratory-determined concentrations ranging from
a low of 0.0 to -a high of 446. This ratio was generally
consistent for a given sampling location between the
two sampling times; however, some ratios varied by one
to two orders of magnitude (i.e., CPT-08 from the Hill
AFB site and CPT-09 from the Layton site). The average
ratio of field to laboratory determined ground-water
hydrocarbon concentrations was greater than 1 for both
sampling events at both sites and ranged from 4.9 to
32.1. This result suggests that the field ATH
procedures used in this study provided a conservative
estimate of contaminant concentration from most
sampling locations by a factor of 5 to 30.
These field and laboratory comparison data are plotted in
Figures 5-10 to 5-15 to explore the sensitivity of the field
method for the quantitative prediction of differences in
concentration observed throughout the sites based on
laboratory determined purge-and-trap data. Figure 5-10
shows a "linear regression of field versus laboratory TPH
data for the Hill AFB site collected during both July and
December 1992. One data point, that of MLP-44 for the
July data set, was excluded for this analysis because it
was identified as a clear outlier.
5-15
-------
Table 5-1. Field Versus Laboratory Total Hydrocarbon Results from the Hill AFB, UT, Field
Site Collected July and December 1992
Hill AFB -7/92
Sample
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I^LP39(9.7)
fiCPS§fl6'.2) "
MtNiiXiO^r"
MtP44(12.9J "
MW3
<*******«««««yj *vi ***"""**«***»•
MW4
MWS
'"""""'"ftSWg" ' ""
Watho
-------
Table 5-2. Field Versus Laboratory Total Hydrocarbon Results from the Layton, UT, Field
Site Collected July and December 1992
Layton - 7/92
Sample
CPT-bi
Fiefd
"ATHTiesulls
(ng'A-j
441
-GPT-02 : '872
CPT03 r~ ~4",5D7
"CPT:^~ll ~
-------
60000
y » 0.67x + 278, r2 = 0.9843
p = 0.0001
0 10000 20000 30000 40000 50000 60000 70000 80000 90000
Lab P&TTPH Concentration (ng/L)
Figure 5-10. Relationship between laboratory- and field-determined ground-water TPH
concentrations for Hill AFB for data collected July and December 1992.
_ 2-
D
5
"tn
(D
o;
T5
Q)
o
1 -2
-3'
-4-U
0 10000 20000 30000 40000 50000 60000 70000 80000
Lab P&T TPH Concentration (|a.g/L)
Figure 5-11. Normalized residuals for Hill AFB data shown in Figure 5-10.
5-18
-------
140000
y = 1.7x + 3680, r2 = 0.6883
p = 0.0001
10000 20000 30000 40000 50000
'. Lab P&TTPH Concentration (|j.g/L)
60000
Figure 5-12. Relationship between laboratory- and field-determined ground-water TPH
concentrations for Layton for data collected July and December 1992.
c
jO
Jr
i
GO
o
"^
CD
Qd
T3
'•o
b
T3
C
OO
O1
2.5'
2-
1.5'
1 ,
1
.5'
0
-.5
_1
-1.5
-2
.O
O °
o
o
1
0 O
1 § 0
"~BL O •
TO
0 0
0
° 0
0 10000 20000 30000 40000 50000 60000
Lab P&TTPH Concentration (ng/L)
Figure 5-13. Normalized residuals for the Layton data shown in Figure 5-12.
5-19
-------
u
x
£
I
33
£
140000
120000
100000
80000
60000
40000
20000
0
y = 1.32x + 2160, r2 = 0.6415
p = 0.0001
0 10000 20000 300QO 40000 50000 60000 70000 80000 90000
Lab P&T TPH Concentration (p,g/L)
Figure 5-14. Relationship between laboratory- and field-determined ground-water TPH
concentrations for the combined Hill AFB and Layton data collected July and December 1992.
O
4
« 3
o
J n
-------
As indicated in the figure, a statistically-significant
relationship was found between laboratory and field
data, with a background field concentration of 279 |j,g/L
found when laboratory results indicated a 0 TPH
concentration. The slope of this relationship is less than
one, however, indicating that for the Hill AFB site, when
true ground-water concentrations (as defined by
laboratory purge-and-trap results) exceed 842 |ag/L,
field ATM values under predict actual ground-water TPH
concentrations. Figure 5-11 is a plot of the normalized
residuals for the regression relationship shown in Figure
5-10. If the regression relationship is a valid description
of the regressed data, the normalized residuals plot
should be randomly distributed when plotted against
laboratory purge-and-trap concentration results. This
random distribution requirement appears to be met by
the data in Figure 5-11, suggesting that the assumption
of linearity between field and laboratory determined
ground-water concentrations is a valid one for the Hill
AFB site data.
Figure 5-1-2 shows the laboratory versus field ground-
water TPH relationship observed for the Laytqn data.
Data from the Layton site were more scattered than
those from the Hill site but also produced a statistically-
significant relationship based on a 95 percent
confidence interval. Again, a data point (CPT-08 from
the December sampling event) was visually identified as
an outlier and was not included in this analysis'. At the
Layton site, background field ATH readings indicated
much higher background ground-water concentrations
than was observed at the Hill AFB site. Here, a ground-
water concentration of 3,680 p,g/L was indicated from
ATH readings before laboratory purge-and-trap methods
detected TPH contamination. The slope of the Layton
relationship was greater than one, however, indicating
that unlike the Hill AFB data, field ATH measurements
consistently over predicted laboratory purge-and-trap
ground-water concentrations by nearly a factor of 2.
Figure 5-13 shows the normalized residuals for the
Layton data set, suggesting the validity of the
regression relationship found for the laboratory versus
field determined ground-water TPH concentrations at
the Layton site.
Figure 5-14 shows the combined concentration data
from the Hill AFB and Layton sites with the two outliers
removed from the analysis as mentioned above. For this
combined data set; a significant relationship between
laboratory and field determined ground-water TPH
concentrations exists. This relationship indicates that
throughout the range of concentrations determined at
the two sites, the ATH method was found to consistently
overpredict actual laboratory-determined ground-water
concentrations. The normalized residuals indicate an
increasing residual value with increasing ground-water
concentrations, suggesting an increase in uncertainty of
ATH predictions with increasing concentrations for the
combined field data.
The data summarized above for the Hill AFB and Layton
sites support the,findings of Bobbins et al. (1989) which
suggest that for a given distribution of contamination, for
example, at a given site, it can be expected that field
ATH measurements provide a consistent and
representative indication of the level of contamination in
a given sample. As indicated above based on individual
site results versus those from the combined data set,
specific laboratory versus field concentrations
relationships were site-dependent. ATH measurements
appeared more sensitive to the contaminant distribution
found at the Layton site compared to that observed at
the Hill AFB site based on the slope of the laboratory
versus field concentration relationships observed at
each site. The slope of this relationship was less than
one at the Hill AFB site, while it was nearly two at the
Layton site. In addition, the combined data set
normalized residuals suggested that the combined
regression loses its accuracy at high ground-water
concentrations. This later finding was not observed for
either of the individual site data sets.
The results of the individual site laboratory versus field
concentration relationships can be rationalized based on
the observation of free product at the Layton site and
the lack of such an observation at the Hill site. It follows
that the fraction of aromatic, volatile, constituents
dissolved in the ground-water at a site with evidence of
free product, or high levels df residual saturation would
be higher than if this free product did not exist. With a
higher fraction of volatile constituents in the aqueous
phase, a higher concentration of hydrocarbon in the
equilibrated headspace would result, with a higher ATH
response, and higher method sensitivity, expected for a
given aqueous phase TPH concentration.
The findings of this field data evaluation are significant in
that they suggest there is a general relationship
between laboratory and field ATH determined
hydrocarbon concentrations, but this relationship is.very
much site-specific. The use of these field ATH
measurements appears then to be in the initial site
assessment phase, as was done in this study, where
rapid, semi-quantitative results generated from the
method are used for detailed plume delineation efforts.
Field ATH measurements can be used to effectively
guide initial ground-water quality investigations and to
optimize ground-water monitoring probe and monitoring
well placement for long-term site monitoring. Once this
initial screening is completed, however, it appears that
laboratory analyses are necessary to provide accurate
ground-water quality data for further site fate-and-
transport and intrinsic remediation evaluation.
5-21
-------
-------
Chapter 6
Results and Discussion-^Site 1
Building 1141 Site, Hill Air Force Base, Utah
Site Description and Site History
This site is located in the west area of Hill Air Force Base
(HAFB), south of the city of Ogden, Utah. The site is
immediately north of Building 1141, located at the
convergence of Aspen Road and 6th Street (Figure 6-
1). Surrounding buildings are used for maintenance,
motor vehicle offices, and for storage of U.S. Air Force
railroad engines. Underground utilities are located on
and adjacent to the site property. Building 1141 was
used by the Air Force for small vehicle maintenance. An
18,000-gallon UST was located in the subsurface
immediately northwest of Building 1141 (Figure 6-1).
Geologic Setting
HAFB is located along the Wasatch Front of northern
Utah. The area west of the Wasatch Front was the site of
prolonged marine basin and shallow water sediment
accumulation during earliest Precambrian time through
the Paleozoic era. Structural deformation and limited
depositional events persisted until Pleistocene times
when lakes inundated the Wasatch Front area
(Engineering Science, 1991). The site lies on sands
and gravels of the ancient Weber Delta and associated
beach deposits. These deposits coalesce with similar
sediments of adjacent and smaller deltas to the north
and grade to the west and south into finer grained
lacustrine and flood-plain deposits. Shallow soils directly
beneath the site consist of interbedded sands, silts, and
clays (Engineering Science, 1991).
Generally, the regional shallow and deep ground-water
flow direction through the fluvial and lacustrine deposits
underlying the base is from the mountains on the east
toward the Great Salt Lake on the west. Water level
information gathered at the site indicates that the
regional flow direction of the shallow ground-water table
is also from east to west.
The regional hydraulic conductivity of the
unconsolidated sediments underlying Hill AFB has been
reported to be in the range of 0.1 to 1 cm/s. However,
hydraulic conductivity values of the shallow soils at the
Building 1141. site, as determined by slug tests per-
formed on selected wells by Engineering Science, were
found to be significantly lower between 1.0 x 10'5 and
7.7 x 10'5 cm/s (Engineering Science, 1991).
Previous Site Activities
In December 1989, an 18,000-gallon bare steel gasoline
UST was excavated and removed from the subsurface at
the Building 1141 site. No free-phase hydrocarbons
were observed at the time of removal although
observations of odors and holes in the UST indicated
that a release may have occurred. To better document
environmental conditions during tank removal, two soil
samples and a ground-water sample were collected and
analyzed for benzene, toluene, ethylbenzene, xylenes
(BTEX), and total petroleum hydrocarbons (TPH). The
analytical data from this sampling event indicated that
residual and dissolved BTEX and TPH contaminants
were present in the soil and shallow ground-water,
respectively (Engineering Science, 1991).
An Abatement and Site Check Report was prepared by
HAFB Environmental Management Directorate
personnel and submitted on June 28, 1990 to the State
of Utah Department of Health, Division of Environmental
Health, Bureau of Solid and Hazardous Waste.
A January 2, 1991, Investigation Report (Engineering
Science, 1991) summarized results from field
investigative activities which were conducted in October
and November 1990. These activities included a soil
gas survey, soil borings, installation of ground-water
monitoring wells, collection of soil and ground-water
samples for laboratory analyses, slug tests, and a site
.survey.
These activities documented the presence of limited
residual phase and dissolved hydrocarbons in soil and
ground-water beneath the site. The highest levels of
BTEX and TPH contaminants in soils were detected in
the nested pair of borings and. wells (MWU1141A-03
and MWU1141A-06, Figure 6-1), located 5 ft west of the
former UST location. Only one other soil sample, from
soil boring MWU1141A-04, located approximately 50 ft
6-1
-------
AFPRmUTE
OF BEIX
SOIL COXTAUDUmOiC
UlUt141A-02
kXlUII Of UMJJCTK
SOB. CtflTUlflXATlDM
AS OOJXUTED BT IKE SOB. CAS'SBffET
SOLS r-sr
Figure 6-1. Site map for Hill AFB, UT, Site 1141 (Engineering Science, 1991).
6-2
-------
southwest of the former UST, had detectable xylene
concentrations. Ground-water contamination in the form
of dissolved BTEX and TPH was determined to be
restricted to the upper portion of the shallow aquifer and
only immediately downgradient and adjacent to the
former UST.
A second round of ground-water sampling was
performed in March 1991. In addition, new flush mount
surface well completions were installed to better protect
the wells. A May 31, 1991, report (Engineering
Science, 1991) summarized ground-water analytical data
and documented surface elevations for newly
completed wells. Levels of dissolved contaminants
found during the March 1991 sampling event were very
similar to those documented in November 1990. Of
significance was the higher TPH value for MWU1141A-
03 in the March 1991 data. In addition, the laboratory
stated that the TPH gas chromatograph profile for the
March 1991 sample more closely resembled gasoline,
while the November 1990 sample resembled diesel. For
analysis purposes, the laboratory used a diesel standard
for the November 1990 sample, while a gasoline
standard was used for the March 1991 sample. The
results of the analyses imply that some volatile
constituents of the hydrocarbon contamination
persisted in the shallow aquifer and vadose zone at the
site. The apparent increase in volatiles may have been
due to the transfer of more mobile gasoline constituents
from the vadose zone due to increased infiltration of
water to the aquifer due to spring thaws. .
Gasoline and/or diesel related residual and dissolved
contaminants appear to have migrated from the former
UST, due to either tank leakage or surface spills, into
near surface soils and into the shallgw ground-water
system. The lack of free-phase product indicates that
the bulk of the released product was bound in capillary
pore spaces of the shallow soils. The restricted extent
of contamination was likely due to seasonal fluctuations
in the water table and indicates that migration occurred
both laterally and downward within the former sandy fill
material and into native soils immediately surrounding
the UST (Engineering Science, 1991).
Migration of contaminated ground-water was minimal,
presumably due to the low hydraulic conductivities of
the native sediments and to the relatively low levels of
BTEX and TPH contaminants present in the upper
portion of the shallow aquifer. No dissolved
hydrocarbon was detected in the upgradient well
(MWU1141A-02) and what was thought at the time to be
a downgradient well (MWU1141A-04) during the
November 1990 and March 1991 sampling events.
Moreover, lack of contamination in the bottom depth of
the nested pair of monitoring wells (MWU1141A-06, 10
ft below the ground-water table and MWU1141A-03
screened across the ground-water table) demonstrated
that vertical migration of dissolved hydrocarbons had not
occurred by March 1991.
UWRL Site Activities
As indicated in Chapter 5, site investigation protocols
utilizing CPT soil textural data collection and small
diameter ground-water piezometer sample placement
for detailed plume delineation were evaluated in July
and August 1992 at the Hill AFB site. CPT data were
collected at 44 locations throughout the Hill AFB site to
augment the existing monitoring network consisting of
five conventional ground-water monitoring wells. CPT
soil profile data collected at the Hill AFB site successfully
identified a subsurface stream channel (Figure 5-9)
existing at the ground-water table which produced a
significant northerly flow component to the ground-
water flow observed at the Hill AFB site (Figure 5-8).
This modified flow pattern significantly changed the
conceptual model of the Hill site, resulting in a plume
that was found to move north and west from the former
UST location, rather than west and south (Figure 6-1) as
was originally proposed from limited site data available
prior to this study. With the additional ground-water data
collected in this study, it was found that MWU1141A-04
was an upgradient monitoring point, not a downgradient
one which was initially thought. No true downgradient
monitoring location actually existed at the site with the
original monitoring network in place in March 1991 as
shown in Figure 6-1.
Seven sampling events were used at the Hill AFB site to
describe the distribution and movement of contaminants
and electron acceptors taking place at the site between
April 1992 and January 1994. These sampling events
included: April 1992, prior to installation of the
piezometer sampling network; July 1992, immediately
following installation of the piezometer sampling
network; November to December 1992; February 1993;
June 1993; September 1993; and January 1994.
Ground-water hydrocarbon composition data for these
sampling events are summarized in Appendix F, while all
nutrient, iron and manganese data collected at the Hill
AFB site are summarized in Appendix L. These data
were used to determine steady-state plume conditions
and to estimate total mass and mass center values for
these various analytes at the Hill AFB site over time as
prescribed by the intrinsic remediation assessment
protocol described in Chapter 4.
Determination Of Steady-State Plume
Conditions
Contaminant Centerline
Concentrations
Once the true centerline position was determined
during site assessment activities that took place in July
1992, a centerline transect was used to make a
determination regarding'steady-state plume conditions
6-3
-------
at the Hill AFB site. This centerline transect was
composed of data collected from the following single-
level ground-water piezometers (see Figure 5-6 for their
specific locations throughout the site): CPT-18 in the
source area, and downgradient locations within the
dissolved plume at CPT-07, CPT-09, CPT-23, CPT-12,
CPT-29, CPT-15, CPT-21, CPT-30, and CPT-19.
The traditional compounds of concern from a health and
fate-and-transport perspective include BTEX and
naphthalene. These compounds were used along with
TPH to generate centerline concentration profiles for
each sampling event to evaluate plume steady-state
conditions at the site. Appendix F contains summarized
BTEX, naphthalene, and TPH data for each sampling
event, while Figures 6-2 through 6-5 show the plume
centerline concentration data for combined BTEX and
TPH concentrations at the Hill AFB site over time,
respectively.
It appears from these figures that a significant decline in
centerline concentrations for both BTEX components
and TPH occurred in the dissolved plume between July
and December 1992. The expanded concentration
scale plots of Figure 6-3 and 6-5 indicate that following
this initial decline in centerline concentration, the
concentration profile for BTEX and TPH constituents
remained at pseudo-steady-state. While both a BTEX
and a TPH concentration spike were observed in
monitoring point CPT-21, no consistent patterns of
increasing concentrations downgradient of the source
over time were evident, again suggesting that this
criteria for steady-state was satisfied at the Hill AFB site.
Dissolved Contaminant Plume Mass
and Center of Mass Calculations
As indicated in Chapter 4, Thiessen areas were
generated for each sampling event using a fixed outer
plume boundary and individual areas determined based
on the actual sampling locations used in a given
sampling event. This outer plume boundary is shown in
Figure 6-6 along with Thiessen areas based on the July
1993 sampling event. A summary of specific Thiessen
area calculations for each sampling event is provided in
Appendix C.
Based on the Thiessen areas associated with each
sampling point used for plume monitoring at each
sampling time, estimates of the total dissolved plume
mass and center of mass of BTEX, naphthalene, and
TPH were made following the procedures described in
Chapter 4. The results of the total mass and center of
mass calculations are provided in detail in Appendix G,
while summary data are provided in Table 6-1.
Several items are important to note from Table 6-1. The
need for a finely gridded sampling network is evident
from a comparison of April 1992 data with that from
subsequent sampling events. Results from April 1992
were based only on the five well monitoring network
established at the site prior to this study. As indicated in
Table 6-1, this limited sampling grid underestimated the
actual dissolved contaminant mass that was present at
the site by a factor of approximately 10 for all analytes of
interest due to improper initial sample location
placement and the large area of the plume assigned to
each of only five points. With an increased number of
sampling points in the grid and much finer spacing of
these points, an improved total mass estimate is
possible. This finer grid also allows more sensitive
tracking of the change in dissolved plume contaminant
mass and the position of its mass center over time.
The data in Table 6-1 can be used to assess whether the
plume has reached steady-state conditions from both
the time course of total mass of each analyte and the
center of mass of each analyte over time. Graphical
representations of the total mass of contaminant over
time are presented in Figures 6-7 and 6-8, while Figures
6-9 to 6-14 show the position of the center of mass for
each analyte over time at the Hill AFB site. Because of
the small number of data points that could be sampled in
December of 1992 due to adverse site conditions, this
sampling event produced significantly lower dissolved
mass estimates than the balance of the 1992 and 1993
sampling results (Table 6-1). As a consequence, this
sampling event was not thought to be representative of
true conditions throughout the site and was omitted
from the total mass and center of mass analyses shown
in Figures 6-7 through 6-14.
Specific compound mass data shown in Figure 6-7
suggest that steady-state conditions existed for some of
the compounds (benzene, toluene, naphthalene)
during a portion of the study period, while a
continuously declining mass was seen for ethylbenzene
and p-xylene during the entire study period. All of the
specific compounds of interest did show a significant
decline at the end of the study, suggesting that steady-
state conditions did not persist. Dissolved plume TPH
mass confirmed the non-steady-state conditions
existing at the Hill AFB site, as contaminant mass was
found to exponentially decay over time (Figure 6-8).
Center of mass plots in Figures 6-9 to 6-14 show
migration of the mass center downgradient from its
location in August of 1992, although the total
downgradient distance traveled was small, ranging from
a maximum of 106 ft for TPH, to a low of only 17.2 ft for
naphthalene (Table 6-2). Based on the interpretation of
the changes observed in the center of mass over time as
presented in Table 4-5, this decreasing contaminant
mass and center of mass moving downgradient
suggests that the source was finite, and despite plume
migration, contaminant attenuation was indicated.
6-4
-------
1800
1600-
1400'
1 200'
o 1 000.
! 800'
CD
O
§ 600'
O
400-
200
0
o BTEX - 7/92
o BTEX - 12/92
& BTEX - 2/93
4> BTEX -6/93
* BTEX - 9/93
U BTEX -1/94
0 20 40 60 80 100 120 140 160 180
Distance Downgradient of CPT-18 (ft)
Figure 6-2. Combined BTEX plume centerline concentration data collected from Hill AFB, UT,
Site 1141 from July 1992 to January 1994.
400'
o BTEX - 7/92
o BTEX - 12/92
A BTEX - 2/93
« BTEX - 6/93
+ BTEX - 9/93
20
40 60 80 100 120 140 160
Distance Downgradient of CPT-18 (ft)
180
Figure 6-3. Expanded concentration scale for combined BTEX plume centerline concentration
data presented in Figure 6-2.
6-5
-------
o TPH-7/92
*TPH- 12/92
+ TPH - 2/93
« TPH - 6/93
A TPH - 9/93
o TPH-1/94
20
40 60 80 100 120 140
Distance Downgradient of CPT-18 (ft)
160 180
Figure 6-4. TPH plume centerline concentration data collected from Hill AFB, UT, Site 1141 from
July 1992 to January 1994.
3000
2500
§> 2000
o
0>
o
o
O
1500
1000
500
O TPH - 7/92
X TPH -12/92
* TPH - 2/93
TPH - 6/93
A TPH - 9/93
0 TPH - 1 /94
20 40 60 80 100 120 140 160 180
Distance Downgradient of CPT-18 (ft)
Figure 6-5. Expanded concentration scale for TPH plume centerline concentration data
presented in Figure 6-4.
6-6
-------
PT-22
Figure 6-6. Outer plume boundary used for Hill AFB site plume total mass and mass center
calculations. Thiessen areas for the July 1993 sampling event are shown.
Estimation of Contaminant
Degradation Rate
The estimation of contaminant degradation rates with a
declining mass within the plume is carried out using
dissolved plume mass changes over time as described
in Chapter 4. This procedure is highlighted below as
applied to the Hill AFB site.
Dissolved Plume Mass Changes Over
Time
The total mass of each dissolved constituent in the Hill
AFB ground-water plume over time from Table 6-1 was
used to estimate contaminant degradation rates through
linear regression of zero and first order rate law
descriptions of these data. The entire ethylbenzene, p-.
xylene, and TPH data sets were used in the regression
analysis as these contaminants displayed continuously
decreasing masses over time. For benzene, toluene,
and naphthalene, only the data showing mass declines
over time (toluene and naphthalene data after 307 days,
and only the last two data points for benzene) were used
in their degradation rate estimates.
Table 6-2 summarizes contaminant transport and
degradation rate calculations for BTEX, naphthalene,
and TPH observed at the Hill AFB site, while Figures 6-
15 through 6-20 graphically show the data used to
calculate these estimated contaminant degradation
rates.
As indicated in Table 6-2, the projected lifetime of the
ground-water plumes generated from the BTEX
components is quite short, being less than two weeks
from the last sampling event, due to the low mass of
contaminant remaining in the plume as of January 1994.
The naphthalene and TPH plumes could persist for a
much longer time period but were estimated to last only
slightly longer than two years at the current rate of
degradation, if all site conditions remain the same as
those observed during the study. The TPH plume mass
center is projected to move a total of 156 ft
downgradient from its position in January 1994 during its
768 day lifetime. This puts the mass center
approximately 50 ft downgradient of the existing
monitoring network, still within the boundaries of Hill
AFB, and without impact to a downgradient receptor.
6-7
-------
Table 6-1. Summary Total Mass and Center of Mass Coordinate Data for BTEX,
Naphthalene, and TPH Estimated from Data Collected at the Hill AFB Site from March
1992 to January 1994 , •
Sampling bate
Parameter
Benzene Mass (g)
Toluene Mass (g)
Ethylbenzene Mass (g)
p-Xylene Mass (g)
Naphthalene Mass (g)
TPH Mass (g)
Benzene-x (ft)
Benzene-y (ft)
Toluene-x (ft)
Toluene-y (ft)
Ethylbenzene-x (ft)
Ethylbenzene-y (ft)
p-Xylene-x (ft)
p-Xylene-y (ft)
Naphthalene-x (ft)
Naphthalene-y (ft)
TPH-x (ft)
TPH-v (ft)
4/92
2.8
2.7
3.9
14.1
2.3
127.3
16.7
32.9
1.8
43.6
1.0
44.1
-1.3
45.7
16.7
32.9
14.8
37.8
8/92
11.4
17.3
33.9
32.6
26.2
3,955
36.6
36.4
58.9
41.0
74.0
66.4
58.4
59.2
63.1
60.2
63.4
-17.1
12/92
10.3
,11.6
8.9
8.9
2.3
138
52.4
11.3
40.7
80.4
58.4
38.1
55.1
15.1
62.9
68.8
59.9
37.4
2/93
10.6
20.0
15.1
14.0
29.5
1,167
66.8
85.7
42.7
47.9
40.6
42.7
47.3
49.0
39.5
35.2
37.6
38.7
6/93
11.7
21.7
11.8
14.5
35.5
348
61.3
53.1
57.4
39.7
57.4
42.1
58.7
38.4
72.8
90.0
64.0
54.8
9/93
.11.9
14.5
5.6
7.1
1.0
316.7
98.4
103.6
94.5
98.9
92.9
88.6
100.9
108.7
55.2
36.4
86.6
88.5
1/94
0.4
0.7
0.5
0.8
0.1
28.8
21.8
57.4
67.1
93.7
79.8
108.9
82.6
109.2
62.2
77.4
73.1
88.2
o Benzene
o Toluene
A Ethylbenzene
p-Xylene
* Naphthalene
100
200 300
Time (days)
400
500
Figure 6-7. Time course of total dissolved plume mass estimates for BTEX and naphthalene
contaminants at the Hill AFB site over the course of the study.
6-8
-------
0 100 200 300 400 500
Time (days)
Figure 6-8. Time course of total dissolved plume mass estimates for TPH at the Hill AFB site
over the course of the study.
100
80
CD
o
CO
20
0
-20
2/93, 10.6g
1/94,0.41 g
9/93, 11.9 g
6/93, 11.7 g
8/92, 11.4 g
0 20 40 60 80 100
North Distance (ft)
Figure 6-9. Center of mass positions for benzene at the Hill AFB site during the study.
6-9
-------
100
80.
|60
CO
«> 40
b
I 20]
-20.
1/94, 0.66 g
2/93, 20.0 g
4/92, 2.7 g
9/93,
> 6/93, 21.7 g
8/92, 17.3 g
4.5 g
0
20
100
40 60 80
North Distance (ft)
Figure 6-10. Center of mass positions for toluene at the Hill AFB site during the study.
P
1 20
100
80
60 J
or
to
5 40J
20.
-20.
1/94, 0.53 g
8/92, 33.9 g
4/92, 3.9 g
9/93,
2/93, 15.1 g 6/93, 11.8 g
5.6 g
20 40 ' 60 80
North Distance (ft)
100
Figure 6-11. Center of mass positions for ethylbenzene at the Hill AFB site during the study.
6-10
-------
120
100
* 80
g 60
to
Q 40
"to
.2 20
0
-20
41'
1/94, 0.80 g
'2, 14.1 g
2/93, 14.0 g
9/93,
6/93, 14.5g
7.1 g
0 20 40 60 80 100
Njprth Distance (ft)
Figure 6-12. Center of mass positions for p-xylene at the Hill AFB site during the study.
I2U-
100-
£- 80'
0)
o
Jj 60-
to
e 40.
CO
CD
^ 20-
0-
-20-
6/93, 35.5 g
1/94, 0.13 g if"
/^j/ 8/92, 26.2 g
4/92, 2.3 g f^r £
A A 9/93, 0.96 g
2/93, 29.5 g
0 20 40 60 80 100
North Distance (ft)
Figure 6-13. Center of mass positions for naphthalene at the Hill AFB site during the study.
6-11
-------
i^u —
100-
§ 80-
8
§ 60'
1
§ 40-
^ 20-
-20-
Figure 6-14. Center of mass
9/93, 31 7 g
I 10 A 00 p _. ^-— ^
>/
2/93, 1 , 1 67 g ^^^^
+ jr^*^ 6/93, 348 g
4/92, 128 g \
\ 8/92, 3,995 g
0 20 40 60 80 100
North Distance (ft)
positions for TPH at the Hill AFB site during the
study.
Table 6-2. Contaminant Center of Mass Velocities and Degradation Rates Based on Ground-
Water Data Collected at the Hill AFB Site from March 1992 to January 1994
Benzene Toluene benzene p-Xylene Naphthalene TPH
Distance Traveled (ft) =
Contaminant Velocity (ft/d) =
Contaminant Velocity (ft/yr) =
Zero Order Degradation
Rate (g/d) =
Zero Order Degradation
Rate (g/yr) =
First Order Degradation
Rate (1/d) =
First Order Degradation
Rate (1/yr) =
Remaining Mass as of
1/94 (g) =
Time to Degrade Remaining Mass
- Zero Order (dl) =
Time to Degrade 99.9% Mass -
First Order (d) =
Travel Distance in Degradation
Time (ft) =
25.70 53.30 42.90 55.60
0.05 0.10 0.08 0.11
18.00 37.40 . 30.10 39.00
=0.10 =0.10 0.06 0.06
=36.90 =28.50 23.40 22.30
17.20 106.00
0.03 0.20
12.10 74.20
=0.03 0.01
=9.50 3.29
0.41 0.66 0.53 0.80
=4.10 =6.70 8.41 13.79
0.13 28.80
=266.00 767.53
=0.20 =0.67 0.67 1.52 =8.00 153.51
6-12
-------
14
y = =-0.1 Ox + 55.2
NOTE: Two point regression
yields only an estimate of
potential degradation rate
400
420
440. 460 480
Time (days)
500
520
Figure 6-15. Zero order regression for changes in dissolved benzene mass in the ground-water
plume at the Hill AFB site over time.
o>
D
22.5'
20
. 17.5'
15
12.5"
CD
•5 101
CD
7.5'
5-
2.5-
y = -0.099x + 53.1, r2 = 0.9725
p = 0.1061
0
300
325 350 375 400 425 450 475 500 • 525
Time (ofays)
Figure 6-16. Zero order regression for changes in dissolved toluene mass in the ground-water
plume at the Hill AFB site over time.
6-13
-------
afta
y = -0.06 x + 31.5, r2 = 0.9668
P = 0.003
LU
200 300 400
Time (days)
r 'time" I""9" '" diSS°'Ved
600
•»-• «"
ground-
0>
y = -0.06 x + 30.6, r2 = 0.9474
p = 0.005
100
200 300 400
Time (days)
500
600
the
-water
6-14
-------
T3
-------
Plume Centerline Concentration Data
The centerline ground-water concentrations and
dissolved plume mass changes over time indicated that
over the life of the project the plumes were not at
steady-state but were declining. Because of this, the
centerline ground-water concentration approach for
estimating contaminant degradation rates was not
applicable to the Hill AFB site, and consequently, was
not carried out.
Estimation of Source Mass/Lifetime
As indicated in Chapter 4, when a decreasing plume
mass and pulse source is identified at a site, the
estimation of source mass and source lifetime can be
based on the dissolved plume mass observed at a given
point In time. Since the plume at the Hill AFB site was
observed to have evolved from a continuous source into
a pulse source with declining mass during the course of
this study, lifetime calculations based on observed
contaminant degradation rates are applicable here.
These calculations are summarized in Table 6-2 and are
based on the estimated degradation rates for BTEX,
naphthalene, and TPH generated from dissolved plume
mass changes over time. Only estimates of degradation
rate and remaining contaminant lifetime could be made
for benzene, toluene, and naphthalene due to a limited
data set available for these compounds and regression
relationships that were not significant at the 95,percent
confidence level. Due to the small dissolved mass of
these compounds, however, their projected lifetimes at
the site were low, with naphthalene, the most slowly
degrading specific compound, having a lifetime less
than one year. The projected TPH plume lifetime, based
on its observed first order degradation rate, was slightly
over two years.
Predicting Long-Term Behavior of
Plume
The long-term behavior of the dissolved plume at the Hill
AFB site is controlled by the apparent pulse nature of
the release. Consideration of a source removal scenario
for this site is not relevant as data indicate that the plume
has moved away from the original source area following
depletion of the initial contaminant mass there. The
source area has effectively been removed through
intrinsic processes of contaminant dissolution,
dispersion, and degradation. The long-term behavior of
the plume is then dependent upon the degradation
rates of the contaminants within the "detached"
dissolved plume and the rate at which the contaminants
are migrating within the aquifer.
Contaminant degradation and transport analyses are
summarized in Table 6-2 above. These data suggest
again that naphthalene is the specific compound with
the greatest potential mobility since its degradation rate
Is low relative to the other compounds of interest at the
site. The time required for 99.9 percent naphthalene
degradation Is projected to be approximately 266 days,
during which time the center of mass of the naphthalene
plume would have moved downgradient approximately 8
ft. Based on these estimates, none of the specific
compounds investigated in this study will move off the
Hill AFB site and beyond the monitoring network
currently in place. The non-specific anaiyte, TPH, plume
is expected to persist for more than two years (time for
99.9 percent TPH removal). During this time its plume
center of mass migrates only 156 ft downgradient,
approximately 50 ft downgradient of the current
monitoring network. The plume should remain on Hill
AFB property, but residual mass would not be
detectable with the current ground-water monitoring
network.
Decision Making Regarding Intrinsic
Remediation
Decisions regarding the acceptability of an intrinsic
remediation management approach for a given site
should be made based on the potential impact a plume
has on susceptible downgradient receptors, along with
evidence that exists regarding the presence and rate of
intrinsic attenuation reactions taking place at a site that
provide contaminant plume containment and control.
Evidence of contaminant degradation is provided
through plume analysis and degradation rate estimates
described above. Additional evidence related to the
potential aquifer assimilative capacity estimated from an
analysis of. electron acceptor conditions existing
upgradient of the plume is summarized below.
Impacted Receptors
As indicated above, the long-term behavior of the
contaminant plumes existing at the Hill AFB site
projected from contaminant degradation and transport
data suggest that the maximum extent of any plume of
interest will only be 50 ft downgradient of the existing
ground-water monitoring network. This limited extent of
potential contaminant migration indicates that no
downgradient receptors will be impacted by
contamination at the Hill AFB site over the projected
lifetime of the ground-water plume that exists there.
Potential Aquifer Assimilative Capacity
Final evidence related to the feasibility of an intrinsic
remediation management approach is the quantification
of the potential assimilative capacity existing in
uncontaminated ground-water at a site. When quantities
of electron -acceptors moving onto a site equal or
exceed the levels of dissolved contaminant in the
plume, it can be assumed that the availability of electron
acceptors will not limit contaminant degradation and
plume attenuation at the site in the future. Table 4-6
summarizes the hydrocarbon assimilative capacity
relationships for electron acceptors quantified
throughout the Hill AFB site. These relationships were
used along with electron acceptor concentrations
measured in the background ground-water (Appendixes
6-16
-------
Table 6-3. Potential Ground-Water Aquifer Assimilative Capacity at the Hill AFB Site Based on
Ground-Water Data Collected from March 1992 to January 1994
Electron Acceptor
Background
Concentration (mg/L)
Mean HC Equivalent
Stoichiometry
HC Equivalent Assimilative
Capacity
DO
NOi
S042-
AFe
AMn
CH4
2.2 . 3.3
5.8 1-1
53.2 5.0
1.4 23.1
0.45 20.0
Not Measured NA
Potential Assimilative Capacity =
0.66
5.40
10.70
0.06
0.02
NA
16.90 .
Table 6-4. Proposed Long-Term Sampling Schemes for Annual Compliance and Process
Monitoring at the Hill AFB Site
Compliance Monitoring
Purpose
Background
Downgradient
Location
MW-2
MW-5
CPT-15
CPT-30
Centerline
MW-3
CPT-1 8'
CPT-09
CPT-12
CPT-29
CPT-30
Intrinsic Remediation
Transect 1
MW-4
CPT-28
CPT-42
CPT-31
CPT-25
Transect 2
CPT-02
CPT-03
CPT-26
CPT-05
CPT-20
Process Monitoring
Transect 3
CPT-43
CPT-34
CPT-Q8
CPT-1 1
CPT-10
MLP-35
Transect 4
CPT-1 4
CPT-33
CPT-32
Transect 5
CPT-1 6
CPT-15
CPT-1 7
H and L) to estimate the potential assimilative capacity
existing within the aquifer below the Hill AFB site.
The potential assimilative capacity results for the Hill AFB
site are summarized in Table 6-3. The assimilative
capacities related to dissolved oxygen, nitrate, and
sulfate are based on the lowest observed concentration
in background Monitoring Well 2 (MW-2) during the
study. For iron and manganese, their assimilative
capacities were estimated based on the smallest
increase in the soluble concentrations of these solid-
phase electron acceptors observed between MW-2 and
CPT-08 within the center of the plume during the study.
The lowest concentration changes for iron and
manganese were observed in January 1994, where MW-
2 concentrations were 0.181 and 0 mg/L, while those in
CPT-08 were 1.6 and 0.45 mg/L, respectively.
As indicated in Table 6-3, sulfate is the most significant
electron acceptor at the Hill AFB site, accounting for
more than 60 percent of the potential assimilative
capacity at the site. With a maximum TPH concentration
of 184 |j,g/L and a maximum BTEX concentration of 40.5
p,g/L observed at sampling point CPT-05 (Appendix F),
the potential assimilative capacity projected in Table 6-3
is more than 90 times greater than that required to
assimilate the TPH remaining at the site. This result
provides additional evidence that an intrinsic
remediation management option for the Hill site would
be'protective of public health and the environment.
Long-Term Site Monitoring Program
As indicated in Chapter 4, long-term monitoring at the
Hill AFB site should be focused on two primary
objectives. First, monitoring should be carried out for
compliance purposes to ensure no impact to a
6-17
-------
downgradient receptor. This should involve annual
monitoring of the most downgradient sampling points to
ensure that significant changes in plume degradation
and transport have not occurred at the site. Second,
intrinsic remediation mpnttorjng is perhaps more critical
at this site since no nearby receptors exist. In terms of
monitoring for intrinsic remediation process evaluation,
monitoring at four to six locations along the plume
centerline on an annual basis should provide adequate
data to ensure that unexpected plume migration has not
taken place at the site. To validate degradation rates,
which are presented above, additional cross-plume
sampling point measurements are also necessary so that
a representative determination of residual dissolved
plume mass can be made. Based on the ground-water
monitoring network at the Hill AFB site as shown in
Figure 5-6, a sampling scheme for both compliance and
intrinsic process validation monitoring purposes during
long-term monitoring at the site is presented in Table 6-
4.
Specific analyses for samples collected during the long-
term monitoring phase should be similar to those used in
this study. The analytes specified by the State of Utah
Department of Environmental Quality for compliance
monitoring purposes would be expected to include:
ground-water elevation; field ground-water dissolved
oxygen concentrations; and BTEX, naphthalene, and
purge-and-trap TPH ground-water concentrations. In
addition, other electron acceptors (nitrate, sulfate, and
dissolved iron and manganese) should be quantified for
intrinsic remediation process evaluation along with
general ground-water quality parameters such as pH,
temperature, and total dissolved solids (TDS).
Summary of Intrinsic Remediation
Evaluation at the Hill Site
As indicated in the data presented and discussed
above, there appears to be ample evidence that intrinsic
remediation has effectively contained the hydrocarbon
plume at the Hill AFB Building 1141 former UST site.
Significant specific compound and TPH degradation
rates, coupled with large pools of electron acceptor
moving onto the site, support the implementation of an
intrinsic remediation management option. Degradation
rates for the most potentially mobile species, TPH and
naphthalene, suggest that contaminant levels will fall
below detection limits by early 1996, and that the
maximum extent of contaminant migration will be
contained completely within Hill AFB boundaries.
Additional monitoring should take place at the site to
verify that contaminant degradation has continued at the
rates observed in this study so that complete
contaminant assimilation at the site can be verified, and
site closure actions can be initiated.
6-18
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Chapter 7
Results and Discussion—Site 2
Blaine Jensen RV Site, Layton, Utah
Site Description and Site History
The Blaine Jensen R.V. facility was used as a
recreational vehicle sales and service facility during the
study and consisted of a service shop, an R.V. sales
building, and associated sales and display lots (Figure 7-
1). The majority of the site is covered by asphalt, and
several underground utilities are present as indicated in
Figure 7-1. The ground surface slopes gently toward
the southwest and toward U.S. Interstate Highway 15
which borders the site directly to the west.
The property was in agricultural production until
approximately 1958, at which time it was leased to
Sinclair Oil for retail gasoline sales from a newly
constructed gasoline station building (the present
service shop). The fuel storage and dispensing system
consisted at that time of four USTs (2,000 gallons each)
located in the area labeled "Excavation 1" in Figure 7-1,
with suction pumps located to the west of the tanks.
The property was subsequently utilized for camper sales
between 1968 and 1974, followed by a lease to DBA
By-Rite Distributing for retail gasoline sales until 1984.
The site was upgraded in 1974 by By-Rite Distributing
with a fifth UST (6,000 gallons) installed in the
"Excavation 1" area and two additional USTs (8,000 and
10,000 gallons) placed in the area labeled "Excavation
2" in Figure 7-1. These last three tanks were equipped
with pressurized dispenser systems. The tanks were
-reportedly emptied in 1984, and the property was
subsequently utilized for the recreational vehicle sales
and service facility that occupied the site during the
study.
The site is located within the Weber Delta Hydrologic
District near the south central portion of Section 28,
Township 4 North, Range 1 West. The area surrounding
the site is characterized as mixed residential and
agricultural. Only one active water right was
encountered within this area, a shallow (10-ft completion
depth) well used for irrigation purposes. This well is
located to the northeast, upgradient from the site. The
water right search was subsequently expanded to a
radius of one mile (Wasatch Geotechnical, 1991).
Several wells were located within this larger area; none,
however, were used as municipal water supply wells.
Geologic Setting
Ground-water in the Weber Delta Hydrologic District
occurs in a shallow, unconfined aquifer as well as under
artesian conditions in a multi-aquifer reservoir (Wasatch
Geotechnical, 1991). Most of the production wells in the
Weber Delta district are completed in the two major
artesian aquifers: the Sunset Aquifer lying between 250
and 400 ft, and the more productive Delta Aquifer lying
between 500 and 700 ft below land surface. Between
the shallow ground-water and deeper artesian aquifers
lies a thick confining layer of clay and mud. Recharge to
the artesian aquifers is mostly from precipitation along
the Wasatch Range front, with ground-water moving
generally westward toward the Great Salt Lake.
Soils encountered at the site are primarily sands in the
southern portion of the site and silts and clays in the
northern half of the site. Ground-water is encountered
at approximately 8 to 10 ft below grade at the site. The
direction of shallow ground-water flow is predominantly
southwest (Wasatch Geotechnical, 1991), although a
westerly and northwesterly flow were observed at the
site during the study. There are no streams or other
occurrences of surface water within 1,000 ft of the site.
No regional hydraulic conductivity data were reported in
original site reports; however, hydraulic conductivity
values of the shallow soils at the Layton site, determined
by slug tests performed during this study, indicate
conductivity values ranging from 0.78 to 3.1 ft/d, with an
average of 1.5 ft/day.
Previous Site Activities
A soil-gas survey was performed between November 2
and 6, 1990, at a depth of approximately 4 ft below
ground surface. The organic vapor content of soil-gas
samples was measured with a portable organic vapor
monitor (OVM) equipped with a photoionization detector
. 7-1
-------
w \ .
V™--
I I—i A
0 20 40
LEGEND
Underground Utility Lines; -G- Gas,
—T - Telephone.—W- Water, —S- Sewer
Figure 7-1. Map for Blaine Jensen RV, Layton, UT, site (Wasatch Geotechnical, 1991).
7-2
-------
(PID). The portable instrument was calibrated to a 100
part per million by volume (ppmv) isobutylene standard,
with a reporting range of 0.1 to 2,000 ppmv.
A total of 36 locations were surveyed for volatile organic
vapors with detected concentrations up to 1,975 ppmv.
The projected plume footprint based on measured
vapor concentrations was constructed by Wasatch
Geotechnical (1991) as indicated in Figure 7-2.
Elevated vapor concentrations covered much of the
north and west portions of the property. The highest
vapor concentrations (from 250 to 1,975 ppmv) were
found in the two tank excavations and in the dispenser
island area between the former tanks. An outer area of
lower vapor concentrations (from 0 to 250 ppmv)
extended to the west and southwest. Overall, results of
the survey defined an area of elevated vapor
concentrations of approximately 18,400 ft2 in horizontal
extent. This area of vapor contamination appeared
elongated in the direction of shallow ground-water flow
(Wasatch Geotechnical, 1991).
The vertical and horizontal extent of petroleum
hydrocarbon migration was investigated by Wasatch
Geotechnical with six exploratory soil borings. Boring
locations were selected based upon the results of the
soil-gas survey. Four of the borings were drilled on
January 7, 1991, with a CME 55 truck-mounted drill rig
utilizing a hollow-stem auger. The other two borings (B5
and B6 in Figure 7-2) were drilled with a hand auger.
Soils encountered in the borings consisted of mostly
sands, with discontinued layers of silt and clay. Product
odor was noted in several of the samples. Results of
OVM screening of boring soil samples qualitatively
agreed with results of the soil-gas survey. The highest
readings (620 ppmv) were recorded in samples from B2,
between the excavations and below the north dispenser
island, while the lowest OVM readings were from B4, at
the mapped edge of soil-vapor contamination. Vapor
concentrations were observed to be highest
immediately above the water table.
Three ground-water monitoring wells were installed to
evaluate shallow ground-water quality and flow direction
at the site. Two wells were installed into the UST
excavations at locations B1 and B3, while a third well was
installed in location B4. The wells were constructed of 4-
in diameter, schedule 40 PVC pipe, and screened
across the water table from 7 to 17 ft below ground
surface. The wells were developed (pumped) until the
discharge was clear to remove sand and silt that had
accumulated in them. Prior to ground-water sampling
with disposable PVC bailers, a minimum of three well
volumes were pumped from each of the wells to ensure
that a sample representative of water quality within the
formation was actually collected.
The wells were surveyed to allow the determination of
water depths and the direction of surface flow. Results
of well completion and ground-water level data are
presented in Table 7-1 and indicate that the water table
was approximately 8 to 10 ft below grade in January
1991. The ground-water flow was toward the southwest
at that time.
UWRL Site Activities
As indicated in Chapter 5, site investigation protocols
utilizing CPT soil textural data collection and small
diameter ground-water piezometer sample placement
for detailed plume delineation were evaluated in July
and August 1992 at the Layton site. CPT data were
collected at 27 locations throughout the Layton site
(Figure 7-3) to augment the existing monitoring network
consisting of three conventional ground-water
monitoring wells.
This detailed site investigation effort provided soil
textural features existing from the surface to a depth of
22 ft. Figure 7-3 shows these CPT data collected at the
ground-water table. CPT data generally confirmed the
site subsurface characterization data originally
developed from soil boring information. This CPT
information did, however, suggest a finer grained
material than was indicated from soil boring data and
identified a clay to silty clay lens 2 to 6 ft thick covering
most of the Layton site 12 to 14 ft below ground surface
(Figure 7-4).
The rapid screening-level site investigation data
collected in this study .from the Layton site generally
confirmed the site conceptual model shown in Figure 7-
2. There were times during the study, however, when
the downgradient well, MW4, was actually upgradient of
the site based on localized ground-water flow
conditions. During this field study, the ground-water
flow was generally more westerly than southwesterly as
had been originally suggested from previous site
investigation activities.
A total of seven sampling events were part of this study
at the Layton site to describe the distribution and
movement of contaminants and electron acceptors
taking place at the site between April 1992 and January
1994. These sampling events included: April 1992
limited sample collection prior to installation of the
piezometer network; July 1992 immediately following
installation of the piezometer sampling network;
December 1992; March 1993; June 1993; September
1993; and January 1994. In addition, BTEX,
naphthalene, and TPH ground-water concentration data
were collected from the Layton site in February 1995 as
part of a separate EPA-sponsored field evaluation of in-
situ air sparging and in-well aeration technology. .These
1995 data were made available to this project to allow an
7-3
-------
APPROXIMATE SCALE (FT)
20
LEGEND
High Concentrations of Petroleum Hydrocarbons
Low Concentrations of Petroleum Hydrocarbons
Exploratory Boring
Monitoring Well
Underground Utility Lines; - G- Gas,
—T — Telephone,—'w- Wafer, — S - Sewer
Figure 7-2. Conceptual site map for Blaine Jensen RV, Layton, UT. Soil and ground-water
contamination based on field and laboratory soil, soil-gas, and ground-water data available 1990
to 1991 (Wasatch Geotechnical, 1991).
7-4
-------
Table 7-1. Summary of Well Completions and Measured Water Levels at the Layton,
Well
No.
B1
B3
B4
Depth
(ft)
17
17
17
Screened
Interval
(ft)
7 to 17
7 to 17
7 to 17
Elevation
(TOCinft)
101.53
100.00
99.12
Water
Elevation (ft)
January 11, 1989
91.38
91.08
90.40
Water
Elevation (ft)
January 25, 1991
91.71
91.58
91.29
*AII elevations are relative to an assigned datum of 100.00 ft at the top of casing (TOG) elevation for Well
B3.
100.00
-150.00
_JSand
-200.00
-100.00 -50.00
0.00 50.00 100.00
East Coordinate (ft)
150.00
Figure 7-3. Soil textural profile observed at the ground-water table from CPT data collected at
the Layton, UT, site in July 1992.
7-5
-------
Layton, UT. Fine Grained Soil Profile. 12' and lower. I
60.0
NS coord, (ft.)
0.0
Depth (ft.)
23.0i
-140.0
EW coord, (ft.)
Sand
120.0
Soil Type
Silt
Clay
Figure 7-4. Fine-grained soil profile observed at the Layton, UT, site at the 12 to 16 ft depth
from CPT data collected in July 1992.
update of plume information for the Layton site and have
been incorporated in the data reduction and summary
information included in this report.
Ground-water hydrocarbon composition data for the
1992 through 1994 sampling events are summarized in
Appendix I, while all nutrient, iron, and manganese data
collected at the Layton site are summarized in Appendix
L. These data were used to determine steady-state
plume conditions and to estimate total mass and mass
center values for these various analytes at the Layton
site over time as prescribed by the intrinsic remediation
assessment protocol described in Chapter 4.
Determination of Steady-State Plume
Conditions
Contaminant Centerline
Concentrations
Once the plume centerline position was verified during
site assessment activities in July 1992, a westerly
centerline transect was used to make a determination
regarding steady-state plume conditions at the Layton
site overtime. This centerline transect was composed of
data collected from the following single and multi-level
ground-water piezometers (see Figure 7-3 for their
specific locations throughout the site): CPT-19, CPT-
20, and CPT-16 in the source area, and downgradient
locations within the dissolved plume at CPT-04, MLP-
05, CPT-07, and MLP-06.
The traditional compounds of concern from a health and
fate-and-transport perspective include BTEX and
naphthalene. These compounds were used along with
TPH to generate centerline concentration profiles for
each sampling event to evaluate plume steady-state
conditions at the site. Appendix I contains summarized
BTEX, naphthalene, and TPH data for each sampling
event conducted in this study from July 1992 to January
1994, along with the data from February 1995. Figures
7-5 and 7-6 show plume centerline concentration data
for combined BTEX and TPH concentrations at the
Layton site from July 1992 to February 1995,
respectively.
7-6
-------
It appears from these figures that pseudo-steady-state
centerline concentrations for both BTEX components
and TPH occurred in the dissolved plume below the
Layton site. Both BTEX and TPH concentrations
increased and decreased along the plume centerline
transect shown in Figures 7-5 and 7-6. No consistent
pattern in transect concentrations downgradient of the
source over time was evident, again suggesting that this
criteria for steady-state was satisfied at the Layton site.
Dissolved Contaminant Plume
and Center of Mass Calculations
Mass
As^ indicated in Chapter 4, Thiessen areas were
generated for each sampling event using a fixed outer
plume boundary and individual areas were determined
based on the actual sampling locations used in a given
sampling event. This outer plume boundary for the
Layton site is shown in Figure 7-7 along with Thiessen
areas based on the July 1993 sampling event. A
summary of specific Thiessen area calculations for each
sampling event is provided in Appendix C.
Based on the Thiessen areas associated with each
sampling point used for plume monitoring at each
sampling time, estimates of the total dissolved plume
mass and center of mass of BTEX, naphthalene, and
TPH were made following the procedures described in
Chapter 4. The results of the total mass and center of
mass calculations are provided in detail in Appendix J.
Summary data are provided in Table 7-2. April 1992 data
were not included in these calculations as this sampling
period occurred before the installation of the piezometer
network, and data resulted from only four existing large-
diameter monitoring wells.
Upon inspection of Table 7-2, it becomes apparent that
long-term monitoring of intrinsic bioremediation sites
should be carried out due to the variability in dissolved
mass that can occur from natural ground-water table
fluctuations. Despite the decline in dissolved
contaminant mass that was observed at the Layton site
.from July 1992 to September 1993, further sampling in
January 1994 and particularly in February 1995 indicated
that the mass of the specific contaminants of interest, as
well as TPH, have remained essentially constant over
the 2.5-year project period. The contaminant mass data
in Table 7-2 are graphically represented in Figures 7-8
and 7-9, which again clearly show that despite the
decline in contaminant mass after March 1993,
significant dissolved mass persists within the plume
below the Layton site.
Figures 7-10 to 7-15 show the position of the center of
mass for each analyte over time at the Layton site and
provide additional information regarding steady-state
conditions within the plume over time. As indicated in all
of these figures, the mobility of the center of mass of all
of the specific contaminants of interest and
CO
c
'-5 15000-
ca g
^ o 10000
Is
o
CD
20 40 60 80 100
Distance Downgradient of CPT-19
120
Figure 7-5. Combined BTEX plume centerline concentration data collected at the Layton, UT,
site from July 1992 to February 1995.
7-7
-------
O TPH - 7/92
TPH- 12/92
A TPH - 3/93
TPH - 6/93
+ TPH - 9/93
X TPH-1/94
TPH - 2/95
20 40 60 80 100
Distance Downgradient of CPT-19 (ft)
120
Figure 7-6. TPH plume centerline concentration data collected at the Layton, UT, site from July
1992 to February 1995.
MLP-06
Figure 7-7. Outer plume boundary used for Layton site plume total mass and mass center
calculations. Thiessen areas for the July 1993 sampling event are shown.
7-8
-------
Table 7-2. Summary Total Mass and Center of Mass Coordinate Data for BTEX,
Naphthalene, and TPH Estimated from Data Collected at the Layton Site from July 1992
to February 1995
Parameter
Benzene Mass (g)
Toluene Mass (g)
Ethylbenzene Mass (g)
p-Xylene Mass (g)
Naphthalene Mass (g)
TPH Mass (g)
Benzene-x (ft)
Benzene-y (ft)
Toluene-x (ft)
Toluene-y (ft)
Ethylbenzene-x (ft)
Ethylbenzene-y (ft)
p-Xylene-x (ft)
p-Xylene-y (ft)
Naphthalene-x (ft)
Naphthalene-y (ft)
TPH-x (ft)
TPH-y (ft)
7/92
3,139.9
3,309.0
1,372.3
6,093.3
191.6
34,849.3
54.9
-17.6
71.9
-8.1
54.3
-8.0
59.1
-9.1
31.4
-19.3
55.4
-3.0
1 2/92
4,926.2
3,120.7
1,527.6
8,169.9
296.3
48,766.7
45.5
-11.4
53.2
-10.0
47.3
-4.6
51.3
-10.9
44.0
-15.5
53.2
-7.4
3/93
6,057.5
4,922.6
2,822.1
11,457.0
650.0
86,469.1
62.3
-7.1
70.5
-3.2
47.1
-6.1
60.9
-3.6
45.2
-13.2
69.4
-3.3
6/93
3,689.0
. 2,461.0
956.9
5,732.3
500.1
34,165.6
70.3
-4.8
89.6
5.9
72.6
-6.8
71.9
-4.3
66.9
-2.9
70.0
-4.3
9/93
2,147.8
1,130.8
141.2
1,986.3
61.3
13,792.2
54.8
-15.3
69.8
-5.9
48.7
-33.8
72.2
-0.3
55.4
0.6
66.3
-7.0
1/94
2,864.3
550.7
9.3
2,648.3
454.8
18,689.0
65.0
-12.2
68.1
-13.9
-10.7
4.0
69.8
-9.9
66.0
-5.7
64.6
-14.1
2/95
3,695.5
1,556.4
867.8
4,371,1
531.8
78,194.1
66.5
-17.2
78.3
-5.3
50.5
-27.7
62.5
-17.4
42.9
-12.1
46.0
-6.2
12000
10000 '
8000
2>
| 6000
| 4000
O. 2000
0
o Benzene
o Toluene
Ethylbenzene
p-Xylene
+ Naphthalene
200
400 600
Time (days)
800
1000
Figure 7-8. Time course of total dissolved plume mass estimates for BTEX and naphthalene
contaminants at the Layton site during the study.
7-9
-------
90000
80000
70000
60000
•~ 50000
co .
.S 40000 '
E
•| 30000
O 20000
10000
0
0 200 400 600
Time (days)
800
1000
Figure 7-9. Time course of total dissolved plume mass estimates for TPH at the Layton site
during the study.
10
5
o
o
o
O
•c
o
-5-
-10
-15-
-20
-25
-30
-35
12/92; 4,926 g
3/93; 6,058 g
6/93; 3,689 g
7/92; 3,1 40 g
] /94; 2'864 9
2/95; 3,696 g
40 45
50,
75 80
55 60 65 70
East Coordinate (ft)
Figure 7-10. Center of mass positions for benzene at the Layton site during the study.
7-10
-------
10'
5'
0'
^ -5
|. -10
^ i«
o -15
o
2-201
t
o -9=;
-z. ^
-30
-35
6/93:2,461 g
3/93; 4,923 g
12/92:3,121
,131 g
2/95; 1,556 g
1/94; 551 g
40
50
90-
100
60 70 80
East Coordinate (ft)
Figure 7-11. Center of mass positions for toluene at the Layton site during the study.
1
10'
5'
0
-5
-10
o -15
-20
-25
-30
-35
-20
94; 9 g
12/92; l,528g
X
6/9.3; 957 g
2/95; 868 g
9/93; 141 g
20 40 60 80
East Coordinate (ft)
100
Figure 7-12. Center of mass positions for ethylbenzene at the Layton site during the study.
7-11
-------
0)
tg
5
0
Q
o -in
o
-20-
-25'
9/93; 1,986 g
3/93; 11, 457 g
12/92; 8,170 g
7/92; 6,093 g
6/93; 5,732 g
1/94; 2,648 g
2/95; 4,371 g
30 40
TOO
50 60 70 80 90
East Coordinate (ft)
Figure 7-13. Center of mass positions for p-xylene at the Layton site during the study.
10
5
0
-5
I
"B
o
o
O
.
o -15
z:
-20'
9/93; 61 g
2/95; 532 g
6/93; 500 g
1/94; 455 g
3/93; 650 g
12/92; 296g
7/92; 192g
30 40
100
50 60 70 80 90
East Coordinate (ft)
Figure 7-14. Center of mass positions for naphthalene at the Layton site during the study.
7-12
-------
10
0 ..
I. -5
o -101
o
O
jz -15-
-20
7/92; 38,849 g
2/95; 78,194 g
V
12/92;
3/93; 86,469-g .
'93; 34,166 g
9/93; 13,792 g
1/94; 1 8,689 g
30 40 50 60 70 80
East Coordinate (ft)
90
100
Figure 7-15. Center of mass positions for TPH at the Layton site during the study.
TPH was limited. Only TPH showed any actual
downgradient movement of its center of mass, with only
10 ft movement over the two and one-half year field
study (Table 7-3). Based on the interpretation of the
changes observed in the center of mass and total mass
values at the Layton site over time from Table 4-5, these
pseudo-steady-state contaminant mass levels and
limited center of mass movement downgradient suggest
that a continuous source exists at the Layton site which
reflects a plume stabilized by continuing intrinsic
attenuation mechanisms.
Estimation of Contaminant
Degradation Rate
The estimation of contaminant degradation rates, with a
steady-state mass within the plume, is carried out,
according to the protocol developed in this study, either
through the calibration of the fate-and-transport model
described in Chapter 4 to field data collected from the
. site or from an analysis of plume centerline concentra-
tion data. Both of these contaminant degradation rate
estimation procedures are highlighted below as applied
to the Layton site.
Plume Centerline Concentration Data
As indicated above, inspection of the centerline ground-
water concentrations and dissolved plume mass
changes over time indicated that over the life of the
project the plume at the Layton site had reached
apparent steady-state conditions. The BTEX and TPH
concentration profiles shown in Figures 7-5 and 7-6,
respectively, and the naphthalene data for this plume
centerline transect from CPT-20 to MLP-06 were
averaged to generate a steady-state, time-averaged
concentration profile that was used in further
degradation rate estimations. These time-averaged
center line concentration plots are shown in Figures 7-
16 through 7-20, for individual BTEX components:
naphthalene, combined BTEX components, and TPH,
respectively, with 95-percent confidence intervals for
the mean-at each sampling location indicated on each
figure. With these averaged data, first order degradation
rates were estimated using the procedures described in
Chapter 4. An example of the natural log transformed
concentration data used to estimate a degradation rate
for each compound of interest is shown for p-xylene in
Figure 7-21, while the resultant estimated first order
degradation rates are summarized in Table 7-4. Travel
distance was converted to contaminant travel time using
the retarded ground-water velocity for each compound
(pore water velocity/contaminant retardation factors).
The data in Table 7-4 indicate that first order regression
results for all specific compounds observed at the
Layton site were statistically significant at the 95-percent
confidence-level (p value of regressions all < 0.05).
These first order degradation rates ranged from 0.00014
to 0.00087/d, with the highest molecular weight, lowest
solubility compound, (naphthalene), having the slowest
degradation rate. Benzene was found to be the most
degradable of the compounds investigated at the
Layton site.
7-13
-------
Table 7-3. Contaminant Center of Mass Velocities Based on Ground-Water Data
Collected at the Layton Site from July 1992 to February 1995.
Distance
Traveled (ft) =
Direction
Traveled =
Contaminant
Velocity (ft/d)=
Contaminant
Velocity (ft/yr)=
Benzene
11.64
East
0.01
4.39
Toluene
6.94
North East
0.01
2.62
Ethyl-
benzene
20.08
South
0.02
7.57
p-Xylene
8.97
South East
0.01
3.38
Naph-
thalene
13.54
North East
0.01
5.11
TPH
9.93
South West
0.01
3.75 .
8000'
-20 0 20 40 60 80 100
Distance Downgradient of CPT-19
120
Figure 7-16. Time-averaged dissolved plume centerline concentrations for benzene and
toluene measured at the Layton site during the study.
7-14
-------
10000'
o Ethylbenzene
o p-Xylene
-20
20 40 60 80 TOO
Distance Downgradient of CPT-19
120
Figure 7-17. Time-averaged dissolved plume centerline concentrations for ethylbenzene and p-
xylene measured at the Layton site during the study.
-20
20 40 60 80 100
Distance Downgradient of CPT-19
Figure 7-18. Time-averaged dissolved plume
measured at the Layton site during the study.
centerline concentrations for naphthalene
7-15
-------
20 40 60 80 100
Distance Downgradient of CPT-19
120
Figure 7-19. Time-averaged dissolved plume centerline concentrations for combined BTEX
components measured at the Layton site during the study.
80000
-10000
20 40 60 80 100
Distance Downgradient of CPT-19
120
Figure 7-20. Time-averaged dissolved plume centerline concentrations for TPH measured at the
Layton site during the study.
7-16
-------
o
9
8.5
8
7.5
7
6.5
co ,
5.5
5
4.5
y = -0.00024X + 10.0, r2 = 0.8737
p = 0.0063
2500 5000 7500
10000 12500 15000 17500 20000 22500 25000
Contaminant Travel Time (d)
Figure 7-21 j Natural log transformed, time-averaged p-xylene plume-centerline concentrations
versus contaminant travel time from the source area (measured at the Layton site during the
study).
Table 7-4. Summary of Contaminant Degradation Rates Estimated from Time-
Averaged Centerline Concentrations Measured at the Layton Site from July 1992 to
February 1995 Corrected for Contaminant Retarded Velocity
Compound
Benzene
Toluene
Ethylbenzene
p-Xylene
Naphthalene
FirstOrder
Rate (1/d)
0.00087
0.00044
0.00026
0.00024
0.00014
95% Percent
Confidence
Interval (1/d)
0.00057
0.00010
0.00010
0.00013
0.00008
R2
0.8204
0.9742
0.9263
0.8737
0.8243
p Value
0.0129
0.0003
0.0021
0.0063
0.0123
7-17
-------
These degradation rates do not explicitly account for
reductions in concentration due to dispersion and
dilution (i.e., non-degradative) processes taking place
within the Layton aquifer. The more preferred approach
to estimate contaminant degradation, taking into
account dilution/dispersion processes, involves the use
of a ground-water fate-and-transport model that is
calibrated to field-generated data.
Ground-Water Model Calibration
As indicated in Chapter 4, an analytical solution for the
advection-dispersion equation, with degradation, can be
applied with site-specific physical/chemical input
parameters to model the fate-and-transport of
contaminants under actual field conditions so that
"dilution-corrected" degradation rates for these
compounds can be estimated. The modeling effort, also
allows the evaluation of long-term plume behavior based
on the consideration of various source area
management scenarios that may be applicable to a given
site. The analytical solution for this transport with
degradation problem was given in Equation 4-29 for a
continuous source with one-dimensional ground-water
flow, i.e., no vertical flow occurs within the flow field.
Based on these assumptions, the following approach
was used at the Layton site to generate a calibrated
model for contaminant degradation estimates and long-
term plume behavior analysis.
Hydraulic and Chemical Model Input
Parameters
Hydraulic and chemical properties affecting the transport
of contaminants within the subsurface, and which are
incorporated into the multidimensional transport model
used in this study, include aquifer pore-water velocity
and dispersivity, and contaminant retardation. Site-
specific values used for modeling plume transport and
decay at the Layton site are summarized below.
Aquifer pore-water velocities were calculated based on
measured values of hydraulic gradient and hydraulic
conductivity and estimated values of total aquifer
porosity using Darcy's Law. Hydraulic conductivity was
estimated at 1.5 ft/day for the Layton site based on
results of slug tests conducted in April 1992. Total
aquifer porosity was assumed to be 0.38 at the Layton
site. The hydraulic gradients, ground-water flow
direction, and estimated pore-water velocities observed
at the Layton site during the study are summarized in
Table 7-5. The average hydraulic gradient observed
during the study, 0.01 ft/ft, was used with the input data
presented above to yield an average pore water velocity
of approximately 0.037 ft/day at the Layton site during
the study. As indicated in Chapter 4, details of the slug
tests conducted at the Layton site can be found in
Appendix D.
Contaminant retardation factors used in the modeling
effort were estimated from Equation 4-31 with
compound-specific values for the organic carbon
normalized soil/water partition coefficient (Koc), and the
soil organic carbon content, bulk density, and porosity
values (assumed for the Layton aquifer) of 0.3%, 1.15
g/cm3, and 0.38, respectively.
Using the input data listed above, calculations of Kd and
R for benzene, toluene, ethylbenzene, p-xylene, and
naphthalene are summarized for the Layton site in Table
7-6. These data were used as input for the fate-and-
transport modeling described below.
Table 7-5. Summary of Ground-Water Head Gradient, Ground-Water Flow Direction, and
Pore Water Velocity Results for the Layton Site Collected During This Study
Sampling
Date
8/25/92
12/28/92
3/18/93
6/10/93
9/23/93
1/8/94
Average Values
Ground-Water
Head Gradient
(ft/ft) •
0.009
0.008
0.009
0.014
0.010
0.008
0.010
Flow Direction
South Southwest
West
Northwest
Southwest
South Southwest
South Southwest
Estimated
Pore Water
Velocity (ft/d)
0.035
0.031
0.035
0.054
0.037
0.031
0.037
7-18
-------
Table 7-6. Input Data and Estimated Sorption Coefficients/Retardation Factors Used for
Compound
Benzene
Toluene
Ethylbenzene
Xylenes
Naphthalene
KOC*
190
380
680
720
1300
Kd
(mL/g)
0.57
1.14
2.04
2.16
3.90
R
2.7
4.4
7.2
7.5
12.8
"Compiled from U.S. EPA (1991) and API (19941)
Source Area Dimensions
As indicated in the model description, the analytical
solution presented in Equation 4-29 assumes a
constant plane source perpendicular to the direction of
ground-water flow. Based on this assumption, the
source vertical dimension, Z, was set equal to 10 ft, the
approximate maximum thickness of the observed
contaminated ground-water column in monitoring wells
at the Layton site. The simulated plume elevation, z,
was set to one ft, the approximate elevation of single-
level ground probes below the ground-water table. The
lateral source dimension, Y, was based on an inspection
of contaminant concentration profiles perpendicular to
ground-water flow near the source area. For the Layton
site, the transect composed of CPT-21, CPT-19, CPT-
08, CPT-12, and CPT-10 was used to make the
determination of the appropriate cross-plume, Y-
dimension value.
This transect is shown in Figure 7-22 and indicates that
the plume width was relatively constant over the study
period at approximately 100 ft. This 100-ft value was
subsequently used in all plume modeling efforts.
Simulation Times
The simulation time represents the length of time since
the source release occurred. This is an important
modeling parameter since model simulations are carried
out from the source release time at t = 0 to some
designated point in time that corresponds to the data set
used in the calibration process. Plumes grow over time
until they reach a steady-state condition at which the
assimilation rate of contaminant within the plume is
equivalent to the release rate of the contaminant from
the source area. If the simulation time is inappropriately
selected, a different phase of the life of the plume may
be described by the analytical solution and may produce
incorrect degradation rates from the model. The release
at the Layton site could not have occurred before 1958
when the first tanks were placed at the site, and likewise
it could not have occurred after 1984 when the last of
the installed tanks were taken out of service. No
contaminated soil and system leaks were identified
during the placement of pressurized dispenser systems
in a portion of the site in 1974. This suggests that major
releases of product occurred after that time. From this
site history, a range of simulation times from 10 to 25
years was used for model calibration efforts.
As indicated in the protocol (Chapter 4), 'k and t were
varied over ranges applicable for each contaminant to
evaluate the sensitivity of model output to these
parameter values and to determine those combinations
of parameters producing the smallest MSE values. All
compounds of interest in the study were evaluated
together so that one common set of model parameters
was generated from calibration of the model to the field
data. Table 7-7 summarizes results of a portion of the
calibration effort, presenting MSE values for various
combinations of simulation time and A, for the BTEX
compounds and naphthalene. Data from the March
1993 sampling event were chosen for model calibration
for all compounds except naphthalene, as they appear
to be representative of mean conditions existing at the
site during the course of the field study (Figures 7-5 and
7-6)..
The naphthalene data set appeared anomalous as
concentrations observed for this compound along most
of the March 1993 transect were higher than 1 mg/L, a
concentration above the expected ground-water
concentration in equilibrium with gasoline of 200 to 500
p,g/L. Because of the high and persistent
concentrations of naphthalene observed in March 1993,
concentration data averaged over the study period were
used for the naphthalene calibration data set. Based on
7-19
-------
^ 80000
Jl 70000
.g 60000
t! 50000
-| 10000
.S
Q 0
20 40 60 80 100 120
Transverse Distance from CPT-21 (ft)
140
Figure 7-22. Dissolved TPH concentrations in transverse transect of plume at the Layton site
measured from July 1992 to February 1995.
this time-averaged data, concentrations of naphthalene
downgradient of the source area were not found below
the equilibrium aqueous concentration until reaching
monitoring point MLP-05. The transect used for
naphthalene model calibration, outside of the apparent
supersaturated naphthalene area, included only points
MLP-05, CPT-07, and MLP-06 for model calibration
purposes.
Model Calibration Results
From the model calibration effort, a source simulation
lifetime of 25 years resulted in the best overall model fit.
Figures 7-23 through 7-27 show the results of the
calibration effort and reflect the optimal model fit that is
represented by the last entry for each compound in
Table 7-7. It is interesting to note that in all cases the
results from the plume centerline approach summarized
in Table 7-4 overlap those from the model calibration
results in Table 7-7 for all compounds at the 95-percent
confidence level. It appears then that the plume
centerline concentration approach provides statistically
equivalent results to that of the fate-and-transport
modeling approach when the plume has reached
steady-state conditions.
Estimation of Source Mass/Lifetime
As indicated in Chapter 4, when a continuous source is
identified at a site, the estimation of source mass and
source lifetime is based on the total mass of contaminant
at the site both above and below the ground-water table.
This mass is generally estimated from soil-core
concentration data collected within the source area at
the site. Since the plume at the Layton' site was
identified as a continuous source with steady-state
dissolved mass, lifetime calculations of contaminant
mass were estimated from soil core and ground-water
concentration measurements along with contaminant
degradation rates.
Mass Based on Soil Core Data
Soil core data from a variety of locations throughout the
Layton site were used to develop an estimate of the
contaminant mass within the source area below the site.
These soil data included nine soil core locations from
which five to 11 samples from each core were obtained
over soil depths from 2.5 to 10.5 ft below ground
surface. Cores were collected adjacent to MW-01 and
CPT locations 03, 04, 05, 06, 07, 08, 09, and 10. Soil
concentrations of BTEX, naphthalene, and TPH,
ranging from non-detect to a high of only 430 p,g TPH/g
dry wt. soil, were lower than expected based on high
ground-water measurements from ground-water
monitoring probes. Source area BTEX, naphthalene,
and TPH concentration and total-mass estimates were
made by calculating an average concentration across the
site for each core depth, then calculating a depth-
averaged concentration across the entire site. These
depth-averaged concentrations were then applied to
the entire area of the site (41,072 ft2) over a sampling
depth of 11.5 ft to yield the total mass values shown in
Table 7-8. The estimated residual source area masses
appear under predicted by the soil core data as the
dissolved plume masses (measured in February 1995)
7-20
-------
Table 7-7. Summary of Model Calibration Results For BTEX Centerline Concentrations
Measured at the Layton Site in March 1993, and Time-Averaged Naphthalene Centerline
Concentration Data.
Compound
Benzene
Toluene
Ethylbenzene
p-Xylene
Naphthalene
Simulation Time
(vr)
10
10
20
20
25
10
10
20
20
25
10
10
20
20
25
10
10
20
20
25
10
10
20
20
25
k
(1/d)
0.0000
0.0009
0.0000
0.0009
0.0009
0.0000
0.0006
0.0000
0.0006
0.0006
0.0000
0.0002
0.0000
0.0000
0.0002
0.0000
0.0004
0.0000
0.0004
0.0004
0.0000
0.0001
0.0000
0.0002
0.0001
MSE
20,792,893
2,577
62,577,557
10,305
10,320
3,763,063
17,235
16,730,551
37,014
32,984
196,102
195,623
631,985
11,622
12,706
16,054,755
775,097
45,526,903
604,452
430,043
166
159
69
102
1 7
were generally 10 to 25 percent of the masses predicted
from the soil cores. The soil-core data collected from the
Layton site do not appear to yield representative
estimates of source-area residual mass, and an
alternative method of source-mass estimation was used
based on the maximum residual saturation that can be
expected to exist within the soil at the Layton site.
Mass Based on Residual Product
Estimate
Estimates of the maximum product residual saturation
can be made (based on the characteristics of the soil
existing at a given site) by using quantitative
relationships by Parker et al. (1987) and Mobil Oil
Corporation (1995). These relationships describe the
typical residual hydrocarbon saturations within a smear
zone at and below the ground-water table as a function
of soil texture. Using these residual saturation data for
the clay to silty clay soils below the Layton site suggests
that approximately 10 percent of the subsurface porosity
could be expected to be occupied by non-aqueous
phase product material (Mobil Oil Corporation, 1995).
Based on ground-water data collected in February 1995,
the aerial extent of potential residual phase material was
approximated by the shaded polygon shown in Figure 7-
28 and represents approximately 8,360 ft2. It should be
noted that only two of the nine soil borings collected
during the site investigation phase of this study were
included in this area.
The volume of soil below the site which contains this
residual saturation was estimated from the area shown in
Figure 7-28 and the vertical extent of potentially
7-21
-------
Table 7-8. Summary of Average Contaminant Concentration, Estimated Total
Residual Soil Mass, and Dissolved Plume Mass in February 1995 Measured at the
Layton Site
Average Soil
(H.g/g dry
Depth
(ft)
2 to 3
5 to 6
6 to 7
7 to 8
8 to 9
9 to 10
10 to 11.5
Benzene
1.90
0.21
0.15
0.09
0.21
0.80
0.10
Toluene
4.40
0.57
0.62
0.41
6.44
3.10
0.41
Ethyl-
benzene
4.50
0.49
0.33
1.70
0.34
1.80
0.22
Concentration
wt. soil)
p-Xylene
4.00
1.10
0.52
3.20
0.46
3.00
0.38
Naph-
thalene
0.00
0.31
0.24
1.20
0.01
0.74
0.01
TPH
97
20
26
87
3
97
7
Average Concentration Across the Site
((ig/g dry wt. soil)
2tOl1.5 0.49 1.30 1.30 1.60. 0.25 41
Total Mass of Contaminant in Soil Across
the site (Ib)
21011.5 12.80 35.20 33.50 41.30 6.70 1,072
Total Mass of Contaminant in Dissolved Plume
February 1995 (Ib)
8.10 3.40 1.90 9.60 1.20 . 172
contaminated soil of f3.5 ft (10 ft of ground-water
contamination and 3.5 ft of capillary fringe and smear
zone). It was further assumed that 10 percent of the
pore volume of soil contained this residual product
(112,900 ft3 soil volume, 42,900 ft3 pore volume)
yielding an estimated residual product volume of 4,290
ft3, or approximately 241,000 Ib of TPH.
From this estimate of the mass of residual product
remaining below the site, the mass of BTEX and
naphthalene components associated with the product
was determined using Raoult's Law, Equation 7-1, and
associated relationships shown in Equations 7-2
through 7-4. In using these equations, a molecular
weight of the residual product of 120 Ib/lbmol was
assumed. Contaminant ground-water measurements in
February 1995 were used as measured values of the
Equilibrium Concentration in Equations 7-1 and 7-2.
Equilibrium Concentration = (Mole Fraction) (Aqueous Solubility)
Mole Fraction = (Equilibrium Concentration)/(Aqueous Solubility)
Moles in Product = (Mole Fraction) (Mass of TPH)/(MWTPH)
Mass in Product = (Moles in Product) (MWcompound)
(7-1)
(7-2)
(7-3)
(7-4)
7-22
-------
Benzene Ground-Water Concentration
7,000 <
6,000 -
5,000 -
A nnn -
— 3,000 -
2,000 -
1,000 -
• i • Simulation Parameters:
* Degradation rate = 0.00086/d,
• \ R = 2.7, t = 25yr
\
\
\ » Field Measured Data
\
\ Predicted Data
\ .
v.__
0 ' 20 40 60 80 100 '120' 140 160 180 200
Downgradient Distance from Source Area (ft)
Figure 7-23. Results of benzene plume center-line calibration at the Layton site using data
collected in March 1993.
o
4,500 <>•
4,000 -\
Simulation Parameters:
Toluene Ground-Water Concer
3,500 •
3,000 •
•=r 2,500 •
^ 2,000 •
1 ,500 -
1 ,000 •
500
n
- \ . Degradation rate = 0.00062'/d,
\ ' R = 4.4, t = 25yr
V
\
\ • Field Measured Data
V
\ Predicted Data
v
\
1 1 ^" T -E 1 1 1 1 1
20 40 60 80 100 120 140 160
Downgradient Distance from Source Area (ft)
180
200
Figure 7-24.
collected in
Results of toluene plume centerline calibration at the Layton site using data
March 1993.
7-23
-------
2,000 T
1,800 •
•S _ 1,600 -
•i |jj 1,400 -
J^ 1,200 -
15 1,000 -
03 4=
| 1 800 -
| u
* § 600 -
=s o
£ 400 -
m
200 -
•
»
\
\ Simulation Parameters:
>» Degradation rate = 0.0002/d,
• \ R = 7.2, t=25yr
\
\
\ o Field />
\
. • \ Predic
\
N\
Measured Data
ted Data
0.
0 20 40 60 80 100 120 140 160 180 200
Downgradient Distance from Source Area (ft)
Figure 7-25. Results of ethylbenzene plume centerline calibration at the Layton site using data
collected in March 1993.
o
c
Q)
U
c
I
0)
12,000 -,
4
10,000 -
8,000 -
6,000 -
4.000 -
2,000 -
0 .
A Simulation Parameters:
\ Degradation rate = 0.00037/d,
\ R = 7.5, t = 25 yr
• \
\
4
• A
\ » Field Measured Data
s Predicted Data
\
S —
NN^
1 1 —i-,-* — — , IT". I,,.., .1 1 1 1
20 40 60 80 100 120 140 160
Downgradient Distance from Source Area (ft)
180
200
Figure 7-26. Results of p-xylene plume centerline calibration at the Layton site using data
collected in March 1993.
7-24
-------
300 T
^D
"B
T3
3
2
O
(D
C
(D
D
Q.
D
—
i
c
o
"5
"c
0
o
o
U
250 '
200 .
150 .
100 •
50 •
Simulation Parameters:
\ R=12.8,t = 25yr
• \
• \
\
\
\
\
N
\
i r — * i i i
« Field Measured Data
Predicted Data
i i i i
) 20 40 60 80 100 120 140 ' 160 180 200
Downgradient Distance from Source Area (ft)
Figure 7-27. Results of naphthalene plume centerline calibration at the Layton site using
project time-averaged concentration data for transect beginning at MLP-05.
where MWTPH = molecular weight of TPH = 120
Ib/lbmol; and MWcompound = molecular weight of
individual BTEX components and naphthalene, Ib/lbmol.
These calculations are summarized in Table 7-9 along
with the mass of BTEX and naphthalene in the dissolved
plume at the site in February, 1995. As indicated in
Table 7-9, estimates of masses of BTEX and
naphthalene within the residual phase at the site are
significantly higher than those presented in Table 7-8
using the site soil core data. These higher residual soil
mass data are consistent with the dissolved-phase BTEX
and naphthalene mass values determined to be in the
plume in February 1995. They are thought to provide a
more representative picture of site conditions than that
generated from the soil core results. If the data in Table
7-9 are correct, the source area can be expected to last
for a significant time into the future if no source removal
action is taken. The dissolved-phase mass is only a small
fraction of the mass of contaminant remaining within the
source area. Source area lifetime considerations are
addressed in the following section.
Contaminant Mass Lifetime
The lifetime for the mass of contaminant, estimated to be
remaining at the Layton site can be determined
according to the procedures described in Chapter 4 with
the use of Equation 4-16 and the model-calibrated first
order degradation rates for the BTEX and naphthalene
components of the residual-phase material.
Equation 4-16 indicates that for a continuous source
that shows first order degradation, the time for a specific
mass or concentration of contaminant to be reached
(based on initial values) is:
T% = -ln[%remaining]/ki
(7-5)
where T% = the time required to yield a given
percentage of remaining mass or concentration;
%remaining = mass or concentration remaining at time
T%; and ki = model calibrated first order degradation rate
constant for the compound, 1/d. Using Equation 7-5,
the length of time for the destruction of the residual
mass, 99.9 percent of the total mass at the Layton site,
and the time to achieve 10 x and 1 x the MCL with and
without source removal are summarized in Table 7-10. It
should be noted that the total time associated with the
assimilation of a contaminant plume is the sum of the
time for source-area mass assimilation plus the time
required for assimilation of the dissolved plume. With
source removal, the time for the assimilation of the
contaminant plume is then only related to destruction of
mass in the dissolved plume. The results (summarized
in Table 7-10) reflect this effect of source removal on the
projected time to reach contaminant MCLs below the
Layton site. Without source removal, the large mass of
contaminant within the source area could require more
than 100 years before MCLs are reached-based on the
ethylbenzene MCL of 700 jo.g/L and a source-area
ethylbenzene ground-water concentration of
approximately 1,900 |ig/L measured in February 1995.
With source removal, the time to reach the
ethylbenzene MCL requirement is reduced to 14 years.
Benzene becomes the limiting contaminant, requiring
an assimilation time of approximately 22 years before its
7-25
-------
jg,
0)
100.00
50.00
0.00
-50.00
-100.00
-150.00
-200.00
-100.00 -50.00
0.00 50.00 100.00
East Coordinate (ft)
150.00
Figure 7-28. Estimated extent of residual contamination at the Layton site based on ground-
water concentration data collected in February 1995.
7-26
-------
Table 7-9. Summary of Estimated Total Residual Contaminant Mass
Product Volume Estimates, and Dissolved Plume Mass in February
Based on Residual
1995, Measured at
Compound
Benzene
Toluene
Ethylbenze
p-Xylene
Naphthalene
TPH
MW
(Ib/lbmol)
78.1
92.1
106.2
106.2
128.2
120.0
Aqueous
Solubility
(mg/L)
1,780
759
135 .
221
31
2/95 GW
Concentration
(mg/L)
4.9
3.2
1.9
6.3
0.8
86.1
Mole
Fraction
0.003
0.004
0.014
0.029
0.026
Ibmol in
Product
5.5
8.5
285.0
57.5
52.1
Mass in
Product
(Ib)
431
782
3,025
6,111
6,681
241,000
Mass in
Plume
2/95
(Ib)
8.1
3.4
1.9
9.6
1.2
17.20
Table 7-10. Summary of Estimated Residual Contaminant Mass Lifetime Based on
Model Calibrated Degradation Rates Determined for the Layton Site.
Mass in i
Mass in i Compound!
... J....,, [.- ;.,
i Residual Plume 2/95J
Compound j
Benzene i
Toluene i
Ethylbenzenei
p-Xylene !
Naphthalene;
TPH j
i
i
Benzene i
Toluene !
Ethylbenzenei
p-Xylene I
Naphthalene!
TPH !
(Ib) !
431 i
782!
3,025 i
6,111!
6,681 i
241,000!
Percent!
Total !
Mass in I
Residual
98.21
99.61
99.9!
99.8!
100.0!
99.9!
(Ib) !
8.1 !
3.4!
1.9!
9.6!
1.2!
1 72.0i
i
Percent !
Time for ! Time for 99.9 !
First Order i Residual Mass ! Percent Total !
Rate(l/d) !
0.00086!
0.00062!
0.00020!
0.00037!
0.00012!
Decay (yr) I Mass Decay (yr)!
12.7! .
24.0! .
101.0!
47.8!
196.9!
22.0!
30.5!
94.6!
51.1!
157.7!
Time to Reach
lOxMCLj
(yr) !
27.3!
NAJL
NA!
NA!
NA!
MCL
(yr)
34.7
29.2
"115.0
NA
NA
! with 100 percent Residual Product Removal
Total iCompound 1
j— " ' • !"
Mass in j First Order !
Plume !
1.84!
0.43!
0.06!
0.16:
0.02!
0.07!
Rate(l/d) !
0.00086:
0.00062 1
0.00020!
0.00037!
0.00012!
i
Time for Specified
Percent Mass Removal
! Time to Reach
(vr) !
99 ! 99.9 !
1.9!
NA!
NA!
NA!
NA!
- 9.3!
6.5:
NA!
3.3!
NA!
lOXMCLi
(yr) !
14;6.L,
NAi
NA!
NA!
:...NA!..
MCL
(yr)
21.9
'5.1
14.0
NA
NA
7-27
-------
MCL is reached below the site. Source removal greatly
reduces the length of time for assimilation of the mass of
all contaminants at the Layton site, suggesting the need
for some source removal effort for this site, making the
duration of site management more acceptable.
Predicting Long-Term Behavior of
Plume
Since the Layton site has been shown to contain a
significant source area, which produces a continuous
source plume, long-term plume behavior can be
evaluated based on various source removal scenarios. If
source removal does not occur, a worst-case scenario
develops in terms of the length of time the plume will
persist. Table 7-10 indicates that this time frame could
be approximately 100 years - based on ethylbenzene
MCL requirements. If 100 percent of the contaminant
Source were removed, Table 7-10 indicates that the
overall time for site remediation is reduced significantly,
by a factor of nearly ten for ethylbenzene, nearly six for
toluene, and by a factor of nearly two for benzene.
As indicated in Chapter 4, the long-term behavior of a
contaminant plume can be predicted for a variety of
source removal options. This is carried out by the
superposition of a continuous-source plume (with a
source concentration equal to -Co) with the steady-state
plume concentration profile (at a point in time
corresponding to the time of source removal). If it is
assumed that site management will be required as long
as the plume at the Layton site exceeds the MCL values
for any of the constituents of public health concern,
e.g., BTEX, then a time to reach the MCL (following
source depletion) can be predicted for each component
using the fate-and-transport model described in this
report, calibrated to the Layton field data, using this
superposition approach. This modeling approach is
more rigorous than the simple first order decay
approximation described • by Equation 7-5 and
presented in Table 7-10, since it accounts quantitatively
for sorption, dilution and dispersion in addition to
biodegradation mechanisms taking place at the site.
Table 7-11 presents a summary of this modeling effort.
Figures 7-29 through 7-33 show the simulation runs for
BTEX for simulation times from 0 to 18 years after 100
percent source removal/depletion depending upon the
contaminant being modeled. These results are slightly
lower than those presented in Table 7-1. This would be
expected from the additional mechanisms that act to
reduce contaminant concentration and that are
accounted for in this fate-and-transport modeling
approach. Results from both the approximate first order
and the more rigorous modeling approach do suggest,
however, that once source removal or depletion is
complete at the Layton site, the persistence of the
plume and the duration of site management will be
controlled by benzene. A benzene plume of greater
than the MCL of 5 |ag/L is projected to persist for 18
years following source removal/depletion, while all other
contaminants of concern are projected to reach their
MCL values everywhere within the plume in only 1.5
days to 7.5 years after source removal.
Decision Making Regarding Intrinsic
Remediation
Decisions regarding the acceptability of natural
attenuation for a given site should be based on the
potential impact a plume has on susceptible
downgradient receptors, and-evidence regarding the
presence and rate of intrinsic attenuation reactions that
occur at a site that provide contaminant plume
containment and control. Evidence of contaminant
degradation is provided through plume analysis and the
degradation-rate estimates described in this report.
Assessment of the potential aquifer assimilative
Table 7-11. Summary of Estimated Time to Reach MCL Levels within the Contaminant Plume
at the Layton Site for BTEX, Naphthalene and TPH Compounds Based on Field Calibrated
Fate-and-Transport Model Results
Compound
Benzene
Toluene
Ethylbenzene
p-Xylene
Naphthalene
TPH
MCL
(UQ/U
5
1,000
700
10,000
NA
NA
Aqueous
Solubility
(mg/L)
1,780
759
135
221
31
3/93 GW
Concentration
(ua/L)
6,996
4,473
1,946
11,441
1,544
99,832
Time to Reach
MCL Following
Source Removal (yr)
18.00
3.25
7.50
0.01 (1.50d)
NA
NA
7-28
-------
c 7,000 -
o
Simulation Parameters:
Degradation rate = 0.00086/d,
R = 2.7, Steady-State Plume
• Predicted Data with No
Source Removal
• Predicted @ t = 5 yr After
100% Source Removal
1 Predicted @ t = 10 yr After
100% Source Removal
40 60 80 100 120 140 160
Downgradient Distance from Source Area (ft)
180
200
Figure 7-29. Predicted impact on plume centerline benzene concentrations 5 and 10 years after
100 percent source removal based on the field data calibrated fate-and-transport model for the
Layton site.
c
.g
J5
0)
o
o
O
CD —
|1
c
0
O
(D
C
a
c
(U
03
100 j
90 -
80 •
70 -
60 •
50 .
40 •
30 •
20 •
10 •
0
Simulation Parameters:
Degradation rate = 0.00086/d,
R = 2.7, Steady-State Plume
Predicted Data with No
Source Removal ,
: Predicted © t = 10 yr After
100% Source Removalr.
Predicted © t = 18 yr After
100% Source Removal
20
40 60 80 100 120 140 160
Downgradient Distance from Source Area (ft)
180
200
Figure 7-30. Predicted impact on plume centerline benzene concentrations 10 and 18 years
after 100 percent source removal based on the field data calibrated fate-and-transport model for
the Layton site.
7-29
-------
4,500
Simulation Parameters:
Degradation rate = 0.00062/d,
R = 4.4, Steady-State Plume
Predicted Data with No
Source Removal
— n — Predicted Data @ t = 2 yr
After 100% Source Removal
Predicted Data @ t = 3.25 yr
After 100% Source Removal
"°*~°°™™ Predicted Data @ t = 5 yr
After 100% Source Removal
•4-
-4-
-4-
20 40 60 80 TOO 120 140 160
Downgradient Distance from Source Area (ft)
180
200
Figure 7-31. Predicted impact on plume centerline toluene concentrations 2, 3.25, and 5 years
after 100 percent source removal based on the field data calibrated fate-and-transport model for
the Layton site.
Simulation Parameters:
Degradation rate = 0.0002/d,
R = 7.2, Steady-State Plume
' - Predicted Data with No
Source Removal
° ~ Predicted Data @ t = 5 yr
After 100% Source Removal
predicted Data @ t = 7.5 yr
After 100% Source Removal
Predicted Data @ t = 10 yr
After 100% Source Removal
---- o ---
-4-
-4-
20
40 60 80 100 120 140 160
Downgradient Distance from Source Area (ft)
180
200
Figure 7-32. Predicted impact on plume centerline ethylbenzene concentrations 5, 7.5, and 10
years after 100 percent source removal based on the field data calibrated fate-and-transport
model for the Layton site.
7-30
-------
o
I
-------
Table 7-12. Potential Aquifer Assimilative Capacity at the Layton Site Based on Ground-Water
Data Collected from March 1992 to January 1994
Electron Acceptor
DO
N03-
S042-
AFe
AMn
CH4
Background
Concentration
(mg/L).
2.5
21.0
148.5
1.4
0.6
Not measured
Potential
• Mean HC Equivalent
Stoichiomelry
(q/q HC Equivalent)
. 3.3
1.1
5.0
23.1
20.0
NA
Assimilative Capacity =
HC Equivalent
Assimilative Capacity
(mq/L)
0.76
19.63
30.00
0.06
0.03
NA
50.47
removal, intrinsic remediation appears marginally
protective of public health and the environment.
Long-Term Monitoring Program for Site
As indicated in Chapter 4, long-term monitoring at the
Layton site should be focused on two primary
objectives. First, monitoring should be carried out for
compliance purposes to ensure no impact to a
downgradient receptor. This should involve monitoring
of downgradient sampling points on a three- to five-year
sampling frequency to ensure that significant changes in
plume degradation and transport have not occurred at
the site. Second, intrinsic remediation monitoring for
remediation process evaluation is perhaps more critical
at this site since no nearby receptors exist. Monitoring at
four to six locations along the plume centerline on a
three- to five-year sampling frequency should provide
adequate data to ensure that unexpected plume
migration has not taken place at the site. To validate
degradation rates that are presented above,.additional
cross plume sampling point measurements are also
necessary so that a representative determination of
residual dissolved plume mass can be made. Based on
the ground-water monitoring network in place at the
Layton site (Figure 5-6) a sampling scheme for both
compliance and intrinsic remediation process monitoring
purposes at the site is presented in Table 7-13.
Specific analyses for samples collected during the long-
term monitoring phase should be similar to those used in
this study. The analytes specified by the State of Utah
DEQ for compliance monitoring purposes would be
expected to include: ground-water elevation; field
ground-water dissolved oxygen concentrations; and
BTEX, naphthalene, and purge-and-trap TPH ground-
water concentrations. In addition, other electron
acceptors (nitrate, sulfate, and dissolved iron and
manganese) should be quantified for intrinsic
remediation process evaluation along with general
ground-water quality parameters such as pH,
temperature, and TDS.
The proposed sampling frequency of three to five years
is based on the projected lifetime of the source and
dissolved plume of 35 to 115 years without source
removal (Table 7-10). As indicated in Table 7-10, with
complete source removal, the projected lifetime is
reduced significantly, (being only slightly greater than 20
-years). If source removal activities were carried out at the
Layton site, a monitoring frequency of every two to three
years would be recommended to account for the
reduced source/plume lifetime.
Summary of Intrinsic Remediation
Evaluation at the Layton Site
As indicated in the data presented and discussed
above, there appears to be ample evidence that intrinsic
remediation has stabilized the hydrocarbon plume at the
Layton site. The efficacy of intrinsic remediation alone,
however, is questionable because of the significant
mass of contaminant existing at the site, the relatively
low contaminant degradation rates (one order of
magnitude lower than those observed at the Hill AFB
site), and the limited pools of electron acceptors moving
onto the site.
The contaminant plume appears to be stabilized for all
contaminants of concern; however, the time for residual
mass assimilation (without some form of source removal
and controlled by the ethylbenzene MCL value), is
estimated to exceed 100 years. This estimate is
significantly reduced with the removal of mass from the
source area; however, reduction of benzene below the
MCL across the site may still require more than 20 years
7-32
-------
with 100 percent source mass removal. Additional
monitoring should be carried out to develop a better
estimate of the residual mass existing within the source
area and to verify that contaminant degradation, has
continued at the rates observed in this study.
Finally, investigation of the effectiveness of active
remediation alternatives for contaminant removal at and
below the ground-water table should be conducted in
an effort to accelerate the removal of hydrocarbon
contamination below the Layton site and to reduce the
duration of site management and plume monitoring
activities to reasonable levels.
Table 7-13. Proposed Long-Term Sampling Schemes for Compliance and Intrinsic Process
Monitoring at the Layton Site ^ '
Compliance Monitoring
Purpose Location
Intrinsic Remediation Process Monitoring
Centerline Transect 1 Transect 2 Transect 3
Background
Downgradient
MW-04
MW-03
CPT-07
CPT-09
MW-01
CPT-19
CPT-20
CPT-16
CPT-04
MLP-06
CPT-21
CPT-08
CPT-12
CPT-10
CPT-01
CPT-18
CPT-15
CPT-17
CPT-05
CPT-03
CPT-11
7-33
-------
-------
Chapter 8
References
Aeckersberg, F., F. Bak, and F. Widdel. 1991.
Anaerobic oxidation of saturated hydrocarbons to
carbon dioxide by a new type of sulfate-reducing
bacterium. Arch. Micro. 156: 5-14.
Atlas, R.M., and R. Bartha. 1987. Microbial Ecology:
Fundamentals and Applications. Menlo Park, California:
Benjamin/Cummings.
'APHA. 1989. Standard Methods for the Examination of
Water and Wastewater. 19th Edition. Washington, DC:
American Public Health Association.
API. 1994. Transport and Fate of Ndn-BTEX Petroleum
Chemicals in Soils and Groundwater, API Publication
Number 4593. Washington, DC: Health and
Environmental Sciences Department, American
Petroleum Institute.
Barcelona, M. J., and T. R. Holm. 1991. Oxidation-
reduction capacities of aquifer solids. Environ. Sci.
Technol. 25: 1565-1572,
Battersby, N. S., and V. Wilson. 1989. Survey of the
anaerobic biodegradation potential of organic chemicals
in digesting sludge. Applied Environ. Micro. 55(2): 433-
439.
Beller, H.R., D. Grbic-Galic, and M. Reinhard. 1992.
Microbial degradation of toluene under sulfate-reducing
conditions and the influence of iron on the process.
Applied Environ. Micro. 58(3): 786-793.
Blegen, R.P.,'J.W. Hess, and J.E. Denne. 1988. "Field
comparison of ground-water sampling devices." Paper
presented at the NWWA Second Annual Outdoor
Action Conference, Las Vegas, NV, May.
Borden, R.C. and P.B. Bedient. 1986. Transport of
dissolved hydrocarbons influenced by oxygen-limited
biodegradation 1. Theoretical development. Water
Resources Res. 22(13): 1973-1982.
Brock, D.B. and M.T. Madigan. 1991. Biology of
Microorganisms, Englewood Cliffs, New Jersey:
Prentice Hall.
Chow, V.T, D. R. Maidment, and L. W. Mays. 1988.
Applied Hydrology. New York: McGraw-Hill Book Co.
Domenico, P. A. 1987. An analytical model for
multidimensional transport of decaying contaminant
species. J. Hydrol. 91: 49-58.
Downey, D.C., R.E. Hinchee, M.S. Westray, and J.K.
Slaughter. 1988. "Combined Biological and Physical
Treatment of a Jet Fuel-Contaminated Aquifer." In
Proceedings of the NWWA/API Conference on
Petroleum Hydrocarbons and Organic Chemicals in
Ground Water - Prevention, Detection, and Restoration,
Dublin, Ohio: National Water Well Association, 627-645.
Dragun, J. 1988. "Microbial degradation of petroleum
products in soil." In Soils Contaminated by Petroleum -
Environmental and Public Health Effects (E.J. Calabrese
and P.T. Kostecki, eds.), New York: John Wiley and
Sons, Inc., 289-300.
Dupont, R.R., W.J. Doucette, and R.E. Hinchee. 1991.
"Assessment of in situ bioremediation potential and the
application of bioventing at a fuels-contaminated site."
In Proceedings, In Situ and On-Site Bioreciamation: An
International Symposium, San Diego, California, 19-21.
Ekiund, B. 1985. Detection of Hydrocarbons in Ground
Water by Analysis of Shallow Soil Gas/Vapor, API
Publication No. 4394. Washington, DC: Environmental
Affairs Department, American Petroleum Institute, 81
PP-
Engineering Science. 1991. Final Site Investigation
Report, UST Release Response, Building 1141, Hill
AFB, UT. Salt Lake City, Utah, 128 pp.
Evans, R.B. and G.E. Schweitzer. 1984. Assessing
hazardous waste problems. Environ. Sci. Technol.
18(11):330A.
8-1
-------
Frankel, R.B. 1987. Anaerobes pumping iron. Nature
330: 208.
Gee, G.W. and J.W. Bauder. 1986. "Particle-Size
Analysis." In Methods of Soil Analysis, Part 1. Physical
and Mineralogical Methods. Second Edition (A. Klute,
ed.)> Madison, Wisconsin: American Society of
Agronomy, 383-411.
Gerber, B. 1994. Personal Communication 1/13/94.
Lewiston, Utah: Presto Products.
Glaccum, R., M. Nowl, and L." McMillan. 1983.
"Correlation of geophysical and organic vapor analyzer
data over a conductive plume containing volatile
organics." In Proceedings of the 3rd National
Symposium on Aquifer Restoration and Ground Water
Monitoring, Dublin, Ohio: National Water Well
Association, 421-727.
Grady, C.P.L. and H.C. Lim. 1980. Biological
Wastewater Treatment. New York: Marcel Dekker.
Grbic-Galic, D. .1986. Anaerobic production and
transformation of aromatic hydrocarbons and substituted
phenols by ferulic acid-degrading BESA-inhibited
methanogenic consortia. FEMS Micro. Ecol. 38: 161-
169.
Griffith, J.T., G.A. Robbins, and T.M. Spittler. 1988. "A
new method for field analysis of soils contaminated with
aromatic hydrocarbon compounds." In Proceedings of
the FOCUS Conference on Eastern Regional Ground
Water Issues, Stamford, Connecticut, September 27 to
29, Dublin, Ohio: National Water Well Association.
Haag, F., M. Reinhard, and P. L. McCarty. 1992.
Degradation of toluene and p-xylene in anaerobic
microcosms: evidence for sulfate as a terminal electron
acceptor. Environ. Tox. Chemistry 10:1379-1389.
HInchee, R.E., D.C. Downey, and E.J. Coleman. 1987.
"Enhanced bioreclamation, soil venting and ground
water extraction: cost effectiveness and feasibility
comparison.11 In Proceedings of the NWWA/API
Conference on Petroleum Hydrocarbons and Organic
Chemicals in Ground Water - Prevention, Detection, and
Restoration, Dublin, Ohio: National Water Well
Association.
Hinchee, R.E., D.C. Downey, R.R. Dupont, P. Aggarwal,
and R.E. Miller. 1991. Enhancing biodegradation of
petroleum hydrocarbons through soil venting. J
Hazard. Mat. 27:315-325.
Holbrook, T. 1987. "Hydrocarbon vapor plume
definition using ambient temperature headspace
analysis." In Proceedings of the NWWA/API
Conference on Petroleum Hydrocarbons and Organic
Chemicals in Ground Water - Prevention, Detection and
Restoration, Dublin, Ohio: National Water Well
Association, 317-328.
Hutchins, S.R. 1991a. Biodegradation of monoaromatic
hydrocarbons by aquifer microorganisms using oxygen,
nitrate, or nitrous oxide as the terminal electron
acceptor. Applied Environ. Micro. 57(8): 2403-2407.
Hutchins, S.R. Optimizing BTEX biodegradation under
denitrifying conditions. Environ. Toxic. Chemistry 10:
1437-1448 (1991b).
In-Situ Inc. 1991. Operators Manual-Lab in a Bag,
Laramie, Wyoming: In-Situ Inc., 79 pp.
Klopp, R.A., A.M. Petsonk, and B.A. Torstensson.
1988. "In-situ penetration testing for delineation of
ground water contaminant plumes." Presented at the
NWWA Second Annual Outdoor Action Conference,
Las Vegas, Nevada, May.
Kreamer, O.K. 1983. An evaluation of selected
halocarbons and trace gases for potential use as
indicators of source contaminant and ground water
movement in the vadose zone, Completion Report
Project No. A-111-ARIZ, Washington, DC: U.S.
Department of the Interior, 26 pp..
Kuhn, E. P. 1985. Microbial transformations of
substituted benzenes during infiltrations of river water to
groundwater: Laboratory column studies. Environ. Sci.
Technol. 19(10): 961-968.
Lovely, D.R., and E.J.P. Phillips. 1986. Availability of
ferric iron for microbial reduction in bottom sediments of
the freshwater tidal Potomac River. Applied Environ.
Micro. 52:751-757.
Lovely, D.R..and E.J.P. Phillips. 1987a. Rapid assay for
microbially reducible ferric iron in aquatic sediments.
Applied Environ. Micro. 53: 1536-1540.
Lovely, D.R. and E.J.P. Phillips. 1987b. Competitive
mechanisms for inhibition of sulfate reduction and
methane production in the zone of ferric iron reduction
in sediments. Applied Environ. Micro. 53: 2636-2641.
Lovely, D.R. and E.J.P. Phillips. 1988. Novel mode of
microbial energy metabolism: organic carbon oxidation
coupled to dissimilatory reduction of iron or manganese.
Applied Environ. Micro. 54: 1472-1480.
Lovely, D.R., M.J. Baedecker, D.J. Lonergan, I.M.
Cozzarelli, E.J.P. Phillips, and D.I. Siegel. 1989.
Oxidation of aromatic contaminants coupled to microbial
iron reduction. Nature 339: 297-300.
8-2
-------
Lyman, W.J., P.J. Reidy, and B. Levy. 1991. Assessing
UST Correction Action Technology. A Scientific'
Evaluation of the Mobility and Degradability of Organic
Contaminants in Subsurface Environments, EPA/600/2-.
91/053, Cincinnati, Ohio: Risk Reduction Engineering
Laboratory, Office of Research and Development, U.S.
Environmental Protection Agency, 353 pp.
Major, D.W., C.I.-Mayfield, and J.F. Barker. 1988.
Biotransformation of benzene by denitrification in
aquifer sand. Groundwater26(1): 8-14.
Manahan, S.E. 1990. Environmental Chemistry,
Chelsea, Michigan: Lewis Publishers.
Mihelcic, J.R. and R.G. Luthy. 1988a. Microbial
degradation of acenaphthene and naphthalene under
denitrification conditions in soil-water systems. Applied
Environ. Micro. 54(5): 1188-1198.
Mihelcic, J.R. and R.G. Luthy. 1988b. Degradation of
polycyclic aromatic hydrocarbon compounds under
various redox conditions in soil-water systems. Applied
Environ. Micro. 54(5): 1182-1187.
Mobil Oil Corporation. 1995. A Practical Approach to
the Evaluation of intrinsic Bioremediation of Petroleum
Hydrocarbons in Groundwater, Stonybrook, New
Jersey: Prepared by the Groundwater Technology
Group, Environmental Health and Safety Department
and the Health Risk Assessment Group, Stonybrook
Laboratories, 100 pp.
Morgan, C. and C. Klinger. 1987. "The soil gas survey
as a preliminary investigative tool for hydrocarbon
releases: cost-effective field techniques and an
evaluation of factors influencing the effectiveness of the
survey." In Proceedings of the NWWA/API Conference
on Petroleum Hydrocarbons and Organic Chemicals in
Ground Water - Prevention, Detection, and Restoration,
Dublin, Ohio: National Water Well Association, 347-355.
Nelson, D.W. and LE. Sommers. 1982. "Total Carbon,
Organic Carbon, and Organic Matter." In Methods of Soil
Analysis, Part 2. Chemical and Microbiological
Properties. Second Edition (A.L. Page, ed.), Madison,
Wisconsin: American Society of Agronomy, 539-579.
Nelson, R.E. 1982. "Carbonate and Gypsum." In
Methods of Soil Analysis, Part 2. Chemical and
Microbiological Properties. Second Edition (A.L. Page,
ed.), Madison, Wisconsin: American Society of
Agronomy.
NWWA. 1985. Regional Ground Water Issues, Dublin,
Ohio: National Water Well Association, 223-248.
Olsen, S.R. and L.E. Sommers. 1982. "Phosphorus."
In Methods of Soil Analysis, Part 2. Chemical and
Microbiological Properties. Second Edition (A.L. Page,
ed.), Madison, Wisconsin: American Society of
Agronomy, 403-430.
Parker, J. C., R. J. Lenhard, and T. Kuppusamy. A
parametric model for constitutive properties governing
multiphase flow in porous media. Water Res. Research
23: 618-624 (1987).
Pavlostathis, S.G. and G.N. Mathavan. 1992.
Application of headspace analysis for the determination
of volatile organic compounds in contaminated soils.
Environ. Tech. 13(N1): 23-33.
Perry J.A. -1981. Introduction to Analytical Gas
Chromatography: History, Principles, and Practice.
Chromatographic Science, New York: Marcel Dekker,
Inc., 426 pp.
Rienhard, M., N.L. Goodman, and J.F. Barker. 1984.
Occurrence and distribution of organic chemicals in two
landfill leachate plumes. Environ. Science Technol. 18:
953-961.
Robbins, G.A., V. D. Roe, J. D. Stuart, and J. T. Griffith.
1987. "Use of headspace sampling techniques in the
field to quantify levels of gasoline contamination in soil
and groundwater." In Proceedings of the NWWA/API
Conference on Petroleum Hydrocarbons and Organic
Chemicals in Ground Water - Prevention, Detection, and
Restoration, Dublin, Ohio: National Water.Well
Association, 307-315.
Robbins, G.A., R.D. Bristol, and V.D. Roe. 1989. Afield
screening,method for gasoline contamination using a
polyethylene bag sampling system. Ground Water
Monitor. Rev. 9(4): 87-97.
Roe, V.D., R.D. Bristol, and G.A Robbins. 1989. Manual
headspace method to analyze for the volatile aromatics
of gasoline in groundwater and soil samples. Analytical
Chemistry 61(22): 2584-2585.
Schmidt, C., and E. Balfour. 1983. "Direct gas
measurement techniques and the utilization of
emissions data from hazardous waste sites." In
Proceedings of the 1983 ASCE National Specialty
Conference on Environmental Engineering, Boulder,
Colorado, Washington, DC: American Society of Civil
Engineers, 690-699.
Schink, B. 1984. Degradation of unsaturated
hydrocarbons by methanogenic enrichment cultures.
FEMS Micro. Ecology 31: 69-77.
Smythe, J.E., P.B. Bedient, R.A. Kloop, and C.Y.
Chiang. 1988. "An advanced technology for the in-situ
measurements of heterogeneous aquifers." Presented
8-3
-------
at the NWWA Second Annual Outdoor Action
Conference, Las Vegas, Nevada.
Sorensen, J. 1982. Reduction of ferric iron in
anaerobic, marine sediment and interaction with
reduction of nitrate and sulfate. Applied Environ. Micro.
43(2): 319-324.
Strutynsky, A.L., R.E. Sandlford, and D. Cavaliere.
1991. "Use of piezometric cone penetration testing with
electrical conductivity measurements (CPTU-EC) for the
detection of hydrocarbon contamination in saturated
granular soils." In Current Practices in Ground Water and
Vadose Zone Investigations (D. M. Nielsen and M. N.
Sara, eds.), ASTM STP 1118, Philadelphia,
Pennsylvania: American Society for Testing Materials.
U.S. EPA. 1984a. Ground-Water Protection Strategy,
Washington, DC: U.S. Environmental Protection
Agency, Office of Ground Water Protection.
U.S. EPA. 1986a. Underground Tank Leak Detection
Methods: a State-of-the-Art Review. Cincinnati, Ohio:
U.S. Environmental Protection Agency, Office of
Research and Development, Hazardous Waste
Engineering Research Laboratory.
U.S. EPA. 1986d. Test Methods for Evaluating Solid
Waste, Vol. 1A. SW-846, Third Edition. Washington,
DC: U.S. Environmental Protection Agency, Office of
Solid Waste and Emergency Response.
U.S. EPA. 1986e. Test Methods for Evaluating Solid
Waste, Vol. 1B. SW-846, Third Edition, Washington,
DC: U.S. Environmental Protection Agency, Office of
Solid Waste and Emergency Response, 1986e.
U.S. EPA. 1989. Test Method. The Determination of
Inorganic Anions in Water by Ion Chromatography-
Method 300.0. Cincinnati, Ohio: U.S. Environmental
Protection Agency.
U.S. EPA. 1990a. Field Measurements: Dependable
Data When You Need It, EPA/530/UST-90-003.
Washington, DC: U.S. Environmental Protection
Agency, Office of Underground Storage Tanks, 92 pp.
U.S. EPA. 1990b. Measurement of Petroleum
Hydrocarbons: Report on Activities to Develop a Manual.
Washington, DC: U. S. Environmental Protection
Agency, Underground Storage Tank Work Group.
U.S. EPA. 1991. Assessing UST Corrective Action
Technology. A Scientific Evaluation of the Mobility and
Degradability of Organic Contaminants in Subsurface
Environments, EPA/600/2-91/053. Washington, DC:
U.S. Environmental Protection Agency, Office of
Research and Development.
Wasatch Geotechnical. 1991. Compliance Report for
Release Site AGDU Elaine Jensen R. V. Layton, Utah,
Project No. 1017-21B. Salt Lake City, Utah: Wasatch
Geotechnical Inc.
White, Hal. 1995. Personal Communication.
Washington, DC: U.S. Environmental Protection Agecy,
Office of Underground Storage Tanks.
Winfrey, M.R. and D.M. Ward. 1983. Substrates for
sulfate reduction and methane production in intertidal
sediments. Applied Environ. Micro. 45(1): 193-199.
Zdeb, T.F. 1987. "Multi-depth soil gas analyses using
passive and dynamic sampling techniques." In
Proceedings of the NWWA/API Conference on
Petroleum Hydrocarbons and Organic Chemicals in
Ground Water - Prevention, Detection, and Restoration,
Dublin, Ohio: National Water Well Association, 329-343.
Zemo, D. A., Y. G. Pierce, and J. D. Gillinatti. 1994.
Cone penetrometer testing and discrete-depth ground
water sampling techniques: a cost-effective method of
site characterization in a multiple-aquifer setting. Ground
Water Monit. Review Fall: 176-182.
Zeyer, J., E. Kuhn, and R. Schwarzenbach. 1986.
Rapid microbial mineralization of toluene and 1,3-
dimethylbenzene in the absence of molecular oxygen.
Applied Environ. Micro. 52(4): 944-947.
8-4
-------
Chapter 9
Bibliography
AWMA. Confluence: containing ground-water
contamination. J. Amer. Water Works Assoc. 77(5): 89-
91(1985).
Bras, R.L. Hydrology. Reading, Pennsylvania:
Addison-Wesley Pub. Co., Inc., 1990.
Ground-Water Microbiology and
New York: John Wiley & Sons, Inc.,
Chapelle, F.H.
Geochemistry.
1992, 424 pp.
DeAngelis, D. "The Analysis of Volatile (Gasoline)
Hydrocarbons in Soil." In Sampling and Analytical
Methods for Determining Petroleum Hydrocarbons in
Groundwater and Soil, Washington, DC: American
Petroleum Institute, 1984, 233-253.
Dever, J.I. The Geochemistry of Natural Waters.
Englewood Cliffs, New Jersey: Prentice-Hall, 1982.
Dragun, J. The Soil Chemistry of Hazardous Materials.
Silver Spring, Maryland: Hazardous Materials Research
Institute, 1988, 458 pp.
Freeze, R.A. Groundwater. Englewood Cliffs, New
Jersey: Prentice-Hall,.Inc., 1979.
Frick, C.S. "Analytical Techniques for Soluble
Component Analysis." In Sampling and Analytical
Methods for Determining Petroleum Hydrocarbons in
Groundwater and Soil. Washington, DC: American
Petroleum Institute, 1984, 109-130.
Gan, D.R., and R.R. Dupont. Multiphase and
multicompound measurements of batch equilibrium
distribution coefficients of six volatile organic
compounds. Hazard. Waste Hazard. Mat. 6(4): 363-383
(1989).
Geraghty, J.J., D.W. Miller, L.F. Van Deer, and F.L.
Troise. Water Atlas of the United States, New York:
Water Information Center, 1973.
Hausenbuiller, R.L. Soil Science Principles and
Practices, Dubuque, Iowa: William C. Brown Company
Publishers, 1972, 504 pp.
Kemblowski, M'.W., G. Urroz, and Y. Ma. Spreading and
Mixing of Soluble Contaminant Plumes in Self-Similar
Porous Media, Report to the 'USGS 105
Program.Logan, Utah: Utah State University, Utah Water
Research Laboratory, 1992.
Kemblowski, M.W., J.C. Parker, O.K. Stevens, K. Unlu,
l.M. Kamil, and P.K..Choong. Screening Models for
Land Disposal of Exploration and Production Wastes,
Washington, DC: American Petroleum Institute, 1992.
Lindberg, R.D., and D.D. Runnels. Ground water redox
reactions: an analysis of equilibrium state applied to Eh
measurements and geochemical modeling. Science
225: 925-927 (1984).
MacQuarrie, K.T.B., E.A. Sudicky, and E.O. Frind.
Simulation of biodegradable organic contaminants in
groundwater, 1. numerical formulation in principal direc-
tions. Water Res. Research 26(2): 222 (1990).
Miralles-Wilhelm, F., L.W. Gelhar, and V. Kapoor.
"Effects of heterogeneities on field-scale biodegra-
dation in groundwater," Presented to the 1990 Annual
AGU Meeting, December 3 to 7, 1990.
Reidy, P.J., W.J. Lyman, and D.C. Noonan. Assessing
UST Corrective Action Technologies: Early Screening
of Clean-Up Technologies for the Saturated Zone.
Cincinnati, Ohio: U.S. Environmental Protection
Agency, Risk Reduction Engineering Laboratory, Office
of Research and Development, 1990, 124 pp.
Richter, J. The Soil as a Reactor: Modelling Processes
in the Soil. Cremlingen, Germany: Cremlingen-Dested,
CATENA, Verlag, D-3302, 1987, 192 pp.
Riser-Roberts, E. Technology Review-In Situ/On-Site
Biodegradation of Refined Oils and Fuels, Purchase
9-1
-------
Order Number N68305-6317-7115, Port Hueneme,
California: Naval Civil Engineering Laboratory, 1988.
Shang, H. and Y.L. Zhai. Standard Operating Procedure
for Purge-and -Trap Analysis, Logan, Utah:
Environmental Quality Laboratory. Utah State University
1993, 6 pp.
Siegel, E. Oxidation of aromatic contaminants coupled
to microbial iron reduction. Nature 339: 297-300 (1989).
Sims, R.C., D.L. Sorensen, J.L. Sims, J.E. McLean, R.
Mahmood, R.R. Dupont, J. Jurinak, and K. Wagner.
Contaminated Surface Soils In-Place Treatment
Techniques. Park Ridge, New Jersey: Noyes
Publications, 1986, 536 pp.
Stumm, W. and J.J. Morgan. Aquatic Chemistry.
Second Edition. New York: John Wiley and Sons, 1981.
Thiros, J. Personal Communication. Salt Lake City,
Utah: Utah Department of Environmental Quality,
Division of Environmental Response and Remediation
1/31/94.
Thomas, J.M., M.D. Lee, P.B. Bedient, R.C. Borden,
L.W. Canter, and C.H. Ward. Leaking Underground
Storage Tanks: Remediation with Emphasis on In Situ
Biorestoration, EPA/600/2-87/008. Ada, Oklahoma:
U.S. Environmental Protection Agency, Robert S. Kerr
Environmental Research Laboratory, Office of Research
and Development, 1987,144 pp.
Tompson, A.F.B., E.G. Vomvoris, and L.W. Gelhar
Numerical Simulation of Solute Transport in Randomly
Heterogeneous Porous Media: Motivation, Model
Development,'and Application, Rep. UCID-21281,
Livermore, California: Lawrence Livermore National
Laboratory, 1987.
Tompson, A.F.B. and D.E. Dougherty. Particle-Grid
Methods for Reacting Flows in Porous Media with
Application to Fisher's Equation, Rep. UCRL-JC-
104762, Livermore, California: Lawrence Livermore
National Laboratory, 1990.
U.S. EPA. Description and Sampling 'of Contaminated
Soils. A Field Pocket Guide, EPA/625/12-91/002.
Washington, DC: U.S. Environmental Protection
Agency, Office of Research and Development, 1991,
122 pp.
U.S. EPA. Site Characterization for Subsurface
Remediation. Seminar Publication, EPA/625/4-91/026.
Cincinnati, Ohio: U.S. Environmental Protection
Agency, Center for Environmental Research
Information, Office of Research and Development
1991,259pp.
U.S. EPA. Cleanup of Releases from Petroleum USTs:
•Selected Technologies, EPA/530/UST-88/001.
Washington, DC: U.S. Environmental Protection
Agency, Office of Underground Storage Tanks, 1988,
110 pp.
U.S. EPA. Field Screening Water and Soil for Volatile
Organic Contamination with Total -Organic Vapor
Detectors, Course Materials. Atlanta, Georgia: U.S.
Environmental Protection Agency, Region IV,
Underground Storage Tank Section, Instructors G.A.
Robbins, G. Coker, D. Ariail, H. Lundsford, 1992.
U.S. EPA. Interim Guidelines and Specifications for
Preparing Quality Assurance Project Plans, QAMS-
005/80. Washington, DC: U.S. Environmental
Protection Agency, 1980.
U.S. EPA. Methods for Chemical Analysis of Water and
Waste, EPA-600/4-84-017. Cincinnati, Ohio: U.S.
Environmental Protection Agency, 1984b.
U.S. EPA. Overview of the Application of Field
Screening Techniques for Expediting and Improving
LUST Site Investigation and Remediation. State
Program Managers Meeting Course Materials. Atlanta,
Georgia: U.S. Environmental Protection Agency,
Region IV, Underground Storage. Tank Section.
Instructor G.A. Robbins, 1992, 102 pp.
U.S. EPA. Permit Guidance Manual on Unsaturated
Zone Monitoring for Hazardous Waste Land Treatment
Units, EPA/530-SW-86-040. Washington, DC: U.S.
Environmental Protection Agency, Office of Solid Waste
and Emergency Response, 1986c.
U.S. EPA. RCRA Ground-Water.Monitoring: Technical
Enforcement Guidance Document (TEGD), OSWER-
9950.1. Washington, DC: U.S. Environmental
Protection Agency, Office of Solid Waste and
Emergency Response, 1986b.
U.S. EPA". Underground Storage Tank Corrective
Action Technologies, EPA/625/6-87-015. Cincinnati,
Ohio: U.S. Environmental Protection Agency,
Hazardous Waste Engineering Research Laboratory, .
1987. -
U.S. EPA. Underground Storage Tank Corrective
Action Technologies, EPA/625/6-87-015. Cincinnati,
Ohio: U.S. Environmental Protection Agency,
Hazardous Waste Engineering Research Laboratory,
1987.
9-2
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Appendix A
Cone Penetrometer QA/QC Procedures Implemented by Terra
Technologies-Southwest, Inc., at the Hill and Layton Field Sites
Field Quality Assurance/Quality
Control (QA/QC)
The following QA/QC program can be initiated for the
field portion of this project.
Step: Hydrologic measurement.
Goal: Establish static water level to determine depth
correction for soil gas analysis.
Action: Measure the water level to 0.03 cm (0.1 foot).
Step: Well purging.
Goal: Removal of stagnant water which could bias
ground water chemistry results. This is an op-
tion which would aid in the initial setting of the
analytical instrument.
Action: Pump water until purging parameters such as
pH, Temperature, Ohms, Eh, or chemistry
stabilize to ±10% over at least two well
volumes.
Step: ' Soil gas sample collection.
Goal:- Collection of samples with minimal disturbance
of sample chemistry.
Action: Dedicated sample containers, Vacutainer
samples where possible and pumping rates
less than 10 ml/min for volatile organics.
Step: Soil gas sample collection.
Goal: To minimize cross-contamination between
samples.
Action: Where possible, dedicated sampling
equipment should be used. All samples are to
be placed in sterile containers. All non-
dedicated sampling equipment should be
thoroughly decontaminated by steam
cleaning or other approved method.
Step: Field determinations.
Goal: Field analysis of samples will avoid bias in
determinations of samples which are highly
volatile or do not keep well.
Action: Where possible, field screening should be
conducted. A minimum of an initial volatile
organic compound (VOC) scan should be
conducted on all samples.
Step: Field analytical test equipment.
Goal: To accurately monitor organic compounds.
Action: Equipment used during the screening
process is to be calibrated in a clean
environment with specialty samples of organic
compounds known to exist ,in the soil and
ground water in the area.
Step: Field blanks/standards.
Goal: To permit the correction of analytical results for
changes which may occur after sample collec-
tion, preservation, storage, and transport.
Action: Where appropriate, at least one blank and one
standard should be made up in the field
during sampling. Spiked samples should also
be sent to the laboratory for analysis, if
required.
' Step: Sample storage/transport.
Goal: To minimize any chemical alteration of samples
prior to analysis.
Action: All samples shall be either refrigerated or
placed on ice immediately upon collection.
Guidelines for maximum sample holding times
or storage periods shall be adhered to. It
should be noted that soil gas samples are very
photosensitive and that holding times should
be kept to a minimum.
Step: Sample documentation.
Goal: To determine the handling and liability of
samples during shipment and analysis.
Action: If samples are transported off-site, they need
to be accompanied by a completed Chain of
Custody form, properly signed and dated.
Analytical Quality Assurance/Quality
Control QA/QC
1. Calibration of GC System - The system
calibration is conducted after all tuning criteria
A-1
-------
have been met and before any samples or
blanks are analyzed, the calibration is also
verified for each 12 hour period.
a. Linearity Response - The system is
calibrated at varipus concentrations to
determine the linearity response by use
of standards. The calibration also
requires that the relative retention time
of each calibration compound in each
calibration run is within reason based on
• retention time units. The percent
relative standard deviation for each
calibration check compound is also
checked for variance against standards.
b. Performance Check - The system
performance check is performed each
12 hours during analyses using a known
calibration standard.
c. Initial Calibration Check - The validity of
the initial calibration is checked using
calibration check compounds. Minimum
difference are reviewed for various
compounds to have a valid calibration.
d. Method Blank Analysis - Blank analyses
of deionized water or pure sample matrix
is performed before sample analyses to
minimize artifacts due to contaminants in
solvents, reagents, glass ware, etc.
Internal Standard Response - Internal standard
responses are evaluated in all samples so that
the changes in retention times are not more
than a factor of two.
Concentration, Readjustment - The sample is
diluted and the internal standard concentration
readjusted if any compound in the sample
exceeds the initial calibration range. If dilution
causes any compound to be undetectable, the
results of both analyses are considered.
Qualitative Analyses - The elution of the sample
component must be at the same GC relative
retention time as the standard component.
Peak identification will also be conducted and
must agree within 20 percent of the standard.
A-2
-------
Appendix B
Detailed Analytical Methods for Ambient Headspace Measurements
Appendix B-1. UWRL Procedure
The UWRL method is carried out as follows. Water and
headspace are placed in a Ziplock® freezer bag which
has a septa bonded to the outside with adhesive tape.
Forty mL of water are placed in the bag through the
zipper opening and 0.75 L air headspace is injected
from a sample pump through the septa. Figure B-1
shows the Ziplock bag system for the UWRL method.
The system is allowed to equilibrate in a 20°C incubator
for 15 to 30 minutes before the headspace is routed to
the detector through the septa for analysis.
Ziplock® Bag
Hypodermic Needle
Adhesive Tape
Figure B-1. Schematic of Ziplock® bag system for UWRL Method
B-1
-------
Appendix B-2. Lab-ln-A-Bag (LIB)
Procedure (In-Situ, Inc., 1991)
The LIB apparatus operates on a principal similar to that
of the UWRL method, but the device automates many of
the sample handling tasks involved in headspace
analysis. A nipple at the top of the device penetrates
the bag and seals to the side of the polyethylene bag.
The point of bag penetration is connected to a system of
valves, tubing, and a pump which is capable of:
1. Filling the bag with headspace air. A pressure
sensitive switch automatically turns off the
compressor when the bag is full. This allows the
operator to fill bags with a consistent headspace
volume.
2, Isolating the bag while phases equilibrate.
3. Routing the headspace gases to sampling
point.
4. Purging the apparatus of residual vapors from
the previous sample prior to the next sample
preparation sequence.
The apparatus is also equipped with a magnetic stirrer
which can stir the bag contents while the bag is attached
to the unit. Speed and time of agitation are adjusted
before beginning agitation. Agitation is used to speed
equilibration of the phases (water/air or soil/water/air).
The procedure for analysis of samples using LIB is as
follows.
1. Attach and seal a bag to the penetrator. A hole
must first be cut in the side of the bag with the
hole cutter supplied with the LIB kit.
Check the bag and connection to the apparatus
for leaks. Seal the opening of the bag, adjust
valves for filling the bag with air, and start the
pump. A short time after the pump stops, start
the pump again. The amount of time the pump
is on the second time is an indication of how
leaky the bag and/or the connection to the
apparatus is (are). Replace the bag with a new
one if necessary.
To minimize loss of volatiles, prepare the bag for
sample introduction. Put a magnetic stir bar in
the bag. If a soil sample is to be analyzed, put
100mLDDWinthebag.
Fill the bag with sample and heaspace. The
sample can be 100 mL water or 25 grams soil.
Fill the bag with headspace.
Isolate the bag and agitate the sample. Adjust
valves to isolate the bag and start magnetic
stirrer. Stir time can be adjusted on the
apparatus between 1 and 11 minutes in 1
minute increments. Unlike the UWRL method,
the sample equilibrates at ambient temperature.
Analyze the headspace with a detector.
Connect the detector inlet to the sample port on
the LIB apparatus and adjust valves to route
headspace gases to the sample port.
Dispose of the sample and bag and purge the
system. Remove the bag from the penetrator.
Adjust valves to purge the system and turn the
pump on. Purge until the detector reaches
background readings with the valves in the
sampling position.
B-2
-------
Appendix C
Thiessen Polygon Method for Assignment of Areas to Ground-Water
Monitoring Points for Plume Mass Estimates
The Thiessen Method is borrowed from the water
resources discipline, where it is routinely used to assign
areas associated with rain gauge measurements in the
determination of integrated rainfall values. The method
involves the identification of specific sampling locations
within a sampling network (monitoring well and gravel
point sampling locations in this study) and the
determination of associated areas based on the
construction of polygons surrounding these sampling
points. The method for polygon construction is as
follows:
1. The outer boundary of the sampling network is
identified based on logical, physical boundaries
of the problem. When applied to ground-water
contamination in this study, the area boundary
was assigned based on site characteristics and
plume delineation provided from monitoring
points and interpolated isoconcentration plots.
2. Each sampling location is then connected to all
adjacent points to form a series of polygons with
the sampling point as their corners.
Monitoring Points
Plume Boundary
drawn at the bisection points. These perpen-
dicular lines are then extended so that they
intersect one another.
Monitoring Points
lume Boundary
4.
Finally, the intersecting lines are connected to
form polygons associated with each original
sampling location to yield arbitrary, but unbiased
and consistently generated areas associated
with sampling points. These areas are then
used in the generation of associated ground-
water and soil volumes that allow the determina-
tion of the mass of contaminant within the
assigned plume boundary and the changes in
that mass over time.
3. The lines between these sampling points are
then bisected, and perpendicular lines are
C-1
-------
McmKxing PoWs
Plume Boundary
- Bl»act«x*
• Bitector Extension
• Associated Area
Boundary
During the 2-year field study described in this report, the
actual sampling points used for data collection varied at
each sampling event due to various reasons (freezing,
dry sampling point, etc.). When sampling locations did
change, the procedures above were repeated to
redistribute area within the plume boundaries to those
sampling points for which data were collected. A check
on the accuracy of the method was carried out by
comparing the sum of the areas assigned to each
sampling point with the total area calculated using the
entire sampling network. If the difference in total areas
was more than 5 percent, the procedure was repeated
and areas were recalculated until the 5 percent criteria
was met. Summaries of the actual areas associated with
each sampling point are provided in Tables C-1 and C2.
C-2
-------
Table C-1. Thiessen Polygon Areas Determined for the Hill AFB, UT, Site During the Course of the Reid Study Blank
Entries Indicate Sampling Locations that Could Not Be Sampled Due to Freezing, Being Above the Ground-Water
Table, etc.
C-3
-------
Table C-1. (Continued)
}/«/93 Sampinq Event
W«l NumbOf
MW
MW
MW
MW
MW
cpr
"'tPt
gejj|~
c?r
_§£L
CHI
CPI
CPI
J2PJ_
CM
V«
,C'fl
CHI
CM
CM
CM
CHI
_££L
CPI
V'
Vi
Cfl
v«
CPI
,,CHI
CPi
MIP
MIP
"wTF
MIP
MO1"
SlP
MtP
,,V',
MIP
2
3
•»
*
«
~T~~
4
5
&
a
y
10
11
i*
13
14
li
'4
17
18
19
*0
2)
W.
!i4
27
28
29
31
3*
"3-t
35s
~32T
"37T
~38T
~3?T
15m
TFST
^
44s
X|H)
43,,
14,7
•21.2
33.7
20,<
O
2X7
""ss'.T'
27.$
36.4
52,4
50.2
4!M
43.4
48.V
60.6
w.t,
B4.9
113.7
37.9
128,0
85.4
110,9
84-5
18.3
47,1
2,4
73.6
40-6
S/.2
30.6
397?
44.3
51.7
~~K7
3TCT
4T.S
78 ,5
W.I
113.3
Y|lt|
-112.7
3*,y
60. (
124.7
36.4
52.3
82.2
48.5
59.0
77.5
43.9
74.7
93.4
79.1
39,5
99.4
132.2
153.4
110.7
30.9
165.9
36.3
147.7
22.7
67.7
54,8
38.3
95./
2/.0
50.8
W3
7^5
6-1,6
61,2
56.5
41.5
43.9
S6.2
95.0
110.7
OIAI
Area
Jt£SL
2,498
917
728
1,353
171
413
400
155
125
259
212
151
153
392
190
350
673
1,031
1,007
1,743
555
705
884
3.386
434
227
685
1.663
1.798
1,522
300
157
191
274
206
225
123
361
637
1,007
28.264
6/9/93 Sampling Event
Well Number
MW
MW
MW
MW
MW
CRT
CPT
~CfT~
CPt
CPI
CPI
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPI
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
MLP
MLP
MLP
MLP
MLP
MLP
MLP
Cpr
CPT
2
3
4
"5
6
2
3
4
5
6
8
9
10
11
12
13
14
15
16
17
18
20
21
25
26
27
28
29
30
31
32
33
34
35s
36m
~W
38s
39s
'4br
41s
~4T~
43
X(ft)
63.6
16.7
-21.2
33.7
20.J
-1.C
8.2
33J
23.1
27.5
'3'5^
52.-I
50.2
42.3
63.6
68.2
50.6
99.0
84.9
113.7
37.9
85.4
110.8
84.5
18.3
67.1
2.4
73.6
119.5
60.6
87.2
79.7
30.6
59.4
46.3
","5"1 ^
30.7
39:4
61.5
78.5
— "ffij
23.1
,XV48.5
59. C
Trs"
43.9
74.7
93.4
79.1
99.4
132.2
153.4
110.7
30.9
36.3
147.7
22 7
67.7
38.3
95.7
159.0
27 0
50.8
77 7
'97.9
73.8
95.0
OTAL
Area
J2£2J»
2,484
672
482
1,385
175
692
324
""1243-
""""550"
Jjg.
464
551
161
241
549
914
1,036
2,042
465
730
588
2,866
346
681
913
773
672
1,546
884
258
380
719
28,257
C-4
-------
Table C-2: Thiessen Polygon Areas Determined for the Layton, UT, Site During the Course of the Field Study. Blank
Entries Indicate Sampling Locations that Could Not Be Sampled Due to Freezing, Being Above the Ground-Water
Table, etc.
7/92 Sampling Event
|
Well Number
CPT 1 1
CRT | 2
CPT
CPT
3
4
"Unit s
_CPL,
CPT
CPT
CPT
CPT
CPT
CPT
CPT
_CEL_
CPT
CPT
CPT
MLP
MLP
_MW_
MW
8
9
10
12
•13
14
15
16
18
20
21
4-9.0
6 -9.0
X(ft)
-8.4
54.6
-47.5
-4.5
-36.3
108.7
59.4
•-5 1.3
63.4
64.7
108.7
19.0
14.3
26.2
-4.3
Y(ft)
-80.6
-122.4
-52.8
-42.8
-74.6
55.4
13.7
24.9
...58,1.
Area
(ftA2)
1,464
3,777
1,723
1,194
2,168
1,270
,™JL965L
^3i8JML
....1,386...
35.9 1 899
_JJL^L3,266_
™| ™~
15.4) 1,470
. -35.4] 1 ,495
\
-61 .9] 672
|
28.5 j -58.4
37.8 [ -82.8
3 1.2 j 28.1
j
-59.9
1 rZposj),
3 1 0.0
MW ! 4 I -17.2
1 1
L™a3^
35.7
0.0
-137.5
TOTAL
1,655
2,874
3,584
^L5Q2^
899
™L41JL
1,795
41,140
12/92 Sampling Event
|
Well Number
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
1
3
4
5
8
9
12
13
IcpfTil^
"cpT|T5^
CPT
_JJL»
CPT I 18
™CPTTj9_
CPT { 20
J3PTJ 21
MLP
JyUvfL
MW
MW
5-9.5
X(ft)
-8.4
-47.5
-4.5
-36.3
59.4
-51.3
64.7
108.7
19.0
14.3
_J26.2
-4.3
52.0
28.5
37.8
-7.3
A^JiSJL^?-.
1
103.0
3 | -17.2
1
Y(ft)
-80.6!
-52.8:
-42".8!
-74.6!
13.7!
24.9!
35.9!
1 1 .5!
-8.9
15.4!
«^§5.4j
-61.9!
-40.6
<™jiui
-82.8
-14.3
-4.2
35.7
-137.5
TOTAL
Area
[ftA2J
3,344
1,671
945
3,586
1,71?
^SJ^,
^
2,699
2,538
956'
2,884
849
672
3,227
772
6,253
761
-^LH3-
_2J58.,
846
41,072
3/935
Well Number
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
MLP
1
. ~
4
5
7
8
,™JL™
10
11
12
_13_
14
15
16
_J2_
18
19
>™20_
21
4-9.5
ZH|Z —
jiiELL™
MW I 3
MW ! 4
|
ampling Event
X(ft)
-8.4
-q^J
-4.5
«^3U
m=4L£
59.4
-51.3
63.4
-16.0
64.7
108.7
19.0
14.3
26.2
9.1
-4.3
52.0
28.5
37.8
30.5
103.0
_™_CLO
-17.2
JK2L
-80.6
~~~352£
-42.8
«^Z±i
-2.2
13.7
24.9
58.1
16.5
35.9
11.5
-8.9
15.4
-35.4
33.8
™±L2.
-40.6
-58.4
-82.8
27.4
35.7
™JLO
-137.5
TOTAL
Area
(ftA2)
1,464
"~T753~
1,185
_..2J68_
™JLZS§™
HiziZ
1^578_
1,108
795
_Z538^
956
536
849
2,009
672
3,296
815
5,387
962
HZIE
^™Z9J™
4,086
41,072
C-5
-------
Table C-2. (Continued)
6/93 Sampling Event
Well Number
CRT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
MLP
MM3
MAP
MW
MW
MW
I
3
4
5
7
_&_
9
10
11
12
13
14
15
17
18
19
20
21
4-9.5
5-9.0
tf -9.0
1
3
4
X(ft)
-8.4
-47.5
-4.5
-36.3
-41.9
59.4
-51.3
63.4
-16.0
64.7
108.7
19.0
14.3
9.1
-4.3
52.0
28.5
37.8
30.5
-7.3
-59,9
103,0
o.o
-17.2
Yfft)
-80.6
-52.8
-42.8
-74.6
-2.2
13.7
24.9
58,1
16.5
35.9
11.5
-8.9
15.4
33.8
-61.9
-40.6
-58.4
-82.8
27.4
-14.3
-3.2
35.7
0.0
-137.5
TOTAL
Area
fftA2)
1,464
1,671
1,102
2,168
953
1,556
2,601
1,618
1,101
839
2,538
1,221
536
2,009
672
3,574
974
5,387
962
752
863
2.013
413
4,086
41,072
9/93 Sampling Event
Well Number
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
MLP
MW
MW
MW
3
4
5
8
9
10
11
12
13
14
15
17
18
19
20
21
4-9.5
1
3
4
X (ft)
-47.5
-4.5
-36:3
59.4
-51.3
63.4
-16.0
64.7
108.7
19.0
14.3
9.1
-4.3
52.0
28.5
37.8
30.5
103.0
0.0
-17.2
Y(ft)
-52.8
-42.8
-74.6
13.7
24.9
58.1
16.5
35.9
11.5
-8.9
15.4
33.8
-61.9
-40.6
-58.4
-82.8
27.4
35.7
0.0
-137.5
TOTAL
Area
(ftA2)
2,259
1,375'
2,352
1,556
3,466
1,578
1,458
795
2,538
1,206
536
2,009
1,273
3,539
991
5,743
962
2,097
906
4,345
40,985
1/94 Sampling Event
I
Well Number
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT j
CRT
CPT
fZpj
CPT
CPT
CPT
CPT
CPT
MW
MW
MW
1
3
4
5
8
9
10
1 1
12
13
14
15
17
18
19
20
21
1
3
4
X(ft)
-8.4
-47.5
-4.5
___j
59.4
-5L3J
63.4
-16.0
64.7
108.7
19.0
14.3
9.1
-4.3
52.0
28.5
37.8
103.0
0.0
-172
Y(ft)
-80.6
-52.8
-42.8
-74.6
13.7
_24s2,
58.1
_JA£j
__35.9,
11.5
-8.9
15.4
33.8
-61.9
-40.6
-58.4
-82.8
35.7
0.0
-137.5
TOTAL
Area
(ftA2)
1,491
2,238
1,345
2,152
.
1,867
_3^4JLL,
_JL622_
1,452
1,037
l_™_
1,195
76.1
2,430
699
3,540
1,024
5,271
2,043
914
4,086
41,070
C-6
-------
Appendix D
Ground-Water Slug Test Data and Conductivity/Ground-Water Velocity
Calculations from the Layton and Hill AFB, Utah, Field Sites
Collected April 8 to 10, 1992
The slug test data for the Layton and Hill AFB sites used
in these calculations are presented in Tables D-1 and D-
2, respectively.
Calculation of Hydraulic Conductivity
Two different methods were used in the calculation of
hydraulic conductivity at each observation well, the
Hvorslev method (Fetter, 1988) and the method from
Bouwer and Rice (1976).
The Hvorslev Method
If the length of the piezometer is more than eight times
the radius of the well screen (L/R), the following formula
applies:
IX __, _
2ln(L/R)
0)
where K = the hydraulic conductivity, L/T; r = the radius
of the well casing; R = the radius of the well screen, L; L
= the length of the well screen, L; and T0 = the time it
takes for the water level to rise or fall to 37 percent of the
initial change, T.
These results are presented in Table D-3. T0 can be
calculated by plotting the log (h/ho) versus time, where
ho is the initial head, and h is the measured head at
some time after the beginning of the slug test. These
data for the determination of T0 for all of the slug tests
conducted at the Layton and Hill sites are attached.
The Bouwer and Rice Method
The Bouwer and Rice method allows the estimation of
the hydraulic conductivity of a formation using the
following relationship:
;ln(R6
2Let
Yt
(2)
where rc = the inside radius of the casing, L; rc = the
radius of influence, L; rw = the effective radius of the
well, L; Le = the effective aquifer thickness, L; yt = the
drawdown in the well at time t, L; and yo = the drawdown
in the well at time zero, L.
The radius of influence can be computed by the
empirical equation:
A + Bln((H-Lw)/rw)x
ln(Lw/rw) ' (Le/rw)
|
+
(3)
where A and B = empirical constants; Lw = the length
from the water table to the bottom of the aquifer, L; and
H = the thickness of the aquifer, L. The results of these
calculations are presented in Table D-4.
Calculation of Pore Water Velocity
Geometric Hydraulic Conductivity
The geometric hydraulic conductivity is used to calculate
the pore water velocity and can be calculated from the
geometric mean of conductivities measured throughout
a site using the following equation:
(4)
where n = the number of observation wells.
From Table D-4 data using Equation 4, the mean
hydraulic conductivities for the two sites are found to be:
for Layton: K=1.20ft/d
for Hill AFB: K=1.53ft/d
D-1
-------
Pore Water Velocity
the pore water velocity is calculated using Darcy's Law:
= 0.00106 —= 0.00177
V =
Kdh
(5)
where V = the pore water velocity, L/T; K = the hydraulic
conductivity, L/T; n = the porosity; and 3h/3l = the
hydraulic gradient, L/L.
Porosity. For the Layton site, there are no data available
for porosity, and the porosity of each observation well is
estimated using typical values for the geologic materials
described in boring logs from the site. These values
were weighted based on the relative thickness of each
geologic layer. The results of these porosity estimates
a're presented in Table D-5. The porosity used for the
Layton site was 0.38 as shown in Table D-5. This is
geometric average value of the porosity of all three
observation wells for which slug tests were conducted.
For the Hill site, the porosity stated in the Corrective
Action Plan report from Engineering-Science of 0.25
was used for all calculations.
Hydraulic Gradient For Layton, the coordinate system
was set to originate at Well B4 with the North direction
being Y, X being in the East direction, and using water
table data from the January 25,1991, Corrective Action
Plan report prepared by Wasatch Geotechnical, Inc. The
observed piezometer head distribution data were used
to develop a regression equation relating head to
piezometer location. Well B4 (0,0) water level was equal
to 91.29', while Well B3 (55,131) and Well B1 (163,140)
had water levels at 91.58' and 91.71', respectively. The
equation of piezometer head as a function of X, Y
position was determined to be the following:
h (ft) = 0.00106 X + 0.00177 Y + 91.29
(6)
So,
(7)
(8)
For the Hill site from the Engineering Science Corrective
Action Plan report, the hydraulic gradient was found to
be:
(9)
From these hydraulic gradient and site permeability data
determined above, the pore water velocity can be easily
calculated for each site and were found to be:
for Layton: V = 0.006 ft/d
for Hill AFB: V = 0.183 ft/d
References
1. Bouwer, H. and R.C. Rice. 1976. A slug test for
determining hydraulic conductivity of uncon-
fined aquifers with completely or partially
penetrating wells. Water Res. Research,
12:423-428.
2. Fetter, C.W. 1988. Applied Hydrogeology.
Macmillan Publishing Company, New York, New
York.
3. Engineering-Science. 1991. Corrective Action
Plan Building 1141 Release Response.
October.
4. Wasatch Geotechnical, Inc. 1991. Compliance
Report for Release Site, Blaine Jensen R.V.,
Layton, Utah. July.
D-2
-------
Table Dl: Layton slug test sampling 1 !
Well#l I
Time
(min.)
0.00
1.02
2.30
3.47
4.47
5.62
7.02
8.97
11.33
GWT
(ft)
19.20
19.10
19.00
18.95
18.90
18.85
18.80
18.75
18.70
Well #3 i (Rep. 1)
Time
' (min.
0.00
1.50
2.22
3.30
4.50
6.32
7.08
8.75
GWT
(ft) '
17.20
17.19
17.17
17.16
17.15
17.14
17.13
17.12
-
'
Well #3 (Rep. 2)
Time
(min.)
0.00
0.07
0.17
0.28
0.80
1.73
3.57
5.67
8.28
10.43
GWT
(ft)
17.32
17.31
17.30
1 7.29
17.25
17.20
17.15
17.12
. 17.10
17.09
Well #4
Time
(minj
0.00
0.55
0.85
1.07
1.50
1.75
1.98
2.22
2.47
2.93
3.50
4.08
4.68
5.30
6.07
6.95
.7.52
8.37
9.28
10.28
11.35
13.32
16.07
GWT
(ft)
19.36
19.22
19.15
19.10
19.00
18.95
18.90
18.85
18.80
18.70
18.60
18.50
18.40
18.30
18.20
18.10
18.00
17.90
17.80
17.70
17.60
" 1 7.40
17.20
, : - ; ,•::
Table D2: Hill AFB Slup Test Sampling I '•!
Well #3
Time
(min.)
0.00
GWT
(ft)
17.50
0.95! 17.20
1.60! 17.10
2.58
3.10
17.00
17.00
3.88! 16.90
5.12J 16.90
7.23
14.00
16.80
16.80
Well #4
Time
(min.)
~ 0.00
0.07
0.12
0.15
0.20
0.28
0.33
0.45
0.65
1.07
3.10
3.63
(Rep. 1)
GWT
(ft)
15.50
15.60
15.70
Well #4
Time
(min.)
0.00
0.05
0.10
15.80! 0.17
15.90! 0.23
16.00
16.10
16.20
16.30
16.40
16.50
• 1 6.50
0.28
0.40
0.62
3.12
2.07
3.72
5.00
(Rep. 2)
GWT
(ft)
15.60
15.70
T5.80
15.90
16.00
16.10
16.20
16.30
16.40
16.50
16.50
'16.50
Well #5
Time
(min.)
0.00
1.43
^ 5.97
6.98
13.32
GWT
(ft)
Well #6
Time
(min.)
20.30 0.00
20.20 2.00
20.20
20.20
20.14
5.08
21.05
GWT
(ft)
16.90
16.80
16.80
16.80
D-3
-------
Table D3: Hydraulic
Well
Layton #1
Layton #3'
Layton #3 {rep. 2)
Layton #4
HfAFB#3
.' HiilAFB^
Hill AFB #4 (rep. 2)
Hill AFB #5
Hill AFB #6
conductivity
calculated [from The Hvorslev Method.
r[in) i L(ft) 1 R
1
.. ..
1
2i
'ti,
2!
2i
!
Ii
•ll
1!
l!
l!
10;
10! .
iOI
10!
f
5!
5!
Si
5!
si
(in) i
2;
2|
2!
2!
' 1
l]
ii
1!
ii
1!
To (min) !
5.18!
4:64J
2.60!
7.29;
2.17!
0.42;
0.42!
3.30J
5.30!
K (ft/day)
1.58
1 .77
3.15
1.12
1.89
9.70
9.63
1 .24
0.77
;,J: ;. ' !' ! ', J "mil1!!1 I1,11!1 ii f
Table D4: Hydraulic conductivity calculated from Trie Bouwer & Rice Method. 1 j
Well
Layton #1
Layton #3
Layton #3 (rep. 2)
Layton #4
rw(ft)
1/6
Lw(ft)| Le(ft) Le/rw
17.0: lol 60J
1/6J 17.0J ib! 60J
1/6J 17.0! 10! 60J
1/6J 17.0! lOJ 60
ill!
Hill AFB #3
Hill AFB #4
Hill AFB #4 (rep. 2)
Hill AFB #5
Hill AFB #6
1/121 13.l1 5! 60;
1/12[ 13.2J 5l 601
1/12J 13.2J 5! 60!
1/12
i i i
11.7! 5; 60i
1/12J 26.0! 5! 60i
A B ln[(H-Lw)/rw]
4.05J 0.68751 6
4.05! 0.6875! 6
4.05: 0.6875] 6
4.05! 0.6875! 6
! i
4.05! 0.6875! 6
R
86.9
86.9
86.9
86.9
202.4
4.05! 0.6875! 61203.2
4.05! 0.6875! 6! 203.2
4.05; 0.6875! 6
4.051 0.6875! 6
194.9
253.7
K (ft/d)
1.11
1.25
2.00
0.78
,
1.45
7.62
7.10
0.86
0.61
Table D5:| Porosity calculation for Layton.
Well No.
Depth (ft)
SP
Bl ! 17= 10.1-11
B2 | 17i 8.9-10.5
1 . B3 f 17! 10.0-17
Intervel (ft)
SC
11-17
10.5- 17
CL
8:9-'To;o"
Screen
7-17
7-17
7-17
Porosity
for Weils
0.44
0.46
0.31
Porosity
for Site
0.38
D-4
-------
Figures:
Slug Test for Layton Well #1
y = 1.0612 * iO*(-S.8389e-2x) R*2 = 0.989
\
0 24 6 8 10 12
Time (tnin.)
Slug Test for Layton WelMO (Rep.2)
y = 0.96698 * HXX-O-ieOMx) RA2 = 0.998
I
o
JG.
\
2 4 6 8 10
Time (min.)
Slug Test for Layton Well#3 (Rep.I)
y = 1.0776 * ICX^-0.1001 Ix) RA2 « 0.981
"ET
02468
Time (day)
Slug Test for Layton Well #4
y = 1.0477 * I0*(-6.2036e-2x) R*Z = 0.993
1
bv
2 4 6 8 10 12
Tim« (min,)
D-5
-------
Slug Test for Hill AFB Well #3
y - 0.93958 • 10^-0.18657*) RA2 « 0.998
I -ar-r
~ .1
JZ
.01
2 ' 4 6
Time Coin.)
8
Slug Test for Hill AFB WeU#4 (Rep.2)
y = 0.90095 • I0*(.0.91025x) RA2 » 0-973
1 -9-T
o
-c
.1
\
S
0.0 0.2 0.4 0.6 0.8 1.0 1.2
Time (min.)
Slug Test for Hill AFB WelWS
y =- 0.94199 • 10A(-7.6543e-2x) RA2 = 0.965
a
"2
123456
Time (min.)
Slug Test for BUI AFB WelMW (Rep.l)
y . 0.95597 * 10«(-0.97732x) RA2 « 0.981
I -Q-
o
-e
N
S
S
.1
0.0 0,2 0.4 0.6 0.8 1.0 1.2
Time (min.)
Slug Test for Will AFB WeU#S
y ^ 0.85584 * 10^-0.11035x) RA2 = 0.962
1 -9-
S
^
N
2468
Time (min.)
D-6
-------
Appendix E
Raw Data for Field ATH Versus Laboratory TPH Data Comparison
Hill AFB- 7/92 i HiJ! AFB-.12/.92. v
^^Reid^J Lab
ATH Results
^^^^s^is^^^l^iiis^i^^
~™™££tsL™™J 326
CPT-02
CPT-03
CPT-04
CPT-05
CPT-06
CPT-07
CPT-08
CPT-09
326
326
326
3,711
1,196
P&T Results
(ufl/tlj
\
Lab/Reid
Response
" 6b~i ai8
™™™Hm£l 6-6°
41
• 172
544
992
25,080 I 40,135
___J^,3J2i 653
2,868.
™™™£EH2™~™J 1 -729
CPT-l 1
CPT-12
• CPT-J3
CPT-l 4
CPT-l 5
2,301
2,397
>™™™LZ65m
1,298
™™A]£U
0.13
Sample
CPT-03
6.53 f CPT-04
0.15 | CPT-05 i
6.83 | CPT-06" !
1.60
0.47
2.16
1 2"i" ! 6.07
___n07J 0.05
736
1,234
141 J
574 I 294
CPT-i 6 ' " '" 1 2,354 T 8
CPT-l 7
CPT-l 8
CPT-l 9
CPT-20
CPT-21
CPT-22
CPT-25
CPT-26
CPT-27
CPT:2g
CPT-29
CPT-30
CPT-31
Qpj. 39
CPT-33
CPT-34
CPT-42
CPT-43
. MLP38(9.6)
1,832
57,510
930
1.197
1.053
0.31
0.70
CPT-08 J
CPT-l 1 :
CPT-12 1
CPT-l 3 i
Reid ,.,.,Lab
ATH Results 1 P&T Results
^JisaOL™
16
1,505
292
191
^JUflflL™.
58...
vvuvwuuuuwwvwww*
Lab/Reid
-^esEonse_
3.73
213 i 0.14
57 i 0.20
257
™™J^Z§X™^™J51.
m__JJ675M,
2,014
16
____^OjiJ C>T-Jl____J^mmJJ84£,
0.51
0.00
8 I 0.00
^8J^509j • 1 .42
6
2,517
0
326™I 3
667 f 0.
-------
Layton-7/92
Sample
CPT-Ol
CPT-02
CPT-03
CPT-04
CPT-05
CPT-06
CPT-07
CPT-08
CPr-09
CPT-10
CPT-1 1
CPT-12
CPT-1 3
CPT-14
CPT-15
CPT-1 6
CPT-1 7
CPT-1 8
CPT-19
CPT-20
CPT-21
MLP4(9.0I
MUM 9,5)
MLP6 9.0)
MW1
MW3
MW4
Method Blanks
Reid
ATM Results
(ua/U
1,343
1,774
5,409
64,425
73
0
23,955
25,513
1.798
1.313
10,744
25.493
42,526
51.514
45,418
22,934
15,279
1.329
2,010
85,026
897
2,096
1,755
4,487
5,107
30.842
56.470
902
Lab
P&T Results
(tia/L)
0
0
0
7,840
4
3
5,993
7,661
796
313
28,269
43,478
23.351
24,504
30,322
3,537
17
41,899
135
15,472
3,785
52
397
3,354
4
Average
St.Dev.
C.V (%)
Lab/Reid
Response
0.00
0.00
0.00
0.12
0.05
0.25
0.30
0.44
0.24
1.11
1.02
0.45
0.54
1.32
0.23
P,Q1
0.49
0.15
7.38
2.16
0.01
0.08
0.11
0.00
0.69
1.52
221.31
Layton - 12/92
Sample
CPT-01
CPT-03
CPT-04
CPT-05
CPT-08
CPT-09
CPT-12
CPT-1 3
CPT-14
CPT-15
CPT-1 6
CPT-1 7
CPT-1 8
CPT-19
CPT-20
CPT-21
MW1
MW3
MW4
Method Blanks
Reid
ATH Results
(Hq/U
2,047
2,616
57,130
1,067
___Jj067_
4277
34,407
100,852
402
26,138
56,024
27,052
2,539
35,269
131,845
——Jsfi&L
5,107
30,842
56,470
1,067
Lab
P&T Results
(UQ/L)
2
392
1 5,923
33
__ Z§i090_
148
15,341
34,394
41,841
8,532
36,698
136
32,583
52,403
13
3,313
2111
Average
St.Dev.
C V (%)
_J.gb/Field_
Response
0.00
0.15
0.28
0.03
73.19
0.03
0.45
0.34
104.08
0.33
6.66
005
092
0.40
6.61
0.65
0.07
10.68
29.84
279 32
E-2
-------
Appendix F
Summarized BTEX, Naphthalene, and TPH Ground-Water Concentration
Data Used for Plume Centerline and Mass
Calculations for the Hill AFB Site
Hill AFB Site 4/92 Ground-Water Data
Well
MW
MW
MW
MW
M W
Mw1
No
1
2
?
4
"5
^
X-Coord
" (ft)
74.3
63.6
16.7
-21 2
33 7
20.8
Y-Coord
(ft)
24.3
-112.7
32.9
60.0
126.7
35.6
Benzene
(H9/L)
3.2
0.0
36.3
0.0
0.0
0.0
Toluene
(lig/L)
0.0
0.0
21.2
20.2
0.0
0.0
Ethvlbenzene
(lig/U
0.0
0.0
29.2
30.2
0.0
0.0
3-Xylene
(na/U
0.0
0.0
95.3
126.1
0.0
0.0
Naphthalene
(WJ/L)
0.0
0.0
29.6
0.0
0.0
0.0
Total
IW?/L|
13.4
24.8
1284.8
204.0
12,3
0.0
F-1
-------
Hill AFB Site 7/92 Ground-Water Data
JtiSL
MW
MW
MW
MW
MW
MW
CRT
CRT
CPT
CRT
J5EL
CPT
CRT
CPT
CPT
CPT
-££L
CPT
CPT
CPT
CPT
_CPT
jgpjr.
CPT
CPT
CPT
CPT
CPT
CPT
CPT
_
§PT
PT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
MLP
MLP
MLP
MLP
MLP
MLP
MLP
MLP
MLP
"ML?
MLP
MLP
MLP
MLP
MLP
"ML"P"
MLP
MLP
MLP
MLP
MLF
MLP
CRT
CPT
MLP
MLP
MLP
jSk*
1
2
~JLj
4
5
6
1
2
3
4
5
6
7
8
9
id
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35s
35m
35d ;
35dr;
36s
^36m:
J|6dJ
37s ;
37m j
37d
38s :
38m
38d
39s
39m
39d
40s
46m
40d ;
41s i
4 1 rri
41d
42 1
43
44s
44m
44d
X-Coord
^JilL™
___2M
63.6
K6.7
-21.2
33.7
20.8
38.2
-1.0
™- ,, 8-2
22.7
23.1
27.5
38.0
35.44.
52.4
50.2
42.3
63.6
68.2
50.6
99.0
84.9
1 1 3.7
37.9
128.6
85.4
110.8
126.4
61.9
99.5
84.5
18.3
67.1
2.4
73.6
119.5
60.6
87.2
79.7'
30.6
59.4
59,4
59.4
59.4
46.3
46.3
46.3
51.7
51.7
51.7
30.7
30.7
30.7
39.4
39.4
39.4
61.5
61.5
61.5
78.5
78.5
78.5
42.7
23.1
113.3
1 13.3"
113.3
Y-Coord
,™JflL~
24.3
-112.7
32.9
60.0
126.7
35.6
-11.6
70.7
52.3
82.2
48.5
59.0
44.2
77.5
43.9
74.7
93.4
79.1
39.5
99.4
132.2
153.4
110.7
30.9
165.9
36.3
147.7
89.2
74.5
1 34.6
Benzene
JE3&L,
0.0
™~__M
0.0
0.0
11.0
0.0
_™~M:
b'.o
18.1
' 37.1
369.6"
37.8
0.0
0.0
6.0
0.0
0.0
0.0
0.0
6.6
6.6
L™M.
0.0
6.6
0.0
22.71 0.0
67.7
54.8
38.3
95.7
159.0
27.0
50.8
77.7
i yTj
_Z3J.
73.8
73.8
73.8
84.6
84.6
84.6
61.2
61 .2
61.2
56.5
56.5
56.5
41.5
41 .5
41.5
43.9
43.9
43.9"
56.2
5"6.2
56.2
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
~™J£U°
0.0
0.0
Toluene
.JaaEL,
0.0
30.5
0.0
0.0
9.3
0.0
0.0
0.0
10.0
0.0
159.0
0.0
85.7
0.0
0.0
6.9
22.2
0.0
0.0
0.0
0.0
Ethylbenzehe
_Jaa2kL™»
0.0
28.4
0.0
b.6
9.8
0.0
0.0
0.0
18.9
0.0
321.0
6.6
73.4
0.0
j>Xylene^
Uto/tU
0.0
^__Xl,8
0.0
o-a
0.0
_™™2^
0.0
0.0
0.0
0.0
839.0
Naphthalene
(ttgZU
6.6
30,0
6^6"
-,.., ,..0,0,
0.0
o.o
0.0
6.6
40.4
23.5
349.0
6.6| 15,5.
97.0
0.0
208.0
6.6
6.6} 0.0| 0.0
41.8| "io.Oi 6.3
Total
JttsZU.
36
2,586
o
4
60
0
41
172
544
992
40,135
653
6,196
124
: 1.07
736
___^Ji.O| 6.6| 2.2] 1,234
0.0
21.0
0.0
0.0
6.6'i ' 0.6
60.6J 84.4
"6.0'j 6.6
0.0
0.0
6.6] 6.6
6.0
6.6
6.6
5.6
6.6
6.6
6.6
29.8
6.6
6.0
™™™fix2
0.0
0.0
27.6
0.0
0.0
0.0
9.2
0.0
161.0
0.0
0.0
0.0
0.0
|
ZZZ3 I
6.3J 0.0
95 .or 6/6
110.7
110.7
110.7
0.0
0.0{ 2.7
0.0
0.0
6.6
1 ao
24.5
6.6
3.7
0.0
6.6
• , 6.6
55.1
6.6
™™™1ML~ °-6
6.6
0.0
3574
0.0
0.0
0.0
6.6
0.0
1" 63",6
0.0
6.6
6.6
5.9
0.0
0.0
0.0
6.6
' 7.8
177.6
0.0
o.oj 6.0
i
0.0:
' . o.b":
„.._ J i
::::::::::::::i:::::::::::::::::::::::::
0.0
0.0
"" :
r
rz;
l * i
50.1
0.0
18.0J 0.0;
6.6F 6.6";
f
0.6
0.0
:.:::........ i i
71 .8{ 281.9! 117.7$ 67.6
141
294
14
jOHs£
0
12,517
0
3
0
0
266
25
18
0
29
, 1196
10,362
0
16
£
27
4
962
180
7,505
F-2
-------
Hill AFB Site 11 to 12/92 Ground-Water Data
F-3
-------
Hill AFB Site 2/93 Ground-Water Data
Well
MW
MW
MW
MW
MW
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CHI
CPT
CPT
CPT
CPT
UM
CPT
CPT
CPT
MLP
MLP
MLP
MLP
MLP
MLP
MLP
MLP
MLP
MLP
MLP
MLP
MLP
MLP
MLP
MLP
MLP
MLP
MLP
CPT
MLP
MLP
MLP
No.
2
3
4
5
6
3
4
b
6
8
y
10
1!
12
13
14
16
16
17
18
20
21
26
26
2/
28
29
31
32
34
36s
36m
35d
36dr
36s
36m
36d
3/s
3/m
3/d
38s
38m
38d
39s
39m
39d
40m
41m
4ld
43
44s
44m
44d
X-Coord
(ft)
63.6
16.7
-21.2
33.7
20.8
8.2
22.7
23.1
27.5
35.44
52.^
50.2
42.3
63.6
68.2
50.6
99.0
84.9
113.7
37.9
85.4
110.8
84.5
18.3
67.1
2.4
73.6
60.6
87.2
30.6
59.4
59.4
59.4
59.4
4o.3
46.3
46.3
51.7
51.7
51.7
30.7
30.7
30.7
39.4
39.4
39.4
61.5
78.5
78.5
23.1
113.3
113.3
113.3
Y-Coord
(ft)
-112.7
32.9
60.0
126.7
35.6
52.:
82.2
48.5
59.0
77.5
43.9
74.7
93.4
79.1
39.5
99.4
132.2
153.4
110.7
30.9
36.3
147.7
22.7
67.7
54.8
38.3
95.7
27.0
50.8
97.9
73.8
73.8
73.8
73.8
84.6
84.6
84.6
61.2
61.2
61.2
56.5
56.5
56.5
41.5
41.5
41.5
43.9
56.2
56.2
95.0
110.7
110.7
110.7
Benzene
(W/L)
o.c
15.0
0.0
0.0
0.0
lO.f
0.0
0.0
0.0
0.0
0.0
5.9
0.0
0.0
0.0
0.0
49.9
0.0
0.0
3.9
0.0
O.C
0.0
0.0
2.5
0.0
0.0
0.0
3.1
0.0
0.0
0.0
0.0
0.0
3.3
0.0
0.0
7.4
4.0
0.0
0.0
0.0
4.6
4.1
0.0
0.0
0.0
0.0
13.9
0.0
0.0
0.0
0.0
Toluene
(HQ/D
0.0
37.7
2.^
0.0
2.5
28.1
0.0
0.0
0.0
0.0
2.6
6.1
0.0
0.0
25.4
0.0
6.2
0.0
4.7
19.8
6.5
0.0
0.0
0.0
3.3
0.0
0.0
0.0
6.8
1.9
OrO
0.0
2.9
12.5
4.7
0.0
0.0
7.7
9.9
2.7
6.4
12.2
5.2
10.0
1.0
0.0
1.7
0.0
29.1
6.5
0.0
0.0
3.9
Ethylbenzene
(na/U
0.0
3.9
0.0
0.0
1.4
41.0
0.0
0.0
0.0
0.0
0.0
1.6
0.0
0.0
5.4
0.0
2.1
0.0
2.8
32.1
3.3
0.0
0.0
0.0
2.2
0.0
0.0
0.0
3.6
0.0
0.0
0.0
6.9
19.8
3.2
0.0
0.0
2.0
5.5
0.0
17.4
7.3
0.0
5.9
0.0
0.0
0.0
0.0
15.6
1.8
0.0
0.0
0.0
_p^X^l£ne
(W3/U
0.0
5.5
0.0
0.0
2.4
39.8
0.0
0.0
0.0
0.0
1.7
1.8
0.0
0.0
9.2
0.0
2.9
0.0
2.8
19.2
3.7
0.0
0.0
0.0
3.2
0.0
0.0
0.0
3.6
0.0
0.0
0.0
3.9
12.3
3.3
0.0
0.0
2.9
6.1
1.5
7.6
11.8
0.0
6.0
0.0
0.0
0.0
0.0
71.0
3.0
0.0
0.0
5.6
Naphthalene
fua/u
0.0
0.0
0.0
0.0
0.0
8.5
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
12.3
0.0
0.6
6.6
0.0
96.4
0.0
0.0,
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
51.8
170.0
0.0
0.0
3.3
0.0
1.5
0.0
59.5
0.0
0.0
0.0
0.0
0.0
0.0
0.0
23.3
. 2.4
0.0
0.0
0.0
Total
(W3/L)
0.7
285.0
9.3
0.0
22.6
235.0
0.0
1.5
0.0
24.0
90.9
21.2
0.0
36.5
801.0
0.0
244.5
0.0
44.5
2910.0
31.2
9 3
9.1
0.0
122.0
175.0
2.6
0.0
34.2
2.8
1.0
16.8
1386.0
4668.0
18.2
0.0
8.6
190.0
84.8
7.8
1928.0
170.0
115.0
46.9
2.7
63.3
3.6
5.2
1301.0
45.6
5.6
5.4
12.7
F-4
-------
Hill AFB Site 6/93 Ground-Water Data
F-5
-------
Hill AFB Site 9/93 Ground-Water Data
"Well
MW
jMW^
MW
MW^
" M w"
CRT
CPT
CRT
PPT
CPT
CPT
.,_
,™™.«
CPT
S£L<
CPT
CPT
..CPT...
JPPT
CRT™
CPT
,CPT,
CPT
CPT
CPT
CPT
CPT
CPT
JSFJL
MLP
MLP
JidLE.
MLP
CPT
CPT
~ior
2
3
4
5
™6
T"
4
5
6
8
....„.„.
10
IT
13
14
15
16
17
™2T
25
26
27
28
29
30
31
32
33
35s
36m
37?
40s
42:
43 i
X-Coord
.."ffiL
63.6
16.7
-21.2
33.7
20.8
-J.-0
8.2'
22.7
23.1
27.5
35.4
52.4
50.2.
42.3
68.2
50.6
99.0
84.9
......i..i.3.7
37.9
110.8
84.5
18.3
67.1
2.4
73.6
119.5
60.6
87.2
79,7
59.4
46.3
51.7
61.5
42.7
23.1
Y-Coord
Hfl:
-112.7
32.9^
60.0
126.7
35.6
70.7
52.3
82.2
48.5
59.0
77.5
43.9
L™ 74.7
93.4
39.5
99.4
132.2
153.4
110.7
30.9
147.7
22.7
67.7
54.8
38.3
95.7:
159.0
27.0
50.8i
™_ZLZj
73.8;
84.6!
.........61,21
43.9!
6.3!
95.0
Benzene
.....tea/H....
3.7
0.0
, -A2
4.0
2.1
0.0
0.0
. 0.0
4.4
0.0
0.0
0,0
oTb"
0.0
0.0
1.7
0.0
38.9
1.1
74.0
0.0
1,8
0.0
0.0
6.0
0.0
0.0
0.0
13.4
0.0
0.6
0.0
0.0
0.0
4.0
Toluene
(US/LI
4.0
11.9
._ 3.1x
2.0
9.2
0,9
6.6
™™™~SAPJ
9,3
0.0
0.0
0.3
9.4
0.9
0.3
0.6
1.6
0.0
.43.4
0.0
92.0
0.6
1.8
0.7
0.0
11.8
0.0
1.9
0.3
6,5
0.0
0.0
0.0
0.0
1.4
4.4
(W3/L1
1.6
3.4
1.6
0.9
2.9
0.0
0.0
' 6To
4.0
0.0
0.0
0.2
4.5.,
0.2
0.0
0,2,
0.0
6.6
25.3
OO
.....(|ig/LL..
1.4
Ui9^t)xqleiTgljoiaL
L __ __ (M/L) .. ... J teg/Lj.
0.0
5.2! 6.6
f.2| 6.6
2.1
4.0
0.0
0.0
0.0
2.4
0.0
0.0
0,0
4.0
0.0
0.0
0.0
0.5
0.0
i 0.0
0.0
0.0
; o.o
0.0
! 113.0
134.0
71.5
73.0
114.0
42.0
17.0
5.0
6.6! 671.6
6.6
6.6
o.o
o.o
o.o
o.o
o.o
^^Zis^sJ o.o
5"^2
6.3) 6.6
0.6
0.2
0.0
5.8
0.0
2.3
0.0
6,0
0,0;
6.6;
0.0;
0.0;
6.6:
4.0i
0.0
™™™°J2j
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
o.o
o.o
0.8
0.0
0.0
™ ^P-=Q
6.6
20.9
0.0
0.0
0.0
6.6
b.of 6.6
o.6| i .3
0.8
0.0
0.0
2.2
238.0
4.0
""TsTo
38.0
18.0
1 1.0
67.0
186.0
744.0
36.0
1390.0
70.0
85.0
16.0
0.0
207.0
19.0
137.0
16.0
210.0
0.0
22.0
66.0
57.0
22.6
126.0
F-6
-------
Hill AFB Site 1/94 Ground-Water Data
Well
MW
MW
MW
_CPT
CRT
CRT
CRT
r^PT
_CPJL
_CP]_
CRT
CRT
_CPT_.
CRT
CRT
CRT
CRT
CRT
CRT
PPT
CRT
CRT
CRT
CRT
_SEL
MLR
CRT
No.
2
4
2
0
c
£
8
o
~1£L
__n i;:
12
JA
15
16
18
20
21
25
26
28
29
30
32
33
35d
42
-Coord
™J!!L
63.6
16.7
21 2
33.7
20 8
-1.0
8.2
23J..
27.5
35.4
52 4
50.2
42.3
63.6
50.6
99.0
84.9
13.7
37 9
85.4
110.8
84.5
18.3
2 4
73 6
119.5
87.2
3QJ
59.4
42.7
Y-Coord
JLJ.
-112.7
32 9
60.0
26.7
35 6
70.7
52.3
48,5.
59.0
77.5
43.9
74.7
93 4
79.1
99 4
132 2
153.4
1 1 0.7
30.9
36.3
147,7
22.7
38 3
95 7
159.0
50.8
.^^--Try— --—
97 9
73.8
6.3
Benzene
(na/L)
0.0
0.0
0.0
0.0
1.4
0.8
.20.7.
0.6
0.0
0.9
O.C
o.c
O.C
o.c
o.c
0.0
(X0_
0.?
o.c
0.0
o.c
0.8
o.c
0.0
0.'
0.
0.
95.0} 0.
oluene
JaslL
0.0
0.5!
0.4
0.6
0.1
0.0
13.6
0.0
0.5
0.0
0.6
0.4
0.8
0.3
1.2
1.1
0.6,
_
1.3
0.0
0.0
0.8
1.7
0.0
0.7
0 9
! 0 4
0.4
O.C
• LJ
(M-g/1-
0.0
0.4
0.3
™ go
0.0
0.0
5.1
0.0
0.3
0.0
0.4
0.2
__ _ __—
0.3
1.3
1.3
0.6
0.0
0.0
1.7
0.0
o o
0.0
2-, 2.
0.0
0.6
~ 10
0 4
0.1
0.0
(M-g/U
0.0
0.8
0.3
0.0
—
0.0
0.0
1.1
0.0
0.5
0.0
0.8
0.3
0.6
0.^
i 1.8
1.7
0.9
0.0
2.4
0.0
0 0
_
2.
O.C
1.0
1.5
0.7
0.6
T o.c
1.2i 1.8
_j£a/LL™
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
o.c
0.0
0.0
o.c
o.c
_
o.c
o.c
Total
(w?/L)
___._
2.9
2.3
6.9
184.0
4.3
18.7
3.8
20.4
17.9
_3Ld
19.2
46.0
26.3
64.6
7.1
3..!
2.,5
35.6
7.2
30.2
) 18.5
) 6.0
i 52.0
F-7
-------
-------
Appendix G
BTEX, Naphthalene, and TPH Ground-Water Dissolved Plume Mass and
Mass Center Calculations for the Hill AFB Site
Hill AFB Site, 4/92 Data
G-1
-------
Hill AFB Site, 8/92 Data
G-2
-------
Hill AFB Site, 8/92 Data (continued)
G-3
-------
Hill AFB Site, 8/92 Data (continued)
WrttoM^T*
**W
MW
""::,»»•.:
=^cr
lJ§_
^1
rn*ji „ .
•"«*»
w
.. w
<*'"
a*
01
c#*
01
MT
en
t*i
WI .
— S—
a
CR
CH
01
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— 'A—
en
in
art
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Z4sL_
MM"
MI«-
., :, 01
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14
It
SO
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?7
3ft
_?»
»
31
_2_
34
A
a-HJ
ara
"Tf"
I2EI
44d
ro*-o«
2
3
&
4
1
3
3
.. 4
'*
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7
,£
?
—ft-
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[3
ij
IJ
—44—
(T_
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21
22
jl
ZIH_
w
y>
-41—
^STT
..33 .
34
•~sS—
— *UM
•*?
a
[tn
63.4
I4,/
SJ.7
1 $5
.1,0
«
t-'i
T
3
*0
»,4
SJ.4
" 5K!
42.3
43.4
6d.^
S0.6
yv,u
«4.Y
113.7
85. 1
1104
1 " ' iM.4
64.5
18,3
*/.!
1,1
. . 734
i mi
60-6
87.2
»«
W-4
46.3
*(./
42,?
23, t
113,3
•*<»ffi"°'«,,
$3,4
14,7
33,7
!08
M,Z
.1.11
_8-2
22.7
«.')
27.5
30,0
35,4
524
XW
«.4
M.I
s>:2
?9-0
S4.9
113.7
imo
as.<
iinn
)26<
•4.5
I3,i
47,1
3.4
?3.A
119^
iO.4
fl7.2
79,7
, »f
•tf-J
4,5
45.7
53:i
HM.
— nti —
•1 12.7
sty
126.7
^z^
70.7
52J
04*
48^
59.0
•44.U
77^
43.9
tfj
93.4
79.1
.jy.3
99.4
IJJU
I±»J.^
110.7
36,3
147.7
B9.2
52.7
67.7
W.S
3».3
95.7
liMJ
27.0
50.8
97.9
?3.e
84,6
61.2
W
95,0
I10J
y Cofdirrale
-112.7
32.9
i26./
35.6
-11.4
70.7
5?.3
87.5
«J
59,0
44,2
111,
43.9
74,7
79,1
39-5
99^
132,3
153.4
IT6!>
145,9
34.3
U7.7
89.2
22.7
W7
54.8
3i.3
95.7
159.0
27.0
MJ
77.7
97.9
84.4
ali
4,3
9iZ
Area ( IA2)
2,494
6IL
lisSS
245
992
341
2m
18V
244
3/4
250
283
151
150
120
:i6u
620
UyO
i,ti.v
98.8
98.1
98.7
98.3
yy.ii
98.2
98.9
yfj.!
97.7
98.1
W.O
--.rrr- , rr-r-rrrr^f
9&;t
Vij.6
98.6
99.2
97.1
99.4
99.5
98.2
ytu
98.7
97.5
9A7
98.9
98^
97.6
98.0
97.8
98.4
1 — w#
97.7
98.7
Elevation
104.2
98.9
93.8
101.1
98.1
98.7
98.0
98.3
99.2
98.9
98.1
98.1
99.0
— 97$
98.1
96,6
*s!i
96.4
99.2
w.\
99.6
99.5
"•""" W$
93 7
98 7
97.5
96.7
98.9
: $8.8
98. t
97.6
97.9
$7!6
99,6
' ' TO
-
BOG (ftl
88.0
88.6
88.6
BU;
87^
88.6
o/,;
87.2
87.5
BB.6
87.0
(i'5"^)
Bs.v
85.1
88.5
84^
t!i.O
88.8
88.0
" ' yy.i
88.8
86,8
""""""TO
88.6
BT3
87^
87.8
89,4
87.6
86.3
Me
L^^f-
91.0
gffB
88.6
87.8
88,0
88.7
BA8
88.6
87.7
_^_gj,5
88,6
—""BTS
85.5
85.9
55.1
84.1
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86.0
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886
88^
86.8
84.4
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87.5
89;4
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89.0
89.6
89.1
88.8
89.6
'tUi.7
88.2
88.5
88.0
86.5
86.y
87.t
89.5
85.8
89.0
" ' B93"
89.8
87.8
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89.7
89.0
88.5
68.8
90.4
88.6
87.1
t Depth (m|
IM ibp'bt.:.
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89":0'
89.6
88.8
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89.1
89,6
88.7
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86,5
86.9
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89.2
89.8
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88.5
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1.00
6.99
1.01
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1.01
0.99
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2.01
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0.99
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0.99
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1.02
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0.66
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5.025
2.788
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1,996
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380
491
503
^'""""570
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301
242
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1,097
1,415
1,412
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1,970
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1,158
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320
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1,228
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0.0
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10,362
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0.00
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0.43
0.33
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1,794
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G-4
-------
Hill AFB Site, 12/92 Data
G-5
-------
Hill AFB Site, 12/92 Data (continue^)
location
0»fi®*K)*on
MW
MW
MW
CPT
CCl
$•"*
in
-- 5"
'.-T-Tl!iOI
M W'
MW
en
en
"— cw
en
, S^
JEW, „
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C"
C>T
Cn
•• SB
CM
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en
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MW
MW
MW
CPT
en
SB—
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en
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CPT
.. .Cff
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M „ VH „,
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en
in - -
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&
3
*
4
4
7
s
11
1*
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u
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30
31
34
4V
4«
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2
» '
5
*
4
7
»
11
12
13
14
21
iti
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43
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2
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4
7
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11
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21
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2V
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42
4i
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(111
63.1
16.7
41.1
30,8
22,7
3B.(
35'
42,;
43,4
«,:
1164
2,'
73.6
119.5
60.t
30.6
42,7
». 1
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(HI
63, (
14,7
33.7
20.1
22.7
38.0
34.4
42,3
43.6
48.2
46.6
iio,a
2.4
73,4
119.5
60.4
90,6
42,7
23,1
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«.«
14,7
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20.8
22,»
380
3S.4
423
43,4
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2,4
73.6
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42.7
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146.7
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82,4
44,2
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79.1
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99.4
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95.7
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9>.9
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35,9
126.7
34J
82,2
44.2
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93.4
>9.l
. 39.5
99.4
147.7
' ' ' 48.3
95.7
159.0
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97.9
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74
6
96
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23'i 3
4
489
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0
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0
b
0
0
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0
0
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63
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1,432
9
342
14
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31:
48
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302
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3
532
8
2,883
205
77
8.263
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(q-ft)
0
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0
0
0
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0
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t™~T2
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156
69
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12.537
17
1 ,286
24
305
25
68
106
™~™~JL!JS
58
594
1,600
40
692
TT
1^284
30
316
5,162
G-6
-------
Hill AFB Site, 2/93 Data
xicafon :
Designation
.___,M.W......J..
__MW_gjj
M~W~W 1
ZSEZ1
MW
CPT
__CPT___
nsL~i
' CPI i
CPT i
-§PM
™~££L~~J
CPT
CPT
CPT {
CPT j
CPT
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— gpp..-}
CPT
c'pt
CPT i
CPT vtj
CPT
MLP
U_ 1
MLP
MLP
CPT
^Location .
Designation
MW '
MW
MW
MW
MW
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CPT
cpr m,ir,
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ZZEIZ
CPT
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— cgi:
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CZSHIZ
CPT
CPT
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jjj-f
CPT
CPT
MJ..P
MLP
• — MTp —
— j-..^ —
MIP
CPT
""M'LP-"
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Site
3
4
~~ — «
6
3
8
11
"!•>""
,,,13....
14
_l£2
16
17
~TH
19
""55™
JiLL;
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31
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34
35s
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37s
38s
40m
-ft-
Site
_^J
3
~J~™
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8
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11
: 12
13
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16
17"
18
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21
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32
34
36s
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41m
.43
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— ^W-
16.7:
-21.2
nzzMzt
2Cj.8vL
8.2 i
23. i
ftw,v,v;y^..g.
_35.4J
^u'x
42.3
63.6:
68.2
50.6
— 99-35-;
84.9J
113.7:
-^j-sfi
128.0
'" ' 85.4:
^^ ljfj.8
84.5
,__LIlf
2.4
iu-:::u-nft
60.6
. ^
30.6
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4T3:
51.7
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61.5
23.1
i 13.3"
X Cordinate
—12V
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20.8
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22 7
23.1
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35.4
:|[|[[[[:|52\4.
50.2
§3
68.2
• M^:
99.0
84.9
fryy
37.9
128.0
85.'
110.8
ST3
18.3
67.1
73.6
60.6
M 87.2
30.6
. i
issociatec
ABOJ^
^
1.353
17
40 ;
155
^
255
—pfi
is;
^
19C
— — 338
1.031
pj,^
1.74:
^^^705
88'
^gg^
43.
227
1.66:
^
1.52:
301
19
27
-PS
36
63
i;oo:
Elevation
TOCJf^
98.9
98.1
™™«~^™.v
98.8
98.7
" 'slTEf
™"™*^O'
98.2
98.9
"™ 9*8~T
97.7
9'8'.i
99.0
^fjT
98.6
98.6
^g.
96.4
""99 2
97.1
99.5
^_£
9S.7
9^77
97.5
98.9
98.8J
97.6
98.0
9?ty
98.4
98.4
98.8
98.7
97.7
^
Elevation
T^C (ft|
164.2
"" 98. i
98.9
98.£
98.7
98.C
5^3-
98.;
^"BT9
98.1
97..7
5CT
99.C
-9T6"
98.1
98.6
m
99.:
96.'
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97.
99 5
98.;
98.7
97.5
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98.1
97..
97.9
98.'
'9'8'"
98.1
w,i
98.'
97.
98T
Bevation
BOC l»l
88.6
"' ""BsVd
87.8
88.6
87.2
87.5
88.6
87.C
"" as3
85.9
85.1
84.
~88.5
84.8
88.8
gsT5
88.6
88.'!
86.8
88.6
geTT
|7J
sTs
87.E
87.6
S'6".j
^at^FCgT
iiev'i'tn f
92.7
~™*™M9*W!?W
9 .9
92.4
91.3
zztit
92.3J
™~M
89.9
89.6
"s's^s
92.3
"=9V.9:
91.2
90.7
92.3
9TS
90.9
9TO
91.6
9 .^
. M°7ePth I"1!-
Elevation
BOC (ft|
88.6
87.E
gg-g
87.!
88.6
87.;
87.2
§73
88.1
"8"7."t
85.5
85,!
gSH
84.
[ 66.1
84.1
^
88.1
88.^
••"""•"''•'gQ"!
86.:
SK"
88.
87.
87.
'
87.
^ 86.1
Water Col
! Hev fftl {
91.9
j^i
91.9
9;.'i
91.6
91.3
9TS
92.;
91.1
89.;
"""""""iJSM?
g9^
^n?
88.5
91.1
— m
9c.;
9^
91. i
90.5
91.:
" 9TT
Max Depth Jm
Safer CoT
Depth (ft)
4.06
4~i2
J™,™r*..£-v-^
• 4.0-1
3.84J
4.09
"TZP?
3.7(
4.07
™_
4.55
3.36
3.67
3.5C
O3
2.61
3.8E
3.6E
3"~56
3.3!
3.37
4.0'
—~^
5".4
Water Co]
Depth (ft)
•• — —m
4.12
3V9i
4.04
s'.S'
3.93
^
3.7
"" 4.:
3.7
~:~~~5^i
431
~~ "'3^3
3.6
^
3.9
2.6
— ™™^9"
3.8
3^
3.5
3.2
, 4.0
u "" "' stT
5.4
i^Slsi
|ttA::| i
4,957:
3,936
KSn
927
2.231
•™ms
_J3||
1.400
1.147
829
.....,.m
1.028
1,893
$16*3?
5.571
5,444
Z23M
2.999
3. ill
_jyz4
18.298
— 53T6
1.224
3.703
8,990
9.717
i;62i
848
— nssi?
1,482
fjjj
1.21E
•666
~™TlS
'""TSJS
5,44'
Volume
-^^
3.93.
7.31
92i
T.23T
2,16(
836
^g.
1.400
'" '1.147
816
829
2-fjjj
1.028
1,89;
3.639
5.571
SUll
2,99?
JJJJJ3^81 1
4.777
18,298
2.346
1.22'
87990
^jy^
8,228
1.62
— ™T4j
1.03;
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— rm
1.211
1.95;
3.44;
5 — 5TT
""^er^er^^
IIW/L)
_.
0.0
"^"""""ao^
0.0
10.8
0.0
~ CT
0.0
~~*.
5.9
,™,,M
0.0
0.0
" 49.9
0.0
0.0
37
*~~
0.0
0.0
0.0
::::::::::i§
b.c
0.0
0.0
57T
0.0
0.0
1.1
— fl
1.4
0.0
0.0
g-jj.
Totals =
Toluene
"T3~
0.0
" 2.5
28. l'
0.0
0.0
jy-g.
0.0
• o.'o
fo
25.4
C .
6.2
0.0
isTs
O.C
O
O.C
3.3
0.0
jSJ^
6.
1.9
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3.7
T/
14.,
Totals
"J^™"C'ente
Benzene
Mass (q|
o"jOO
ESS
0.00
0.68
""""" aoo
"™"™S33J
o.ool
6^0
0.14
-TOO"
0.00
0.00
0.00
"~™"™~Tjj4
0.00
0.00
0.00
g-g.,
0.09
__ _.
0.00
Q-yjj
0.00
0.00
b'.o's
0.16
™---jjvjj.|
0.05
0.00
""~"~~:~J :::L: b;38!
0.00
)OT
10.59
of Mass (ft.ft)
Toluene
. g^,
O.OC
0.07
~jj
O.OC
0.00
jj—
0,00
0.0!
0.00
0.14
5D3!
0.74
o.oi
0.6'
0.00
~~-
O.OC
-.-.j
0.00
0.01
0.
O.OC
bTSB
1.5:
^0,0;
0.0
0.2
0.
---~'Q";O*
0.8
0.6
19.9
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'"""e'en'zefwBc
(p-ftl
35
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0
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0
1
0
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0
~™~™ o
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0
0
0
8
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c
c
0
8
^ ^ s
0
6
Toluene-x
la-ftl
~~~~r~~~~~3-
0
0
0
0
0
"" ". b
50
C
200
0
C
c
i
0
131
6
85
la-ftl
b
8
0
36
™~™~~ o
0
13
0
0
0
™™"™™™~™~™c
0
c
0
0
10
c
1
b
8(
Toluene-v
(g-ftl
174
— — -r?
i":
"~~~^J&
®
163
IZZZI1I
~™~~?I
_2£|
G-7
-------
Hill AFB Site, 2/93 Data (continued)
Locoflen
o»*mo(ton
MW
M W
MW
M W
MW
n^'C"
CPI
CPI
en
CM
CPt
CM
CM
CM
CM
CM
CM
CM
CM
----- £"-
. £w
CPT
CM
C«
C"
1 ' CM1 '
CM
CM
111 64
CPI
1— EH
Mil*
MIP
MtP
MtP
Mil*
MIP
MIP
, CM
MIP
__loeo*«m
IctVmoHor
MW
MW
MW
MW
MW
CM
CP?
CM
C**T
S"
e«
CPT
yfi
CPI
•in ""
CM
CM
ewr""
CPt
... . CPI
CM
5"
._.. Cft
CPt
Gft ,
CPI
— SB—
:±15p1
, CM
.,... MIP
V,^
MIP
MIP
MtP
....MVP
MLP
CPT
MIP
Stl«
2
3
4
s
6
3
4
s
*
5
^
10
11
-il-
ia
14
IS
I*
t>
18
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JO
21
TT^
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J8
2?
SI
32
5*
M«
Wf
97.
Mf
4*j
40m
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....43
441
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4
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_a_
4
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s
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IS
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M
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16
17
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27
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40m
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44)
XCwolnole
110
4S--4.
U.7
-21.2
«.7
20,8
«,2
22,7
23,1
2>,S
35,4
H4
W2
42,3
«1«
§2,
£
99.0
84.9
113,7
§,9
15
85.4
110.8
84,5
18,3
6?,1
2.4
73.6
46,6
§,2
6
5».4
46.3
51,7
§.7
.4
61 5
78.?
».T
113.3
* CoroTnate
(HI
*3.4
14,7
-21,2
33,7
ms
8,2
45.7
23.1
27,5
3S.4
52.4
SO.S
42.3
43,6
48,2
50,4
»9.0
84,9
113.7
37,9
128,0
85,4
110.8
84,5
18,3
47,1
2,4
73,4
§i
.2
30. 6
;»,4
46.3
SI.7
30.7
37.4
4I.S
78,?
231
113.3
r Cordinote
(III
-112.7
32.9
40.0
126.7
35.6
52.3
82.2
48.5
59.0
77.5
43.9
74,7
93,4
79,1
39.5
99.4
132.2
153.4
110.7
30.9
Us1,*1
34.3
147,7
' ' 22.?
47.7
54.8
38.3
95.7
27.0
50.8
97.9
73.8
84.4
61.2
56.5
41.5
43.9
56,2
95,0
110.7
' Corrfmate
Iftl
-112,7
32.9
60.0
124.7
35.6
52.3
82,2
48.5
59.0
77.5
43.9
74,7
93.4
79.1
39.5
99,4
132.2
153.4
110.7
30.9
1659
36.3
, ,'47,7
22,7
67.7
54.8
38.3
95.7
27.0
50.8
97.9
73.8
84.4
61,2
56.5
41,5
43.9
54.2
95.0
110.7
glaciated
«»a IftA2;
2.49C
917
728
1.353
171
412
400
155
125
259
212
151
153
392
190
3SQ
673
1.031
1.007
1.743
555
705
884
3,386
434
337
685
1,663
i.79d
1.522
300
157
191
274
206
225
123
361
637
1,007
\siocialed
Area ilt"2l
2,498
917
728
1.353
171
413
400
155
125
259
212
151
153
392
190
350
673
1.031
1,007
1.743
555
705
884
3,386
434
227
68$
1,663
1,798
1,522
300
157
191
^ 274
206
225
123
361
637
1,007
Elevation
IOC Iftl
104.2
' 98.9
98.1
98.9
98.8
98.7
98.0
98.3
98.2
98.9
98.1
97.7
98.1
99.0
97.4
98.1
98.4
98.6
99.0
£__.
99.2
97.1
9'9".5"
98.2
98.7
98.7
97.5
98.9
98.8
97.4
98.0
97.9
98.4
98.4
98.8
98.7
98.7
97.7
98.4
Elevation
TOC Iff)
104.2
98.9
98.1
98.9
98.8
98,7
98,0
98,3
98.2
__9&9
98.1
97.7
98.1
99.0
97.4
98,1
98,6
98.4
99.0
96.4
99.2
97.1
99.5
98,2
98,7
98.7
97.5
98.9
98.8
97.6
98.0
97,9
98.4
98.4
98.8
98.7
__2&7,
97.7
98,6
Elevation
BOC (III
• -
88.6
87,8
88'.'6'
87.8
88.6
87.7
87.2
87.5
88.6
s#:6
85.5
85.9
85.1
84.1
88.5
84.8
88.8'
88.0
88.6
88.8
86.8
88.6
88.1
87.5
87.5
"TO"
87.6
86.3
Max
Elevation
BOC (HI
88.4
87.8
88.0
97.8
88.4
87.7
87.2
87.5
fa1:?
87.0
85.5
85.9
85.1
• 84.1
88.5
84.8
88.8
"" 88.6
88 6
9*?'^
86.8
88,6
88.1
87.5
87.5
87.8
87.6
86.3
Top of
Wdier to
Elev (ft) '
92.7
91.9
91.9
91.9
92.4
91.6
91.3
91.3
92.3
TTT
89.3
89.9
89.6
91.9
88.5
fel
91.9J
zzis
92.7
90.7
$;s"
91.4
90.9
90.9
"TiTs"
91.8
)epth {m|
Top of
Wafer Col
Elev (ftl
92.7
91.9
91.9
91.9
92.4
91.6
91.3
91.3
92.3
91.1
89.3
89.9
89.6
91.9
88.5
92.3
91.9
91 2
92.7
90.7
9J.3
?1.6
90.9
90.9
91,8
91,8
Max peoth Iml
Wafer Col
Depth (ft|
. JJ-g-J
4.12
5.90
4.04
3.84
3.93
_____4.g9_
3.85
3.70
_j_
3.78
3.95
™~"Os"
3.36
3.67
3"50"
3.90
"~ 2."61
3.97
3.88
3.68
3.56
3.35
3.37,
4,04
,,,,,,5'4°,
5.40
Wafer C'o'l
Depth (ft)
4.Q4
4.12
3.90
Jjjy
3.84
3.93
4.09
3.85
,3,70
4.07
~ 3^8"
3,95
4,55
3,36
_*_Jil&7,
3.50
3.90
2 61
?,97
______J1g8,
__&£§.
_~_2»&1
3,35
3.37
4.04
5.40
5.40
volume
(ffA3l
13,498
4,957
3,936
"™T3lT
927
tgffi"
2.140
836
478
1,400
1.147
SlL
___J29,
"~TT58
1,028
zSi
3.639
5.571
5,444
9,418
2,999
3,811
4,777
"TE59T
2,346
1,224
3.703
8.990
9,7"l7'
8,228
_JUi2J.
848
__JJ032,
™JJM
_LiIi
u™LiS
666
l.?52
~_SdS
5,444
Volume
IftASI
13^49a_
4,957
_~2i22i
7,311
927
2,231
2,160
836
™™£Sl
1,400
1,147
816
829
2,120
iloW
1,893
3,639
5,571
5,444
ZS3I
2,999
_MJi
™AZZZ
18,298
z2s
1 224
3,703
~JiiS23.
™^tZJ7,
™SS£
,1.621
§4§_
-JLfiiJi,
1,482
1,1)4
1,218
66^
~J*9J>2_
__3j4J3L
__^14J4_
:thytbenzene
(H9/U
O.C
3.9
0.0
—™~jy.J
1.4
TT?
0.0
0.0
S.O
0.0
0.0
0.0
1.4
™~™™™"™5S
5.4
— -g-J,
2.1
0.0
-~~~~~~-^g
32.1
3.3
0.0
1 olf
0.0
""" "52
0.0
0.0
""67o
3.6
0.0
6.7
I.I
2.5.
8.2
j-g.
0.0
7.8
~_™_Ji
0.0
• otals =
:tny [benzene
Mass (a)
0.00
- 0.55
0.00
"™™™~™S?bo
0.04
~™~ S9
0.00
0.00
zznz^i]
0.00
o.bo
6.66
0.04
™™™™~aob"
0.16
gftfcH
0.21
0.00
""(SuiT
8.56
b.66
0.36
0.00
838"
0.00
zzms
0.00
0.00
™™™~fliBS.
0.84
6.66
0.16
0.03
ZZIZJS3Z
0.26
6*.07
0.00
0.43
www-wlljslJjL
o.pp
rsrgf
Center of Mass (ft.ftl
p-Xylene
(ua/U
0,0
5,5
0,0
0.0
2.4
39.8
0.0
_™M
«™™™™«™0^fi
0.0
1.7
0.0
1.8
O.Q
~Tf
0.0
2.9
0.0
2.8
19.2
3^7.
™™_™_in.
0.0
0.0
3 2
OjO.
____£.£
&&
3.6
jQi
™— «JLL
JJL
3.5
6.5
2.0
Afi
?i,4
3.Q:
1,9
Totals =:
ymtwj£Xylenem
Mass [at
OtlOCJ.
0.77
•~™™™PJ39,
0.00
O.Q^
2.51
6.00
™__™MO.
™___MS-
6.66
_™_P-21
0.00
»™™™™M1
0.00
0.27
0.00
™_2jS
0.00
JM3_
5^12.
0-CJ2,
_E4o_
™™™™&B8.
0.00
0.00
0.1 1
O.pp
Jjjgg.
o.op
^^ww^w^^wfiiS4*
OSS,
p. 10
™__™fiiS3.
p.l^
P.2P
____fli2Z.
0^00
™™_™_U2ji
a?i
0.29
14.00
Center of Mass (ft ftl
Glnyjbenzene-x
is-ffi
0
9
0
T
,j
~>^j-
0
0
o"
0
"6
0
_™_™2,
£
n
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21
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325
0
30
0,
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P
5
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0
L««™«*«»*«*«*JL
73
P
u_ 10
1
£zzrzzz3.
8
3
P
34
4
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41
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(q-ftl
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13
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0
1
21
p
0
p
0
3
™™™™™»»™»»^
2
0
' Ts"
™S,
29
p
49
194
„_",
3_4
vfffmJKHff^ffmfflfff^f
P
,.,._..,.. g.
7
p
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p
73
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6
1
fi.
VHKfwfffffffffMMflfH^
_________J_
0
l£i
7
_J&
662
47
|iftvj6e^^n^j
(B-ftl
0
18
P
"™WMM*™W™™V15
1
135
P
0
-™—~~™~-~ft
0
™"™™"T>
0
h™™_~™4
—~s
6
" ij
28
0
4*8'
264
T
13
0
0
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4
0
0
S
43
g
12
3
6
15
3
0
„,.,..„;,.,.,„, 2,4.
17
P
643
43
p^ie'fii^
(q-ft)
p
25
, p.
0
, 2.
131
0
0
4
p
__ 2.
0
4
0
1 1
0
39
^ p_
48
1S8
0
15
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0
— nuns
6
0
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m_™™l™™Si
0
7
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9
it
3
p_
ua
, J2.
687
49
G-8
-------
Hill AFB Site, 2/93 (continued)
"Tocalfon™
MW
MW
MW
J""M"W"~"*
MW
CRT
CRT
CRT
CPT
OT
CPT
CPT , „
^
CPT
cTf
CPT
CPT
.jpj ,
CPT
CPT
CPT
CPT
TPT
CPT
CPT
CRT
CPT
CPT
CPT
. CPT
MLP
MLP
MLP
MLP
MLP
MLP
MLP
CPT
MLP
x
location
Desiqnation
MW
MW
MW
MW
MW
™f
CPT
CPT
_CPJ_J
CPT
CPT
Site
2
" 3
4
g
6
3
,n,4 „ ,
5
6
_g —
9 •
10
1 1
12
~rr~
14
15
~iT~
17
18
20
21
"™2T"
26
27
TT^
29
31
32
34
35s
36s
37s
"56s
39s
40m
41m
43
™44T
Site
2
3
4
f~5
*
3
1 —
5
6
8
9
>_™££L™J '°
CPT
_gr_
CPT
CPT
CRT
§PT
PT
CPT
CPT
CPT
-™£EJ__
,CPT
_
CPT
CPT
CPT
CPT
CPT
MLP
-*~
MLP
MLP
MLP
MLP
CPT
MLP . .
11
-Hh
14
15
16
_1L-
18
19
20
21
_~25~~
™21_
mzz
28
29
_JT__
32
...34...
_2£s™
3^s_
""S'7'r
38s
-J2S~
JSffl.
.lUa.
_43__
_44s__
% Coralriate
(ft)
63.6
' 16.7
-21.2
S3".'7
20.8
8.2
227?
23.1
27.5
S31
52.4
50.2
™" Ti"3
63.6
' CordHTaie
(ft)
-112.7
32.9
60.0
ran
35.6
52.3
'" ' 82.5
48.5
. 5?,C
7-7.3
43.9
74.7
93.4
79.1
68.21 39.5
50.61 99.4
99.0
~ """sT?
113.7
__3£9
85.4
110.8
84.5
18.3
67.1
yy
..., 73,6
60.6
87.2
30.6
59.4
46.3
51.7
30.7
39.4
61.5
fa.s
23.1
1133
X. Cordinale
(ft)
63.6
16.7
-21.2
^5T7
20.8
8.2
22.7
23.1
27.5
35. A
5.2.4
to
42.3
63.6
""""wz
^^JSA
99.0
84.5
,™_U3iZ.
^73
_™J3a^
153.4
110.7
30.9
iV~'ra
36.3
147.7
22T7
67.7
54.E
3"8^
95.7
2"7"c
50.E
97.9
_ yg-J
84.6
61.2
56.5
41.5
43.9
56.2
95.C
1 10.7
Y Cordinate
(ft)
-112.7
32.9
6Q.O
126.7
35.6
„..„ .Mi
8,2.2
48.5
59.(
77.5
43.9
m
93.4
79.1
39.5
. 99,4
JCssociafeH
Area (ffA2l
2,498
9,7
, 728
353
171
413
400
155
125
,.., m
212
. 151
""IS
392
190
350
673
u53T
1.007
1.743
705
884
3V&6
434
227
,„„„%&>
1.663
1.796
1.522
30C
T57
191
274
206
225
123
361
Elevation
TOC (ft|
104.2
~™98S>~
98.1
9"S.'9'
98.8
98.7
98.0
98.3
^
98.9
98.1
S>7.7
98.1
99.0
•97.6
98.1
98.6
98.6
99.0
99.2
97.1
^
98.2
98.7
98.7
97.5
98.9
98.8
97.6
98.0
97.9
98.4
98.4
98.8
98.7
98.7
___^637j 97.7
LOW
Associated
Area (ftA2)
2.498
917
728
1 ,353
171
413
400
155
125
259
, 212
: is
153
392
190
3.50
132:2 673
153.'
110.7
30.9
128.0! 165.9
85.4
110.8
84.5
18.3
67.1
2.4
73.6
60.6
-,„ ..... ,,,87,2
mnsl
59.4
46.3
5J^7
30.7
39.4
__™_&LJ
_™Z§«
23,
Hi;
3_6.3
147.7
22.7
67.7
54.i
38.3
95.7
27.(
,, 5.0,8
97.9
73.8
,,,„¥.*
6l,S
56.£
__iU
__|
_J&J
95.C
ns:';
1.031
,.1,007
1,743
555
705
884
3,38$
„.,. A34
..: .227
685
jm,m],66?
1,796
1.522
,, M
157
.,.191
,,..,.,.274
206
225
12;
361
637
1,007
98.6
Elevation
TOC (ft)
104.2
98.9
98.1
98.9
98.8
98.7
98.0
98.3
98.2
98.9
98.1
97.7
Elevation
BOC (It)
88.6
87.8
_§&§
88.6
87.7
-— -JJ772
S&.6
87.C
85.5
8'5.9
85.1
88.5
84.£
SS.J
88.0
88.6
66.t
86.8
..,VVV,,,,M,«
88.1
87.5
87.5
87.£
87,6
^^Topof
^aieruoT
Elev [ftl
92.7
91.9
........ 9L5!
92.4
j
Water CoT
Depth (ft)
4.06
4.12
3.90
-""""""4S4
3.84
91.6} 3.93
91 .3| 4.6*
, ,m?M.....vv....,.3.M
92.3} 3.70
91J| 4.07
™_™893™~~3i7Jl
8^.9J 3.95
89.6
91.9
88.5
" ?£S
91.9
91.2
9S.7
90.7
92.3
91.6
"™™™~W?
90.9
91.8
4.55
3.36
,...., 3,67
$%B
3.90
2.61
3*.9*7
..., 3,88
3.68
3.56
"""3:35
3.37
4.04
i"
§
86.3! 91.8
Max Depth [mj
Elevation
BOC (ft)
8*8.6
,, 87,8
88.C
: §74
88.6
: gy-y
87.2
fop o'f
Water Co
Elev (ftl
9^2
,, ,..?.].;?
91.9
91.9
Volume
IHA3)
^425
^47957
3.936
7.311
927
2.231
~2.f615
836
678
TJBB
1,147
816
82*9
2,120
1.028
1.893
3.639
S.571
5,444
9,418
3.811
4.777
18.298*
2,346
1.224
" 3.70S
8.990
9.717
8.228
'1,621
'•""848
1,032
1,482
1.114
1.218
666
1.952
3.443
5.401 5.444
_ ~~&M—~~-
-.1
Water Col
Depth (ft)
4.06
4.12
3.90
4.04
92.41 3.84
91.61 3.93
91.31 4.09
98,1 j ,_87,5t ..., 2.1.,$ .3,85
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97,6
98.1
98.6
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88.8
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98,71 88,6
98.71 88.8
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98.9
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98.4
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98.7
98.7
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87.5
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91.1
89.3
89.9
89.6
91.9
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1 3,49€
4.957
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7.311
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2.16C
836
676
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1,147
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4.07i 1.893
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3.90
91.21 2,6J
92.71 3.97
90.711. 3M
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91.6
90.9
90.9
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3.639
5,571
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2.999
3,81 1
4,777
18,298
2,346
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8,990
Nlaph'tTialene
(Bfl/LI
0.0
0.0
0.0
S.6
.,..,, ,.P,9
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0.0
0.0
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0.0
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0.0
12.3
0.0
0.6
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0.0
96.4
0.0
0.0
b.b
0.0
NapnThaienel Naphtha ene-x
Mass (a)
0.00
05)0
0.00
0.00"
0.00
___«4i
0.00
0.00
0.00
6.00
0.00
0.00
.B.DO
0.00
6.36
0.00
0.06
o'.'oo
0.00
25.70
0.00
0.00
6.6B
•o.oo
.^0,01. „.„,„., ,0.00
. 24
0.0
o.d
0.0
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55.5
i.i
0.5
19.8
0.0
0.0
11.7
2.4
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,.,,,,.,Totals.J
L^—^M0,
0.00
0,00
0.00
o.oo
1.33
6.03*
0.02
0.63
0.00
0.00
6.64
0.23
0.66
29.54
Center of Mass (ft.ft)
la-ft)
0
J5-
0
0
0
4
6
0
0
b
0
0
6
„„ ,.,, o
24
0
6
6
0
975o
0
0
6
0
0
0"
,,„.,.....: o
0
0
o
,„,, ,,,,,,,,79,
.!.
1
19
0
0
5i
5
0
1.166
39
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(a-ft)
0
0
6
Q
28
0
0
0
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0
0
6
0
14
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6
0
0
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1
35
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„ .0
36
22
0
1.040
35
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Totals Total! otal-xj Total-v
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285.6} 40.00) 668
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12
122
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-------
Hill AFB Site, 6/93 Data
G-10
-------
Hill AFB Site, 6/93 Data (continued)
G-11
-------
Hill AFB Site, 6/93 Data (continued)
UK***!
3*lSonafoo
MW
MW
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63.6
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20,8
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22.7
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113.7
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85,4
110.8
04.3
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67.1
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73,6
119.5
60.4
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79.7
30,6
49.4
44.3
51.7
30,7
39.4
61.5
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42,7
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63.6
16,7
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33.7
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63,6
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37,9
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84,5
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119.5
60.6
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79.7
30.6
46.3
51.7
36.7
39.4
61,5
78.5
42.7
23.1
V Corothate
|h|"
-1 12.7
32,9
6b'.6
126.7
35.6
70.7
52,3
82,2
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S*'J6
77.5
41.9
74.7
93.4
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39.5
99.4
1 145.2
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110.7
30,9
34.3
147.7
22.7
67.7
54.8
33.3
95.7
159.0
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£6.2
77,7
97,9
73.8
84.6
41.4
56.5
41.5
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54.2
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95.0
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35.4
70.7
54.3
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48,5
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77.5
43.9
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79.1
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132.2
153.4
116.7
30.9
34.3
147.7
22.7
' 67,?
54.8
38.3
95.7
159.0
27.0
Jo'.S
77.7
97.9
84.6
61.2
56.5
41.5
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54.;
6.3
«,6
Associated
Area iliA2!
2.484
509
476
1.385
164
443
317
398
lai
lii
249
208
i'SS'
153
199
208
578
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1.969
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685
588
2,866
329'
123
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9"33'
773
$23
1.373
822
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264
163
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182
217
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4S6
3.535
637
Associated
Araa II1A2)
2.484
5M
476
1.38^
164
448
317
3?S
188
135
S49
208
res
199
2M
578'
914
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588
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123
691
933
773
523
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822
257
163
322
re?
217
123
250
3.535
<37
Elevation
"fdc"nir
104.2
98.9
98'.1
98.9
98.8
98.1
98.7
98.0
9'8'.4
98.2
98.9
"w.'i
97.7
V8.I
99.6
97.6
J'O
98.4
98.6
9^.6
99.4
97.1
99.5
98.2
98.7
W.7
»a
96.7
98.*
98.8
98.1
97.6
98.6
97.9
98.4
98.4
98.8
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1 96.7
97.7
98.4
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104.2
98.9
98.1
98 .91
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98.1
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553
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9"8"3
98.9
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98.1
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98.1
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99.0
99".2
97.'l
99.5
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.98,7
98.7
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96,7
98.9
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98,1
97.6
97,9
98.4
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98.8
9S.7
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97.7
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Elevation
"szseriHr
88.6
88.6
87.8
§'S:B
87.8
88.6
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87.2
8>.5'
88.6
87.0
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•«»•
85.1
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84.8
88.8
88.0
88.6
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84.4
83.6
88.1
87.3
87.S
87.5
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87.6
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Max
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88.0
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66.6
87-3-
88.6
87.2
87.5
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87:S'
85.5
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8'5n"
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84.8'
88.8
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„„ -8f,6-
88.8
86^.8
84.4
88.6
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87.3
87.5
87.8
87.6
— ™™jnrs'
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92.1
92.7
91.8
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91,8
92.7
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91.2
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91.0
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88.4
92.9
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92,0
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92.8
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91.2
91.2
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91.8
92.6
93.8
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Top
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• 92.1
W3
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92.7
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91.4
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89.5
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92.8
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88.4
92.9
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92.7
90.7
88,0
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91.2
91.2
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92.0
93.8
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Ivicix Depth fml
1
Water Col
"DepiKW
•t'.OB
4.09
4.07
"ras
4.00
4.13
OT
4.01
53TI
" TT5
3.94
g.^
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4.73
j-jg
3.57
4.05
3.97
3.47
3".9"8
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3.59
"™""'"4'J2'
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3.91
4'.56
4.27
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6.19
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6.19
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Depth (III
4.08
TW
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jj^j
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4.13
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3.91
471^
S^'J
3.94
1 g;^,,
^73
4'J)S
3.57
4.05
j,^
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3.98
3.9 [
3.59
4.12
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3,9J
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4.24
6.19
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Volume
-JffXST"
15,371
3.149
23*33
8,570
1,014
2.771
1,963
2.463
"""irres
sss
1,538
rjjig
"'• 9*42
949
1.432
' 1,284
3,580
S35-3
— ras
12,185
2,72$
3239
3.640
17,7^35
2,637
762
4,2^
5^513
4,781
5.TS7
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5.085
1,593
l.26i
1,007
j-jj.
1,124
1.345
^
j.^
21,872
3,943
1 ?4.505
"voluTneT
. (ItASJ
15,371
J-flS
2.944
8,570
™°™T6T3
2.771
jy^S
2T?S
1.163
-)55j
~™T3S5
1,290
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1.232
j-jgjj
— TCS8B
5,653
— OT3
"rrras
2.729
4,439
3340'
17.735
JS-jgj
_£K
4,276
5,774
_™AZS1
3,237
—5397
508$
1,593
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1,994
Trna
1.345
722
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21,872
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Naphthalene
'""tecr~
0.8
0.0
o.o
6.6
0.0
6.6
6.0
0.0
3T6"
o.o
0.0
. .j-jj.
0.0
0.0
6.6'
66.$
0.0
6.6
4.3
o.o
6.6
6.6
1.2
6.0
o.o
o.o
'""""-""•"t.i'
8^.6
1.3
3.6"
ST6"
3.7
6.3
6.0
o.o
6.6
"5.6
2.5
6.6
— 5-5-
o.o
6.6
Totals s
Cente
Tofdl
(Ufl/U
19
j,j
18
36"
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51
.„„„„,.,„.„„„-,£
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44
9
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187
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170
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45
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27
5
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26
61
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71
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36
42
14
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40
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MaS^qi
O;34
0.00
""""""b.b'o
6.06
0.00
0.00
0.60
0.00
•""-' o.'14
6.66
0.00
6^66
o.oo
0.00
'•• ' 6.60
4.42
0.00
6.66
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0.00
6.66
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0.12
0.00
0.00
0.00
'™™w™™™o7T^
36.96
0.18
6.66
6.66
0.53
6.61
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0.00
6.60
6.18
0.10
6.66
6,66
o.oo
35.56
of Mass jft.ftj
foiaf"""
Mass (g)
a
5
2
7
3
4
5
6
1
6
7
'""' """" r"rr"4
6
-'-"'-'' 9"7",
""-'". I
1
3
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0
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' " , 4
31
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9
76
™™_a
3
9
6
1
1
1
4
1
\
T
25
•"•" "6
" "" ""34S
"Center of Mass Ift.ftl
Naphthalene-x
"' -io^ti'"- -;
21
0
6
6
0
0
0
0
3'
6
0
6
6
0
0
I651
0
0
35
0
6
6
14
0
0
0
6
'"""""J""'"'2,'4!'3
21
6
42
0
0
0
6
5
4
6
•"-"•"•'•'•'•"6
0
4,584
73
JJ"ToJdl-x '
(s-ft'i
612
84
*-33
244
5'4
-4
J9
33
358
™~™*™"™™M*;7S
377
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—"-^ 2^9
125
um ""-tat-r-%5\
1 ' "™ §49
13
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227
2,583
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20
5, \ 76
3?5
198
789
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19
. ....45
35
25
92
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1,054
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3,194
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164
91
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28!
27-i
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295
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465
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167
924
11
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691
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327
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41
2t
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51
G-12
-------
Hill AFB Site, 9/93 Data
G-13
-------
Hill AF^ Site, 9/93 Data (continued)
l&taitm
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MW
MW
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MW
MW
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CW
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CM
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CHI
CM
CM
CM
tiPi
cn
CH
t**l
t**l
CM
Cfl
Mir
MU>
Ml?
Mi.P
Vrl
CM
$««
?
3
4
5
&
2
i
4
s
4
e
9
10
~n
13
14
is1
16
17
ia
21
2S
It,
27
-jg-
29
30
•^l
32
33
3Is
34m
37«
40t
42
43
Site
2
3
4
S
6
2
3
4
5
6
a
?
iO
11
13
f-JT
!!>
16
1?
IB
21
as
J*
2/
26
29
J4.y
93.4
39.5
99.4
132,2
153.4
110.7
30.9
147.7
22,7
67.7
54\t
38.!
95.7
159.0
2/.t
50.6
77.7
/3.t
84.6
61.2
43.9
6.2
95.C
^ssocloieci
Area {IIA2!
2.484
509
476
1.365
164
448
ii?
398
243
2tk)
320
350
400
153
708
578
914
1,1)25
1.969
465
588
2.866
329
175
wr
933
773
52^3
1.553
884
380
163
322
223
3.535
719
Associated
Area (f|A2|
2.484
5O9
476
1.385
164
44&
317
398
1 243
280
320
350
4UU
153
708
573
i*U
1.028
1.969
• 465
588
2.866
329
l?ij
69'l
933
773
£23
1.553
884
3ttt)
163
322
223
3.535
719
itevadon
TOC (ft|
104.2
98.9
J&'I
98.9
98.8
98.1
w^rrmr^JQ
^8.3
98.2
98.9
98.1
97.7
98.1
97.6
98.1
98.6
98.6
99.0
9/Ll
99.5
98.2
98:?
97.5
96.7
98.9
98.8
98.1
98.0
99.6
9?.!'
Elevation
TOC (ftj
104.2
9&.9
98,1
98.9
98.8
98.1
98.7
98.3
98.2
98.9
98.1
97.7
98.1
^.^
w.\
98.6
98.6
99:0
97.1
99.5
98.2
98.7
97.5
V6./
98.9
98.8
98.1
98.0
99.6
97.7
IrlevaHon
BOC lit)
88.0
55.4
88.0
87.8
88.6
87.7
sy.s
87.5
87.0
ss.ji
85.9
85.1
f)4.&
88.8
88.0
'as:s
86.8
84.4
88.6
88.1
87.3
87.5
SX6
Mo
Bevation
BOC (It)
8^.6
88.6
88.0
87.8
88.6
87.1*
87.2
87.5
8?.tt
85.5
85.9
85.1
84.8
88.8
88.0
88.8
86.8
84.4
83.^'
88.1
87.3
87.6
87.6
• Top ol
Water Co
Elev (It)
.
vS.I
89.5
89.2
90.2j
89.2
S8TJ
89.0
88.4
8?.d
8?.S
87.6
90.2
86.2
90.5
89.3
90. 1
88.4
85.9
90.3
89.6
88.8
91.1
x Depth (It)
Top ol
Water Col
Elev (ft)
90.1
89.5
89.2
90.2
8^.2
88.6
89.0
yff.4
' B7.TJ
87.3
87.6
— 913:2
86.2
90.5
89.3
90.1
88.4
85.9
~tffi-g
89.6
88.8
91.1
Max Depth (It)
t
Water Co
Depth (It]
i.^4
.45
.42
.62
.53
7JT
.51
.41
.45
^6
.58
.3y
.65
.22
' '.34
.58
.54
.68"
.58
.51
2.58
Water Col
Depth (ft)
1.44
.45
.42
.62
.53
.41
.51
.41
733
.36
2.58
.39
.65
.22
.34
.58
.iH
,2H
.58
"5\
2.58
"^Vofurne^
(ft A3)
6.416
1.315
''" t,229
3.577
423
1,157
819
1.028,
628
ys'a'
826
904
1,033
3fS
1.829
1.494
2.3^0
2.65S)
™™5ffil
_ijoij
I.S19
7.403
850
452
"T.'TBS
2,410
1.995
1 .351
4,011
2.283
981
420
832
576
9.129
1 ,837
Volume
(f|A3)
6,416
I.31S
1,229
3,577
423
I7T57
819
1,028
£28
723
826
904
T.TOS
396
1,829
f/49J4
2T3OT
2.656
5.086
, f.,^
1.519
7.403
850
4"52
1,785
2,4(0
i,^yi>
"^^"Tsinr
4,011
2.283
981
420
832
576
9,129
1.857
'l-lh^iEenzene*
(Ufl/ij
1.6,
3.4
-'"""""""""""<('%
0.9
2.9
0.0
°™w™™MWMK?n!f
0.0
4.6
0.0
0.0
0.2
4.5
CT2
0.0
6.2
5.0
d.d
«™_™™Sls!<
6.6
ffQ,
0.3
0.6
0.2
0.0
5.8
0.0
2.5
0.0
6.0
0.0
t~~«~«*«J5.0j
0.0
6.6
u °-°
'4.6,
_Jotah_^
Center
^^^^Xvjene
(^g/L)
1.4
~5T2
1.2
2.1
4,0
070
0.0
0.0
~ — ~CT
6'.6
0.0
0.0
™™™™™"™™jn3'
0.0
0.0
t).0
"™tr!>
0.0
25.5
— OTO
54.2
0.0
0.0
0.0
0.0
0.0
0.0
0.6"
0.0
0.0
0.0
0.0
0.0
0.0
O.ti
0.0
Totals =
E^KytBenzene5
Mass |g)
0.29
0.13
"*""""J"m6.'oS
0.09
0.03
6.66
6.66
0.00
0.07
~OTOO
0.00
0.01
0.13
0.00
0.00
0.01
6.60
^0.00
3.64
0.00
fl.66
0.06
0.01
6.00
l^^^ 6.00
0.40
0.00
"tj.6?
0.00
0,39
0.00
'O.'OO
0.00
0.00
0.00
««««w"w«wft.2T
5.62
ol Mass (ft.ft)
^^^j^XvJene
Mass (g)
0.25
07T9
0.04
6.21
6.05
0.06
0.00
0.00
"~™~~™tiOT
0.00
0.00
6.66
0,12
6.66
0.00
0.00
« ^2
0.00
3.67
"'"OOT
2.33
0.66
0.00
EHJO
0.00
0.00
6.66
6.66
0.00
6.66
6.60
0.00
0.00
0.00
0.19
0.00
7.14
Confer ot Mass Itt.tt)
_™~™™™ii™»|~.~~.-»™-™™.
tthYlbenzehe>x|Etf^'lDerizQheJ-v
Is-it)
18
2J
-f
3
1
.0
a™™*™™™™™™^
0
2
6
0
0
7
0
0
0
0
0
414
0
"• • o
5
0
0
i)
29
0
5
0
31
0
6
0
0
0
5
522
93
^^^pjOJvjeneOf
(g-ft)
16
3
-1
7
1
0
0
0
r
0
0
0
6
0
0
6
™g
0
417
U
258
0
0
. 0
0
0
0
G
0
6
0
0
6
0
8
0
721
TOT
is-it:
-3o
4
3
12
b
6
0
3
0
0
0
10
6
0
0
0
403
0
6
1
0
0
38
0
2
0
30
0
0
0
6
0
26
498
89
p-Xylene-y
(s-ft
-29
<>
3
27
2
6
0
0
• 2
0
0
0
9
0
0
Tf
""'•'•"' ""-'-"4
0
406
' 6
344
0
0
0
0
6
Ci
0
0
0
0
0
0
0
1
0
776
PUP
G-14
-------
Hill AFB Site, 9/93 Data (continued)
Center of Mass (ft.ft)i 55
G-15
-------
Hill AFB Site, 1/94 Data
G-16
-------
Hill AFB Site, 1/94 Data (continued)
LtsssSiaid,
MW I
_™MVVJ
JjvgjL^
MW
| TO? — f
I — erf — f
c'p'f
C^T
CPT
ZSi™
CPT
g™. 1
tzssizj
tscij
CPT
CPT
gp;[
CPT
1
32.S
60.C
JJ.J
rot?
SE
48.5
59.C
43.!
74.7
_ j^-j
"~ — f5T5
153..
TTO7
JJ.J
™™~JJi^
22.7
5^3
9'S'7
159.0
27.C
HH
77.;
73.!
6.;
9^j
F"""""""
Associated 1
2,484i
™" " 672'
482
1.385
TrT
692
wf
243
280
320
464
ssr
"1
241
~ 349
914
. — .
2.042
463
^j.
-_ jgg.
2,866
346
681
7751
672
: y-gj^
, gg.-
1™~~~~TT8"
Jgg^
3,424
\ssociated
Area |ftA2i
672"
482
_ f^.
~" 69T
3*2<
243
2TC
g^g.
_~_£j.
55]
— — 2?r
— -g-y
-yf2
1.036
5^j^
i nt
588
2.866
6^1
fK
773
— — "675
"TsTS
884
38(
g-^-j
719
E'evation!
TOC (ft)
.^^.v^™..^^
-™5g7i1
98.9
£g£
j^J
98.7
98.3
9^2
— —75^
98.1
98.1
, —
98.1
'~~-:!': : r9s;6
98.6
""^ ^J99"o
99^2
97.1
' v//v r " 99^5
98.2
: 98.f
96.7
98.9
9S8
98.1
• — " 973
98.C
99.6
Elevation
— tsznr
W4Z
9§T
98.1
9r§J
™M*M*w*w^8Tr
"™ "9"8".7
^
9^.9
98.1
— 5CT
TT^
5rr
98.6
5133
99.2
97,]
99.5
ygj
I 973
96.7
•— ~ — ~?r?
98.J
98.
98.(
. ^
™™ T-yy
Elevation
BOC Iftl
getS"
88.6
88.0
""""'"' sTta*
8°§76
87.7
87.2
87.5
JJJJJJ 873
sTSI
™™**^*MW8579l
85.1
: gg-£
......,,,,....._._...„
"v''''"™"r"'88'.8
88.C
. — — .
""84.4
88.6
88. f
" ^^87^3
873
g^g
S
Elevation
Soci'tl
sTo"
88.6
5CT
g^
§O
87.7
"sTS"
g^g1
«KS
85.9
TBT
sfe.^
84.E
88.E
gj-g
86.8
84.'
88.6
""S'ST
87J
87.5
JT^
ToFol
Elev (ft)
"WWM**™™" g£g
•""A "89.3
88.6
..rrrrrrrHtTt-rTg™
'"89.2
88.4
88.V
88.2
87.8
™™™W*****^B6W!3*
''"""""""SiT"
86.
'gy";
"rm?-"
VJ._v.JJir.85^J
8$-3.j
88.6
":::i':""'r""89.4
"•""U""!!'J 'ffi'g
-852
89.2
1™"****WW%8V8!6
"""""""^STt
88. b
tox"Bepffi"r«)'
• ~
.— ,,,-,l9p..o)
Water Co:
~— S57W
S83
§9"a
~ §o
— ~jg^,
g^2
88.4
'68.^
, ^J
86.8
S2..7
•STE
I 85,f
; 89.;
§9-3
87:'6
85.2
89t2
8TT6
JS§'.''
~ sra
vlSx"bep(irj}(
WalS-Coi
Depth Ift)
3^82
6.73
0.59
0.67
__a&i
0.75
0.74
...,..„„ 0,,7.3.j
Ot83
1.64
olfo
6*^98
6^
0.51
6'.59
0.87
0.5'
::I'''!: 0.55
•""""""""'"b"7lP
j-J-j,
i j
Water Co
Depth (ft
S.8r2
' ~"oss
S3?
™-»
JJ-J.J
0.67
' 51?^
Ki'^
o'.7;
0.83
ro
b.sb
™™_™£L?J
0.45
.(^
6^
b'.75
0.87
0.54
0.55
0.7:
5T3
'\.6.
|ftA3
, y-y.-
2.27J
"""" ^ep
U37
532
399
459
_™___24£
396
"~~~~"™~~9oT
'•|su
T702
3.355
765
: j.-.-
4!708
569
_™T_
j"4'?';
1 T269
1.10-
" J2,54b
nzJs-i
""424
'^^jjgZi
5.624
ns~tj
Volume
— -itw
-___jag4|
79
5ST
""'"""""TT37
532
399
3'S5
906
901
f.'soi
1,702
t £|f
(7t??
966
4,708
trrra
1"J5?
1,269
~~i.T04
'i'.Sii
I.4SJ
624
-~17[y
(lig/U
ZIZU3
0.3
0.0
o?S
o!S
0.0
~ 53
TO
0.4
_«_a^
0.2
53
™T3
~~—rs
0.6
b.b
0.0
j_~
g*~
0.0
b.b
o.c
;:::™p
i.o
S3
o.c
™™
)olals"S'
Cenie
p-Xylene
~ CT
0.3
™~™~™" (OT
b.b
0.0
1.
6.6
, gvg
O.C
0.6
0.4
I.E
' "-•-'--•g-;9
*MM^w**mwlT5'
6^
2^
0.0
^g
2.
2.7
| 07)
CZ__,^
0.4
m™™wmy ins
rs
{ """cent;
Ethylbenzene
Mass [g|
"""""""""oTot
fiS
0.00
~y«~«««-v~™™,™.
jj™
0.06
0.05
b.bo
""^™™™™o^(5c
"""""""TToS
o.oc
0.00
•""""^":<^"Q'JX
0.0£
O.OC
™™™™™™Ct'54
i. ^^
b'.bb"
™™™*™*vgvgg
0.00
""""""""ITSS
p-Xylene
Mass |g
*™°™™™°™cTo5
0.01
o^55
b.Ob
b.b'b
d.bd
0.01
b'icxJ
0*^6"
,.m,,,,,,-.-r™™.v«-.^-.
™ o^5"
o.bi
°™*°™™™™o76"
0.08
O.OE
"-'-"-"'-"--Qffi
i 0.00
£LP2
0.00
rara
b.b*
0. 0
b.bti
"" b.o7
b.b5
'o'bl
rjrp
^^cTol
, ujjj
,r of Mass Ift.ftl
~HfiylBenzSfi*.x
. (g-flll
i^wm*w™r™™m™o
wvw™-™™.-*™*™**^
0
mi""""™nv'"^
— , — ^
0
0
0
•Mf~~M*MW*~~~~~~fi
6
0
.^.UM,,,™,,,™,,™™,-.-.-.- —
MA,/™™™™™---™^-
0
""""""""""""o
C
4
0
™™™™*MW*W™WW*T
C
r
32
E^!2a^
«™™-™-_^
0
0
-""""-"--'"-• -0J
-JJ_-_,™_mr-r§-
0
b
-/,/,,.1a™-™J™,-.v.-.-rrJ«r-.
mm~mMfmMf™~ft
1
c.c.^TrrrTrrT.nrrr.tt-r-^gi
™ 'i
8
*-«-™vv-™™™™^.
.„.„.....,..„„„.?.
0
b
u
_ £
Uv*W«uw«WUW*MMyUW«V
«- r
8C
Ethylb^zene-y
' (g-ft
C
C
{
<
----=— y^
™~™mw™w™™*™c
'" T;
— — .
!T?1
p-Xylene-'
(g-ft
ZZZZZ]
""" ., <
<
1 (
li
p — J
G-17
-------
Hill AFB Site, 1/94 Data (continued)
G-18
-------
Appendix H
Dissolved Oxygen Concentrations Measured in Ground-Water Monitoring Wells
and Sampling Points During the Study at the Hill AFB Site
Well Number
MW
MW
MW
MW
MW
MW
cpt
cpt
cpt
cpt
cpt
cpt
cpt
cpt
cpt
cpt
cpt
cpt
cpt
cpt
cpt
cpt
cpt
cpt
cpt
cpt
cpt
1
2
3
4
5
6
2
3
4
5
6
8
9
10
11
12
13
14
15
16
17
18
20
21
25
26
27
DO
(mg/L)
7/31/92
2.5
1.9
3.2
2.0
DO
(mg/L)
10/9/92
2.2
0.1
2.5
1.3
1.4
1.0
0.2
0.2
0.3
0.1
0.4
1.3
0.1
0.3
0.3
1.3
2.2
0.1
DO
(mg/L)
11/6/92
0.2
7.7
2.5
3.8
9.4
10.9
0.4
0.2
0.6
0.5
4.1
0.3
0.2
0.3
1.0
1.9
0.6
0.3
1.8
3.9
0.3
DO
(mg/L)
3/19/93
6.8
0.7
3.7
4.8
4.5
3.0
5.3
0.1
4.6
0.1
0.1
1.8
0.3
0.1
0.1
3.6
0.2
0.7
7.4
0.1
0.1
0.1
0.9
5.5
0.1
DO
(mg/L)
6/26/93
7.9
4.1
4.3
3.7
1.8
5.4
0.9
3.8
0.6
0.1
0.1
0.1
1.3
2.1
0.1
0.1
0.2
0.2
0.4
5.9
0.8
0.2
0.1
1.9
0.1
DO
(mg/L)
9/21/93
5.5
1.3
5.0
3.0
1.5
4.5
3.3
2.6
2.5
0.6
0.9
1.4
0.4
1.6
0.7
1.2
0.7
0.8
0.6
2.5
1.4
2.5
0.4
3.4
2.8
0.8
DO
(mg/L)
1/7/94
3.5
0.5
3.2
1.9
4.9
4.8
1.7
2.4
2.4
0.8
5.6
0.8
3.3
0.3
2.5
3.4 '
0.5
0.5
1.2
2.7
2.3
0.8
4.0
3.9
0.6
H-1
-------
Well Number
opt
opt
cpt
cpt
cpt
cpt
cpt
cpt
cpt
MLP
MLP
MLP
MLP
MLP
MLP
MLP
MLP
28
29
30
31
32
33
34
42
43
35-8.6'
35-9.7'
35-10.7'
36-8.5'
36-9.6'
36-10.4'
37-8.56'
37-9.65'
37-10.15'
37-10.65'
38-8.5'
38-9.6'
38-10.1'
39-8.58'
39-9.7'
39-10.2'
40-8.65'
40-9.75'
40-10.25'
41-9.0'
41-10.15'
41-10.65'
44-12.4'
44-12.9'
DO
(mg/L)
7/31/92
DO
(mg/L)
10/9/92
1.2
0.3
0.5
1.2
0.1
0.1
3.4
3.8
2.5
4.2
4.2
1.1
0.3
0.1
0.8
1.6
0.4
DO
(mg/L)
11/6/92
9.9
0.4
0.3
0.3
0.4
13.5
1.0
15.6
4.7
. 5.6
0.3
5.8
0.5
0.8
7.6
3.1
1.5
0.5
0.5
5.7
5.4
2.7
DO
(mg/L)
3/19/93
3.5
0.1
3.4
0.1
0.1
1.3
5.2
0.8
3.4
DO
(mg/L)
6/26/93
5.8
0.1
0.3
0.2
0.2
0.2
4.1
1.6
3.3
3.0
1.2
2.9
3.8
0.2
1.5
2.8
0.1
2.9
1.2
0.1
1.6
2.9
0.1
0.2
0.2
0.2
0.2
0.1
0.1
DO
(mg/L)
9/21/93
3.6
0.5
1.2
1.4
0.4
0.4
2.7
1.0
2.9
5.2
2.2
1.3
3.4
1.5
2.3
7.6
3.0
5.8
1.2
0.5
2.9
1.9
2.3
3.2
2.5
1.3
DO
(mg/L)
1/7/94
5.2
0.3
1.2
2.3
0.6
0.3
2.7
2.2
1.1
0.4
H-2
-------
Appendix I
Summarized BTEX, Naphthalene, and TPH Ground-Water
Concentration Data Used for Plume Centerline and
Mass Calculations for the Layton Site
7/92 Ground-Water Data
Well
Type
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
MLP
MLP
MLP
MW
MW
MW
Well
Number
1
2
3
4
5
6
7
8
9
10
12
13
14
15
16
17
18
20
21
4-9.5
4-9.0
6 -9.0
1
3
4
X-Coord
(ft)
-8.4
54.6
-47.5
-4.5
-36.3
108.7
-41.9
59.4
-51.3
63.4
64.7
108.7
19.0
14.3
26.2
9.1
-4.3
28.5
37.8
30.5
31:2
-59.9
103.0
0.0
-17.2
Y-Coord
(It).
-80.6
-122.4
-52.8
-42.8
-74.6
55.4
-2.2
13.7
24.9
58.1
35.9
11.5
-8.9
15.4
-35.4
33.8
-61.9
-58.4
-82.8
27.4
28.1
-3.2
35.7
0.0
-137.5
Benzene
(ng/U
0!
01
0!
22
0
0
651
0
0
756
3,969
3,490
650
5,947
29
0
5,656
0
0
0
0
137
861
0
Toluene
(ng/U
0
0
0
79
0
0
635
139
0
268
6,864
3,139
137
3,729
83
6
4,277
0
0
89
0
49
.82
0
Ethylbenzene
fcs/U
0
0
0
363
0
0
419
0
0
1,474
1,630
1 ,054
1 ,408
1,345
72
0
2,009
0
0
52
0
21
283
0
p-Xylene
(H9/L)
0
0
0
1,714
0
0
1,716
0
0
5,167
8,554
4,747
4,789
6,120
50
0
9,274
0
1 1
214
0
0
210
0
Naphthalene
(ye/Ll
0
0
0
3
0
0
105
0
0
13
13
225^
10
209
5
0
548
0
5
165
0
0
49
0
Total
(ng/U
0
0
0
7,840
4
3
5,993
7,661
796
313
28,269
5_43,478
23,351
24,504
30,322
3,537
17
41,899
135
3,785
15,472
52
397
3,354
4
1-1
-------
12/92 Ground-Water Data
Weil
Type
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
MtP
MLP
MW
MW
Well
Number
1
3
4
5
8
9
12
13
14
15
16
18
19
20
21
5-9.5
6-8.5
1
3
X-Coor
(ft)
-8.4
-47.5
-4.5
-36.3
59.4
-51.3
64.7
108.7
19.0
14.3
26.2
-4.3
52.0
28.5
37.8
-7.3
-59.9
103.0
0.0
Y-Coor
(ft)
-80.6
-52.8
-42.8
-74.6
13.7
24.9
35.9
11.5
-8.9
15.4
-35.4
-61.9
-40.6
-58.4
-82.8
-14.3
-4.2
35.7
0.0
Benzene
(ua/L)
0
45
2,693
0
6,032
12
1,473
2,428
7,381
413
7,127
4
2,808
5,500
0
3,664
83
532
524
Toluene
(|J-9'/L)
1
57
1,907
4
4,555
21
153
3,347
6,163
9
3,285
4
899
4,916
3
564
59
136
69
Ethylbenzene
(ug/y
0
31
1,030
• 0
2J370
6
557
373
1,130
441
2,123
5
737
1,044
0
420
38
449
24
p-Xylene
0
64
3,375
u_ 0
^_™JL8?JL
22
2,383
5,955
8,923
859
7,591
0
6,037
9,399
0
,_JL5Q3.
120
523
73
_NapJi1tia[ene
0
0
10
0
567
9
67
| _
36
42
139
0
288
655:
0
300:
8!
01
78i
Total
_iHl£JL.
2
392
15,923
33
78,090
148
15,341
34,394
41,841
8,532
... 36,698
136
32,583
52,403
13
21,799
618
3,313
2,111
3/93 Ground-Water Data
Well
Type
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
_QPJ_
CPT
MLP
MW
MW
MW
Well
Number
1
3
4
5
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
4-9.5
1
3
4
X-Coor
(ft)
-8.4
-47.5
-4.5
-36.3
-41.9
59.4
-51.3
63.4
-16.0
64.7
108.7
19.0
14.3
26.2
9.1
-4.3
52.0
28.5
37.8
30.5
103.0
0.0
-17.2
Y-Coor
(ft)
-80.6
-52.8
-42.8
-74.6
-2.2
13.7
24.9
58.1
16.5
35.9
11.5
-8.9
15.4
-35.4
33.8
-61.9
-40.6
-58.4
-82.8
27.4
35.7
0.0
-137.5
Benzene
(Hfl/L)
0
60
1,165
0
33
4,491
14
84
257
1,215
6,644
7,646
1,176
4,664
34
6
2,051
6.996
0
166
1,831
377
21
Toluene
(H9/L)
3
347
371
0
109
2,675
50
51
862
210
8,805
5,661
185
2,773
23
16
936
4,473
0
61
577
146
23
Ethylbenzene
(M-9/U .
0
77
432
0
59
1,727
18
38
1,778
77
2,599
7,334
1,158
1,517
39
0
777
1,946
0
406
83
0
•9
p-Xylene
lug/y
0
331
1,479
0
393
7,566
150
140
9,836
1,634
15,763
2,914
3,315
6,317
51
0
3,977
11,441
0
1,365
1,448
781
46
Naphthalene
^^iika/kL.^
0
1 1
37
0
42
545
13
9
795
52
' 497
49
81
' 55
0
0
280
1,544
0
230
34
31
29
Total
JliS/LL
16
__A£95
7,116
56
L_3J50
32,537
902
i ~™?22
37,614
10,5.15
156,219
37,438
19,256
30,300
783
81
23,230
99,832
0
15,212
8,017
5,732
347
1-2
-------
6/93 Ground-Water Data
...weJL
CRT
CPT
CPT
CPT
CPT
' CPT '
Well
Number
1
C3
4
5
7
8
J3PT ]_JL__
""cpfl io
CPT j 11 •
™££LJZ1JJ™™
CPTJ 13
CPT
CPT
CPT
CPT
CPT
CPT
CPT'
MLP
MLP
MLP
jMLP_
MLP
MW
KAW
MW
14
15 '•
17
. 18
19
20
21
4-9.5
5-9.0
X-Coor
(ft)
-8.4
-47.5
-4.5
-36.3
-41.9
Y-Coor
_Jf3I_.
-80.6
-52.8
-42.8
-74.6
-2.2
59.4J 13.7
-51.3
63.4
24.9
58.1
_JA2LjAJL
64. 7 j 35.9
1 08.71 11-5
19.6] -8.9
14.3J 15.4
9.1
-4.3
52.0
28.5
37.8
30.5
-7.3
5-8.5 } -7.2
6 -9.0
6-8.5
1
3
4
-59.9
-59.9
103.0
0.0
-17.2
Benzene
-Jm/LLj
2
12!
0
15
0
5,273
0
30
39
933
5,545
2,506
593
33.8J 87
™^6K9F___£
-40. 6 1 2,218
-58.4 j 5,201
-82.8 "j 7
zzizzizzznz
_™| __
-15.4
-3.2
-4.2
• 35.7
0.0
-137.5
2,049
7
Toluene \ Ethylberizene
(us/!) 1 (jig/L)
0
22
4
19
6
2,974
3
6
66
136
7,297
293
190
79
10
679
979
11
92
374
___3Jj3
15
111 31
1 ,7331 670
____2TT___34
6| 2
3
9
0
9
7
1,136
0
69
0
206
1,591
0
515
52
0
1,007
640
1
80
595
13
5
28
218
0
1
p-X^1enig_
3
19
57
73
3
8,315
2
20
2,060
1,202
10,325
52
1,815
38
3
4,672
4,343
14
752
3,249
3,002
92
78
916
1 1
0
Naphthalene
0
9
0
9
2
502
0
0
369
260
883
0
87
70
0
403
330
0
177
209
177
0
0
33
32
2
Total
JttS/LL
92
1,570
372
395
1,109
36,004
211
227
8,886
8,689
63,463
4,417
14,001
3,240
112
23,757
33,917
279
8,138
14,938
13,068
1,618
1,607
6,667
689
54
1-3
-------
9/93 Ground-Water Data
Well
Tfcee.
CPT
CRT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
MLP
MW
MW
MW
Well
Number
3
4
5
8
9
10
11
12
13
14
15
17
18
19
20
21
4-9.5
1
3
4
X-Coor
(ft}
-47.5
-4.5
-36.3
59.4
-51.3
63.4
-16.0
64.7
108.7
19.0
14.3
9.1
-4.3
52.0
28.5
37.8
30.5
103.0
0.0
-17.2
Y-Coor
(ft)
-52.8
-42.8
-74.6
13.7
24.9
58.1
16.5
35,9
11.5
-8.9
15.4
33.8
-61.9
-40.6
-58.4
-82.8
27.4
35.7
0.0
-137.5
Benzene
•(W3/U
3
655
0
1,860
0
34
3
717
2,429
4,782
41
3
0
2,007
3,221
1
22
192
87
0
Toluene
(ug/L)
9
225
0
1,023
0
18
31
261
2,444
1,838
51.
0
2
762
831
1
27
48
14
0
Ethylbenzene
' IvQ/l) .
5
0
0
30
0
1
0
202
0
0
3
2
0
358
267
0
30
0
0
0
p-Xylene
jug/LL
5
575
0
2,680
0
68
85
416
4,684
3,248
4
0
0
728
925
0
160
68
0
3
Naphthalene
(H^/LI
0
39
0
27
0
0
39
145
93
98
2
0
0
22
41
0
36
0
0
0
Total
(US/LI.
96
3,657
7
13,724
25
373
1,258
5,252
26,389
1 8,339
577
39
20
9,697
13,586
7
2,618
'553
245
17
1-4
-------
1/94 Ground-Water Data
Well
Type
CPT
CPT
CPT
Well
Number
1
3
4
CPT | 5 .
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
MW
MW
MW
8
9
10
1 1
12.
13
•14
15
17
18
19
20
21
1
3
4
X-Coor
(ft)
-8.4
-47.5
-4.5
-36.3
59.4
-51.3
63.4
-16.0
64.7
108.7
19.0
14.3
9.1
-4.3
52.0
28.5
37.8
, 103.0
0.0
-17.2
Y-Coor
(ft)
-80.6
-52.8
-42.8
-74.6
13.7
24.9
58.1
16.5
. 35.9
11.5
-8.9
15.4
33.8
-61.9
-40.6
-58.4
• -82.8
35.7
0.0
-137.5
Benzene
(ng/U. I
1 i
i
105
25
2,301
2
3
23
141
4,344
4,724
6
6
0
3,696
218
22
150
24
5
Toluene
Jtia/LL.
3
0
17
4
330
5
0
15
153
1,122
275
23
25
4
307
1,471
0
1
103
3
Ethylbenzene
(ng/L)
0
0
0
0
0
7
0
0
0
0
0
0
0
3
0
0
0
0
95
0
p-Xylene
Jys/LL
0
0
66
19
3,977
7
0
383
106
5,093
310
0
3
3
1,538
5,600
0
1
95
4
Naphthalene
•(H9/D
0
0
418
0
558
0
0
1 1
609
JL56,
17
0
0
0
19
1,081
0
0
0
0
Total
(H9/L)
8
3
1,992
91
18,409
122
13
2,306
3,877
30,691
10,032
85
84
126
15,727
36,006
33
222
1,416
61
2/95 Ground-Water Data
Well
Type
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
__j
CPT
CPT
CPT
CPT
CPT
MW
MW
MW
Well
Number
1
3
4
5
7
8
9
10
1 1
12
13
14
15
17
18
19
20
21
1
3
4
X-Coor
(ft)
-8.4
-47.5
-4.5
-36.3
-41.9
59.4
-51.3
63.4
-16.0
64.7
108.7
I 19.0
14.3
9.1
-4.3
52.0
28.5
37.8
103.0
0.0
-17.2
Y-Coor
(ff)
-80.6
-52.8
-42.8
-74.6
-2.2
13.7
24.9
58.1
16.5
35.9
11.5
-8.9
15.4
33.8
-61.9
• -40.6
-58.4
-82.8
35.7
0.0
-137.5
BenzeneJToluene
JASS/LLJ
0
o:
965
1
0
2,442
0
0
0
70
4,344
71
u__ 406
2
2
4,170
4,893
1
1,226
3
1
JH3/LL
0
4
12
1
8
922
1
1
125
37
3,207
4
148
98
2
655
2,647
1
592
19
1
Ethylbenzene
(ng/L)
0
1
48
1
0
915
0
0
7
1
232
2
541
3
7
1,221
1,915
0
95
1
2
p-Xylene
JjiS/LL
0
, 0
21
5
1
5,332
0
1
1
38
3,742
7
1,553
3
.8
5,085
6,332
2
876
2
6
Naphthalene) Total
(H9/L)
0
4
153
7
2
571
0
0
JM1
19
90
_JL§65_
65
118
53,981
1,751
37
6051 40,185
101
265
. o..
524
69
9
421
794
0
42
9
0
[4,091
50,681
5,025
34,265
64,067
464
68,268
86,090
29
11,617
1,721
53
1-5
-------
-------
Appendix J
BTEX, Naphthalene, and TPH Ground-Water Dissolved Plume Mass
and Mass Center Calculations for the Layton Site
7/92 Ground-Water Data
Location
Desianation
CPT
CPT
CPT
CPT
^
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
., CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
M'L'P
Ki'L'p
MLP
MLP
MLP
—_____,
,__
MLP
MLP
MW
MW
MW
Site
1
2
3
4
5
6
_ 7
8
9
10
11
12
13
14
15
16.
17
„,..„„
19
20
21
4-9.5
4-9.0
jLjyti
HUSO
5-9.0
5-7.5
6 -9.0
6-8.5
6-7.5
1
3
. 4
X Coor.
(ft)
-8.4
r 54.6
-47.5
-4:5
-36.3
1 — ioO
-41.9
59.4
_JUL
™J>Li]
-16.Xylene
Mass
(ai
0
» 0
0
167
6
0
0
276
0
0
: ~~g.
>™™~329
2,281
73| 329
™~™_JM~- 575
164
0
6
0
„ 271
0
0
15
0
0
0
0
0
0
0
2
33
• 0
1.372
747
0
Naphthalene
Mass
la)
0
0
0
0
0
0
0
k 17
0
0
0
1
3
.__ 1.6
. 1_
26
0
bi o
0]
1.253
0
0
63
0
0
0
0
6
6
0
0
24
0
6.093
0
74
0
0
48
0
0
0
0
6"
0
0
0
6
0
192
Total
Mass
(a)
0
0
0
764
1
0
0
1,231
248
35
0
2,074
1 1 ,592
_U621.
. 2,941
""""SlTO?
0
1
0
5.659
3*2
0
4,526
0
0
0
0
6
v,,,...,...o
0
29
L_2§Z
i
34,849
J-1
-------
7/92 Ground-Water Data (continued)
loco Mon
gwlpnolton
CPT
CPT
CPT
CPT
CPI
CPT
CPt
CPT
CPT
cpr
CPI
CM1"
— c?| —
• "cpr"
CM
— • m
CM
CPT
CPI
CPI
CPT
MLP
MLP
MIP
MLP
MLP
MLP
MIP
MLP
MIP
MW
MW
MW
Site
1
2
3
4
5
6
7
8
9
10
11
12
~-fS~
u
'IS
16
17
18
19
20
21
4-9.5
4-9,0
4-7.5
5-9.5
5-9.0
5-7.5
6 -9.0
& -8.5
6-7.5
1
3
4
Tola1i=
COM (iut)=
Benzene
Center of Mass
x
la-Ill
0
O
0
-10
0
0
0
4218
0
0
0
3.590
tl'5,627
4,6ll
i.n?
19.616
0
0
0
21,789
0
0
0
0
0
0
0
0
0
0
1,035
0
0
172,388
55
V
(a-ft)
0
0
0
-92
0
0
0
1,437
0
0
0
WOT
12,127
-2.148
U9'S
-25.6
-------
12/92 Ground-Water Data
""LocatiorTj
3esianatfonl Site
1
'X Coor.
(ft)
YCoor."
Area
(ft'] 8 (fi/\2)
CPT i- 1 i -8.41 -80.6 S 3,344
CPT
CPT
.^gr^
CPT
CPT
CPT
CPT
CPT
"""CPT
CPT
__JT1 54.6i -122.4]
3
4
7
8
9
10
1 1
12
13
14
CPT i .1.5....
CPT
" ' CPT
16
™rr~
-47.5
-4.5
-36.3
108.7
-41.9
59.4
-51.3
63.4
-i"6"."b"
64.7
108.7
19.0
14.3
-52.8| 1,671
-42".8! 945
""-74.6T"3,586"
5^4
-2.2
13.7
24.9
58.1
TO
35.9
11.5
-8.9
15,4.
126.21 -35.4
9".T "3"3.8
CPT i 18 f -4.3
CPT ! 19 f 52.0
"""CPT 121
MLP \ 4 - 9.5
MLP
. . . . u VilriiiAi m*
MLP
"TSiuLZ
MLP
MLP
MLP
MLP
MW
"""MW™"
4-9.0
"4" 7.5
5-9.5
,JL5;£L
6 -9.0
6" - 8".5
6-7.5
1
™^L?-
-40.6
1,719
i i
BevaftoYij Etevaffon;
TOC (ft) } BOC ('ft) i
97.4
97.2
97.9
97.1
98.9
96.9
99.6
3,4821 97.1
1 98.2
f "97.4
2.699} 99.6
2,538
956
849
672
3,227
28.5] -58.4 f 772
36.5
3a6"
-7.3
-7.3
L~v^ZJI
-"59.9
-59.8
103.0
-- f-j-^rff
27.4
28T
28.0
-14.3
-\'SA
I^jfL
-5,3.
35.7
0.0
i i
-f "" f
76T
99.7
6.71:
6.91:
7.32i
Wafer Col
Depth (ft)
2.28
3.28
3.11
^^65| "3.39
^jsiyj^QedJ
""^6J5l
', 8.861 2.35
7.331 2.38
7.58!
6.65;
8.24
9.30
98.5] 7".68"
98.1 1 7.12
9"8.5f
97. 7t 6.80
97.7| 7.00
99.5! 8.94
98.4
98.8
98.5
~ 9^5
98.4
97.7
97,8
| 96.7
1,7131 95.8
2,158
846
96.8
99.7
7.85
8.20
7.24
7.00
6.90
3.33
2.80
Volume.
(ftA3i
10.522
0
5,258
2,974
iT,"287
b"
0
5,410
10,957
0
b
8,492
7,987
2.451 3,009
"3.26! 9.075
| 2,671
^3.10F"^i3
4.39S 2,il"3
3.35] 16.155
2.ii) 2.428
3.03
7.21 f 0.55
7.1 5J 6.67
7.13
r srps"
2.34^
6.80
': 8.49
____-£ZJL___jLZfi,
96.2| 5.89
|
Max Depth =
1.21
19,679
0
0
0
2,394
0
0
0
5.39C
.,.„ 1 0
8.01 ! 6,792
9.39] 2,662
10.49J 0
T049
Totals =
Benzene 'Toluene
Mass 1
(a)
0
0
7
227
6
0
0
924
4
0
0
Mass
(a)
Ethylbenzene 3p-XyIene!Naphthalene
Mass j Mass ] Mass
(a) S fa) ! (a)
01 01 01 ' 0
0
9
161
0} Of 0
__, 5j
87
T: 0:
of o
of... 61
698
6
0
0
354J 37
549f 757
™™l2it™-52i
106] 2
539 f 248
b'j "b
of o
8071 258
378
P
0
ff
S,
6
0
b1
T3
0
102
39
338
1
440!
2
0
b
134
84:
96
113
1 61
'"&
lOf 0
ZZ5MZZZZZ
of o
b
0
1,516
7
0
0
573
1,347
760
221
574
o
0} 0
21 2| 1 (736
72"! 546
0,
0
87
cr
Total
Mass
1
0
58
1,341
11
o
1 1 ,960
46
0
o" o
1 6^ 3/689
™~^v™™™12i
3^
1 1
ii
b
b
83
45
ol ol o
P 0[ 0\ 0
6\ bi bl b
o] .P.C-,-w-,Qi -P-
38! .28
b) b"
0
b
9
0
26,
5
™~™J2L™~JD,
I
4,9265 3,T2"1
0
""""" b"
6"
0
86
2
0
"" 1",52"8"
373
0
0
0
"""18
0
100
6
_, P.
8,170
20,
b
0
7,778
3,564
2,192
•2,775
b
8
9,367
3,603
7
0
0
1.478
0
P
bj o
1 ^ 94
Pi o
0
6
0
296
637
159
0
48", 757
J-3
-------
12/92 Ground-Water Data (continued)
locollon
QoilflnaHon
CPT
CPT
CPT
CPT
CPT
cpr
CPI
CPI
CPT
CPT
CPT
CPI
CM
'CM
CM
CP«
CM
CPT
<;pr
CPT
CPI
MIP
MtP
MIP
MIP
MIP
MIP
MIP
MIP
MIP
MW
MW
MW
Si»«
i
2
3
4
5
6
7
8
9
10
11
~w~
13
14
1"S
16
17
18
19
20
21
4-9.5
4-9.0
•4-7.5
5-9.5
5-9.0
5-7.S
& -9.0
6-8.5
6-7,5
1
3
4
Totals »
COM HMD »
Benzene
Center of Mass
x
(o-ltl
0
0
-316
-1.013
0
0
0
54,905
-184
0
0
22.920
59.681
11,966
ra*
U.tU
6
-i
42,000
10.786
0
0
0
0
-1.802
0
0
0
-755
0
10,535
0
0
224,357
46
V
(fl-lt)
0
0
-351
-9,697
0
0
0
12.
y
0
4,308
1,284
0
0
6
6
-i48
0
0,
0
__JJZi
0
0
6
b
-__J3J027,
44
__X™_
(a-ft)
0
o
0
-35
0
0
0
1,193
67
0
0
579
117
-27
166
-372
6
0
-3,363
-2,630
0
0
0
0
-290
0
0
0
-i
0
0
0
0
-4,600
-16
Total. . ...
Center of Mass^^
X
(g-ft)
-5
0
-2,770
-5,990
-383
0
0
710,802
-2,353
0
0
"~2ss7ny
845,423
67,842
31,391
72,675
0
-35
487,351
102,763
274
0
0
0
-10,720,
0
0
0
-5,644
0
65,608
0
0
2,594,934
53
_JL_~_
(a-ftl
-48
.0
-3,081
-57,338
-787
0
0
1 64,327
'.i.4j?
0
0
rss'sss
~~8~9,l3'i
-31,604
33,676
-98,125
b
-503
-380,430
-210,433
-600
0
0
0
™j£L°Z5
0
0
0
-400
0
22,736
0
0
-7
J-4
-------
3/93 Ground-Water Data
Location"
Desianation
CPT
~™£EL™~<
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
•CPT
.Site
1
2
X Cbor."
(ft)
-8.4
54.6
3 \ . -47.5
TcSST
Iff)
-80.6
I
Area [Elevation
(ftA2) i toe Iff)
1,464
-122.4)
-52.8i 1,753
... 4 1 -4.5"? -42.8
"5"""| -36:3)""-74"."6"
ziz
^-ISSiZL™^!
-41.91 -2.2
8 { 59.4
9
10
11
13
14
,....1.5......
1 6
63.4
"-T676"
64.7
- 108.7
19.6
14.3
26.2
CPT 17 [ 971"
CPT" | J8 I -4.3
CPT
CPT
CPT
•~~mf~"-
MLP
MLP
MLP
MLP
1 9 i 52.0
20 [ 28.5
2l"
4-9.5
4 - 9.6
TT?f
5-9.0
5-7.5
"MLP : 6 -9.0
37.8
30.5
. 31.2
30.0
-7.3
-7.3
.-7.2
.-59.9
13.7
24.9
58.1
T6":5"
iT?
1,185
2,16"8
1,738
1,565
97.^
97.2
El'ev'afio'n
Water Col
B"6£ ("ft) j Depth Iff)
; 6.71 ! 5.20
;
6.91
97.91 7.32
9"7.ij 6.65'
98".9! plugged
96.9| 6.75
99.61 8.86,
2,724| 97.1
1,578J 98.2
l,108f "97.4
79"5 j 99.6
2,538
^8.9) 956
1 5.4 j 536
-35.4
"-risi
-58.4
-82.8
g^y
28.1
™~2§.0,
-14.3
-14.3
-™dM,
-3.2
^yLJlljL- 8-5_l_^59.9Xl^__-4".2
M^~^
MW ;
MW :
6- 7.5 f -59.8 1 -5.3
1 \ 103.6
«_2_mj O.Oi
4
-17.2!
35.7
0.0
-137.5!
849
2,009
672
3,296
815
--5,387
962
99.7
"98.5
98.1
98.6
7.33
7.58
5.03
4.82
Volume
^"fftAST*"
5,625
0
; 4£K
5.7'i)' 8V333
\ b
1.82
2.92
£§
6.65\
8.241 "4.55
9.30[ 3.91
7.68
7.12
9'7".7f 6.8"6
97".7f 7.00
99.5? 8.94
98.4
98.8
98.5
j 98.4
2,097
79,1,
97.7
97.8
™™™2L§
~~~~^~~
\ 7.85
8.20
7.24i
3.95
6,016
10,468
6,064
4;259
"3,656
9,754
3,674
2,061
\ 3,262
^^^^ZL^ZiJlI
6.14^ 2,58 1
™™™IiiSSf 12,668
3.60
4.78
7.0'oi
6.90 1 0.29
7.21? 1.39
7.15
7.13;
6.1 $':
oommx$2.|rm>o_2^4]
~ 96lif 6.80;
99.7J 8.49
97.S
^£56196.2
1 '
6.70'
5.89;
_ j
1.78
1.04
3,132
20,702
3,698
!.,»™™^J3
0
0
0
0
.,...,...,,,.,,i,,.,. ,,.,,,, s.
KOT| o
9.07
10.95
12.81
J Maximum Depth' - } 1 2.81
8,061
3,041
15,702
Totals =
Benzene
Mass
(g'i
a
o
Toluene ? Ethylbenzene
Mass i Mass
™73T1 1ST
L. 0? 0
0
1 1{ 66
150
o
48,
oi... b
6
765
4
14
3r
ios
1,835
795'
21
456
,...,....1.5
0
15
56,
0
6
11
294,
5
104
18
2,431
589
~-~~~^2i™~~JJ.
431") 256
7
0
736
0
17
0
0
0
0
5
336
o"
214"
718
p-Xylene
Mass
la)
Naphthalene
•Mass
(g)
0? 0
0
63
. i"9i
0
6
74
1,288
44
24
b'
2
5
o'
5
^[sJslL.
Mass
(a)
0
1,144
917
"8 1 596
93J 5.542
~™^~4j 267
2
i,T8"6") 96'
1 41 J 4
4,3531 137
7631 303
' 68 i 193
1 40j 583
6
279
173:
o;
6 i 42
Oi 0":
1 1
0
1,426
1,014
0
143
6"
5,
5
0
0
100
137
158
4,535
910
43,139
1.12;
2798
• 171
6
a852
24| 1,593
0
0 ? oi 0 1 0
0
0
ofc>i
6] 6i
Eo
0;
418;
32;
9;
— 63ss;
132;
o? 6? 6
o^ 6"
^^^"^^o| o
o;
0!
0;
19i
6;
"'"'"'"Yor™""" 4J
1' ;
0
o;
o;
330;
67
20;
0
0
6;
0
0
0
0
0
0
6
0
IZIII!ZIII§t~""~o
8 i 1 ,830
Si 493
13;
""'479231 2",822" n.4S7l 'iSBI
154
§6,469
J-5
-------
3/93 Ground-Water Data (continued)
«"••—"-—
JtSSSfel-
aetlottallon
u™£EL«.
_^£.PI
,....SP!™.
~MJXL~»
_S£L
.™.SPJL...,
i
— OT —
TUFT — "
— 2P, —
•~~m~~
""™Cpl —
'CPT
CPI *
CPI
~ Mi"p"
___MMLw.
n Mlf
IZSSEZL
~w^!iL~~
MIP
nj5u»!ZL
MIP
......Mill..™.
MW
~™HiL™.
MW
Site
1
«_JL~_
9
4
5
6
8
9
10™'
11
~~w~
. j^
•~TT~
Tr™
~Hry~
fiT"*
™J.ft™
19
_J2™.
2'
j]35L
4 - 9,0
J.~.,l~L
5-9,5
JL^&JL
JS.-.Z&,
AZI>$L
.AdyL
Jfc.Z&
_JL_
4
Tolpis *
CoM (1MI) =
Benzene
CenTer of Moss
X,
(0-ft)
0
0
-546
-67T
0
0
,~^™z2£d
45.44T
-214
l_^9iA
-496
OTS
"T9933T
— TS:T3?'
— ~-s>fg5
— ("17^
™ 61
-2
™_2§«2Z2
J7,(J94
0
528
0
0
0
0
6*
0
0
™_dM22
0
-15E
377^56
62
y
(q-ft)
0
0
-607
-6,422
0
0
-14
10,510
104
840
512
. .gyyg
— 2TS52
— ^.533
"' 1.6SS
"-VI5529-
, ggy
-2«
-29,874
-36,233
0
,™™™S§
0
0
^ 0
0
t °
1 0
0
0
~™Hs2!3_
™™™™ja.
-1.259
-43.256
-7
Toluene
Center of Mass
X
tq-ft)
0
-3,f42:
-214
L™™™™9,
0
-864
27,078
-752
557
-1.662
U76
564,2"97
— rnss?
™ TSS
"zm
4^
-5
17,465
~™JL_~
|q-ft)
-32
0
-3,495
-2,045
0
0
-46"
6,260
366
511
1,718
"ggf
27,S"64
-5,222
166
— 335?
— \n
-71
-13.633
11,3131 -53.166
0! 0
194
0
6
0
0
0
o"
0
6
13.561
0
-174
346,941
70
175
0
0
0
0
0
0
0
0
4,700
0
-1,388
-15.568
_2
Ethylbenzene
Center of fvipss
X ' •
(fl-ft) :
o:
0
-700
-249
0
0
-471
17,482
-278
414
-3.429
4"33
7§,0"13"
"™T4*^f
. pg~
S^9
n
0
14,498
4,922
~,
1,293
0
0
b
0
0
0
0
0
1,944
0
-71
™L23(93&
47
~™J!™~.
- (q-ft)
0
0
-779
-2,381
0
0
-25
4.042
135
379
3,543
' "'"'2T6'
3-355
-6,?<5s
"'"• rx53S
-4~,S>53
ggS
0
-11,317
-10,079
0
....,...!.,!«
0
o
6
0
0
0
0
0
674
0
-568
-17,142
-6
p-Xylene
Center of Wldss
x i
(q-ft) i
Oi
Oi
-2.997
-852
0
Oi
-3,116
76.527
^£2£L
1,524
-18,968
£"(39-
473, 154
"" S.770
'2',?$
f"5,277
foT
b
74.207
28,937
0
4,354
0
0
o
0
0
0
o
0
34,032
0
-35C
™™X™_
(q-ft)
0
0
-3,334
-8,153
0
c
-166
! 7,692
1,109
1,397
19,601
5,07.4
[""4^4
-2/688
2,97 1
-20,6"26
'"375
C
-57,926
^^9,255
3,922
0
C
C
C
C
0
0
(
1 1 ,79^
0
-2.80C
1
^69/^237,
61
-41,131
-'
Naphthalene. ____
Center
X
(q-ft)
0
0
-96
-21
0
0
-335
5,517
-201
99
-1,533
^§9
V479T8
96
68
134
b
0
5,225
3,905
0
_™™Z32
0
c
0
c
c
2.
c
c
79'
C
-21 £
.™2?J24
45
D1 Mqss
™™JC™~~
(fi-ftr
0
0
-107
-205
0
0
-18
™™li27S
9£
91
1,584
721
TJ5X3
-45
73
-"IS1!
0
0
m.,.r.4,p7S
-7,997
0
659
0
C
0
c
c
c
c
0
275
...P
-1,742
-8,583
Total '
™£SDteL
X
fq-ffl
-22
0
-54,286
-4,098
-481
0
-24)979
329,358
™J3^02
1 0,035
-72,536
5S.877
'4,'6'S'9",t83
74, 1 28
16,087
' 73,276"
1,550
-26
433/449
^252,495
0
™3l52?
0
0
0
0
0
0
Sf Mass
(q-ft)
-209
0
-60,381
™^n
0
-1,331
, 76,143
v™™^^
9, "198
74,957
"4"9"4,37"6
fT2SS
-98/936
5,785
-368
,~^33Ml2
j™^JZi2i^
0
.^.ZQS
0
0
0
0
0
0
0!~w~v~v2
b
188,424
0
-2,654
^29^03
69
i 65,296
0
-21.211
~^3§&55d
J-6
-------
6/93 Ground-Water Data
Benzene: TolueneiEthylbenzene ip
J-7
-------
6/93 Ground-Water Data (continued)
J-8
-------
9/93 Ground-Water Data
'X'Coor.'lY'Coor."! Area
j (ft) j (ft)
Elevation
Elevation:
BOCW
DepthW
(ftA3)
Benzene j Toluene
CPT
54.61 -122.4
-47.51-52;^
2,259
97.2!
6.91:
2.81
CPT
CPT
1,375
7.32!
"6.651
2.57J
_6,304
3,836
^
^ 5574
BIIi
-51.3
98.9|
JSJ_.
24.9
1,556
2.10J
4,341
229
3,466
97.11
7.33:
1.85J
9,671
126!
3291
0
0
17
397
3LL
™™
L458
795
lmmm:mm1~
Z65| 4^068
^AMMUU
9
10:
0:
46
145
330
CPT
n.5
"9977T
487
490!
939 i
19:
5,290
2;Q5
JZ5;
1,747
CPT
16
-35.4
98.6
s
CPT
CPT
"
33.8
"
-4.3
-61.9
...2.009 97,7
2.95
5,604
3,551
0:
0:
52.0
-40.6
-58.4
_v561J
252:
.30,5
.27.4
"™~~
~~~~-~~~~~
2,685
™~~~
0
199
.ML.P.
4.n9.Q.i
30.0
28.0
6.90
0.00
.ML.P
5-9.5
MLP
Z5T
5 - 7.5 :
6 -9.0
15.4
-3.2
971!
96.7
-59.9
J&S,
96.8
6.801
2
bl o
MW
MW
103.0:
35,7 j 2.097
99.7
0.0
5^52
321
-17.2:
4.34.5
96.2
Max Depth =
"9.30J Totals =
141i 1,986
6lTl3,792
J-9
-------
9/93 Ground-Water Data (continued)
JogaUon
3Xyjene:
Center of Mass
X
(n-ft)
j}
0
-45
-279
0
. 0
0
1 9,577
0
540
— rrjg
1,691
1 02,074
5,89'b
2~
0
0
'0
10,588
2,066
0
371
0
~rj
b
0
0
0
0
0
1,152
0
-20
143,450
72
_XL_
(g-ft)
0
0
__^5Q
-2,671
0
0
0
4,526
0
495
TiS2"
r p-Jjjg
FT6776T
l_-2,744
2
0
0
0
-8,265
-4,230
0
334
0
8
b
0
0
0
0
d
399
0
-160
-503
0
_J^SE£Hffi!§!2£L™
Center of Mass
X
(a-ft)
0
CL
Oj
*_™d£j
0
_J2]
„,
197
___U2J
0
~~ 7T
589
— 2^024
178
T
0
0
0
321
91
0
84
0
b
ff
0
0
0
b
0
0
0
0
3,397
55
—-JL^™
ffl-ftl .
0
0
0
-180
0
0
0
46
0
0
tmuz!
3'2*7
2T3
-83
"~~~ 5
| 0
0
»_— °
u_^5i
-187
0
76
0
g
0
0
0
0
0
b
0
0
0
36
1
..-Total •
Center of Mass
X
(q-ft) :.•••,
0
0
. -817
—iZZsl
-48
. 0
0
100,250
-351
2,947
-2,3l8
2T3*S6"
™SI2^
"~"™3"3"3S§
"—"gjiy
0
57
-8
141,031
30,340
115
6,063
0
ff
fl
OJ
0
0
0
0
™_j
0
-98
914,851
66
™__JL_
(q-ft)..
0
0
- -908
-16.987
-98
0
.0
23,176
171
2,702
2"393
"'" iTSIb
~60T6^§
-15,493
37S
0
211
-121
-110,090
-62,128
-252
5,461
0
b
b
0
0
0
0
0
3,270
0
-783
-96,632
-7
J-10
-------
1/94 Ground-Water Data
j
location' |
Sesiqridfioni Site
X Coor.
iff!
CRT I . 1 I -8.4
CRT
__ ,
CRT
CRT
CRT
CRT
CRT
CRT
CRT
CRT
CRT
CRT
CRT
CPT
' CRT
CRT
CRT
CRT
,CPT
MtP
MLR"
MLR
MLR
MLR
MLR
MLR
MLR
MLR
MW
MW
MW
2
3
4
g ,
6 •
7
8
9
10
11
12
13
14
IS
16
17
18
19
20
21
4-9.5
4-9.0
4-7.5
5-9.5
5-9.0
5-7.5
6 -9.0
6-8.5
6-7.5
1
3 •
4
54.6
-47.5
-4.5
-36.3
108.7
-41.9
59.4
-51.3
63.4
-16.0
YCoor.
Ift)
Area
(ftA2)
™_££Lii- i'491
-122.4
-52.8
-42.8
-74.6
55.4
-2.2
13.7
24.9
58.1
16.5
64.7! 35.9
108.7J TT75
1 9.6] -8.9
14.3
26.2
9.1
15.4
-35.4
g—.
-4.31 -6 '.9
52.0
28.5
37.8
30.5
31.2
30.0
-7.3
-7.3
-7.2
-59.9
-59.9
-59.8
103.0
0.0
-17.2
-40.6
-58.4
-82.8
27.4
28.1
28.0
-14.3
-14.3
-15.4
-3.2
-4.2
-5.3
35.7
0.0
-137.5
2,238
1,345
2,152
1,697
3,41 1*
1,622
1.452^
1 ,037
2,492
>__U95,
761
Elevation
TOC (ft)
97.4
97.2
97.9
97.1
98.9
96.9
99.6
97.1
98.2
97.4
99.6
99.7
98.5
98.1
98.6
g430| 97.7
_™lz£
3,540
1.024
>_Ji50£
2,043
L™2i!
4,086
97.7
99.5
98.4
98.8
98.5
98.5
98.4
97.7
97.8
97.8
96.7
96.8
96.8
99.7
97.5
96.2
Elevation
BOC Iff)
6.71
-
6.91
7.32
6.65
.,'?=:
Water Col
Depth (ft)
2.94
2.96
j__2.82
_.
,,,,F?|ugsadj
6.75
8.86
7.33
7.58
6.65
'8.24
9.30
s_ 7'68
7.12
-
6.80
: —^
8.94
7.85
8.20
7.24
7.00
6.9*6*
7.21
7.15
_™ZJli
6.18
2.34
6.80
8.49
_™JbZ2<
5.89
Max Deptfi =
0.24
r 2.23
1.25
3.03
3.00
• 3.26
2.35
2.25
1 _
!™__jyS
4.03
2.95
1.72
2.60
7.75
9.22
9.77
9.77
Volume,
(ft*3)
4.370
0
6,560
3,943
6,308
0
0
4,974
_2i22§
4,753
4.255
3,040
7,303
3,501
2.232
0
7,123
2,048
10,376
3,000
13,201
0
0
0
0
0
0
0
0
0
5,989
2,678
1 1 .976
Totals =
Benzene
Mass
la)
0
Toluene
Mas's*
(al
0
_™_Jt_— a,
of d
_ZI!S 2
4
0
0
324
0
0
3
-^
898
468
0
0
0
0
_L2§&
19
8
_™_2|
_ _j
6
0
0
o1
0
0
0
25
2
_____2
1
L™», °
0
46
^ '
0
, 2
13
232
27
1
0
0
! 6
^_ 90
zmn]
0
0
0
01
,. 0
0^
' o
0
[ZZS!
0
zmHj
L 8
1
2,86*41 551
Ethylbenzene
Mass
la)
_,,,_,,-,,,°,
0
0
0
0
0
0
0
„,„,._„,..„?
0
0
0
0
0
0
0
0
— ^~
0
0
0
0
0
0
0
0
0
0
0
0
0
7
0
9
p-Xylene
Mass
(a)
^ 0
0
r.,0
7
3
0
0
560
_-,2
0
46
9
1,053
. 31
0
0
0
0
452
476
0
5"
0
. 0
0
0
,™™™_2,
0
0
0
0
7
1
2,648
Naphthalene
Mass
fat
0
0
0.
47
0
b
___j
79
0
0
1
52
177
2
• 0
0
0
""""• " t5"
5
—is,
0
0
., s.
^™™™~™2,
6
0
^™-™™™™™Sj
™-yi
o1
0
—~—~~ff
0
_.,
455
Total
Mass
(a)
1
0
1
L^i
0
0
2,592
34
2
278
334
6,345
994
. 5
0
0
7
™4^20
3,059
12
0
0
0
0
0
0
0
0
0
38
107
21
18,68'9
J-11
-------
1/94 Ground-Water Data (continued)
™~"-™>~
location
SSjitanaftocv
>«J2L^H
. cpr 1
~~££L j
,....£.?.?„„.
£PF ,
§T ..
L
VCPT
^cpr
,^Jt£L~.
CRT
e"p"t
"""CT
— £pj~~~
•^^cpr""
eijy—
"""•CM -
,^PI
«_£E!™_
«~££JL™
Cpt
My
MIP
M^P
«_JsSAI!™«
MIP
„ MJ,p_
MIP
~_M!£™.
...^JStt?.™.
MW
MW
MW
™,
"sn^T"
^»L^i
z
3
4
s
6._
8
9
-J£«.
11
"""IT"'
rer™
14
xtr
-76™
•~~T7~~
18
19
20
„?>
.±i2£.
4-9.0
4-7.5
5-9.5
JL£0,
^i^Z-5
-------
2/95 Ground-Water Data
Location
Designation:
CRT
CRT
CRT
™jr£L_
C.P.T....
CRT
CRT
~™££L_™
CRT
CRT
CRT
CRT
CRT
' CRT
CRT
CRT
... CRT
CRT
CRT
CRT
MLR
MLR
1
2
3
4
5
7
8
10
1
13
14
is
16
1 7
9
20
21
4-9.5
4-9.0
.ArJJL
MLP i 5-9.0
MLR
MLP
jy\tp
MLP
MW
5-7.5
6 -9.0
..A^jyL
1
3
4
X Coor.
JW
-8.4
54.6
-47.5
-4.5
-36.3
-41.9
59.4_
63.4
-16.0
108.7
19.0
14.3
26.2
£-_.
-4.3,
52.0,
28.5
37 8
— Sas1
31.2
™~2££,
-7 3
-72
-59.9
-59.8
103.0
0.0
-17.2
' Coor.
lW
-80.6
-122.4
-52.8
-42.8
-74.6
2 2
_J3sI
58.1
16.5
11.5
-8 9
15.4
-35.4
33.8
-40.6
-58.4
-82.8
27.4
28.0
-14.3
-14.3
-15.4
-3.2
c ".
35.7
0.0
-137.5
Area
1,490
,767
272
, 52
,745
,737
,600
,108
2,492
_Ji207,
763
2,479
3.540
1,046
5,384
2,043
791
4.086
Eieva ion
97.4
97.2
97 9
97.1
Elevation;
6.71
-
6.91
7.32
6.65
96.9J 6.75
99.6
98.2
97.4
99 7
98.5
98.1
98.6
97.7
i-""-."""""-"-"!
99.5
98.8
98.5
98.4
97.6
97.£
96.7
96.S
99.7
97.5
96.;
8.86
7.58
6.65
9.30
7.68
7.12
-
6.80
8.94
8.20
"'"7.24
6.90
7.15
7.13
6. IS
6.80
8.49
6.70
5.89
Water Col
4.24
3.95
3.90
4.27
1.17
3.19
3.7C
- 3.8C
3.251
3.32
4.2;
3.9C
3.96
3.75
1.26
0.35
1.35
0.32
2.3;
0.2C
8.51
10.3C
1 .1
.~~-~.
Volume
4,967
0
5,889
4.24C
7, 73
_._
5.79
5,333
8.30*
4,02!
2,54;
C
8,261
1,799
17,94*
0
i c
c
(
(
6.81
2,637
13,61!
Mass
™«w~«
0
0
0
116
0
0
400
0
0
1,021
8
29
0
0
1,393
i
6
c
c
0
b
23^
c
c
Mass
rf
o|
0
1
1
6
~—ff
i
15
0
13
754
0
11
0
219
_.
0
o
0
0
o
0
"'""""&"
11*
1
c
Mass
™_™~.
0
0
0
6
0
o
""" 6
150
6
i
..55,
Mass
al
0
0
0
3
1
""°™"™""~cf
0
874
0
0
880
,..., .,.„.„ Q.; l.
39
0
1
_
o"
6
o
0
=
0
b
' '" b
b
18
0
1
~~~.
1 2
0
T699
" T
0
0
0
. _
0
• b
o
' b
169
™. 1
0
0
1
18
1
_™_— — ,
0
94
0
0
63
'""" ""-::"'~ ]'o
0
38
16
1
141
78
___ -_
g^
b
™~™^™™QL
b
0
b
0
0
8
OS 1.
2
^-gy-
0
~~™
Total
™~T5T"
3
0
15
584
13
19
8,850
6
4,202
11,915
572
2,467
™22,804
8 495
15
C
0
0
-
0
0
2,240
129
20
J-13
-------
2/95 Ground-Water Data (continued)
l9
37,89^
~0~
~~~SSS^\J
-1,878
-926,114
-496,206
-1,220
0
0
0
0
0
0
0
0
0
79,941
0
-2,810
-482,976
-6
J-14
-------
Appendix K
Dissolved Oxygen Concentrations Measured in Ground-Water
Monitoring Wells and Sampling Points During
the Study at the Layton Site
Well
JJ£E!L
CRT
CRT
CRT
CRT
CRT
CRT
CRT
CRT
CRT
CRT
CRT
CRT
CRT
CRT
CRT
CRT
CRT
CRT
CRT
CRT
CRT
MLR
MLR
MLR
MLR
MLR
MLR
MLR
MLR
MLR
MW
MW
MW
Well
Number
1
2 !
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
4-9.5
4-9.0
4- 7.5
5-9.5
5-9.0
5-7.5
6 -9.0
6-8.5
6- 7.5
1
3
4
GWDO
(mg/L)
4/92
0.9
0.8
1.2
GW DO
(mg/L)
3/93
0.9
0.8
0.8
0.91
7.5
0.6
0.6
0.9
0.7
1.7
0.8
2.1
0.6
0.6
0.6
1.6
0.8
0.8
5.4
0.6
0.6
0.7
, 1.3
1.6
0.6
0.8
0.7
0.7
| 7.5
GWDO
(mg/L)
6/93
0.2
0.2!
0.3
0.21
0.3
0.2i
0.2
0.2
0.3
0.3
0.2
0.2
0.2
0.3
0.3
0.2
0.2
0.3
0.3
0.3
0:3
0.2
0.3
0.2
0.2
1.0
2.5
1.4
1.3
GW DO
(mg/L)
9/93
0.2
0.5i
1.7!
0.6
0.5
• 0.6
0.4
0.8
1.0
0.3
0.3
0.5
61T
0.5
0.4
0.4
0.1
0.1
0.2
0.2
0.8
0.2
0.2
1.0
0.5
0.9
GW DO
Jtoa/LL
1/94
1.7
1.7
1.6
3.3
2.8
2.0
1.2
1.6
1.0
1.1
1.0
3.2
2.1
1.0
1.7
0.7
2.1
i
1.0
0.3
1.5
K-1
-------
-------
Appendix L
Laboratory Nitrate, Sulfate, Iron, and Manganese Data for Ground-
Water Samples Collected from the Hill and Layton Field Sites
Hill Site 4/92 Data
Sample
MW
MW
MW
MW
MW
MW
Trip
Equipment
ID
1
2
3
4
5
6
Blank
Blank
NO3
(mg/L)
0.7
7,1
2.4
6.3
7.5
5.4
0.0
0.0
S04
(mg/Lj
11.9
I_mm69,.5
ija.3.
69.7
61.4
64.8
0.0
0.0
Fe-
(mg/L)
Mn
(mg/L)
L-1
-------
Hill Site 7/92 Data
Sample ID
MW
MW
MW
MW
MW
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
MLP
MLP
MLP
MLP
MLP
MLP
Equipment
2
3
4
5
6
3
4
5
6
8
9
10
1 1
12
13
•14
15
16
17
18
20
21
25
26
27
28
29
30
35d
36s
37d
39s
40m
41m
Blank
N03
(mg/L)
5.5
0.4
5.6
7.5
5.6
8.4
8.0
0.0
0.0
0.4
2.4
3.9
2.5
0.3
4.5
0.5
1.2
2.9
2.8
0.7
3.3
0.8
7.3
7.8
0.3
6.6
0.8
3.5
5.5
4.6
1.9
2.1
0.4
0.4
SO4
(mg/L)
70.6
23.1
69.0
64.7
69.3
57.0
59.0
23.7
21.0
23.8
65.7
45.6
26.5
54.6
59.7
67:7
53.9
49.8j
56.9
70.8
60.4
44.1
136.0
115.8
65.0
107.8
121.5
41.4
57.4
28.5
92.4
55.0
" Fe
(mg/L)
0.12
0.13
0.14
0.14
0.14
0.08
Mn
(mg/L)
6.02
0.02
0.02
0.07
0.02
0.01
L-2
-------
Hill Site 2/93 Data
1
Sample ID
M-W
MW
MW
MW
MW
CRT
CRT
CRT
CRT
CRT
CRT
CRT
CRT
CRT
CRT
™~JZL™,
CRT
CRT
CRT
CRT .
CRT
CRT
CRT
CRT
CRT
CRT
CRT
CRT
CRT
CRT
MLR
MLR
MLR
MLP
MLR
MLP
MLP
MLP
MLP
2
3
4
o
6
4
5
6
8
9
10
11
NO3
,Jl™S/kL.
•
12 1 -
13 1
14
16
_T7J
18
20
™JOi~__™
25 i
26
27
28 \
29
_1Q_
31
._32.,i :
33
34
35s 1
35d
36s
36m
...3.MJ
37s
37m
37d
35s
MLP | 38d
MLP 39s
MLP 1 39m
MLP ( 39d
MLP
MLP
MLP
^JvUJL™,
MLP
CRT
_™Mk!L__<
MLP .
MLP
Eaufomenf
_40s_
40m
41s
41m
41d
42
44s
SO4
Jros/kL.
— : — ,
Fe | Mn
(mg/L) 1 (mg/L)
IIZIsIsllIZISsSs!
ZZIoSLlZoJl
6.02| 0.00
6.66] 6.6'i
6.03 1 6.66
6.67 \ 6.66
0.30) 0.48
6.30| 6.62
6.66
| 0.02
:
..........0..0.4.
0.00
0.10
0.03
0.01
0.03
0.00
1 "6.03
0.60
0.00
1 0.03
imm__^T__a.oo.
1 0.04
| b'.b'o
ZZZZJUlMl
0.03
0.03
0.01
i_jMi
~~| OJ03~
Lj^op,
1 ^06
[ 6.66
! o.oo
™™Z1™J °-02
j :I-
44m
44d
Blank
0,00
0.03
0.02
' 0.05
0.04
0.01
0.20
0.39
0,22
0.21
0.80
0.24
0.27
0.00
0.00
0.33
0.36
0.00
1™™mMi
0.00
6.73
0.01
0.68
0.00
0.03
6.03
0.37
0.00
0.00
0.01
0.01
0.01
0.30
0.00
,^^o&2
. 0.02
o.bi
0.54
0.00
6,i2l 6..61
6.1 6j 6.61
0.91
™™™M9,
0.00
mvmm0.02.
0.40
0.03
0.00
\ 0.00
I 0.02
1 6.66
0.70
1.03
0.02
0.13
1.40
0.16
0.04
0.03
0.05
0.00
L-3
-------
Hill Site 6/93 Data
1
Sample ID
MW
MW
MW
MW
MW
CPT
CPT
CPT
.CPT
CPT
CRT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
a>f
CPT
CPT
CPT
CPT
CPT
CPT
™™£EL™_
CPT
CPT
MLP ;
MLP
MLP
MLP
MLP
MLP
MLP i
MLP
MLP :
MLP
MLP
.MLP i
MLP i
MLP
MLP
MLP
MLP
MLP :
MLP
CPT :
CPT
Trio
2
3
4
5
6
2
3
4 '
5
6
8
9
10
1 1
12
13
14
15
16
17
" 18
20
21
24
25
26
27
28
29
30
31
32
33
34
35s
35m
35d
36s
36m
36d
37s
37m
37d
38s
38m
38d
39s
39m
39d
40s
40m
40d
41s
41m
41d
42
43
Blank
NO3
(mg/L)
•7.6
4.1
8.6
•9.3
5.C
16.0
21iO
1 1 .0
9.9
1.5
0.0
7.7
15.3
11,9
0.0
4.2
6.5
2.2
11.3
>34.6
21.1
4.5
1.8
7.7
11.7
0.0
32.6
0.9
5.0
SO'4
Mmg/L)
.•••-53.2
• 1 7.2
66.7
•63,£
75.3
.64.4
50.0
54.4
25.1
11.7
13.6
40.6
27.4
29.6
48.4
72.2
20.0
59.5
36.1
52.9
37.2
62.0
59.7
65.3
57.0
27.9
45.9
52.2
62.6
»™™JMI 53.4
5.0
, 5.3
13.0
3,2
10.8
2.9
19.7
13.2:
19.7
18.9
16.4
4.2
15.8i
8.0
2.1
24.5
18.5
2.0
0.0;
0.0:
12.6i
0.0
O.Oi
0.0!
6.0
8.3:
0.0:
70.4
63.7
S2".8
10.6
29.2
43.6
31.5
17.9
31.5
29.1
68.9
50.2
51.8
34.1
26.3
47.7
40.7
36.1
65.3
44.0
67.5
41.0
66.5
64.2
71.3
58.8
0.0
Fe |. M,n
(mg/L)*
i -.'0,00
: 6.0§
-"0.00
i 6.06
0.02
U—Mfi
0.24
O.'Ol
: 0.00
0.00
: 0.00
0.78
0.00
I 0.19
! 6.66
: 0.00
0.01
0.35
i 0.01
JJSSM~
'• •'•; 0.00
0.09
-~~™j5Jjj
O.OD
0.00
0.01
0.00
0.60
0:24
0.00
0.18
0.03
0.03
0.55
0.39
0.29
0.48
.Q,Ql
0.01
! O.OO'P 0.02
0.97
6.03
6.02
0:00
, ~~~~,
6.60
0.12
0.00
,__jxoo.
0.00
0.00
0.27:
0.03
0.00
0.00
0.01,:
0.20
0.08
6.65]
0.00
0.00
0.00
0.00
O.OOi
0.00
0.00
0.28
0.77
0.4
0.39
.0.00
0.00
6.5i
0.09
0.74
0.00
0.98
0.25
0.01
0.00
0.01
0.08
0.26
0.05
0.10
0.01
0.00
0.16
0.00
0.01
0.11
0.00
0.00
0.62
1
0.08
0.00
0.07
0.00
0.01
0.14
0.88
0.96
0.00
0.00
b.bb'i bob
L-4
-------
Hill Site 9/93 Data
[
Sample
_J\/[W_i
MW i
MW
MW
MW
MW
CRT
CPT i
CRT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
MLP
CPT
CPT
\
ID
1
2
3
4
5
6
2
3
4
5
6
1 1
12
14
16
18
20
...2.1
25
26
27
28
29
30
31
33
34
35d
42
43
NQ3
(mg/L)
!i
SO4
(mg/L)
|
i
, Fe j
(mg/L)
O.OOi
0..64!
0.00:
0.00
0.00!
O.OOi
0.00
0.00
0.19
0.06
0.02
0.03
[_™JL02.
0.04
0.00
0.00
0.04
0.01
0.00
0.04
0.00
i 0.08
0.10
0.02
0.54
. 0.04
j 0.00
0.00
0.01
Mn
(mg/LL
0.00
0.42
0.00
0.00
0.01
0.00
0.00
0.00
0.53
0.71
0.18
0.53
0.93
0.05
0.32
0.03
0.45
0.01
0.02
1.17
0.00
0.55
0.05
0.01
0.38
0.00
r_a.36
L_OJ!
1 7JDO
L-5
-------
Hill Site 1/94 Data
™™_S9G!£>!§
MW
MW
MW
MW
CPT
CRT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
Equipment
> ID
2
3
4
5
2
3
5
6
8
,JL~.
10
1 1
12
13
14
15
16
18
20
•21 ;
,25 i
26 i
28 I
29 |
30 |
31 i
33 I
34 i
43 j
Blank !
IMQ3
(mg/L)
5.8
0.8
7.9
9.2
8.8
9.6
0.6
8.5
3.8
3.1
7.1
4.7
0.3
6.2
0.8
1.7
4.1
0.4
7.4
2.3
8.4
11.1
0.5
1.9
8.7
>25.76
0.2
10.4!
8.3
O.Oi
SO4
(mg/L)
71.4
39.0
76.9
73.7
76.5
73.2
9.0
63.1
45.6
47.6
57.4
40.7
65.8
72.4
26.2
64.4
59.0
65.2
69.1
71.1
75.7
67.7
5.5;
75.1
78.4i
73.8i
73.1
62.6
74.5
0.0
Fe
(mg/L)
0.18
6.46
0.00
Q.06
0.27
0.04
2.28
0.15
0.22
0.29
0.03
0.18
0.45
0.06
0.04
6.03
0.03
1.61
0.03
™™™jLSi
0.02
__0.04j
1.01
0.09
0.03
0.09
0.06
0.20
0.04
0.05
, Mn
Jms/kL
0.00
0.38
0.00
0.00
0.02
0.02
0.45
0.00
0.58
0.54
0.67
0.07
0.43
1 oTos
0.45
0.17
u™™™£L22
6.45
0.02
0.29
0.00
0.00
0.60
0.60
0.00
0.09
0.33
. 0.00
0.00
0.00
L-6
-------
Layton Site 4/92 Data
Sample ID
MW
MW
MW
Trip
Equipment
1
3
4
Blank
Blank
NO.3
(mg/L)
1.2
0.4
9.9
0.0
0.0
SO4
(mg/L)
41.7
0.0
57.0
0.0
0.0
Fe
(mg/L)
Mn
(mg/L)
Layton Site 7/92 Data
i
Sample ID
MW
MW
MW
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
Eauipment
1
3
4
}
2
3
4
6
7
9
10
1 1
12
15
16
17
19
20
Blank
NO3
(mg/L)
1.2
0.4
9.9
1.1
>21.1
0.0
0.0
0.4
0.3
0.0
0.0
0.0
0.3
0.3
0.3
0.0
0.3
0.3
0.0
SO4
(mg/LJ
41.7
0.0
57.0
45.5
148.5
0.0
0.0
83.4
0.0
0.0
46.8
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
Fe
(mg/L) j
2.76!
2.72
0.15!
'
Mn
Jmg/L)
0.98
0.76
0.13
L-7
-------
Layton Site 3/93 Data
i
Sample ID
M.W
MW
M.W
CRT
CRT
GPT
CPT
CPT
CPT
GPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
MLP
Trip
Equipment
] :
3
4
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18 '
19
20
21
4-9.5
Blank
Blank
NO3
(mg/t)
Ll
0.8
0.5
2.1
6.4
1.0
>9.0
2.8
0.5
0.3
0.6
7.7
Q.O
0.5
0.6
0.4
0.6
1.4
0.6
0.9
0.9
3.5
>16.2
0.7
6.8
0.6
SO4
(™9/L)
4.6
7.3
8.7
,.21.8
16.8
3.4
41.7
>117
'4.8
3.9
4.8
>118
3.4
4.3
2.6
3.6
3.4
5.8
32.3
5.0
6.6
16.5
>91.2
15.4
22.8
2.6
Fe
(mg/L)
5.27
1 .69
0,00
0.00
0.00
0.00
0.00
0.00
0.29
1.06
0.00
0.13
0.17
3.73
0.66
0.00
0.19
0.00
0.81
0.38
0.00
0.82
0.00
0.00
0.00
Mn
(mg/L)
1.01
0.28.
0.00
0.11
0.36
0.11
0.00
0.57
0.10
0.37
0.35
0.61
0.06
0.30
0.28
0.48
0.04
0.23
0.19
0.37
0.13
0.07
0.00
0.00
0.00
L-8
-------
Layton Site 6/93 Data
1
Sample ID
MW
MW
MW
CRT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
. CPT
CPT
CPT
1
3
4
1
3
4
5
8
9
10
1 1
12
13
14
15
16
17
18
19
20
21
NO3
(mg/L)
0.6
0.0
0.0
2.5
Ul
•1.4
3.5
1.1
-
1.1
-
0.6
0.5
2.5
4.6
0.7
-
0.5
-
0.5
>16.9
SO4
(mg/L)
,9.8
4.3
. 4.6
9.1
21.6
4.6
29.1
3.2
2.3
>103
2.5
-
2.4
8.9
16.1
4.1
34.0
3.3
4.1
-
>89.2
Fe
(mg/L) j
0.03
1.46!
0.07
0.27
0.01
0.83
0.00
0.18
0.00
0.37
0.00
0.11
0.42
1.46
1.23
0.00
0.15
1.46
Mn
(mg/L)
0.09
0.63
0.04
0.35
0.46
0.23
0.35
0.64
0.07
0.35
0.27
'0.52
0.19
0.22
0.50
0.02
0.21
Layton Site 9/93 Data
I
Sample ID
MW
MW
MW
CPT
CPT
CPT
CPT-
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
MLP
1
3
4
3
4
5
8
9
10
13
14
15
17
18
19
21
4-9.5
NO3
(mg/L)
SO4
(mg/L)
Fe
(mg/L) ;
1.04
2.46
0.56
0.02
0.23
0.06
2.25
0.03
0.14
0.97
0.04
0.04
0.00
0.06
0.00
0.00
Mn
.JmS/LL.
1.61
0.58
1.88
0.48
0.10
0.41
0.32
0.29
0.72
0.34
0.13
0.18
. 0.09
0.26
0.07
0.05
0.26'i 0.09
L-9
-------
Layton Site 1/94 Data
Sample ID
MW
MW
M-W
CPT
CRT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
CPT
Equipment
1
3
4
1
3
4
5
8
9
10
12
13
14
15
16
17
18
19
20
21
Blank
NO3
(mg/L)
0.7
<0.50
2.8
O.50
0.0
<,5
0.3
0.0
<0.50
0.0
0.2
0.2
0.4
O.50
2.1
0.2
0.4
0.5
<0.50
11.7
0.50
SO4
(mg/L)
37.9
,5.7
62.9
17.3
5.3
<5
30.4
0.0
<5.0
135.3
<5
<5
2.3
<5.0
32.2
6.8
2.3
0.0
<5.0
65.1
<5.0
,Fe
(mg/L)
0.98
• 2.19
0.15
0.68
0.52
8.46
0.00
2.09
0.22
0.07
3.99
6.50
1.75
2.00
0.16
0.55
0.28
0.24
5.03
0.22
0.00
Mn
(mg7L) :
1 .45
0.45
1.35
0.38'
0.48
0.11
0.14
0.27
0.34
0.60
0.23
0.22
0.43
0.08
0.16
0.13
0.37
0.12
0.15
0.03
0.00
L-10
&U.S. GOVERMENT PRINTING OFFICE: 1998 -650-001/80219
------- |