sxEPA
United States
Environment a I Protection
Agency
Risk Reduction Engmeenng
Laboratory
Cincinnati OH 45268
EPA 5405-89003a
April 1989
Superf LI nd
Technology Evaluation
Report:
SITE Program
Demonstration Test
Terra Vac In Situ Vacuum
Extraction System
Groveland, Massachusetts
Volume
SUPERFUND INNOVATIVE
TECHNOLOGY EVALUATION
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EPA/540/5-89/003a
April 1989
Technology Evaluation Report:
SITE Program Demonstration Test
Terra Vac In Situ Vacuum Extraction System
Groveland, Massachusetts
Volume I
Risk Reduction Engineering Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, OH 45268
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NOTICE
The information in this document has been funded by the U.S. Environmental
Protection Agency under Contract No. 68-03-3255 and the Superfund Innovative
Technology Evaluation (SITE) Program. It has been subjected to the Agency's
peer review, and it has been approved for publication as an EPA document.
Mention of trade names or commercial products does not constitute an
endorsement or recommendation for use.
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FOREWORD
The Superfund Innovative Technology Evaluation (SITE) program was author-
ized in the 1986 Superfund amendments. The program is a joint effort between
EPA's Office of Research and Development and the Office of Solid Waste and
Emergency Response. The purpose of the program is to assist the development
of hazardous waste treatment technologies necessary to implement new cleanup
standards which require greater reliance on permanent remedies. This is
accomplished through technology demonstrations which are designed to provide
engineering and cost data on selected technologies.
This project was a demonstration of Terra Vac Inc.'s in situ vacuum
extraction process on the property of an operating machine shop. The property
is part of the Groveland Wells Superfund Site in Groveland, Massachusetts.
Information on the performance and cost of the process was obtained as the
result of extensive field observations, data collection, and sampling and
analytical work. This information may be employed in assessments at other
sites. The documentation of the demonstration will consist of two reports.
This Technology Evaluation Report describes the field activities and labor-
atory results. An Applications Analysis Report will follow and provide an
interpretation of the data and conclusions on the applicability of the
technology.
Additional copies of this report may be obtained at no charge from EPA's
Center for Environmental Research Information, 26 West Martin Luther King
Drive, Cincinnati, Ohio, 45268, using the EPA document number found on the
report's front cover. Once this supply is exhausted, copies can be purchased
from the National Technical Information Service, Ravensworth Building,
Springfield, VA, 22161, (702) 487-4600. Reference copies will be available
at EPA libraries in their Hazardous Waste Collection. You can also call the
SITE Clearinghouse hotline at 1-800-424-9346 or 382-3000 in Washington, DC to
inquire about the availability of other reports.
Margaret M. Kelly, Acting Director Alfred W. Lindsay, Acting Director
Office of Program Management Office of Environmental Engineering
and Technology and Technology Demonstration
m
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ABSTRACT
An evaluation was made of the performance of Terra Vac Inc.'s vacuum
extraction system during a 56-day demonstration test run at Valley Manufac-
tured Product Company's site in Groveland, Massachusetts. This site is part
of the Groveland Wells Superfund site, a source of drinking water for the
town of Groveland, and is contaminated mainly by trichloroethylene.
The report includes a detailed discussion of the operations of the vacuum
extraction unit, a process description and diagram of the system, and a sum-
mary of the sampling and analytical protocols. The final sampling and analy-
tical report prepared by the sampling and analytical contractor, including
the quality assurance project plan, is an integral part of this document. An
overall cost evaluation of the process is included and conclusions are drawn
regarding the efficiency of the process and its applications to other
Superfund sites across the country.
Results of the demonstration test are promising, and it is felt that a
site remediation can be accomplished using this technology. Both shallow
soil gas and soil VOC concentrations were reduced substantially and wellhead
VOC gas concentrations showed a decline with time, which was correlatable.
The process worked well in soils of both high and low permeability.
The system operation was very reliable during the 56-day demonstration
test run, and the only operation attention required was to replace the spent
activated carbon canisters with fresh canisters.
IV
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VOLUME I - CONTENTS*
Foreword i i i
Abstract iv
Figures vi
Tables viii
Abbreviations and Symbols ix
Conversions xi
Acknowledgements xii
1. Introduction 1
2. Executive Summary 3
3. Process Description 6
3.1 Introduction 6
3.2 Site Characteristics 6
3.3 Theory of VOC Extraction from Soil 11
4. Field Operations Documentation 16
4.1 Operational History 16
4.2 Operating Conditions Summary 18
5. Sampling and Analysis Program 26
5.1 Sampling Procedures 34
5.2 Analytical Procedures 37
6. Performance Data and Evaluation 43
6.1 Introduction 43
6.2 VOC Removal from the Vadose Zone 43
6.3 Effectiveness of the Technology in Various Soil Types . 69
6.4 Correlation of Declining VOC Recovery Rates 69
6.5 Prediction of Time Required for Site Remediation ... 71
7. Economics 91
7.1 Introduction 91
7.2 Cost Elements 92
7.3 Overall Cost Evaluation 95
Bibliography 97
* Volume II contains the Sampling and Analytical Report including a
Quality Assurance section and eight appendices, with tables
of soil boring analyses, soil gas analyses, wellhead gas analyses,
physical properties of soil strata, and analytical SOPs.
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FIGURES
Number Page
3.1 Schematic diagram of equipment layout 8
3.2 Schematic diagram of an extraction well 9
3.3 Soil formations 10
3.4 Soil contamination contours (ppm) 12
5.1 Soil boring locations 27
5.2 Soil gas sampling locations 28
5.3 Sample locations 29
6.1 Pretreatment shallow soil gas concentration 65
6.2 Midtreatment shallow soil gas concentration 66
6.3 Posttreatment shallow soil gas concentration 67
6.4 Wellhead TCE concentration vs time: EW1S 73
6.5 Wellhead TCE concentration vs time: EW1D 74
6.6 Wellhead TCE concentration vs time: EW2S 75
6.7 Wellhead TCE concentration vs time: EW2D 76
6.8 Wellhead TCE concentration vs time: EW3S 77
6.9 Wellhead TCE concentration vs time: EW3D 78
6.10 Wellhead TCE concentration vs time: EW4S 79
6.11 Wellhead TCE concentration vs time: EW4D 80
6.12 Wellhead TCE concentration vs time: MW1S 81
6.13 Wellhead TCE concentration vs time: MW1D 82
6.14 Wellhead TCE concentration vs time: MW2S 83
6.15 Wellhead TCE concentration vs time: MW2D 84
VI
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FIGURES (cont.)
Number Page
6.16 Wellhead TCE concentration vs time: MW3S 85
6.17 Wellhead TCE concentration vs time: MW3D 86
6.18 Wellhead TCE concentration vs time: MW4S 87
6.19 Wellhead TCE concentration vs time: MW4D 88
vn
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TABLES
Number Page
3.1 Equipment List 7
4.1 Chronological Operational History 17
4.2 Terra Vac Unit Operating Conditions 19
5.1 Pretreatment Sample Type, Location, and Frequency 30
5.2 Active Treatment Sampling Schedule 31
5.3 Posttreatment Sample Type, Location, and Frequency 32
5.4 Analytical Methods 33
5.5 TCLP Regulatory Levels 40
6.1 Flow Rates and Flux Rates, EW1S 44
6.2 Flow Rates and Flux Rates, EW1D 48
6.3 Flow Rates and Flux Rates, EW2S 52
6.4 Flow Rates and Flux Rates, EW2D 54
6.5 Flow Rates and Flux Rates, EW3S 56
6.6 Flow Rates and Flux Rates, EW3D 58
6.7 Flow Rates and Flux Rates, EW4S 60
6.8 Flow Rates and Flux Rates, EW4D 62
6.9 Reduction of Weighted Average TCE Levels in Soil 68
6.10 Extraction Well 4 TCE Reduction in Soil Strata 70
6.11 Monitoring Well 3 TCE Reduction in Soil Strata 70
6.12 Comparison of Wellhead Gas VOC Concentration and Soil
VOC Concentration 72
7.1 Overall Cost Element Breakdown 93
7.2 Economic Model for Terra Vac 96
viii
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ABBREVIATIONS AND SYMBOLS
API American Petroleum Institute
ASTM American Society for Testing and Materials
CERCLA Comprehensive Environmental Response, Compensation, and Liability
Act
cm/sec centimeters per second
cu ft cubic feet
cu yd cubic yard
DCE trans 1,2-dichloroethylene
ECD electron capture detector
EPA Environmental Protection Agency
EW extraction well
FID Flame ionization detector
GC/MS Gas Chromatograph/Mass Spectrometer
g/ml grams per milliliter
gmol gram mole
GPM gallons per minute
in Hg inches of mercury
KPa kilopascal
Kw kilowatt
m/sec meters per second
MeCl methylene chloride
mg/kg milligrams per kilogram
mg/1 milligrams per liter
MW monitoring well
NPDES National Pollutant Discharge Elimination System
NPL National Priorities List
ix
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ABBREVIATIONS AND SYMBOLS (cont.)
OLM Organic Leachate Model
ORD Office of Research and Development
OSHA Occupational Safety and Health Act
OSWER Office of Solid Waste and Emergency Response
PAHs Polycyclic Aromatic Hydrocarbons
ppb parts per billion
ppm parts per million
ppmv parts per million by volume
ppmw parts per million by weight
psi pounds per square inch
RCRA Resource Conservation and Recovery Act
RI/FS Remedial Investigation/Feasibility Study
ROD Record of Decision
RREL Risk Reduction Engineering Laboratory
SARA Superfund Amendments and Reauthorization Act of 1986
SCFM standard cubic feet per minute
SITE Superfund Innovative Technology Evaluation Program
TCE trichloroethylene
TCLP Toxicity Characteristic Leaching Procedure
TOC Total Organic Carbon
TRI 1,1,1-trichloroethane
u micron
ug/1 micrograms per liter
VOC Volatile Organic Compound
VHS Vertical and Horizontal Spread Model
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CONVERSIONS
English (US) Metric (SI)
Area: 1 ft2 9.2903 x 10"3 m2
1 in 2 6.4516 cm2
Flow Rate: 1 gal/min 6.3090 x 10"5 m3/s
1 gal/min 6.3090 x 10'2 L/s
1 Mgal/d 43.8126 L/s
1 Mgal/d 3.7854 x 103 m3/d
1 Mgal/d 4.3813 x 10'2 m3/s
Length: 1 ft 0.3048 m
1 in 2.54 cm
1 yd 0.9144 m
Mass: 1 Ib 4.5359 x 10~2 g
1 Ib 0.4536 kg
Volume: 1 ft3 28.3168 L
1 ft3 2.8317 x 10'2 m3
1 gal 3.7854 L
1 gal 3.7854 x 10"3 m3
O O
ft = foot, ft£ = square foot, ft0 = cubic foot
in = inch, in2 = square inch
yd = yard
Ib = pound
gal = gallon
gal/min = gallons per minute
Mgal/d = million gallons per dav
m = meter, m2 = square meter, trr = cubic meter
cm = centimeter, cm2 = square centimeter
L = liter
g = gram
kg = kilogram
trr/s = cubic meters per second
L/s = liters/sec
nr/d = cubic meters per day
XI
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ACKNOWLEDGMENTS
This report was prepared under the direction and coordination of Mary
Stinson, EPA SITE Program Manager in the Risk Reduction Engineering Laboratory
- Cincinnati, Ohio. Contributors and reviewers for this report were Mr. James
Ciriello of EPA Region I - Remedial Project Manager for the Groveland
Superfund site; John Kingscott from the Office of Solid Waste and Emergency
Response; Greg Ondich from the Office of Research and Development; James Malot
and Neil James from Terra Vac Corporation; and Patrick Ford and James Thomas
from Alliance Technologies, Inc.
This report was prepared for EPA's Superfund Innovative Technology
Evaluation (SITE) Program by Peter A. Michaels of Foster Wheeler Enviresponse,
Inc. for the U.S. Environmental Protection Agency under Contract No.
68-03-3255.
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SECTION 1
INTRODUCTION
Environmental regulations enacted in 1984 (and recent amendments to the
Superfund program) discourage the continued use of landfill ing of wastes in
favor of remedial methods that will treat or destroy the wastes. The Superfund
program now requires that, to the maximum extent practicable, cleanups at Super-
fund sites must employ permanent solutions to the waste problem.
The Superfund Innovative Technology Evaluation (SITE) program is one major
response to the challenge of finding safe ways to deal with waste sites. Part
of the program includes carefully planned demonstration projects at certain
Superfund sites to test new waste treatment technologies. These new
alternative technologies are ones which will destroy, stabilize, or treat
hazardous wastes by changing their chemical, biological, or physical
characteristics.
Under the SITE program, which is sponsored jointly by the Office of
Research and Development (ORD) and the Office of Solid Waste and Emergency
Response (OSWER), the USEPA selects 10 or 12 Superfund sites each year at which
pilot studies of promising technologies can be conducted. Sites are chosen to
match the effectiveness and applicability of a particular technology with
specific waste types and local conditions. The pilot studies are carefully
monitored by the USEPA. Monitoring and data collection determines how
effectively the technology treats the waste, how cost-effectively the
technology compares with more traditional approaches, and that the operation
can be conducted within all public health and environmental guidelines.
The Groveland Wells site was selected for such a demonstration project for
1987. The site is the location of a machine shop, the Valley Manufactured
Products Company, Inc., which employs approximately 25 people and manufactures,
among other things, parts for valves. The company has been in business at the
site since 1964. As an integral part of its building-wide operation of screw
machines, the company has used different types of cutting oils and degreasing
solvents, mainly trichloroethylene, tetrachloroethylene, trans-l,2-dichloroethy-
lene, and methylene chloride.
The contamination beneath the shop apparently is caused by a leaking
storage tank and by former improper practices in the storage and handling of
waste oils and solvents. The contamination plume is moving in a northeasterly
direction towards and into the Mill Pond.
The USEPA has been involved since 1983, when the Groveland Wells site was
finalized on the National Priorities List. The initial Remedial Investigation
(RI) of the Valley property was carried out by the responsible party (RP),
Valley Manufactured Products Company, Inc. A supplemental RI was conducted by
Valley in the Fall/Winter of 1987 to determine more completely the full
1
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nature of contamination at the Valley site. A source control Feasibility Study
was performed by USEPA to evaluate various methods for cleaning up or
controlling the remaining contaminants. A Record of Decision (ROD) for the
site was signed in October 1988 calling for vacuum extraction and groundwater
stripping.
The Terra Vac system is being utilized in many locations across the
nation. This system was first demonstrated at a Superfund site in Puerto Rico,
the Upjohn facility in Barceloneta, where carbon tetrachloride had leaked from
an underground storage tank. The first aquifer was the sole source of drinking
water three hundred feet below. Although groundwater contamination occurred
rapidly, most of the pollutant was in the soil. Since this cleanup began, soil
contamination purportedly has been reduced to nondetectable limits.
This report is based on monitoring the Terra Vac patented vacuum extraction
process (U.S. Patent Nos. 4593760 and 4660639) at the Groveland Wells site
during a four-and-one-half month field operation period, with emphasis on a
56-day demonstration test active treatment period. The report interprets
results of analyses performed on samples and establishes reliable cost and
performance data in order to evaluate the technology's applicability to other
sites.
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SECTION 2
EXECUTIVE SUMMARY
The SITE program demonstration test of the Terra Vac in situ vacuum
extraction process was conducted at the Valley Manufactured Products Company,
Inc. property, which is a part of the Groveland Wells Superfund site, in
Grovel and, MA. The vacuum extraction process is a technique for the removal of
volatile organic compounds (VOCs) from the vadose zone or unsaturated zone of
soils. Various estimates by EPA Region I and the Massachusetts Department of
Environmental Quality Engineering (DEQE) have placed the total amount of
contamination at the Valley site at between 3,000 and 30,000 Ib of volatile
organic compounds (VOC).
This SITE program demonstration test was designed to focus on the periphery
of the main zone of contamination. A triangular configuration of three barrier
extraction wells and one main extraction well was set up with these test
objectives in mind:
o to determine the ability of the technology to remove VOCs from the vadose
zone
o to assess the effectiveness of the technology in various soil types
o to correlate declining recovery rates with time
o to correlate VOC concentrations in soils with those in extracted vapors
The SITE test program at Valley Manufactured Products Company was conducted
from December 1, 1987 to April 26, 1988, when the last soil borings were taken.
During the time that Terra Vac was operating their system, EPA SITE program and
Region I staff along with contractors Enviresponse, Inc. and Alliance
Technologies Corporation were present to observe and record data on the
operation of the technology and to conduct sampling and analytical work. QA/QC
audit teams from S-Cubed, an RREL contractor, validated the test protocols in
both the on-site mobile laboratory for the wellhead gas analyses, and in the
main laboratory in Bedford, MA for the soil boring analyses.
The final Quality Assurance/Quality Control procedures, as prepared by
Alliance Technologies Corporation, appear in Section 4 of Volume II.
Summary of Results
Presented below is a summary of the results relating to each of the above
defined objectives of the test program.
o VOC removal from the vadose zone.
The results of flow measurements of process stream vapors along with
concentration levels in the wellhead vapors analyzed indicate that a total
of 1,297 Ib of VOCs were extracted during a 56-day vacuum unit operating
period. These results were confirmed by analysis of the activated carbon
emission control canisters employed on this project.
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Analysis of the contents of these canisters indicated a total of 1,353 Ib
of VOCs recovered.
Shallow soil gas concentrations, in the vicinity of the extraction wells
were reduced by more than 95% during the course of the 56-day
demonstration.
Soil VOC concentrations were also reduced. The greatest reduction came at
EW4, which showed a better than 95% reduction in soil VOC levels. The
majority of the soil borings in the vicinity of EW4 showed VOC removals to
non-detectable levels. In the vicinity of the other three wells, the
reduction of VOC in soil ranged from 9% to 30%. These three wells acted as
barrier wells to EW4. EW1 was designed to show the highest reduction in
VOC level, but was prevented from doing so by the migration of contaminants
from the unexpectedly high levels around MW3.
o Effectiveness in various soil types
The vacuum extraction system was able to reduce substantially the
concentration of VOCs in the area of MW3, which was described during the
pretreatment drilling period as wet clay. Concentrations were reduced in
this clay area by two orders of magnitude and more during the test period.
From the limited data base, the permeability of a soil may not be a factor
to consider in the application of this technology. It appears that a more
important soil property to consider is porosity.
o Correlation of declining recovery rates
The process of vacuum extraction is an unsteady state process and should
correlate well when the data is plotted on semi-log paper. This has been
found to be the case with the data collected on this project. Plotting the
logarithm of concentration versus time gives the best correlation
coefficients.
o Prediction of time required for site remediation
Given the nonhomogeneous nature of the subsurface contamination, it was not
possible to obtain a good correlation between VOC concentrations in well-
head gas and soil in order to predict site remediation times. Two wells,
EW1D and EW2D, showed similar ratios of concentrations in soil ppmw to
concentrations in wellhead gas ppmv. Predictions of soil concentrations
based on Henry's Law are for the most part lower by an order of magnitude.
A rough estimation of the remediation time can be made by taking the ratio
of soil to wellhead gas concentration and applying this ratio to solve for a
wellhead gas concentration at a determined allowable soil concentration. The
allowable soil concentration may be calculated by use of the Vertical and
Horizontal Spread Model in conjunction with the Organic Leachate Model and
applying an appropriate factor of safety depending upon the particular
contaminant involved. For this particular site using an allowable soil
concentration one order of magnitude lower than the calculated value might be
appropriate since the contaminant involved is TCE and the Maximum Contaminant
Level Goal (MCLG) for TCE is zero. Using this reasoning, an allowable soil
concentration of 50 ppbw may be used for this site, which corresponds to an
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approximate wellhead gas concentration of 8.9 ppb for EW1S. The equation
correlating wellhead gas concentration with time is then solved to give 200
days' running time.
After 200 days the vacuum extraction system can be run intermittently to
see if significant increases in gas concentrations occur upon restarting, after
at least a two day stoppage. If there are no appreciable increases in gas
concentration, the system may be stopped and soil borings taken and analyzed.
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SECTION 3
PROCESS DESCRIPTION
3.1 INTRODUCTION
The vacuum extraction process is a technique for the removal of volatile
organic compounds (VOCs) from the vadose or unsaturated zone of soils. Once a
contaminated area is completely defined, an extraction well or wells, depending
upon the extent of contamination, will be installed. A vacuum system induces
air flow through the soil, stripping, and volatilizing the VOCs from the soil
matrix into the air stream. The effect of increasing the vacuum extraction is
to enhance the volatilization of the VOCs by increasing their partial pressure
in the air stream. Liquid water is generally extracted as well along with the
contamination. The two phase flow of contaminated air and water flows to a
vapor liquid separator where contaminated water is removed. The contaminated
air stream then flows through activated carbon canisters arranged in a
parallel-series fashion. Primary or main adsorbing canisters are followed by a
secondary or backup adsorber in order to insure that no contamination reaches
the atmosphere. Table 3.1 presents the required equipment for the site, Figure
3.1 illustrates the layout of wells and equipment, and Figure 3.2 shows a
schematic diagram of an extraction well.
Four extraction wells (EW1-EW4) and four monitoring wells (MW1-MW4) were
drilled south of the shop. Each well was installed in two sections, one
section to just above the clay lens and one section to just above the water
table. The extraction wells were screened above the clay and below the clay.
As shown in Figure 3.2, the well section below the clay lens was isolated from
the section above by a bentonite portland cement grout seal. Each section
operated independently of the other. The wells were arranged in a triangular
configuration, with three wells on the base of the triangle (EW2, EW3, EW4) and
one well at the apex (EW1). The three wells on the base were called barrier
wells. Their purpose was to intercept contamination, from underneath the
building and to the side of the demonstration area, before this contamination
reached the main extraction well (EW1). It was the area enclosed by the four
extraction wells that defined the area to be cleaned.
3.2 SITE CHARACTERISTICS
Geophysical investigations at the location of the demonstration project
indicate that a northerly to easterly sloping bedrock surface exists
approximately 40 to 50 ft below the higher elevations of the site. (See Figure
3.3.) The groundwater table generally follows the bedrock trends at varying
depths depending on the season and slopes gently towards Mill Pond, some 400 ft
northeast of the northern edge of the Valley Manufactured Products Co., Inc.
building. The test area was located at the southeasterly portion of the Valley
site, with the extraction and monitoring wells installed outside and adjacent
to the building. The vapor-liquid separator, activated carbon canisters, and
vacuum pump skid were located inside the building.
The subsurface profile in the test area consisted of medium sand and gravel
just below the surface, underlain by finer sands and silty sands, a clay layer
3 to 7 ft in depth, and below the clay layer, coarser sands with gravel.
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TABLE 3.1 EQUIPMENT LIST
Equipment
Number Required
Description
Extraction wells
Monitoring wells
Vapor-1iquid
separator
Activated carbon
canisters
Vacuum unit
4 (2 sections each)
4 (2 sections each)
1
Primary: 2 units in
parallel
Secondary: 1 unit
1
2" SCH 40 PVC 24' total depth
2" SCH 40 PVC 24' total depth
1000-gal capacity, steel
Canisters with 1200 Ib of carbon
in each canister - 304 SS
4" inlet and outlet nozzles
Terra Vac Recovery Unit-Model
PR17 (25 HP Motor)
Holding tank
2000-gal capacity, steel
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WELL
MW4
Figure 3.1. Schematic diagram of equipment layout.
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Figure 3.2. Schematic diagram of an extraction well
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The clay layer or lens acts as a barrier against gross infiltration of VOCs
into subsequent subsoil strata. Most of the subsurface contamination was above
the clay layer with the highest concentrations adjacent to it (see Figure
3.4). A considerable amount of water perched on the clay layer and was
extracted by the vacuum system.
3.3 THEORY OF VOC EXTRACTION FROM SOIL
In general, VOCs are present in soils as dissolved constituents in an
aqueous phase, an adsorbed constituent to solid soil material, and as a free
constituent existing in the liquid and vapor phase in the void space of the
soil.
If no motive force is being supplied to aid in removing VOCs from the soil
matrix then the movement of VOCs through the soil is controlled by diffusion
rates. The expressions that are generally used to describe the movement of
chemical vapor through the soil are as follows:
Gv = Dv dCv
dZ
where:
GV = vapor flux in mass/area-time
DV = diffusion coefficient area/time
Cv = concentration of vapor in soil air mass/volume
Z = distance in the direction of diffusion
The gaseous diffusion coefficient is given by the following expression:
where:
a = air content of soil, volume"1
0 = soil porosity
Dvair = diffusion coefficient of chemical in free air
The phase relations of chemicals existing in the soil matrix-water system
is generally defined by the following:
Ca = Kd Cl
where:
Ca = mass adsorbed per mass of soil
C-j = mass dissolved per volume of solution
K,.] = distribution coefficient
This is a simple linear adsorption model that works well for chemicals at
dilute concentrations.
A modified distribution coefficient that takes into account the fact that
11
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organic chemicals mostly adsorb to organic material is:
Kd = Foc Koc
where:
FOC = fraction organic content
KQC = normalized partition coefficient for organic content
Important relationships involving the solubility of vapors or gases in
liquids may also be used to describe the phase relations of chemicals between
soil, water, and air. These are Henry's Law and Raoult's Law. Henry's Law
states that the equilibrium value of the mole fraction of gas dissolved in a
liquid is directly proportional to the partial pressure of that gas above the
liquid surface or
xa = Pa/H
where:
xa = mole fraction of component A in liquid
Pa = partial pressure of component A
H = Henry's Constant, characteristic of system
The relationship is satisfactory at low concentrations, corresponding to
low partial pressures of gas and high values of H.
Raoult's Law, which is for ideal solutions, states
pa*
where:
ya = mole fraction of component A in vapor
Pa* = vapor pressure of component A
Pt = total pressure in system
Raoult's Law is fairly good with nonpolar gases in nonpolar liquids. For
the solubility of nonpolar gases in polar liquids such as water, which forms
highly non-ideal solutions, a correction factor (CF), arrived at empirically,
is applied:
Equating Henry's Law and Raoult's Law it can be seen that the value of
Henry's Constant becomes equal to the pure component vapor pressure multiplied
by an empirically arrived at correction factor.
13
-------
since Pa = Ptya
then P, = P *x, CF
a a a
and x, = P, = P,
3 Ha ?l* CF
therefore H = P * CF
a
A different view of Henry's Law is necessary in order to develop the
concepts of partition coefficients, which expresses the relationship between
total concentrations of a compound and the concentration of that compound in
each phase. Henry's Law may be written as:
Cv = KH C-|
where:
Cv = mass in vapor per volume of air
KH = Henry's constant
An equation may be written to express the relationship between the total
concentration and concentrations in the individual soil, water, and air phases,
CT = dB Ca + fw C1 + fa Cv
where:
dg = soil dry bulk density, mass per vol.
fw = volumetric water content in soil, vol. per vol.
fa = volumetric air content of soil, vol. per vol.
The vapor partition coefficient relationship can be arrived at by
substituting equilibrium relationships in the above equation, e.g.,
For the vapor phase
CT = dB Kd CV/KH + fw CV/KH + fa Cv
Kd/KH + VKH + fa) Cv
where:
Rv = vapor partition coefficient
For the liquid phase
CT = dB KD C-| + fw C-| + fa KH C-|
D + fw + fa KH)
-------
CT = R! G!
where:
R-] = liquid partition coefficient
The vacuum extraction technology works best when it is applied to the
remediation of sites that are contaminated with liquids having both high values
of Henry's Constant and high vapor pressures.
15
-------
SECTION 4
FIELD OPERATIONS DOCUMENTATION
4.1 OPERATIONAL HISTORY
Field activities began at the Groveland, MA, site during the early part of
November 1987 with mobilization activities and concluded with the removal of
the spent activated carbon canisters on May 10, 1988. Table 4.1 provides a
chronological history of the project. A few major disruptions in operation
occurred during the course of the program, which either lengthened the time in
the field substantially or had a negative impact on the extraction process.
o On December 18 it was decided to suspend operations for the holidays and
return in time to start up operations on January 4, 1988. This suspension
of operations occurred right after the finish of the commissioning or well
development period and the decision was made not to start the active
treatment period so close to the holidays.
o On January 5 upon returning to the site, a section of the header connecting
the barrier wells to the main extraction well was found plugged with ice.
It was decided to electrically trace all of the piping from the wells to
the separator to prevent a recurrence. Active treatment commenced on
January 8.
o On January 15 the system was shut down because excessive quantities of
water were being extracted from the ground and were overloading the vapor
liquid separator. In addition the life of the small carbon canisters was
very short owing to the higher-than-expected amounts of volatile organics
being extracted on the site. Larger activated carbon canisters and a
larger vapor liquid separator were eventually installed. The new canisters
were nominal 1000-lb units and were configured as two parallel primary
units followed by a single backup secondary unit. This replaced a four-
parallel 200-lb unit primary and four-parallel 200-lb unit secondary. The
new separator had a 1000-gallon capacity, five times greater than the
original, and was fitted with a level switch to start a pump on high and
stop the pump on low level. The water pump discharged to a new 2000-gallon
storage tank.
o Operations were resumed on February 11, 1988 and a new 56-day demonstration
test run was started from the beginning.
o On March 3 the flow from well EW4D stopped because of siltation. During
the midtreatment shutdown, the well was pulsed with a water pump to remedy
the situation, but the attempt was unsuccessful. This undoubtedly had an
effect on the cleanup efficiency in the study area. As a result of the
pluggage, EW4D failed to prevent contaminant migration into the study area
and failed to extract the contamination from the area around MW3. The only
remedy for this situation would have been to drill a new well adjacent to
the existing one, but this was impossible to do given the press of time.
16
-------
TABLE 4.1 CHRONOLOGICAL OPERATIONAL HISTORY
Date
Activity
November 1987
December 1-10, 1987
December 11-15, 1987
December 16-18, 1987
December 18-January 4
January 5-7, 1988
January 7, 1988
January 8-15, 1988
January 15, 1988
January 15-February 10,
February 11, 1988
February 26, 1988
February 29, 1988
March 3, 1988
March 11, 1988
March 14-16, 1988
March 15-17, 1988
March 18, 1988
April 4, 1988
April 5, 1988
April 18, 1988
April 19-26, 1988
April 19-22, 1988
April 26-May 10, 1988
Site mobilization
Pretreatment soil borings and well
installation
Pretreatment shallow soil gas samples
Well commissioning
Operations suspended for holidays
System thawing and heat tracing
Noise complaint. Shutdown
Started active treatment period
Shutdown for scale-up of system
1988 System redesigned
Active treatment started
Separator pump malfunction, system off
Test resumed
Siltation stops flow from EW4D
System shutdown at midtreatment
Soil borings taken
Shallow soil gas samples taken
Active treatment Phase 2 started
Electrical interruption pump system off
Pump repaired, system back on
System shutdown, demonstration run
complete
Posttreatment boring program
Shallow soil gas samples collected
Site demobilization
17
-------
4.2 OPERATING CONDITIONS SUMMARY
Table 4.2 presents the operating conditions recorded during the 56-day
active treatment period. Data was recorded daily by both Alliance and Terra
Vac personnel. Following are comments on the operating data. The first
three lines of data contain the date the data was taken, the barometric
pressure in inches of mercury, and the ambient temperature.
4.2.1 System Variables
The temperature line is the wellhead temperature measured at the vapor
liquid separator inlet. This remained relatively constant throughout the
test, at between 35°F and 45°F with most readings at 40°F. The vacuum
line item is vacuum in inches of mercury at the separator, and this was a
function of the greatest vacuum pulled on any well. This was controlled by
opening or closing a ball valve located at each well. To increase the vacuum
and regulate the flow on any well, the ball valve is opened more. Terra
Vac's instructions were to keep the deep wells at about 2.5 inches of Hg
vacuum and the shallow wells at about 4 inches of Hg vacuum in order to
promote an upward mobility profile for the contamination.
The percent moisture by Modified Method 4 measures the total moisture in
the wellhead gas including the liquid water brought up from the depths by the
vacuum system. The result is expressed as a volumetric percentage.
4.2.2 Monitoring Hells
The vacuum in inches of H20 column was measured on the monitoring wells
with a manometer filled with an aqueous solution of ethylene glycol. A
correction factor was made for the specific gravity of the glycol solution.
The effects of increasing the vacuum in the deep extraction wells during the
last two weeks of the demonstration can be seen in the increased vacuum
measured in the deep monitoring wells. The increased vacuum in the deep
wells doubled the ground water extracted from the deep wells.
18
-------
TABLE 4.2
GROVELAMO/TERRA-VAC PROGRAM
SITE DEMONSTRATION TEST PROGRAM
TERRA VAC UNIT OPERATING CONDITIONS
Day No.
Date
Pbar(in.
Temp(F)
Hg.)
SYSTEM VARIABLES
Temp(F)
Vacuumd'n. Hg.)
X Moisture(HMA)
MONITORING WELLS-VACUUM (in. Water)
VMW1S
VMW1D
VMW2S
VMU2D
VMW3S
VMW3D
VMW4S
VMW40
EXTRACTION WELLS
EW1D
EW1S
EW2D
EU2S
EU3D
EW3S
EU4D
EW4S
Vacuumdn. Hg.)
Flow(GPM)
X Moisture
Vacuum(in. Hg.)
Flow
-------
TABLE 4.2 (cont.)
GROVELAMD/TERRA-VAC PROGRAM
SITE DEMONSTRATION TEST PROGRAM
TERRA VAC UNIT OPERATING CONDITIONS
Day No.
Date
PbarO'n.
Temp(F)
Hg.)
.. ...............
--
SYSTEM VARIABLES
Temp(F)
VacuumO'n. Hg.)
X Moistur«(MM4)
MONITORING WELLS-
VMU1S
VMW10
VMW2S
VMW20
VMW3S
VMU30
VMVI4S
VMW40
VACUUM (in. Water)
EXTRACTION WELLS
EW1D
EW1S
EW2D
EU2S
EW3D
EU3S
EW40
EW4S
VacuumOn. Hg.)
Flow(GPM)
X Moisture
VacuumOn. Hg.)
Flou(GPM)
X Moisture
VacuumOn. Hg.)
Flow(GPM)
X Moisture
VacuumO'n. Hg.)
Ftou(GPM)
X Moisture
VacuumO'n. Hg.)
Ftow(GPM)
X Moisture
VacuumO'n. Hg.)
Flow(GPM)
X Moisture
VacuumO'n. Hg.)
Flow(GPM)
X Moisture
VacuumOn. Hg.)
Flow(GPM)
X Moisture
10
2/20/88
29.54
42
40
4.5
1.4
3.4
5.2
4.3
8.7
8.3
10.5
1
4.2
2.5
29
0.92
4.5
8
0.99
2.5
16
0.94
4.5
8
0.99
2.5
6
0.92
4.5
4
0.99
2
6
0.9
4.5
6
0.99
11
2/21/88
29.78
28
40
4
0.77
3
5.4
3.1
10
8
10
0.9
4.6
2.5
28
0.91
3.5
8
0.94
2.5
15
0.91
4
12
0.96
2.5
6
0.91
4
5
0.96
2.5
6
0.91
4
8
0.96
12
2/22/88
30.29
27
36
4.5
0.72
3.2
5
5.1
8.9
8.9
10.5
0.9
4.2
3.5
26
0.79
5
9
0.84
3.25
15
0.78
4.5
12
0.82
3.5
5
0.79
4
6
0.8
3.5
5
0.79
4
7
0.8
13
2/23/88
29.92
50
43
5
1.6
3.2
4.4
4.9
7.7
9.1
9.3
1
3.6
2.5
26
1
4.5
9
1.09
3.5
18
1.05
4.5
10
1.09
2.5
8
1.01
4.5
5.5
1.09
3
6
1.03
4.75
7
1.11
14
2/24/88
30.15
35
40
4.5
1.3
2.8
4.8
4.8
8.7
8.7
10.1
0.7
3.9
2.5
25
0.89
4
9
0.94
2.7
20
0.9
4
9
0.94
3
6
0.91
4
6
0.94
3
5.5
0.91
4
7
0.94
15
2/25/88
30.25
30
38
4.5
0.98
3.1
5.5
4.7
9.8
8.3
10.5
0.8
4.4
2.5
26
0.82
3.5
9
0.85
2.5
16
0.82
4
9
0.87
3
5
0.84
4
6
0.87
3
5
0.84
4
7
0.87
16
2/26/ea
30.38
30
40
5
1.3
3.6
5.2
6.3
9.3
10.2
10.1
0.8
4
2
30
0.87
4.5
12
0.95
2.5
16
0.88
4.5
12
0.95
3
5
0.9
4.5
6
0.95
2.5
5
0.88
4.5
8
0.95
17
2/27/88
30.17
54
40
5
1.6
3.8
4.4
6.5
7.9
9.2
10
0.9
3.6
3
27
0.91
4.5
10
0.97
3.5
16
0.93
4.5
16
0.97
2
9
0.88
4.5
10
0.97
4
5
0.95
4.5
12
0.97
18
2/28/88
30.35
39
40
5
1.04
4
4.1
7.3
7
10
8.1
1.1
3.3
3
28
0.9
4.5
12
0.96
3
14
0.9
4.5
16
0.96
4.5
6
0.96
4.5
8
0.96
3.5
4
0.92
4.5
9
0.96
20
1 in H20 = 0.0361 PSI
1 in Hg - 0.491 PSI
-------
GROVELAND/TERRA-VAC PROGRAM
TABLE 4.2 (cont.)
SITE DEMONSTRATION TEST PROGRAM
TERRA VAC UNIT OPERATING CONDITIONS
Day No.
Date
Pbard'n.
Temp(F)
Hg.)
SYSTEM VARIABLES
Temp(F)
Vacuund'n. Hg.)
X Moisture(MM4>
MONITORING WELLS-VACUUM (in. Water)
VMW1S
VMW1D
VMU2S
VMW2D
VMU3S
VMU30
VMW4S
VMW40
EXTRACTION WELLS
EU1D
EW1S
EW2D
EU2S
EU3D
EW3S
EW4D
EW4S
Vacuumd'n. Hg.)
Flow(GPM)
X Moisture
Vacuund'n. Hg.)
Flow(GPM)
X Moisture
Vacuun(in. Hg.)
Flow(GPM)
X Moisture
Vacuund'n. Hg.)
Flow(GPM)
X Moisture
Vacuund'n. Hg.)
Flow(GPM)
X Moisture
VacuunCin. Hg.)
Flow(GPM)
X Moisture
Vacuund'n. Hg.)
Flow(GPM)
X Moisture
Vacuundn. Hg.)
Flou(GPM)
X Moisture
19
2/29/88
30.38
27
35
5.5
1.3
4
4.2
7.1
7.4
10
8.5
1
3.5
3
28
0.74
3.5
13
0.82
3.5
13
0.75
5.5
11
0.82
4
4
0.74
5.5
8
0.82
1
4
0.69
5.5
9
0.82
20
3/3/88
30.29
52
42
5.5
0.87
4.3
4.1
7.8
7.3
10
8.1
1.2
3.3
2.5
23
0.96
4.5
12
1.04
2.5
16
0.96
5
20
1.06
2
5
0.95
5
8
1.06
5
0
1.06
5
10
1.06
21
3/4/88
30.24
33
35
6
1.3
4.6
4
8
6.9
10
7.8
1.2
3.1
2
27
0.72
5
16
0.81
3
14
0.75
5
18
0.81
3
5
0.75
5
10
0.81
5
1
0.81
5
11
0.81
22
3/5/88
30.38
32
36
5.5
1.04
4.4
4.4
7.9
7.6
10
8.5
1.2
3.4
2.5
29
0.76
5
13
0.83
3
20
0.77
5
16
0.83
4
4
0.8
5
10
0.83
3.5
0
0.79
5
10
0.83
23
3/6/88
30.48
48
40
5.5
1
4.2
4.6
7.5
8.5
10
9.2
1.2
3.6
2.5
31
0.89
5
13
0.97
2.5
21
0.89
5
16
0.97
2.5
6
0.89
5
9
0.97
3
0
0.9
5
10
0.97
24
3/7/88
30.12
46
40
5
1.2
4.3
4.7
7.6
8.8
10
9.3
1.3
3.7
3
28
0.91
5
12
0.98
3
18
0.91
5
16
0.98
3
5
0.91
5
8
0.98
2.5
0
0.89
5
10
0.98
25
3/8/88
30.66
48
40
5.5
0.7
4.1
5.2
7.2
9.7
10
8.8
1.1
4.1
2.5
28
0.88
5
14
0.97
2.5
20
0.88
5
18
0.97
4.2
4
0.94
5
8
0.97
2.5
0
0.88
5
10
0.97
26
3/9/88
30.25
53
40
5.5
1.2
3.9
4.8
7.4
9.4
10
9.4
1.1
3.7
2.5
30
0.89
4.5
12
0.96
2.5
21
0.89
5
16
0.98
2
6
0.87
5
7
0.98
5
0
0.98
5
9
0.98
27
3/10/88
29.64
48
40
5.5
1.3
4.1
5.1
7.3
9.5
10
9.9
1.2
4.1
3
32
0.93
5
9
1.01
3
23
0.93
5
15
1.01
4
5
0.97
5
6
1.01
4
0
0.97
5
7
1.01
21
1 in H20 = 0.0361 PSI
1 in Hg = 0.491 PSI
-------
GROVELAND/TERRA-VAC PROGRAM
TABLE 4.2 (cont.)
SITE DEMONSTRATION TEST PROGRAM
TERRA VAC UNIT OPERATING CONDITIONS
Day No.
Date
Pbar(in.
Tenp(F)
Hg.)
SYSTEM VARIABLES
Tenp(F)
VacuumO'n. Hg.)
X Moisture(MM)
MONITORING WELLS-VACUUM (in. Water)
VMU1S
VMW10
VMU2S
VHU20
VHW3S
VMU30
VMU4S
VMW40
EXTRACTION WELLS
EW1D
EW1S
EU2D
EU2S
EU30
EW3S
EW4D
EU4S
VacuumOn. Hg.)
Flow(GPM)
X Moisture
VacuunOn. Hg.)
Flow(GPM)
X Moisture
Vacuum
-------
TABLE 4.2 (cont.)
GROVELAMO/TERRA-VAC PROGRAM
SITE DEMONSTRATION TEST PROGRAM
TERRA VAC UNIT OPERATING CONDITIONS
Day No.
Date
Pbard'n.
Tenp(F )
Hg.)
SYSTEM VARIABLES
Temp(F)
VacuumO'n. Hg.)
X Moisture(MMA)
MONITORING WELLS-VACUUM (in. Water)
VMW1S
VMW10
VMW2S
VMU2D
VMU3S
VMW30
VMW4S
VMW4D
EXTRACTION WELLS
EW1D
EW1S
EW20
EW2S
EW3D
EW3S
EW4D
EW4S
Vacuum(in. Hg.)
Flow(GPM)
X Moisture
VacuumO'n. Hg.)
Flow(GPM)
X Moisture
Vacuum(in. Hg.)
Flow(GPM)
X Moisture
VacuunO'n. Hg.)
Flow(GPM)
X Moisture
Vacuum(in. Hg.)
Flow(GPM)
X Moisture
VacuumUrH Hg.)
Flow(GPM)
X Moisture
VacuumO'n. Hg.)
FlouKGPM)
X Moisture
VacuumOn. Hg.)
Flow(GPM)
X Moisture
37
3/26/88
30.35
66
45
4.5
1.9
3.2
6
4.7
10
9.2
10
1.2
4.7
3
29
1.1
4
13
1.1
3
20
1.1
4
12
1.1
3
5
1.1
4
a
2.2
1
0
1
4
11
1.1
38
3/27/88
29.93
62
45
6
1.47
3.5
5.6
7.3
10
10
10
1.1
4.5
2
26
1.12
5
11
1.2
3
22
1.12
5
14
1.2
2.5
7
1.1
5.5
6
1.23
5
0
5.5
8
1.23
39
3/28/88
30.38
42
40
5.5
1.22
3.6
5.1
6.6
10
10
9.9
1
4.1
2.5
25
0.88
5
12
0.97
3
20
0.9
5
14
0.97
3
6
0.9
5
7
0.97
4.5
0
0.95
5
8
0.97
40
3/29/88
30.54
62
45
5.5
0.64
3.8
5.2
6.6
9.6
10
10
1.1
4.2
2.5
25
1.07
5
12
1.18
3
18
1.09
5
14
1.18
3
5
1.09
5
8
1.18
2.5
0
1.07
5
8
1.18
41
3/30/88
30.71
52
45
5.5
1.53
3.3
5
6.1
9.3
10
9.6
0.7
3.9
3
28
1.08
5
13
1.17
3
20
1.08
5
15
1.17
1.5
6
1.03
5
8
1.17
5
0
1.17
5
10
1.17
42
3/31/88
30.64
56
45
5.5
1.07
3.4
4.7
6.5
8.6
10
9
1
3.9
3
28
1.09
5
13
1.17
3
19
1 .09
5.5
15
1 .19
4.5
5
1.15
5.5
8
1 .19
5
0
1.17
5.5
9
1.19
43
4/1/88
30.67
58
43
5.5
1.4
3.3
5.2
6.2
9.8
10.1
9.6
1
4.2
2.5
31
1
5
13
1.1
3
19
1
5
16
1.1
3.5
4
1
5
8
1.1
5
0
1.1
5
9
1.1
44
4/2/88
30.6
67
45
6
0.97
1.5
3.7
4.1
7.2
10
9.3
0.6
2.8
2.5
22
1.06
5
13
1.17
3
21
1.09
5
16
1.17
4
2
1.12
5
6
1.17
5
0
1.17
5
10
1.17
46
4/4/88
30.14
62
45
3
*
2
3.8
3.9
7.3
7.1
7.5
0.5
3
2
20
1.07
3
a
1.11
2
15
1.07
3
9
1.11
3
4
1.11
3
5
1.11
3
0
1.11
3
6
1.11
23
1 in H20 - 0.0361 PSI
1 in Hg = 0.491 PSI
-------
TABLE 4.2 (cont.)
GROVELANO/TERRA-VAC PROGRAM
SITE DEMONSTRATION TEST PROGRAM
TERRA VAC UNIT OPERATING CONDITIONS
Day No.
........
Date
Pbardn.
Temp(F)
Hg.)
SYSTEM VARIABLES
Tenp
-------
TABLE 4.2 (cont.)
GROVELANO/TERRA-VAC PROGRAM
SITE DEMONSTRATION TEST PROGRAM
TERRA VAC UNIT OPERATING CONDITIONS
Day No.
Date
Pbard'n.
Temp(F)
Ha.)
SYSTEM VARIABLES
Temp(F)
Vacuumd'n. Hg.)
X Moisture(MM4)
MONITORING WELLS-VACUUM (in. Water)
VMW1S
VMW1D
VMU2S
VMW20
VMU3S
VMW3D
VMW4S
VMW40
EXTRACTION WELLS
EW1D
EW1S
EU2D
EW2S
EW30
EW3S
EW4D
EW4S
Vacuumdn. Hg.)
Flow(GPM)
X Moisture
Vacuumdn. Hg.)
Flow(GPM)
X Moisture
Vacuund'n. Hg.)
Flow(GPM)
X Moisture
Vacuumdn. Hg.)
Flow(GPM)
X Moisture
Vacuumd'n. Hg.)
Flou(GPM)
X Moisture
Vacuumd'n. Hg.)
Flou(GPM)
X Moisture
Vacuumdn. Hg.)
Flou(GPM)
X Moisture
Vacuundn. Hg.)
Flou(GPM)
X Moisture
56
4/14/88
30.42
48
40
4
1.24
1.7
7
3.3
13.5
6.5
23
0.7
5.7
4
30
0.93
2.5
10
0.88
4
25
0.93
2
10
0.87
4.5
4
0.95
2
5
0.87
4.5
0
0.95
3
8
0.9
57
4/15/88
30.35
47
40
4.5
0.99
1.9
6.8
3.7
13
7.5
12.5
0.7
5.5
4
30
0.94
3
10
0.9
3.5
23
0.92
2.5
10
0.89
4
4
0.94
3
5
0.9
4
0
0.94
2.5
8
0.89
60
4/18/88
29.7
48
40
4.75
1.32
2.2
6.9
3.6
13
7.9
12.5
0.8
5.5
4
30
0.96
3.5
9
0.95
4
27
0.96
2.5
12
0.91
4
4
0.96
3
5
0.93
4
0
0.96
3
8
0.93
25
1 1n H20 - 0.0361 PSI
1 in Hg - 0.491 PSI
-------
SECTION 5
SAMPLING AND ANALYSIS PROGRAM
The SITE Program demonstration test of the Terra Vac in situ vacuum
extraction process was conducted over a 56-day operating period beginning on
February 11, 1988 and ending on April 18, 1988. A mid-operations break of
six days occurred on March 11, 1988 to take midtreatment soil borings and
samples. The operations that took place between December 16, 1987 and
January 15, 1988 are to be considered an extended commissioning or
development period for the extraction wells. The initial active treatment
period was aborted on January 15, 1988 for reasons explained in Section 4 of
this report.
The sampling and analytical program for the test was split up into a
pretest period, which has been called a pretreatment period; an active
period; mid-treatment; and a posttreatment period.
The pretreatment period sampling program consisted of:
o soil boring samples taken with split spoons
o soil boring samples taken with Shelby tubes
o soil gas samples taken with punch bar probes
Soil borings (see Figure 5.1) taken by split spoon sampling were analyzed
for volatile organic compounds (VOCs) using headspace screening techniques,
purge and trap, GC/MS procedures, and the EPA-TCLP procedure. Additional
properties of the soil were determined by sampling using a Shelby tube, which
was pressed hydraulically into the soil by a drill rig to a total depth of 24
ft. These Shelby tube samples were analyzed to determine physical
characteristics of the subsurface stratigraphy such as bulk density, particle
density, porosity, pH, grain size, and moisture. These parameters were used
to define the basic soil characteristics.
Shallow soil gas concentrations were collected during pre-, mid-, and
posttreatment activities. Four shallow vacuum monitoring wells and twelve
shallow punch bar tubes were used at sample locations (see Figure 5.2). The
punch bar samples were collected from hollow stainless steel probes that had
been driven to a depth of 3 to 5 ft. Soil gas was drawn up the punch bar
probes with a low-volume personal pump and tygon tubing. Gas-tight 50-ml
syringes were used to collect the sample out of the tygon tubing. See Table
5.1 for a summary of pretreatment sampling.
The active treatment period consisted of collecting samples of:
o wellhead gas
o separator outlet gas
o primary carbon outlet gas
o secondary carbon outlet gas
o separator drain water
See Figure 5.3.
26
-------
10
30
40
feet
h-
0
ZD
Q
O
cr
D_
S|
cr <
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^ <
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1 X x B3
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X BM
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X
B!3
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X*x
Bl x
Be
Ox
B6
^
*>
Washington Street
- 3C
10
20
- 50
- 60
L 70
LEGENC-
O EXTRACTION WELLS
VACUUM MONITORING WELLS
x SOIL BORINGS
D ENGINLTRING BORINGS
MANIFOLD
Figure 5.1. Soil boring locations.
27
-------
10
20
feet
30
-50
c/>
\-
o
Q
0
0_ ^
UJ
*» r^
1 1 1 £
Q; ^
Z>
t 0
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11
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>-
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O
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D
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A M3
X
X
EB3
D x
E!° X X X
E30 EB4
EB2
c
E2
D M2 x
X
O
^
j
^^
- 10
- 20
- 30
- 40
- 50
- 60
- 70
LEGEND
O EXTRACTION WELLS
VACUUM MONITORING WELLS
X PUNCH BAR
Washington Street D ENGINEERING BORINGS
. ___ MANIFOLD
Figure 5.2. Soil gas sampling locations.
28
-------
VACUUM
PUMP
SAMPLE
LOCATION 4
SAMPLE
LOCATION 3
SECONDARY
CARBON
CANISTER
PRIMARY
CARBON
CANISTER
SAMPLE
LOCATION 2
1,000 GALLON
SEPARATOR
TANK
CEMENT WALL
STACKOUTLET
FLEX HOSE
SAMPLE
LOCATION 1
I
2,000 GALLON
SURGE TANK
OUTSIDE
BUILDING
EW4D
EW4S
4INCHPVC
MANIFOLD
0 EW1D
IO EW1S
EW3D
EW3S
SEPARATOR
INLET
Figure 5.3. Sampling locations.
EW2D
EW2S
LEGEND
SAMPLE LOCATIONS
1 = Separator Inlet
2 = Primary Carbon Outlet
3 = Secondary Carbon Outlet
4 = Stack Outlet
29
-------
See Table 5.2 for a summary of active treatment sampling.
All samples with the exception of the separator drain water were analyzed
on site. On-site gas analysis consisted of gas chromatography with a flame
ionization detector (FID) or an electron capture detector (ECD). The FID was
used generally to quantify the trichloroethylene (TCE) and trans 1,2-dichloro-
ethylene (DCE) values, while the ECD was used to quantify the
1,1,1-trichloroethane (TRI) and the tetrachloroethylene (PCE) values. The use
of two detectors, FID and ECD, was necessitated by high concentrations of TCE
in the extracted well head gas. Owing to the high TCE concentrations most of
the samples injected on the ECD had to be diluted. Even with dilution factors
of 333 to 1, the TCE concentration on the ECD would exceed the linear range of
the detector, thus necessitating the use of two detectors.
The separator drain water was analyzed for VOC content using SW846 8010.
Moisture content of the separator inlet gas from the wells was analyzed using
EPA Modified Method 4. This method is good for the two-phase flow regime that
existed in the gas emanating from the wellhead.
The posttreatment sampling essentially consisted of repeating pretreatment
sampling procedures at locations as close as possible to the sampling locations
from the pretreatment period. (See Table 5.3.)
The activated carbon canisters were sampled, as close to the center of the
canister as possible, and these samples were analyzed for VOC content as a
check on the material balance for the process. The method used was P&CAM 127,
which consisted of desorption of the carbon with CSo and subsequent gas
chromatographic analysis. For a listing of all analytical methods applied, see
Table 5.4.
TABLE 5.1 PRETREATMENT SAMPLE TYPE, LOCATION, AND FREQUENCY
Sample Type
Soil
Soil
Soil
Boring (SB)
Boring (SB)
Gas (SG)
Sample Location
Extraction wells
1 through 4
Monitoring wells
1 through 4
Twelve strategically
Sampling Frequency
Continuously down
to 24 -ft depth
Same as above
Single grab sample
Number of
Samples
48
48
20
located soil gas punch
bar probes plus four
monitoring wells
at each punch bar
location plus two
samples at each
monitoring well
30
-------
TABLE 5.2 ACTIVE TREATMENT SAMPLING SCHEDULE
Sample
Locations
EW-l-S, 1-D
EW-2-S,D
EW-3-S,D
EW-4-S,D
MW-1-S,D
MW-2-S,D
MW-3-S,D
MW-4-S,D
Separator
Outlet
Primary
Carbon Outlet
Secondary
Carbon Outlet
Meek 1
Twice per
day
Once per
day
Once per
day
Every other
day
Every day
Every other
day
Weeks 2 & 3
Every day
Every other
day
Every other
day
Once per week
Every day
Once per week
Weeks 4 & 5
Every other
day
Every other
day
Every other
day
Once per week
Every day
Once per week
Weeks 6, 7, & 8
Every day
Every other
day
Every other
day
Once per week
Every day
Once per week
31
-------
TABLE 5.3 POSTTREATMENT SAMPLE TYPE, LOCATION, AND FREQUENCY
Sample
Type
Sample
Location
Sampl ing
Frequency
Number of
Samples
Soil Boring (SB)
Soil Gas (SG)
Eight sample borings
near extraction wells
and monitoring wells
Twelve punch bars
located adjacent to SG
pretreatment sample
locations plus four
monitoring wells
Continuously down to 96
same levels at the
extraction and monitor-
ing wells*
Single grab samples 35
Separator Separator drain
Liquids (LQ)
Activated
Carbon
Carbon unit
Single composite
sample representative
of completely mixed
separator liquid
Single composite
sample representative
of completely mixed
activated carbon
contents
Sample size and depth may be adjusted as necessary depending on the actual
field conditions.
32
-------
TABLE 5.4 ANALYTICAL METHODS
Parameter
Analytical method
Sample Source
Grain size
pH
Moisture (110°C)
Particle density
Oil and grease
EPA-TCLP
TOO
Headspace VOC
VOC
VOC
VOC
VOC
VOC
VOC
ASTM D422-63
SW846* 9040
ASTM D2216-80
ASTM D698-78
SW846* 9071
F.R. 11/7/86,
Vol. 51, No. 216,
SW846* 8240
SW846* 9060
SW846* 3810
GC/FID or ECD
GC/FID or ECD
SW846* 8010
SW846* 8010
Modified P&CAM 127
SW846* 8240
Soil borings
Soil borings
Soil borings
Soil borings
Soil borings
Soil borings
Soil borings
Soil borings
Soil gas
Process gas
Separator liquid
Groundwater
Activated carbon
Soil borings
*Third Edition, November 1986.
33
-------
5.1 SAMPLING PROCEDURES
5.1.1 Soil Borings
Soil borings were taken using a hollow stem auger to a depth of 24 ft.
Continuous split spoon samples were taken during the boring activities. Boring
and sample collection responsibilities were divided over the course of the
program between Terra Vac and Alliance. Alliance accepted the pretreatment
split spoon samples from Terra Vac, and was responsible for opening the split
spoons, field screening the samples with an OVA, logging of distribution and
types of soil, and dividing and bottling the samples for analyses. Standard
EPA sample chain-of-custody procedures were used for disbursement of all
samples to the appropriate organization for analyses.
During the mid- and posttreatment phases of the operation, Alliance
directed a drilling subcontractor to create test borings and collect split
spoon samples and was responsible for the field screening and logging of split
spoon samples, sampling bottling, chain-of-custody records, and sample disburse-
ment for analyses.
Each soil boring drilled during the mid- and posttreatment phases was back-
filled with native soils (see Volume II, Appendix A).
5.1.2 Split Spoon Samples
Soil samples were collected from borings in accordance with the Standard
Penetration Test (ASTM D-1586-84). A 24-inch long, 2-inch inside diameter (ID)
split spoon sampler was used to collect soil samples. Each sampler was driven
24 inches into the soil by a 140-pound weight falling 30 inches onto the top of
the sampler sod. The number of hammer blows needed to advance the sampler each
6-inch interval was recorded.
Once the split spoon sample penetrated 24 inches, it was retrieved, opened,
and the sample recovery was measured. The sample then was screened with an
Organic Vapor Analyzer (OVA) for the presence of volatile organics. The sample
was logged, divided into the quantities necessary for the remaining analyses,
and bottled. Once collected, the samples were given a unique sample number,
logged onto a chain-of-custody form, and placed in a cooler.
Split spoons were decontaminated after the collection of a sample. The
decontamination process consisted of placing all split spoon parts into a wash
tub containing Alconoxm detergent and water. All parts were thoroughly
cleaned in this solution using a brush, then rinsed with deionized water and
allowed to air dry before reassembly and reuse.
5.1.3 Shelby Tube Samples
Two 24-ft borings were drilled with hollow stem augers for the collection
of thin-walled Shelby tube samples during the pretreatment phase of the
activity, and an additional two were drilled during the posttreatment phase of
the program. These Shelby tube samples were analyzed by a soil laboratory in
order to determine the physical characteristics (i.e., moisture, bulk density,
34
-------
porosity, pH, and grain size) of the subsurface stratigraphy.
Terra Vac was responsible for the drilling of the soil boring and collec-
tion and sealing of the thin-walled Shelby tube samples taken during the pre-
treatment phase of the program. The Shelby tube samples were sealed by pouring
Gulf paraffin wax into the ends of the tube; the two ends of the tube then were
capped and taped, and the capped and taped ends were dipped into the wax to
complete the seal. Alliance accepted the sealed samples, created the chain-of-
custody records, and shipped the sealed samples to the appropriate laboratory
for analyses.
Alliance was responsible for the drilling of the second set of borings
taken during the posttreatment phase. Alliance was responsible for the
sealing, chain-of-custody recordkeeping, and the shipment of these samples.
5.1.4 Soil Gas Samples
Soil gas samples were collected from the monitoring well piezometers using
a modification of procedures outlined in the RCRA Facility Investigation
Guidance Manual, Volume II (Subsurface Investigations, U.S. EPA Office of Solid
Waste, October 1986 and Method IV-11 from EPA-600/4-84-076). These piezometers
were installed by Terra Vac to measure soil vacuum at various depths and
provided a convenient means of collecting soil gases without further
disturbances at the site. The four piezometers were placed strategically at
the site in a manner that provided a representative horizontal profile. Each
piezometer was the duplicate of an extraction well, and two depths were
isolated and monitored independently of the other. Figure 3.1 provides an
illustration of the spacial placement of the piezometers around the site.
Soil gas samples were collected by attaching a vacuum pump to tubing from
sampling points, indirectly isolated, and drawing a sample to the surface where
it was collected in a gas-tight syringe. To facilitate syringe collections, a
T-fitting was placed in line between the sampling pump and the downhole tubing.
The sampling line was purged with several volumes of sample air prior to the
collection of a sample. In general, 20 seconds of purging at a flowrate of
approximately 1 liter/minute was adequate to purge the 25 feet of quarter-inch
tubing.
Samples were taken using 50-ml gas-tight syringes. The syringe was
inserted into the septum end of the T-fitting and purged with at least two
purge volumes of sample gas prior to the collection of the actual sample. This
syringe then was tagged and delivered to the on-site analytical laboratory for
analysis.
Surface soil gas samples were collected from bar punch probe test holes
according to Method IV-10 specified in EPA-600/8-84-076. The procedures
outlined in the method are described below:
1. Select location free from rocks and debris. Screen locations with metal
detector to verify absence of drums and pipes.
2. Place bar point on ground and raise drive weight, then allow weight to fall
on bar. It is only necessary to guide the weight in its vertical travel.
35
-------
3. Continue until desired depth is reached or any penetration resistance
occurs.
4. Remove bar hole-maker.
5. Attach suitable length of Teflon tubing (stainless steel or brass may be
used in some instances, but may result in some gas adsorption/absorption)
to monitor instrument gas inlet.
6. Lower tubing into test hole and operate monitor or gas sampling device as
listed in Methods IV-1 through IV-8.
7. Record results.
8. Remove sample tubing and observe that instrument readings return to
background. If not, change tubing before proceeding to next test location.
9. Tramp over and recover test hole.
Note that steps 5 and 6 were modified to allow for the collection of gas
samples from the monitoring wells via a vacuum pump and gas-tight syringe as
described above.
5.1.5 Process Gas Sampling
Process gas samples were collected from various points in the vacuum
extraction system using a syringe gas sampling technique. Samples were col-
lected by inserting the gas-tight syringes into gas sampling ports placed at
appropriate points in the process. The ports were provided by Terra Vac and
were adapted with a septum fitting to allow for insertion of the syringe
needle.
The system was under high negative pressure (2- to 12-in. Hg) and care had
to be taken when collecting the gas samples. The gas-tight syringes used in
this project were modified to allow for the placement of a mininert valve
between the needle and luer hub. The valve can be closed after the plunger has
been drawn but before the syringe is withdrawn from the sampling port. Since
the collected gas was under vacuum, closure of the mininert valve was important
to avoid drawing ambient air into the syringe once it was withdrawn from the
port. This avoids having to make volume corrections, a potential source of
error.
5.1.6 Process Liquids and Activated Charcoal
Process liquids and activated carbon samples were collected and analyzed
for volatile organics. Process liquids were collected from the vapor/liquid
separator drain. The drain was equipped with a modified stop cock, which
enables the drain to be isolated and subsequently opened to allow for the
collection of the separator liquids. This valving arrangement is necessary
since the unit is under a high negative pressure. Samples were collected using
a simple grab sampling technique in which the sample container was used as the
collection device.
36
-------
Spent activated carbon samples were collected from each canister after it
was taken off line. Grab samples were collected from as many access points as
possible and composited for analysis. Samples were collected using a trier,
composited, and placed in a single container for delivery to the laboratory.
5.1.7 Process Data Recording
All process operations data made available by Terra Vac was recorded on a
daily basis by Alliance on-site personnel. Data was recorded during all phases
of the Terra Vac demonstration. Table 4.2 summarizes the operating data logged
through the course of the active treatment period.
Note that Terra Vac was responsible for the operation and accuracy of all
temperature, pressure, and flowrate measurement equipment. A portable
rotameter manufactured by Fisher and Porter was used for flow measurement.
Accuracy of this instrument is + 2 percent of full-scale (but was not
calibrated during this program). Vacuum gauges supplied by Continental
Precision Instruments (CPI) were calibrated to Grade B - ANSI B40.1.
thermometers were employed.
CPI dial
5.2 ANALYTICAL PROCEDURES
5.2.1 VOC Analysis of Soil Samples
VOC analyses on soil samples were conducted using Methods 8240 and 5030 of
EPA-SW 846. A portion of the sample was dispersed in methanol to dissolve the
volatile organic constituents. An aliquot of the methanolic solution was
combined with organic-free water in the purging chamber. Analysis then
proceeded using a Hewlett-Packard 5985 gas chromatograph.
Approximately 1 to 5 g of solid sample was transferred into a preweighed
50-ml glass centrifuge tube or 20-ml glass vial, with Teflon-lined caps,
containing 15 ml of methanol. The capped centrifuge tube and methanol was
reweighed on an analytical balance to determine the sample weight. Care was
taken not to touch the sample-transfer implement. The sample was dispersed in
the methanol as expeditiously as possible to prevent loss of volatiles from the
sample. After the sample weight had been determined, additional methanol was
added to the 20 ml mark of the centrifuge tube or glass vial. The sample
container was securely recapped and then vigorously agitated for 1 minute,
manually or with the aid of a vortex mixer. If the sample did not disperse
during this process, the mixture was sonicated in an ultrasonic bath for 30
minutes. The mixture was allowed to stand until a clear supernatant was
obtained. The supernatant solution then was analyzed or stored at 4°C for
future analytical needs in a 10-ml screw cap vial with Teflon cap liner.
Analysis of the methanol extract proceeded by taking an appropriate aliquot
of the methanol solution using a microsyringe. An aliquot of the methanol
extract was dispersed directly into 5-ml reagent water in the purging device.
The sample then was spiked at 50 ug/1 with internal standards and surrogates
and purged according to Method 5030 of SW-846 for GC/MS analysis.
37
-------
Alternatively, the low-level purge-and-trap GC/MS method described in
SW-846 8240 was implemented if headspace screening results indicated sample
concentrations below 3 to 5 ppm. The low-level technique employs a soil
impinger for purge-and-trap GC/MS analysis of a 5-g soil sample. Detection
limits for this analysis are typically less than 1 ppm in the absence of matrix
interference.
Monitoring of surrogate recoveries will give a good indication of the
performance of the analytical system on a sample-by-sample basis. For this
analysis, the surrogates and internal standards listed below were added to the
purge chamber prior to analysis, with surrogate recoveries monitored to
indicate potential problems.
Surrogate Compounds
dg-toluene
Bromofluorobenzene
d4-l,2-dichloroethane
Internal Standards
Chiorobromomethane
1,4-difluorobenzene
dg-chlorobenzene
5.2.2 VOC Analysis of Soils by Headspace Technique
In addition to the analysis of soil gas collected in gas-tight syringes,
selected soil samples were collected in pretared vials, allowed to equilibrate,
and the overlying headspace analyzed for the five chlorinated organics listed
in Section 5.2.4. This screening procedure was used to provide preliminary
data prior to purge-and-trap GC/MS analysis.
Headspace analysis of soil samples collected in pretared vials was per-
formed via syringe injection in GC/FID. This method was modified to allow for
the use of 5 to 10 g soil portions collected in 40-ml or 20-ml VOA vials, or 10
to 50 g portions collected in 125-ml septum-sealed vials. A portion of
headspace from sample vials was injected into the instrument following
equilibration of the sample in a 90°C water bath, as detailed in SW-846
Method 3810. The method is a static headspace technique, which is best-suited
for compounds with boiling points of less than 125°C. A sample was withdrawn
from an equilibrated and sealed glass vial using a gas-tight syringe or
headspace autosampler. Detection limits for this analysis of approximately 5
ppm typically can be achieved.
Instrument calibration was performed by spiking dilutions of stock stan-
dards into empty headspace vials, which then were equilibrated and analyzed
38
-------
prior to program samples. A minimum of three standard concentrations were
analyzed to calibrate the instrument over the expected range of program
samples. Identification and quantitation were provided as with gas sample
analyses. Results were provided on a wet weight basis and later converted to
dry weights, accounting for soil moisture content. Fortified samples were
carried through all stages of sample preparation and measurement and were
analyzed to validate the sensitivity and accuracy of the analysis. Field
replicates also were collected to validate the precision of the technique.
As Method 3810 does not define expected precision and accuracy for the
analysis, a brief program to define these was conducted prior to initiation of
the technology evaluation. A minimum of nine VOC-free soils were fortified
with a known concentration of the analytes of interest and analyzed using
Method 3810.
5.2.3 TCLP
Zero Headspace Extraction--
A total of 103 pretreatment soil samples were shipped from the field to
metaTRACE, Inc., Alliance's subcontract laboratory for the purpose of
conducting the TCLP analysis. Only 20 of the samples were analyzed with the
required holding time, which had a negative impact on the TCLP part of the
program (see Vol. II, pp. 4-47).
Samples were extracted using a Zero Headspace Extraction (ZHE) vessel,
which effectively precludes headspace during liquid/solid separation and
extract filtration. ZHE extract was collected in either Tedlar bags or glass,
stainless steel or PTFE gas-tight syringes. ZHE extraction was performed
according to the method described in CFR 51 (No. 216, November 7, 1986, pp.
40643-40653). Samples were prepared for extraction by crushing, cutting, or
grinding solid portions of the sample to the surface area or particle size
specified in the method. The material was then extracted according to the
specified method.
VOC Analysis--
Zero headspace extracts were analyzed for trichloroethylene, tetrachloro-
ethylene, 1,2-trans-dichloroethylene, 1,1,1-trichloroethane, and dichloro-
methane, using SW-846 Method 8240. A 0.5-ml portion of the aqueous extract was
diluted to 5.0 ml and surrogate-spiked for purge-and-trap GC/MS analysis. This
dilution is required to reduce the concentration of glacial acetic acid in the
extraction fluid and consequently reduce instrument downtime. Detection of the
regulatory levels presented in Table 5.5 was typically achieved in the
leachate.
Calibration--
Calibration procedures described in Method 8240 were employed. Standards
were obtained from Supelco, Inc., of Bellefonte, PA.
39
-------
TABLE 5.5 TCLP REGULATORY LEVELS
Regulatory Level
Component (mg/1)
Trichloroethylene 0.07
Tetrachloroethylene 0.1
1,2-trans-dichloroethylene (a)
1,1,1-trichloroethane 30
Dichloromethane 8.6
(a) Regulatory level not established. Detection
limits of < 0.1 mg/1 are anticipated.
5.2.4 VOC Analysis of Soil Gas and Process Gas
During the course of this program, gas samples were collected using gas-
tight syringes from soil gas pore space at the site and from various points of
the Terra Vac system. Samples were taken at the following points:
o at the wellheads
o within soil gas sampling points
o at the separator inlet
o at the primary carbon unit outlet
o at the secondary carbon unit outlet
o at the vacuum pump outlet
These samples were brought immediately to the Alliance on-site mobile
laboratory for analysis. Analyses were conducted as soon as possible to
prevent degradation of the samples due to analyte decomposition or wall
effects. For that reason, during the active treatment phase of the program,
Alliance conducted analyses as soon as was practical on the submitted gas
samples.
Sample analytes are those chlorinated organics known to be contaminants of
the site soil, namely:
o trichloroethylene (TCE)
o perchloroethylene (tetrachloroethylene) (PCE)
o 1,1,1-trichloroethane (methyl chloroform) (111 TRI)
o trans-l,2-dichloroethylene (DCE)
o methylene chloride (dichloromethane) (MeCl)
Samples were analyzed by Gas Chromatography with Electron Capture Detection
(GC/ECD) or Flame lonization Detector (FID) using the techniques described
below.
40
-------
Samples were returned to the laboratory in 50-ml gas-tight syringes fitted
with valves to prevent dilution of the sample with ambient air or loss of
analyte through an open end. Sample introduction into the gas chromatograph
was by use of a (approximately) 1-ml gas sampling loop. The sample gas was
introduced to the loop by connection of the syringe to an open end of the loop,
opening the syringe valve, and depressing the syringe plunger to fill the loop
to excess, thus flushing the loop with sample. While the sample is overflowing
from the loop, the injection valve is switched, flushing the loop with column
carrier gas and carrying the sample into the GC column. Analysis of the sample
then proceeded under the conditions cited in Volume II, Appendix H.
Analytes were identified in each chromatograph run using peak retention
times from standards as the benchmark. Quantitation was performed using
comparison of the sample peak areas to the calibration curve, described later
in this section, using the formula:
y = mx + b
where: y = concentration of the sample
m = slope of the curve determined by injection of the standard
calibration mixes
b = y intercept of the calibration curve
Detection limits for this analysis are anticipated to be in the range of
15,000 to 30,000 micrograms per standard cubic meter for the FID and 8 to 1000
micrograms per standard cubic meter for the ECD (at atmospheric pressure).
Corrections for actual pressure were made to calculate actual mass flows.
Replicate injections of every fifth sample were made to monitor the precision
of the analysis.
The GC/ECD analysis for the organochloride compounds was conducted using a
Hewlett-Packard 5890 with an ECD and a Perkin-Elmer 3920 Gas Chromatograph with
an FID. The instruments were calibrated daily, or the current calibration
checked daily, prior to the analysis of the samples. Calibration and check
standards were prepared in the following manner:
1. Prepare a stock solution of chlorinated solvents by combining equal volumes
of the components in a septum-sealed vial. The solvents are reagent grade
or better, used as obtained from local distributors. Stock solutions are
prepared weekly.
2. Add 1.0 ul of the stock solution to a nitrogen-purged Supelco 500 ml gas
sampling bulb and allow a 10-minute equilibration period. The concentra-
tion of this standard is approximately 1 g/m .
3. Prepare the working standards by serially diluting the 1 g/m3 gas
standard into the 10 to 2,000 ug/nr range using Hamilton 1001-LT
gas-tight syringes and several nitrogen-purged Tedlar bags. Prepare
working standards daily.
41
-------
5.2.5 VOC Analysis of Separator Liquid
Samples of separator liquid were analyzed by purge-and-trap GC/ECD using
SW-846 Method 8010. Volatile compounds were introduced into the GC by Method
5030 (purge-and-trap). The components were separated via the gas chromatograph
and detected using a Hall electrolytic conductivity detector using method-
specified instrument conditions (SW-846 8010).
Calibration procedures described in the method use a minimum of five concen-
tration levels for each calibration standard. One of the concentration levels
was at a concentration close to, but above the detection limit. Five-point
calibration curves were constructed for each of the five chlorinated analytes
of interest described in Section 5.2.4. The calibration curve for each
compound was verified on each working day.
5.2.6 Total Organic Carbon of Soil
Total organic carbon was determined using EPA Method 9060 as follows. The
sample was combined with acidified persulfate and purged with helium to
transfer inorganic carbon dioxide and purgeable organics to a C02 scrubber.
The purgeable organics was converted to methane using a nickel catalyst and
quantitated using a flame ionization detector. The sample was subsequently
transferred to a quartz ultraviolet reaction coil where the nonpurgeables were
converted to carbon dioxide in the presence of the acidified persulfate
reagent. The carbon dioxide was transferred to a second sparger and carried to
the reduction system and detector via a helium purge. The signal was
integrated, added to the purgeable organic carbon value, and displayed as the
concentration of total organic carbon.
All analyses were performed using a Dohrmann DC-80 Total Organic Carbon
Analyzer equipped with a soil/sediment sampler. The instrument was calibrated
in accordance with the described method. Prior to beginning sample analysis,
the accuracy of the calibration was verified using an EPA demand quality
control sample.
5.2.7 Oil and Grease Contents of Soil
Soil samples were prepared and analyzed for oil and grease according to
SW-846 Method 9071. The procedure employs soxhlet extraction of an acidified
soil sample with fluorocarbon-113. Oil and grease content then was determined
by a gravimetric measurement. A distilled water method blank was analyzed to
demonstrate that all glassware and solvent were free of contamination.
5.2.8 Moisture
Soil moisture at 110°C was gravimetrically determined using ASTM
D2216-80.
5.2.9 Particle Density
Particle density was determined using ASTM D698-78.
42
-------
SECTION 6
PERFORMANCE DATA AND EVALUATION
6.1 INTRODUCTION
The SITE Program demonstration of the TERRA VAC process had as its main
objectives:
o determination of the ability of the technology to remove volatile
organic compounds from the vadose zone
o assessment of the effectiveness of the technology in various soil types
o correlation between declining VOC recovery rates and cleanup levels
o determination of the relationship between VOC concentrations in soils
versus concentrations in extract vapors
6.2 VOC REMOVAL FROM THE VADOSE ZONE
The permeable vadose zone at the Grovel and site is divided into two layers
by a horizontal clay lens, which is relatively impermeable. As explained
previously, each extraction well had a separate shallow and deep section to
enable VOCs to be extracted from that section of the vadose zone above and
below the clay lens. The quantification of VOCs removed was achieved by
measuring
o gas volumetric flow rate by rotameter and wellhead gas VOC concentration
by gas chromatography
o the amount of VOCs adsorbed by the activated carbon canisters by
desorption into C$2 followed by gas chromatography.
VOC flow rates were measured and tabulated for each well section separ-
ately. The results of gas sampling by syringe and gas chromatographic analy-
sis, as shown in Tables 6.1 through 6.8, indicate a total of 1,297 Ib of VOCs
were extracted over a 56-day period, 95% of which was trichloroethylene. A
very good check on this total was made by the activated carbon VOC analysis,
the results of which indicated a VOC recovery of 1353 Ib; virtually the same
result was obtained by two vastly different methods.
The most dramatic view of the reduction in VOC concentrations in the vadose
zone can be seen from examining the three-dimensional shallow soil gas plots.
Soil gas was collected during pretreatment, midtreatment, and posttreatment
periods from punch bar probes and shallow vacuum monitoring wells. The collec-
tion points were located on a coordinate system with extraction well 1 as the
43
-------
TABLE 6.1 FLOW RATES AND FLUX RATES, EW1S
FIRST WEEK OF SAMPLING-COLLECTION TWICE PER DAY
SAMPLE
CODE
EWG1S/1
EWG1S/2
EWG1S/1
EWG1S/2
EWG1S/1
EWG1S/2
EWG1S/1
EWG1S/2
EWG1S/1
EUG1S/2
EWG1S/1
EWG1S/2
EWG1S/1
EWG1S/2
DATE
2/11/88
2/11/88
2/12/88
2/12/88
2/13/88
2/13/88
2/14/88
2/14/88
2/15/88
2/15/88
2/16/88
2/16/88
2/17/88
2/17/88
FLOW
SCFM
27
27
35
35
35
35
31
31
31
31
34
34
28
28
MeCl**
Lbs/hr
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
DCE
Lbs/hr
0.016
0.009
0.007
0.005
0.006
0.005
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
TRI **
Lbs/hr
0.002
0.001
0.000
0.001
0.001
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
TCE
Lbs/hr
0.299
0.141
0.139
0.094
0.103
0.096
0.084
0.068
0.076
0.063
0.092
0.073
0.060
0.054
PCE ** TOTAL FID(a)
Lbs/hr Lbs/DAY
0.001 5.574
0.000
0.001 2.938
0.000
0.000 2.506
0.000
0.000 1.824
0.000
0.000 1.663
0.000
0.000 1.978
0.000
0.000 1.368
0.000
TOTAL ECD
Lbs/DAY
0.037
0.018
0.012
0.009
0.003
0.011
0.007
TOTAL Lbs FID VOC 17.851
TOTAL Lbs ECD VOC
0.097
RESULTS OF MeCt, TRI ,&PCE ARE FROM ECD ANALYSIS:DCE&TCE RESULTS ARE FROM FID ANALYSIS
(a) Average of two samples collected during the day.
44
-------
TABLE 6.1 (cont.)
SECOND THROUGH EIGTH WEEK-COLLECTION ONCE PER DAY
SAMPLE DATE
CODE
EWG1S/1 2/18/88
2/19/88
2/20/88
2/21/88
2/22/88
2/23/88
2/24/88
2/25/88
2/26/88
2/29/88
3/01/88
3/02/88
3/03/88
3/04/88
3/05/88
3/06/88
3/07/88
3/08/88
3/09/88
3/10/88
3/11/88
FLOW
SCFM
28
28
28
30
31
32
33
33
42
35
42
44
42
55
45
45
41
48
42
31
39
MeCl**
Lbs/hr
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.004
0.000
0.000
0.000
0.000
0.000
DCE
Lbs/hr
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
TRI **
Lbs/hr
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
TCE
Lbs/hr
0.052
0.053
0.037
0.048
0.037
0.040
0.056
0.039
0.044
0.046
0.041
0.038
0.027
0.044
0.040
0.037
0.018
0.025
0.052
0.015
0.019
PCE **
Lbs/hr
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.001
0.001
0.001
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
TOTAL FID
Lbs/DAY
1.257
1.269
0.889
1.156
0.878
0.954
1.355
0.927
1.058
1.113
0.993
0.916
0.654
1.067
0.966
0.884
0.439
0.590
1.255
0.369
0.465
TOTAL ECO
Lbs/DAY
0.006
0.009
0.004
0.004
0.001
0.012
0.006
0.000
0.012
0.023
0.024
0.015
0.004
0.004
0.004
0.093
0.009
0.010
0.012
0.007
0.011
** RESULTS OF MeCl, TRI ,&PCE ARE FROM ECD ANALYSIS:DCE&TCE RESULTS ARE FROM FID ANALYSIS
45
-------
TABLE 6.1 (cont.)
SAMPLE DATE
CODE
EUG1S/1 3/18/88
3/19/88
3/20/88
3/21/88
3/22/88
3/23/88
3/24/88
3/25/88
3/26/88
3/27/68
3/28/88
3/29/88
3/30/88
3/31/88
4/01/88
4/02/88
4/04/88
4/05/88
4/06/88
4/07/88
4/08/88
4/09/88
4/10/88
4/11/88
FLOW
SCFM
37
36
40
44
43
52
42
38
47
38
41
41
45
45
45
45
30
58
35
39
34
46
42
38
MeCl**
Lbs/hr
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
DCE
Lbs/hr
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
TRI **
Lbs/hr
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
TCE
Lbs/hr
0.042
0.029
0.077
0.032
0.019
0.388
0.018
0.022
0.019
0.020
0.016
0.014
0.018
0.018
0.014
0.011
0.007
0.015
0.009
0.009
0.009
0.009
0.008
0.007
PCE **
Lbs/hr
0.001
0.001
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
TOTAL FID
Lbs/DAY
1.018
0.687
1.856
0.758
0.466
9.315
0.425
0.534
0.447
0.478
0.377
0.343
0.437
0.437
0.342
0.274
0.178
0.362
0.209
0.211
0.222
0.225
0.202
0.160
TOTAL ECD
Lbs/DAY
0.024
0.017
0.013
0.000
0.010
0.014
0.002
0.010
0.010
0.010
0.008
0.001
0.008
0.009
0.008
0.007
0.003
0.008
0.003
0.001
0.003
0.003
0.004
0.003
** RESULTS OF MeCl, TRI ,&PCE ARE FROM ECD ANALYSIS:DCE&TCE RESULTS ARE FROM FID ANALYSIS
46
-------
TABLE 6.1 (cont.)
SAMPLE
CODE
EWG1S/1
DATE
4/12/88
4/13/88
4/14/88
4/15/88
4/18/88
FLOW
SCFM
32
36
39
38
33
MeCl**
Lbs/hr
0.000
0.000
0.000
0.000
0.000
DCE
Lbs/hr
0.000
0.000
0.000
0.000
0.000
TRI **
Lbs/hr
0.000
0.000
0.000
0.000
0.000
TCE
Lbs/hr
0.007
0.010
0.006
0.007
0.005
PCE **
Lbs/hr
0.000
0.000
0.000
0.000
0.000
TOTAL FID
Lbs/DAY
0.160
0.248
0.149
0.169
0.131
TOTAL ECO
Lbs/DAY
0.002
0.003
0.000
0.000
0.000
TOTAL Lbs FID VOC 40.272
TOTAL Lbs ECD VOC
0.453
** RESULTS OF MeCl, TRI ,&PCE ARE FROM ECD ANALYSIS:DCE&TCE RESULTS ARE FROM FID ANALYSIS
47
-------
TABLE 6.2 FLOW RATES AND FLUX RATES, EW ID
FIRST WEEK OF SAMPLING-COLLECTION TWICE PER DAY
SAMPLE
CODE
EUG1D/1
EWG1D/2
EWG1D/1
EUG1D/2
EUG1D/1
EWG1D/2
EWG1D/1
EUG1D/2
EWG1D/1
EUG1D/2
EWG1D/1
EWG1D/2
EWG1D/1
EUG1D/2
DATE
2/11/88
2/11/88
2/12/88
2/12/88
2/13/88
2/13/88
2/14/88
2/14/88
2/15/88
2/15/88
2/16/88
2/16/88
2/17/88
2/17/88
FLOW
SCFH
62
62
137
132
129
129
115
120
155
155
125
128
98
100
MeCt**
Lbs/hr
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
DCE
Lbs/hr
0.021
0.014
0.038
0.027
0.018
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
TRI **
Lbs/hr
0.003
0.000
0.002
0.002
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
TCE
Lbs/hr
0.292
0.148
0.226
0.171
0.127
0.104
0.068
0.088
0.400
0.158
0.063
0.077
0.046
0.054
PCE ** TOTAL FID(a) TOTAL ECD
Lbs/hr Lbs/DAY Lbs/DAY
0.000 5.737 0.041
0.000
0.000 5.544 0.037
0.000
0.000 2.981 0.000
0.000
0.000 1.874 0.000
0.000
0.000 6.699 0.018
0.001
0.000 1.680 0.000
0.000
0.000 1.198 0.000
0.000
TOTAL Lbs FID VOC 25.713
TOTAL Lbs ECD VOC 0.096
** RESULTS OF MeCl, TRI ,£PCE ARE FROM ECD ANALYSIS:DCE&TCE RESULTS ARE FROM FID ANALYSIS
(a) Average of two samples collected during the day.
48
-------
TABLE 6.2 (cont.)
SECOND THROUGH EIGTH WEEK-COLLECTION ONCE PER DAY
SAMPLE DATE
CODE
EWG1D/1 2/18/88
2/19/88
2/20/88
2/21/88
2/22/88
2/23/88
2/24/88
2/25/88
2/26/88
2/29/88
3/01/88
3/02/88
3/03/88
3/04/88
3/05/88
3/06/88
3/07/88
3/08/88
3/09/88
3/10/88
3/11/88
FLOW
SCFM
110
108
112
108
97
100
97
101
118
102
106
106
89
107
113
120
106
108
116
121
98
MeCl**
Lbs/hr
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
DCE
Lbs/hr
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
TR! **
Lbs/hr
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.001
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
TCE
Lbs/hr
0.048
0.039
0.041
0.038
0.031
0.036
0.095
0.081
0.036
0.055
0.048
0.044
0.033
0.067
0.054
0.046
0.044
0.089
1.158
0.043
0.032
PCE **
Lbs/hr
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.001
0.000
0.000
0.000
0.001
0.000
0.001
0.000
0.000
0.000
TOTAL FID
Lbs/DAY
1.152
0.932
0.973
0.903
0.755
0.860
2.276
1.955
0.863
1.328
1.154
1.051
0.794
1.610
1.285
1.106
1.052
2.128
27.794
1.028
0.775
TOTAL ECD
Lbs/DAY
0.013
0.000
0.000
0.011
0.009
0.011
0.000
0.005
0.007
0.036
0.017
0.022
0.003
0.011
0.000
0.020
0.006
0.022
0.014
0.014
0.011
** RESULTS OF MeCl, TR1 ,&PCE ARE FROM ECD ANALYSIS:DCE&TCE RESULTS ARE FROM FID ANALYSIS
49
-------
TABLE 6.2 (cont.)
SAMPLE DATE
CODE
EWG10/1 3/18/88
3/19/88
3/20/88
3/21/88
3/22/88
3/23/88
3/24/88
3/25/88
3/26/88
3/27/88
3/28/88
3/29/88
3/30/88
3/31/88
4/01/88
4/02/88
4/04/88
4/05/88
4/06/88
4/07/88
4/08/88
4/09/88
4/10/88
4/11/88
FLOW
SCFH
103
136
109
113
80
116
115
101
109
98
97
96
105
105
119
85
78
105
104
109
111
105
103
104
MeCl**
Lbs/hr
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
DCE
Lbs/hr
0.029
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
TRI **
Lbs/hr
0.004
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
TCE
Lbs/hr
0.428
0.072
0.039
0.030
0.020
0.020
0.025
0.019
0.030
0.017
0.012
0.024
0.029
0.029
0.040
0.021
0.021
0.027
0.023
0.018
0.019
0.017
0.014
0.017
PCE **
Lbs/hr
0.001
0.001
0.001
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
TOTAL FID
Lbs/DAY
10.972
1.737
0.942
0.710
0.485
0.479
0.601
0.465
0.713
0.400
0.277
0.582
0.689
0.698
0.959
0.503
0.499
0.641
0.552
0.437
0.456
0.399
0.333
0.401
TOTAL ECD
Lbs/DAY
0.120
0.023
0.018
0.011
0.008
0.011
0.009
0.009
0.009
0.009
0.006
0.008
0.010
0.012
0.015
0.006
0.007
0.018
0.008
0.008
0.006
0.004
0.005
0.005
** RESULTS OF MeCl, TRI ,&PCE ARE FROM ECO ANALYSIS:DCE&TCE RESULTS ARE FROM FID ANALYSIS
50
-------
TABLE 6.2 (cont.)
SAMPLE
CODE
EUG1D/1
DATE
4/12/88
4/13/88
4/14/88
4/15/88
4/18/88
FLOW
SCFM
107
119
109
109
109
MCU I
Lbs/hr
0.000
0.000
0.000
0.000
0.000
OCE
Lbs/hr
0.000
0.000
0.000
0.000
0.000
TRI **
Lbs/hr
0.001
0.000
0.000
0.000
0.000
TCE
Lbs/hr
0.013
0.014
0.013
0.016
0.000
PCE **
Lbs/hr
0.000
0.000
0.000
0.000
0.000
TOTAL FID
Lbs/DAY
0.306
0.341
0.318
0.395
0.000
TOTAL ECO
Lbs/DAY
0.025
0.006
0.000
0.000
0.000
TOTAL Lbs FID VOC 78.065
TOTAL Lbs ECD VOC
0.611
** RESULTS OF MeCl, TRI ,&PCE ARE FROM ECD ANALYSIS:DCE&TCE RESULTS ARE FROM FID ANALYSIS
51
-------
TABLE 6.3 FLOW RATES AND FLUX RATES, EW2S
SAMPLE DATE
CODE
EWG2S/1 2/11/88
2/12/88
2/13/88
2/14/88
2/15/88
2/16/88
2/17/88
2/18/88
2/20/88
2/22/88
2/24/88
2/26/88
3/01/88
3/03/88
3/05/88
3/07/88
3/09/88
3/11/88
3/18/88
3/19/88
3/21/88
3/23/88
FLOW
SCFM
62
52
52
32
62
47
28
34
28
43
33
42
57
69
55
55
55
57
52
49
55
59
MeCl**
Lbs/hr
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
DCE
Lbs/hr
0.014
0.007
0.008
0.000
0.000
0.006
0.000
0.000
0.000
0.000
0.006
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
TRI **
Lbs/hr
0.001
0.000
0.000
0.000
0.001
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
TCE
Lbs/hr
0.297
0.134
0.157
0.074
0.159
0.154
0.130
0.085
0.048
0.020
0.013
0.051
0.018
0.051
0.048
0.037
0.099
0.067
0.077
0.043
0.046
0.041
PCE **
Lbs/hr
0.000
0.001
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.001
0.001
0.001
0.000
0.001
TOTAL FID
Lbs/DAY
7.465
3.395
3.950
1.786
3.811
3.849
3.124
2.028
1.141
0.480
0.466
1.227
0.440
1.232
1.140
0.885
2.379
1.603
1.839
1.033
1.104
0.972
TOTAL ECD
Lbs/DAY
0.031
0.025
0.000
0.000
0.020
0.014
0.007
0.008
0.007
0.000
0.007
0.002
0.006
0.003
0.000
0.012
0.012
0.026
0.030
0.018
0.012
0.014
** RESULTS OF MeCl. TR1 ,&PCE ARE FROM ECO ANALYSIS:DCE&TCE RESULTS ARE FROM FID ANALYSIS
52
-------
TABLE 6.3 (cont.)
SAMPLE DATE
CODE
EUG2S/1 3/25/88
3/27/88
3/29/88
3/31/88
4/02/88
4/05/88
4/07/88
4/09/88
4/11/88
4/13/88
4/15/88
4/18/88
FLOW
SCFM
57
48
48
50
55
50
38
39
42
47
39
46
MeCl**
Lbs/hr
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
DCE
Lbs/hr
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
TRI *«
Lbs/hr
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
TCE
Lbs/hr
0.043
0.007
0.026
0.029
0.035
0.025
0.015
0.016
0.017
0.018
0.018
0.020
PCE *»
Lbs/hr
0.001
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
TOTAL FID
LbS/DAY
1.037
0.175
0.615
0.690
0.849
0.597
0.369
0.392
0.409
0.439
0.431
0.486
TOTAL ECD
Lbs/DAY
0.015
0.003
0.010
0.006
0.006
0.008
0.001
0.004
0.004
0.005
0.000
0.000
TOTAL Lbs FID VOC 51.841
TOTAL Lbs ECD VOC
0.315
RESULTS OF MeCl. TRI ,&PCE ARE FROM ECD ANALYSIS:DCE&TCE RESULTS ARE FROM FID ANALYSIS
53
-------
TABLE 6.4 FLOW RATES AND FLUX RATES, EW2D
SAMPLE DATE
CODE
EWG2D/1 2/11/88
2/12/88
2/13/88
2/U/88
2/15/88
2/16/88
2/17/88
2/18/88
2/20/88
2/22/88
2/24/88
2/26/88
3/01/88
3/03/88
3/05/88
3/07/88
3/09/88
3/11/88
3/18/88
3/19/88
3/21/88
3/23/88
FLOW
SCFM
66
70
83
70
62
72
57
79
62
56
77
62
53
62
76
68
81
81
71
85
101
83
MeCl**
Lbs/hr
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
OCE
Lbs/hr
0.025
0.011
0.033
0.023
0.021
0.016
0.016
0.020
0.014
0.011
0.011
0.012
0.011
0.011
0.015
0.014
0.016
0.015
0.015
0.017
0.018
0.014
TRI **
Lbs/hr
0.002
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
TCE
Lbs/hr
0.315
0.105
0.129
0.090
0.172
0.046
0.045
0.054
0.370
0.021
0.025
0.022
0.027
0.024
0.033
0.126
0.057
0.134
0.048
0.034
0.034
0.038
PCE **
Lbs/hr
0.001
0.001
0.001
0.001
0.001
0.000
0.000
0.001
0.000
0.000
0.000
0.000
0.001
0.000
0.000
0.000
0.001
0.001
0.001
0.001
0.000
0.001
TOTAL FID
Lbs/DAY
8.156
2.787
3.877
2.712
4.623
1.499
1.461
1.778
9.204
0.773
0.868
0.817
0.899
0.834
1.146
3.351
1.754
3.569
1.509
1.220
1.238
1.265
TOTAL ECD
Lbs/DAY
0.076
0.022
0.023
0.018
0.032
0.010
0.009
0.015
0.002
0.002
0.014
0.010
0.018
0.011
0.000
0.000
0.026
0.039
0.027
0.019
0.013
0.016
** RESULTS OF MeCl, TRI ,&PCE ARE FROM ECO ANALYSIS:DCE&TCE RESULTS ARE FROM FID ANALYSIS
54
-------
TABLE 6.4 (cont.)
SAMPLE DATE
CODE
EUG2D/1 3/25/88
3/27/88
3/29/88
3/31/88
4/02/88
4/05/88
4/07/88
4/09/88
4/11/88
4/13/88
4/15/88
4/18/88
FLOW
SCFH
93
83
68
72
79
66
94
87
91
101
85
98
MeCl**
Lbs/hr
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
DCE
Lbs/hr
0.000
0.014
0.000
0.000
0.000
0.011
0.015
0.014
0.000
0.000
0.000
0.000
TRI **
Lbs/hr
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
TCE
Lbs/hr
0.026
0.042
0.021
0.019
0.027
0.029
0.030
0.029
0.029
0.147
0.026
0.022
PCE **
Lbs/hr
0.000
0.001
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
TOTAL FID
Lbs/DAY
0.626
1.351
0.501
0.462
0.637
0.970
1.087
1.040
0.696
3.520
0.616
0.532
TOTAL ECD
Lbs/DAY
0.013
0.018
0.009
0.006
0.008
0.010
0.009
0.006
0.005
0.005
0.000
0.000
TOTAL Lbs FID VOC 67.377
TOTAL Lbs ECD VOC 0.494
** RESULTS OF McCl, TRI ,&PCE ARE FROM ECD ANALYSIS:DCE&TCE RESULTS ARE FROM FID ANALYSIS
55
-------
TABLE 6.5 FLOW RATES AND FLUX RATES, EW3S
SAMPLE DATE
CODE
EWG3S/1 2/11/88
2/12/88
2/13/88
2/H/88
2/15/88
2/16/88
2/17/88
2/18/88
2/20/88
2/22/88
2/24/88
2/26/88
3/01/88
3/03/88
3/05/88
3/07/88
3/09/88
3/11/88
3/18/88
3/19/88
3/21/88
3/23/88
FLOW
SCFH
31
28
35
28
24
17
14
17
14
22
22
21
28
27
35
28
24
28
26
25
29
28
MeCl**
Lbs/hr
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
DCE
Lbs/hr
0.024
0.016
0.016
0.010
0.009
0.006
0.000
0.000
0.000
0.004
0.003
0.003
0.004
0.004
0.005
0.000
0.004
0.000
0.005
0.000
0.000
0.000
TRI **
Lbs/hr
0.007
0.005
0.005
0.003
0.002
0.001
0.000
0.000
0.000
0.001
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
TCE
Lbs/hr
0.849
0.621
0.647
0.439
0.418
0.270
0.045
0.074
0.060
0.220
0.194
0.183
0.269
0.206
0.260
0.134
0.183
0.120
0.256
0.162
0.131
0.131
PCE **
Lbs/hr
0.001
0.001
0.003
0.001
0.001
0.001
0.000
0.000
0.000
0.001
0.001
0.000
0.001
0.001
0.001
0.001
0.001
0.001
0.002
0.002
0.001
0.001
TOTAL FID
Lbs/DAY
20.946
15.303
15.911
10.784
10.263
6.606
1.082
1.770
1.435
5.388
4.747
4.466
6.568
5.043
6.377
3.228
4.494
2.884
6.284
3.883
3.145
3.146
TOTAL ECD
Lbs/DAY
0.190
0.150
0.197
0.082
0.075
0.029
0.007
0.012
0.006
0.032
'0.029
0.009
0.033
0.040
0.023
0.022
0.034
0.021
0.059
0.045
0.028
0.033
** RESULTS OF MeCl, TRI ,&PCE ARE FROH ECD ANALYSIS:DCE&TCE RESULTS ARE FROM FID ANALYSIS
56
-------
TABLE 6.5 (cont.)
SAMPLE
CODE
EUG3S/1
DATE
3/25/88
3/27/88
3/29/88
3/31/88
4/02/88
4/05/88
4/07/88
4/09/88
4/11/88
4/13/88
4/15/88
4/18/88
FLOW
SCFM
25
20
27
27
21
29
23
22
19
19
19
19
MeCl**
Lbs/hr
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
DCE
Lbs/hr
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
TRI **
Lbs/hr
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
TCE
Lbs/hr
0.108
0.145
0.179
0.123
0.083
0.157
0.074
0.097
0.034
0.027
0.043
0.034
PCE **
Lbs/hr
0.001
0.002
0.002
0.001
0.001
0.001
0.001
0.001
0.000
0.000
0.000
0.000
TOTAL FID
Lbs/DAY
2.601
3.476
4.287
2.942
1.991
3.758
1.783
2.326
0.805
0.655
1.031
0.812
TOTAL ECD
Lbs/DAY
0.025
0.042
0.054
0.027
0.014
0.038
0.018
0.014
0.005
0.011
0.000
0.000
TOTAL Lbs FID VOC 170.222
TOTAL Lbs ECD VOC
1.404
** RESULTS OF MeCl, TRI ,&PCE ARE FROM ECD ANALYSIS:DCE&TCE RESULTS ARE FROM FID ANALYSIS
57
-------
TABLE 6.6 FLOW RATES AND FLUX RATES, EW3D
SAMPLE DATE
CODE
EWG3D/1 2/11/88
2/12/88
2/13/88
2/14/88
2/15/88
2/16/88
2/17/88
2/18/88
2/20/88
2/22/88
2/24/88
2/26/88
3/01/88
3/03/88
3/05/88
3/07/88
3/09/88
3/11/88
3/18/88
3/19/88
3/21/88
3/23/88
FLOW
SCFM
39
37
22
19
24
30
19
28
23
19
23
19
21
20
15
19
24
15
32
32
19
19
MeCl**
Lbs/hr
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
DCE
Lbs/hr
0.038
0.036
0.028
0.018
0.016
0.016
0.008
0.010
0.006
0.004
0.004
0.003
0.004
0.005
0.005
0.003
0.006
0.003
0.009
0.007
0.004
0.003
TRI **
Lbs/hr
0.006
0.003
0.003
0.001
0.002
0.001
0.001
0.000
0.006
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.002
0.000
0.000
0.000
TCE
Lbs/hr
0.493
0.268
0.171
0.149
0.159
0.172
0.092
0.108
0.057
0.032
0.048
0.023
0.015
0.036
0.025
0.032
0.063
0.060
0.106
0.059
0.045
0.039
PCE *»
Lbs/hr
0.001
0.002
0.001
0.001
0.001
0.002
0.001
0.001
0.000
0.000
0.000
0.000
0.000
0.001
0.000
0.000
0.001
0.000
0.000
0.001
0.000
0.000
TOTAL FID
Lbs/DAY
12.744
7.302
4.773
3.996
4.191
4.510
2.409
2.822
1.513
0.863
1.233
0.623
0.458
0.988
0.734
0.849
1.647
1.518
2.760
1.596
1.175
1.014
TOTAL ECO
Lbs/DAY
0.173
0.104
0.082
0.058
0.082
0.060
0.035
0.031
0.145
0.010
0.007
0.007
0.017
0.030
0.004
0.009
0.022
0.011
0.038
0.030
0.014
0.006
** RESULTS OF MeCl. TRI ,&PCE ARE FROM ECO ANALYSIS:DCE&TCE RESULTS ARE FROM FID ANALYSIS
58
-------
TABLE 6.6 (cont.)
SAMPLE DATE
CODE
EWG30/1 3/25/88
3/27/88
3/29/88
3/31/88
4/02/88
4/05/88
4/07/88
4/09/88
4/11/88
4/13/88
4/15/88
4/18/88
FLOW
SCFM
24
27
19
18
7
7
14
14
14
14
14
14
MeCl**
Lbs/hr
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
DCE
Lbs/hr
0.000
0.005
0.003
0.000
0.001
0.001
0.003
0.003
0.002
0.000
0.000
0.000
TRI **
Lbs/hr
0.001
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
TCE
Lbs/hr
0.035
0.058
0.037
0.024
0.012
0.013
0.025
0.023
0.023
0.017
0.019
0.018
PCE *»
Lbs/hr
0.001
0.001
0.001
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
TOTAL FID
Lbs/DAY
0.846
1.516
0.959
0.575
0.313
0.354
0.664
0.616
0.610
0.412
0.460
0.435
TOTAL ECD
Lbs/DAY
0.047
0.026
0.015
0.011
0.004
0.005
0.009
0.008
0.007
0.002
0.000
0.000
TOTAL Lbs FID VOC 67.476
TOTAL Lbs ECD VOC
1.105
** RESULTS OF MeCl. TRI ,&PCE ARE FROH ECD ANAIYSIS:OCE&TCE RESULTS ARE FROM FID ANALYSIS
59
-------
TABLE 6.7 FLOW RATES AND FLUX RATES, EW4S
SAMPLE DATE
CODE
EUG4S/1 2/11/88
2/12/88
2/13/88
2/H/88
2/15/88
2/16/88
2/17/88
2/18/88
2/20/88
2/22/88
2/24/88
2/26/88
3/01/88
3/03/88
3/05/88
3/07/88
3/09/88
3/11/88
3/18/88
3/19/88
3/21/88
3/23/88
FLOW
SCFM
24
28
35
28
28
23
25
25
21
25
25
28
32
34
35
34
31
35
30
32
35
34
HeCl**
Lbs/hr
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
OCE
Lbs/hr
0.045
0.034
0.032
0.031
0.025
0.022
0.026
0.026
0.021
0.018
0.018
0.017
0.023
0.015
0.023
0.019
0.022
0.023
0.029
0.027
0.022
0.022
TRI **
Lbs/hr
0.005
0.005
0.006
0.006
0.005
0.002
0.003
0.003
0.002
0.002
0.002
0.001
0.003
0.004
0.001
0.001
0.002
0.002
0.002
0.002
0.002
0.001
TCE
Lbs/hr
0.999
0.929
0.979
1.198
0.941
0.842
0.932
0.932
0.821
0.797
0.866
0.785
1.091
0.729
1.079
0.862
0.905
0.993
1.120
1.017
0.784
0.847
PCE **
Lbs/hr
0.002
0.002
0.002
0.004
0.003
0.001
0.002
0.003
0.003
0.002
0.003
0.002
0.000
0.008
0.001
0.002
0.003
0.003
0.005
0.006
0.003
0.004
TOTAL FID
Lbs/DAY
25.073
23.114
24.272
29.507
23.194
20.736
22.995
22.985
20.199
19.563
21.218
19.256
26.727
17.865
26.467
21.146
22.232
24.396
27.585
25.056
19.358
20.846
TOTAL ECD
Lbs/DAY
0.175
0.171
0.179
0.221
0.186
0.090
0.120
0.140
0.123
0.111
0.135
0.073
0.078
0.273
0.066
0.083
0.111
0.126
0.183
0.196
0.102
0.137
** RESULTS OF MeCl, TRI ,&PCE ARE FROM ECD ANALYSISrDCE&TCE RESULTS ARE FROM FID ANALYSIS
60
-------
TABLE 6.7 (cont.)
SAMPLE
CODE
EWG4S/1
DATE
3/25/88
3/27/88
3/29/88
3/31/88
4/02/88
4/05/88
4/07/88
4/09/88
4/11/88
4/13/88
4/15/88
4/18/88
FLOW
SCFM
35
27
27
30
34
36
38
30
30
29
31
30
MeCl"
Lbs/hr
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
DCE
Lbs/hr
0.021
0.019
0.017
0.012
0.014
0.019
0.019
0.015
0.013
0.010
0.015
0.015
TRI **
Lbs/hr
0.002
0.002
0.001
0.001
0.001
0.002
0.002
0.001
0.001
0.001
0.000
0.000
TCE
Lbs/hr
0.872
0.779
0.745
0.670
0.735
0.820
0.839
0.601
0.519
0.376
0.568
0.580
PCE **
Lbs/hr
0.005
0.005
0.004
0.003
0.003
0.004
0.004
0.003
0.002
0.001
0.000
0.000
TOTAL FID
Lbs/DAY
21.451
19.136
18.289
16.372
17.981
20.123
20.595
14.779
12.765
9.274
13.999
14.275
TOTAL ECD
Lbs/DAY
0.168
0.167
0.115
0.106
0.085
0.144
0.125
0.093
0.067
0.062
0.000
0.000
TOTAL Lbs FID VOC 702.830
TOTAL Lbs ECD VOC
4.214
RESULTS OF MeCl, TRI ,&PCE ARE FROM ECD ANALYSISrDCE&TCE RESULTS ARE FROM FID ANALYSIS
61
-------
TABLE 6.8 FLOW RATES AND FLUX RATES, EW4D
SAMPLE DATE
CODE
EUG4D/1 2/11/88
2/12/88
2/13/88
2/14/88
2/15/88
2/16/88
2/17/88
2/18/88
2/20/88
2/22/88
2/24/88
2/26/88
3/01/88
3/03/88
3/05/88
3/07/88
3/09/88
3/11/88
3/18/88
3/19/88
3/21/88
3/23/88
FLOW
SCFM
32
40
28
26
23
30
35
30
24
19
21
19
15
0
0
0
0
0
4
0
0
0
HeCl**
Lbs/hr
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
DCE
Lbs/hr
0.036
0.066
0.030
0.023
0.011
0.018
0.018
0.013
0.008
0.003
0.005
0.004
0.005
0.000
0.000
0.000
0.000
0.000
0.001
0.000
0.000
0.000
TRI **
Lbs/hr
0.004
0.008
0.005
0.004
0.001
0.002
0.002
0.001
0.001
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
TCE
Lbs/hr
0.228
0.457
0.274
0.300
0.142
0.244
0.244
0.163
0.107
0.040
0.172
0.046
0.042
0.000
0.000
0.000
0.000
0.000
0.012
0.000
0.000
0.000
PCE **
Lbs/hr
0.001
0.003
0.001
0.003
0.001
0.002
0.003
0.001
0.002
0.000
0.001
0.001
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
TOTAL FID
Lbs/DAY
6.339
12.555
7.286
7.753
3.663
6.268
6.287
4.212
2.771
1.021
4.252
1.207
1.114
0.000
0.000
0.000
0.000
0.000
0.319
0.000
0.000
0.000
TOTAL ECD
Lbs/DAY
0.131
0.256
0.153
0.157
0.056
0.088
0.101
0.061
0.058
0.010
0.036
0.019
0.010
0.000
0.000
0.000
0.000
0.000
0.009
0.000
0.000
0.000
RESULTS OF HeCl. TRI ,&PCE ARE FROM ECD ANALYSIS:DCE&TCE RESULTS ARE FROM FID ANALYSIS
62
-------
TABLE 6.8 (cont.)
SAMPLE DATE
CODE
EUG4D/1 3/25/88
3/27/88
3/29/88
3/31/88
4/02/88
4/05/88
4/07/88
4/09/88
4/11/88
4/13/88
4/15/88
4/18/88
FLOW
SCFH
0
0
0
0
0
0
0
0
0
0
0
0
MeCl**
Lbs/hr
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
DCE
Lbs/hr
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
TRI **
Lbs/hr
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
TCE
Lbs/hr
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
PCE **
Lbs/hr
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
TOTAL FID
Lbs/DAY
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
TOTAL ECD
Lbs/DAY
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
TOTAL Lbs FID VOC 65.047
TOTAL Lbs ECO VOC
1.142
** RESULTS OF MeCl, TRI .&PCE ARE FROM ECD ANALYSIS:DCE&TCE RESULTS ARE FROM FID ANALYSIS
63
-------
origin (0,0). Each collection point has an x and y coordinate, and TCE concen-
trations are plotted on a "Z" scale, which gives a three-dimensional plot
across the grid. Values of "Z" between data points and around the grid are
generated by the Kriging technique, which uses given data points and a
regional variable theory to generate values between and around sample
locations. Kriging is the name given to the least squares prediction of
spatial processes and is used in surface fitting, trend surface analysis, and
contouring of sparse spatial data.
A total of twelve shallow punch bar tubes were utilized along with the four
shallow vacuum monitoring wells. The punch bars were driven to a depth of 3
to 5 ft, and as with the vacuum wells, soil gas was drawn up the punch bar
probes with a low volume personal pump and tygon tubing. 50-ml gas-tight
syringes were used to collect the sample out of the tygon tubing. The gas
samples were analyzed in the field trailer using gas chromatographs with flame
ionization detectors and electron capture detectors.
The soil gas results show a considerable reduction in concentration over
the course of the 56-day demonstration period as can be seen from Figures 6.1,
6.2, and 6.3. This is to be expected since soil gas is the vapor halo
existing around the contamination and should be relatively easy to remove by
vacuum methods.
A more modest reduction can be seen in the results obtained for soil VOC
concentrations by GC/MS purge-and-trap analytical techniques. Soil
concentrations include not only the vapor halo but also interstitial liquid
contamination that is either dissolved in the moisture in the soil or existing
as a two phase liquid with the moisture.
Table 6.9 shows the reduction of the weighted average TCE levels in the
soil during the course of the 56-day demonstration test. The weighted average
TCE level was obtained by averaging soil concentrations obtained every two
feet by split spoon sampling methods over the entire 24-foot depth of the
wells. The largest reduction in soil TCE concentration occurred in extraction
well 4, which had the highest initial level of contamination. The majority of
the soil borings taken after the test showed VOC levels that were not
detectable. Extraction well 1, which was expected to have the greatest
concentration reduction potential, exhibited only a minor decrease over the
course of the test. Undoubtedly this was because of the greater-than-expected
level of contamination that existed in the area around monitoring well 3 that
was drawn into the soil around extraction well 1. The decrease in the TCE
level around monitoring well 3 tends to bear this out.
The TCLP or Toxic Characteristic Leaching Procedure tests provides another
tool by which this technology could be evaluated. This test is designed to
determine the potential for the leaching of, in this case, volatile organic
constituent, into ground water. Samples were extracted, using a zero
headspace extraction (ZHE) vessel, by an extraction fluid consisting of an
aqueous solution of glacial acetic acid.
The results of TCLP sampling and analysis program were of limited use in
the evaluation of the technology. Most of the pretreatment TCLP samples were
not analyzed within the required holding time periods. The midtreatment and
posttreatment samples were extracted and analyzed properly, but the data
64
-------
VMU2
0
Figure 6.1. Pretreatment shallow soil gas concentration.
65
-------
MAP VIEW
VMU3
VMU2
EU1
D-
0
VMU4
Figure 6.2. Midtreatment shallow soil gas concentration.
66
-------
MAP VIEW
VMU2
O-
O-
0
VMW3
I
X
VMUI4
Figure 6.3. Posttreatment shallow soil gas concentration.
67
-------
TABLE 6.9. REDUCTION OF WEIGHTED AVERAGE TCE LEVELS IN SOIL
(TCE Cone, in mg/kg)
Extraction Well Pretreatment Posttreatment % Reduction
1
2
3
4
33.98
3.38
6.89
96.10
29.31
2.36
6.30
4.19
13.74
30.18
8.56
95.64
Monitoring Well
1 1.10 0.34 69.09
2 14.75 8.98 39.12
3 227.31 84.50 62.83
4 0.87 1.05
68
-------
obtained were of limited use, because of the large number of nondetect values
obtained.
6.3 EFFECTIVENESS OF THE TECHNOLOGY IN VARIOUS SOIL TYPES
The soil strata at the Groveland site can be characterized generally as
consisting of the following types in order of increasing depth to groundwater:
o medium to very fine silty sands
o stiff and wet clays
o sand and gravel
Soil porosity, which is the percentage of total soil volume occupied by
pores, was relatively the same for both the clays and the sands. Typically
porosity, over the 24-ft depth of the wells, would range between 40% and 50%.
Permeabilities, or more accurately hydraulic conductivities, ranged from 10"4
cm/sec for the sands to 10"8 cm/sec for the clays with corresponding grain
sizes equal to 10"1 mm to 10"^ mm.
Pretest soil boring analyses indicated in general that most of the
contamination was in the strata above the clay lens with a considerable
quantity perched on top of the clay lens. This was the case for extraction
well 4, which showed an excellent reduction of TCE concentration in the medium
to fine sandy soils existing above the clay layer, with no TCE detected in the
clay in either the pretest or posttest borings (see Table 6.10). One of the
wells, however, was an exception. This was monitoring well 3, which contained
the highest contamination levels of any of the wells, and was exceptional in
that most of the contamination was in a wet clay stratum. The levels of
contamination were in the 200-1600 ppm range before the test.
After the test, analyses of the soil boring adjacent to monitoring well 3
showed levels in the range of ND-60 ppm in the same clay stratum. The data
suggest that the technology can desorb or otherwise mobilize VOCs out of
certain clays (see Table 6.11).
From the results of this demonstration it appears that the permeability of
a soil need not be a consideration in applying the vacuum extraction
technology. This may be explained by the fact that the porosities were
approximately the same for all soil strata, so that the total flow area for
stripping air was the same in all soil strata. It will take a long time for a
liquid contaminant to percolate through clay with its small pore size and
consequent low permeability. However, the much smaller air molecules have a
lower resistance in passing through the same pores. This may explain why
contamination was generally not present in the clay strata but when it was, it
was not difficult to remove. Further testing should be done in order to
confirm this finding.
6.4 CORRELATION OF DECLINING VOC RECOVERY RATES
The vacuum extraction of volatile organic constituents from the soil may be
viewed as an unsteady state process taking place in a nonhomogeneous environ-
ment acted upon by the combined convective forces of induced stripping air and
by the vacuum assisted volatilization and diffusion of volatiles from a
69
-------
TABLE 6.10. EXTRACTION WELL 4
TCE REDUCTION IN SOIL STRATA
Depth
ft
0-2
2-4
4-6
6-8
8-10
10-12
12-14
14-16
16-18
18-20
20-22
22-24
Description
of strata
Med. sand w/gravel
Lt. brown fine sand
Med. stiff It. brown fine sand
Soft dk. brown fine sand
Med. stiff brown sand
V stiff It. brown med. sand
V stiff brown fine sand w/silt
M stiff grn-brn clay w/silt
Soft wet clay
Soft wet clay
V stiff brn med-coarse sand
V stiff brn med-coarse w/gravel
Permeability
cm/ sec
10-4
10
10'5.
10
io-4
10"4
10"4
10"p
10"a
10-8
io-4
10"3
TCE Cone.
pre
2.94
29.90
260.0
303.0
351.0
195.0
3.14
ND
ND
ND
ND
6.71
ppm
post
ND
ND
39
9
ND
ND
2.3
ND
ND
ND
ND
ND
TABLE 6.11. MONITORING WELL 3
TCE REDUCTION IN SOIL STRATA
Depth
ft
0-2
2-4
4-6
6-8
8-10
10-12
12-14
14-16
16-18
18-20
20-22
22-24
Description
of strata
M. stiff brn. fine sand
M. stiff grey fine sand
Soft It. brn. fine sand
Lt. brn. fine sand
Stiff V. fine brn. silty sand
Soft brown silt
Wet green-brown silty clay
Wet green -brown silty clay
Wet green-brown silty clay
Silt, gravel, and rock frag.
M. stiff It. brn. med. sand
Permeabil ity
cm/sec
io-5
10"5
10'4
ID'4
ID'4
10
10-8
10 R
10 4
10"4
10'4
TCE Cone.
pre
10.30
8.33
80.0
160.0
ND
NR
316.0
195.0
218.0
1570.0
106.0
64.1
ppm
post
ND
800
84
ND
63
2.3
ND
ND
62
2.4
ND
ND
70
-------
dissolved or sorbed state. As such it is a very complicated process, even
though the equipment required to operate the process is very simple.
Classical unsteady state diffusion processes can be graphically represented
by plotting the logarithm of the rate of diffusion versus time. Although the
representation of the vacuum extraction process presented here might be
somewhat simplistic, the correlation obtained by plotting the logarithm of the
concentration of contaminant in the wellhead gas versus time and obtaining a
least squares best fit line was reasonably good. This type of plot, shown in
Figures 6.4 to 6.19, represents the data very well and is more valid than both
a linear graph or one plotting concentration versus log time, in which a best
fit curve would actually predict gas concentrations of zero or less.
Looking at the plots for extraction well 1, shallow and deep, equations are
given for the least squares best fit line for the data points. If the vacuum
extraction process is run long enough so that the detection limit for TCE on
the BCD is reached, which is 1 ppbv, the length of time required to reach that
concentration would be 239 days on the shallow well and 272 days on the deep
well, not unreasonable lengths of time to be running on an in situ treatment
process for the remediation of a site.
6.5 PREDICTION OF TIME REQUIRED FOR SITE REMEDIATION
Table 6.12 compares wellhead gas TCE concentration with TCE concentration
in the soil, arrived at by weight averaging the concentrations over the
screened depth of each well. In the case of extraction well 4, the
concentrations were averaged over the depth of the shallow section only, since
the deep section became silted up and subsequently no extraction took place
from the deep section after almost four weeks of operation.
The soil concentration that would be calculated from the wellhead gas
concentration using Henry's Law is included in the last column of Table 6.12.
Calculations for the predicted soil concentrations were made assuming a bulk
density of the soil of 1761 kg/m , a total porosity of 50% and a moisture
content of 20%. The calculated air filled porosity of the soil is
approximately 15%. Henry's constant was taken to be 0.492 KPa/m -gmol at
40°F.
TCE concentrations in the soil calculated by use of empirically derived
Henry's constants for aqueous systems, with the exception of well 4S, are not
in good agreement with the data obtained. This is undoubtedly due both to
interactions of TCE with organic matter in the soil and to inhomogeneities of
the contamination distribution in the subsurface.
As was explained previously, the area around extraction well 1 was the area
targeted by the design of the system to get as clean as possible during the
demonstration time period. A remediation level of 50 ppb in the soil may be
used. This concentration is approximately one order of magnitude lower than
that calculated by using an EPA revised Organic Leachate Model in conjunction
with a Vertical and Horizontal Spread (VHS) model (EPA Draft Guidelines for
Petitioning Waste Generated by the Petroleum Refinery Industry) which predicts
soil concentrations from leachate concentrations that have been derived from
maximum compliance point concentrations based on regulatory standards for
drinking water.
71
-------
TABLE 6.12. COMPARISON OF WELLHEAD GAS VOC
CONCENTRATION AND SOIL VOC CONCENTRATION
Extraction Well
TCE Concentration
in Wellhead Gas
ppmv
TCE Concentration
in soil ppmw
Predicted by
Henry's Law
ppmw
IS
ID
2S
2D
3S
3D
4S
9.7
5.6
16.4
14.4
125.0
58.7
1095.6
54.5
7.2
ND
20.4
20.9
18.0
9.1
0.11
0.07
0.20
0.17
1.53
0.74
12.49
72
-------
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The maximum contaminant level goal (MCLG) for trichloroethylene in drinking
water is zero. An achievable detection limit for TCE in water is 5 ppb and the
regulatory limit is 3.2 ppb. It is this regulatory limit value that is used in
the VMS model as the compliance point concentration to solve for a value of
leachate concentration. This value of leachate concentration is then used in
the Organic Leachate Model to solve for soil concentration.
The VHS model is expressed as the following equation:
Cy = C0 erf (Z/(2(azY)0'5)) erf (X/(atY)0'5)
where:
Cy = concentration of VOC at compliance point (mg/1)
CQ = concentration of VOC in leachate (mg/1)
erf = error function (dimensionless)
Z = penetration depth of leachate into the aquifer
Y = distance from site to compliance point (m)
X = length of site measured perpendicular to the direction of ground
water flow (m)
a^. = lateral transverse dispersivity (m)
az = vertical dispersivity (m)
A simplified version of the VHS model is most often used, which reduces the
above equation to:
Cy = CQCf
where:
Cf = erf (Z/(2(azY)0'5)) erf (X/(at;Y)0-5), which is reduced to
a conversion factor corresponding to the amount of contaminated
soil
The Organic Leachate Model (OLM) is written as:
C0 = 0.00211 cs°-678S°-373
where:
CQ = concentration of VOC in leachate (mg/1)
Cs = concentration of VOC in soil (mg/1)
S = solubility of VOC in water (mg/1)
A concentration of 50 ppb TCE in the soil would correspond to a level of
8.9 ppb in the wellhead gas for EWS 1, and to a level of 38.9 ppb in the
wellhead gas for EWD2. Extraction times of approximately 200 days for EWS1 and
180 days for EWD1 are obtained by solving the equations derived for the curves
of log concentration vs. time (Figures 6.4 and 6.5). During the course of this
demonstration project, it had been observed that after stoppages of the
extraction process, there would be significant increases of wellhead gas
89
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concentrations upon restart. Near the end of the projected remediation time,
it should be possible to determine if the site has been decontaminated by
running the vacuum blower intermittently and measuring the wellhead gas
concentration. If there is no significant increase in concentration, then the
process should be stopped.
90
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SECTION 7
ECONOMICS
7.1 INTRODUCTION
The classical cost analysis addresses the cost aspects of a capital
facility in two main categories: capital costs, and operating and maintenance
costs.
Capital costs include both depreciable and nondepreciable cost elements.
Depreciable costs include direct costs for site development, capital equipment,
and equipment installation. Indirect costs include 1) engineering services
prior to unit construction, such as feasibility studies and consultant costs;
2) administrative tasks, such as permitting; 3) construction overhead and fee;
and 4) contingencies. Nondepreciable costs include costs for vendor personnel
and operator training, trial or test run expenses, working capital, and land
purchase, which is a direct cost that is nondepreciable.
Operating and maintenance costs include variable, semivariable, and fixed
cost elements. Variable operating cost elements include utilities and
residual/water disposal costs. Semivariable costs include unit labor and
maintenance costs, and laboratory analyses. Fixed costs include depreciation,
insurance, and taxes.
The above breakdown of cost elements, however, is based on a permanently
sited vacuum extraction unit. The Terra Vac vacuum extraction unit as employed
at the Groveland site is a transportable skid-mounted unit that will not be
located permanently at a site. Cost analysis, therefore, is based on different
sets of cost elements.
In general, the costs for a mobile vacuum extraction unit fall into three
categories: 1) capital costs including all costs that can be amortized over
the service life of the unit; 2) mobilization/demobilization costs associated
with start-up and shutdown at a given site, which can be amortized while the
unit is transported to and located and operated at a given site; and 3) costs
of operating and maintaining the system.
Capital costs can be subdivided into direct, indirect, and nondepreciable
cost elements; mobilization/demobilization costs can be accrued as semivariable
operating and maintenance costs; and operating costs include variable utility,
costs, semivariable labor or maintenance costs, and fixed costs such as
depreciation, insurance, and taxes.
In addition, for a mobile unit, several capital cost elements defined for
the permanently sited unit should be redefined into a different cost element
category. These include the direct costs for site development and the direct
costs for engineering studies, which now will be accrued on a site- specific
basis and as such become mobilization/demobilization costs. They now fall
under semivariable operating and maintenance costs.
91
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Based on the above, an overall cost element breakdown, as illustrated in
Table 7.1, can be developed.
Included in Section 7.3, Table 7.2 is an economic model for a current-case
ideal Terra Vac transportable unit operation that is equivalent in processing
capacity to the unit that operated at the Groveland site. It should be noted
that cost data on the operations at Groveland are high due to the nature of the
demonstration project.
7.2 COST ELEMENTS
A discussion of each of the cost elements defined in Table 7.1 is provided
in the following:
7.2.1 Capital Costs
Direct Costs: Equipment Fabrication and Construction--
The current costs for the design, engineering, materials and equipment
procurement, fabrication, and installation of the Terra Vac transportable
vacuum extraction unit are included as direct costs. These costs include all
the subsystems and components installed on their respective skids and trailers,
but do not include the costs of the tractors for the transport of the trailers.
Indirect Costs: Contingency--
In any cost estimate, contingency costs approximating 10% of the direct
capital cost is an acceptable factor; this allows for unforeseen or poorly
defined cost definitions.
Nondepreciable Costs--
Operations procedures and training--In order to ensure the safe, economical,
and efficient operation of the unit, operating procedures and a program to
train operators are necessary. These associated costs will accrue: the
preparation of a unit health and safety and operating manual; and the
development and implementation of an operator training program, equipment
decontamination procedures.
7.2.2 Operating and Maintenance Costs
Variable costs--
Variable operating cost elements for this unit include power and
residue/water disposal. They are defined as variable operating cost elements
because they can usually be expressed in terms of dollars per unit flow of
waste disposed, and as such, these costs are more or less proportional to
overall facility utilization during specific site operations.
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TABLE 7.1. OVERALL COST ELEMENT BREAKDOWN
CAPITAL COST
Direct
o Equipment Fabrication/Construction
Indirect
o Contingency
Nondepreciable
o Operations Procedures/Training
OPERATING AND MAINTENANCE COSTS
Variable
o Power
o Residue/Water Disposal
o Activated Carbon
Semivariable
o Labor
o Maintenance
o Analyses
o Mobilization/Demobilization
Site Preparation/Logistics
Transportation/Setup
On-Site Checkout
Site-Specific Permitting/Engineering Services
Working Capital
Decontamination/Demobili zation
Fixed
o Depreciation
o Insurance
o Taxes
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Power--The power requirements for the unit include the electrical requirements
for the motors that power the pumps, fans, vacuum pump, and the small separator
water pump. Auxiliary electrical requirements for power for the two field
trailers, site lighting, etc., are minimal and are assumed to be included in
the total power needs.
Activated carbon--Activated carbon requirements amounted to a usage of 15,200
Ib over the course of the demonstration. The cost of the activated carbon
includes the cost of regeneration.
Waste disposal--The waste disposal costs are the costs for disposing of the
contaminated water collected in a fully permitted biological treatment
facility. There were 17,000 gal of water disposed of during the course of the
test.
Semivariable Costs--
iabar--Operating personnel for the Terra Vac unit was 1 person during the day
shift. The main tasks for this operator consisted of taking daily gas samples
and changing out carbon canisters.
Maintenance--Maintenance materials and labor costs are extremely difficult to
estimate and cannot be predicted as functions of a few simple waste and
facility design characteristics, because a myriad of site-specific factors can
dramatically affect maintenance requirements.
Analyses In order to ensure that the unit is operating efficiently and meeting
environmental standards, a program for the intermittent analysis of wellhead
gas and stack gas is required. These costs also include pretest and posttest
soil sampling and analysis.
Mobilization/demobilization--As discussed in Section 7.1, the following costs
will accrue to the Terra Vac unit at each specific site. The costs are site-
specific and may vary somewhat depending on the nature and location of the
site. They include site preparation and logistics, transportation and setup,
construction supervision, on-site check-out, site-specific permitting and
engineering services, working capital, and decontamination/demobilization.
o Site preparation Site preparation consisted of the setup and outfitting of
a trailer, which was used as a base of operations; the provision of
electrical service both for the trailer and for the vacuum pump skid and
water pump; the minor grubbing and cleaning of the site; and installation
of extraction and monitoring wells. The vacuum pump skid required the
extension of an existing 440V, 3pH, 60hz line in the Valley Manufactured
Products plant back to the demonstration area with the installation of a
circuit breaker and electric power meter. The trailer power line was run
from a street pole and a meter installed. Various outside lights and
switches were installed to make the area more secure. The setup and
equipping of the S&A trailer was not considered as a cost for this
demonstration since it would not be a typical cost for this technology.
94
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o On-site check-outOnce the unit has been set up, it is necessary to
shakedown the system to ensure that no damage occurred as a result of
disassembly, transport, and reassembly.
o Site closure Site closure costs include the entire costs accrued on the
project for hazardous waste disposal, and minor demobilization costs.
Hazardous waste disposal required the retaining of a subcontractor
specializing in the preparation for shipment and shipment of hazardous
wastes. The hazardous wastes handled at the site included liquid waste,
both bulk and in drums, which were either extracted by the vacuum system or
collected as a result of decon procedures. This liquid waste was
manifested and shipped to a biological treatment facility that was fully
permitted and in full regulatory compliance. Solid waste consisted of
contaminated soil tailings from drilling operations and was manifested and
shipped to an incineration facility. Demobilization would normally include
dismantling and closure of the extraction and monitoring well installation,
but owing to future consideration this was not done at the completion of
this project.
7.3 OVERALL COST EVALUATION
An economic model for an efficiently operated current-cost Terra Vac vacuum
extraction unit operation equivalent in processing capacity to the unit that
operated at Groveland is presented in Table 7.2. The model is based on vacuum
extraction of the total volume of contaminated soil at the Valley site equal to
6,000 tons.
In actual operation, the Terra Vac unit was on site for approximately 147
days, 56 days of which was an actual demonstration test run. The costs in
Table 7.2 are for this 56-day period during which contaminant levels were
significantly reduced, but a complete remediation was not yet attained.
95
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TABLE 7.2. ECONOMIC MODEL FOR TERRA VAC
CAPITAL COST
Direct - Depreciable
Equipment Fabr./Constr.
Indirect - Depreciable
Contingency (10% Direct Cost)
Indirect - Nondepreciable
Operations Proc./Training
OPERATING AND MAINTENANCE COSTS
Variable
Power ($0.08/kwh) 0.40
Activated Carbon 12.83
Waste Disposal 7.50
Semivariable
Labor 1.87
Living 0.90
Maintenance 0.28
Analyses
- Pretest and Posttest soil 16.66
- Wellhead and Stack Gas During Operation 1.44
Mobilization/Demobilization
Site Prep. 2.83
Transp./Setup &
On-site Checkout 0.84
Decon./Demobil. 0.33
Fixed
Depreciation (10 yrs. St. Line) 0.28
Insurance & Taxes (10% Direct Cost) 0.28
TOTAL COST PER TON 47.12
Not used directly, but is used for the estimate of other costs.
96
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BIBLIOGRAPHY
1. American Petroleum Institute, 1972. The Migration of Petroleum Products
in Soil and Groundwater. Pub. No. 4149. Washington, DC.
2. Eklund, B. 1985. Detection of Hydrocarbons in Groundwater by Analysis of
Shallow Soil Gas/Vapor. API Publication 4394.
3. Goring, C.A.I., Hamaker, J.W., and Thompson, J.M. 1972. Organic
Chemicals in the Soil Environment. Marcel Dekker, Inc., New York.
4. Hougen, O.A., Watson, K.M., and Ragatz, R.A. 1954. Chemical Process
Principles. John Wiley and Sons, Inc., New York.
5. Hutzler, N.J. Gierkc, J.S., and Krause, L.C. 1988. Movement of Volatile
Organic Chemicals in Soils in Reactions and Movement of Organic Chemicals
in Soils. Shawney, B.L., ed. Soil Science Soc. of America, Madison, WI.
6. Kerfoot, H.B. and Mayer, C.L. 1986. The Use of Industrial Hygiene
Samplers for Soil Gas Measurements. Groundwater Monitoring Review.
7. Klute, A., Editor. 1986. Methods of Soil Analysis Part 1 Physical and
Mineralogical Methods, 2nd ed. American Soc. of Agronomy, Inc., Soil
Science Soc. of America Inc., Madison, WI.
8. Malot, J.J. 1985. Unsaturated Zone Monitoring and Recovery of Underground
Contamination. Fifth National Symposium on Aquifer Restoration and
Groundwater Monitoring, Columbus, OH.
9. Werner, M.D. 1985. The Effects of Relative Humidity on the Vapor Phase
Adsorption of Trichloroethylene by Activated Carbon. Journal American
Industrial Hygiene Association.
10. USEPA. 1986. A Primer on Kriging U.S. Environmental Protection Agency,
Statistical Policy Branch, Office of Policy, Planning, and Evaluation,
Washington, DC.
11. USEPA. 1987. Draft Guidelines for Petitioning Wastes in the Petroleum
Refinery Industry. U.S. Environmental Protection Agency, Washington, DC.
12. USEPA. 1988. State of Technology Review Soil Vapor Extraction Systems,
U.S. Environmental Protection Agency, Office of Research and Development,
Cincinnati, OH.
97
- US GOVERNMENT PRINTING OFFICE 1989-648-163/87096
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