United States Office of Research and EPA/60Q/R-97/Q44
Environmental Protection Development August 1997
Agency Washington DC 20460
<&EPA Champion International
Superfund Site,
Libby, Montana
Field Performance
Evaluation
Bioremediation Unit:
In Situ Bioremediation of the
Upper Aquifer
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EPA/600/R-97/044
Champion International Superfund Site, Libby, Montana
Field Performance Evaluation
Bioremediation Unit:
In Situ Bioremediation of the Upper Aquifer
By:
Ronald C. Sims
Judith L. Sims
and
Darwin L. Sorensen
Utah Water Research Laboratory
Utah State University
Logan, Utah 84322-8200
Contract No. 68-C8-0058
Scott G. Haling David S. Burden
Technical Manager Project Officer
Subsurface Protection and Remediation Division
National Risk Management Research Laboratory
Ada, OK
National Risk Management Research Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, OH 45268
Printed on Recycled Paper
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NOTICE
The information in this document has been funded by the United States Environmental Protection
Agency under contract number 68-C8-0058, to Dynamac Corporation (Subcontract to Utah State
University). It has been subjected to the Agency's peer review and administrative review, and it has
been approved for publication as an EPA document. Mention of trade names or commercial products
does not constitute endorsement or recommendation for use.
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Foreword
The U.S. Environmental Protection Agency is charged by Congress with protecting the Nation's
land, air, and water resources. Under a mandate of national environmental laws, the Agency strives to
formulate and implement actions leading to a compatible balance between human activities and the
ability of natural systems to support and nurture life. To meet these mandates, EPA's research program
is providing data and technical support for solving environmental problems today and building a sci-
ence knowledge base necessary to manage our ecological resources wisely, understand how pollutants
affect our health, and prevent or reduce environmental risks in the future.
The National Risk Management Research Laboratory is the Agency's center for investigation of
technological and management approaches for reducing risks from threats to human health and the
environment. The focus of the Laboratory's research program is on methods for the prevention and
control of pollution to air, land, water, and subsurface resources; protection of water quality in public
water systems; remediation of contaminated sites and ground water; and prevention and control of
indoor air pollution. 'Ilie goal of this research effort is to catalyze development and implementation of
innovative, cost-effective environmental technologies; develop scientific and engineering information
needed by EPA to support regulatory and policy decisions; and provide technical support and informa-
tion transfer to ensure effective implementation of environmental regulations and strategies.
The performance evaluation of in-situ bioremediation at the Champion International Superfund
Site in Libby, Montana, was made possible by the Bioremediation Field Initiative established in 1990.
Two objectives of the Initiative were to (1) more fully document the performance of full-scale
bioremediation field applications in terms of treatment effectiveness, operational reliability, and cost;
and (2) to disseminate this information to the public and private sectors. This project represents a
significant cooperative effort between industry (Champion International), academia (Utah State Uni-
versity), and the Environmental Protection Agency. Results from this study provide valuable insight to
the biodegradation of soil contaminants associated with wood preserving wastes and to the operation
of land treatment systems.
Clinton W. Hall, Director
Subsurface Protection and Remediation Division
National Risk Management Research Laboratory
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EXECUTIVE SUMMARY
The Office of Solid Waste and Emergency Response (OSWER) and the Office of Research and
Development (ORD) of the U.S. Environmental Protection Agency (U.S. EPA) jointly established the
Bioremediation Field Initiative (BFI) in 1990 as part of a strategy to develop bioremediation as an
effective alternative remediation technology. The Initiative was designed to address the need for addi-
tional field experience concerning the implementation of bioremediation techniques, including the
collection and dissemination of performance data from field experiences.
Specifically, the BFI has three primary objectives: (1) to document more fully the performance of
full-scale bioremediation field applications in terms of treatment effectiveness and operational reliabil-
ity; (2) to provide technical assistance to U.S. EPA and State remediation managers responsible for
overseeing or considering use of bioremediation as a remedial alternative for hazardous waste sites;
and (3) to develop biotreatability data bases, available through the U.S. EPA's Alternative Treatment
Technology Information Center (ATTIC). This report focuses on Objective 1 by providing an evalua-
tion of a full-scale field application of bioremediation at a specific site, the Champion International
Superfund Site in Libby, Montana.
The Champion International Superfund Site, a former wood preserving facility in Libby, Montana
(referred to as the Libby Site), was nominated by the Robert S. Kerr Environmental Research Labora-
tory (RSKERL), Ada, Oklahoma, as a candidate site for bioremediation performance evaluation. The
potentially responsible party (PRP), Champion International, agreed to cooperate with the RSKERL
and the Utah Water Research Laboratory (UWRL) of Utah State University (USU) in conducting the
proposed bioremediation performance evaluation studies for biological treatment processes in opera-
tion at the Libby Site.
The Libby Site uses three distinct biological processes in the site remediation scenario: (1) surface
soil biological treatment in a prepared-bed, lined land treatment unit (LTU); (2) aqueous phase treat-
ment of extracted ground water in an above-grade, fixed-film bioreactor, and (3) in situ bioremediation
of the Upper Aquifer. Results of the evaluation of in situ bioremediation of the Upper Aquifer are
presented in this report.
Obj ecti ves of the evaluation of the in situ bioremediation in the Upper Aquifer in this BFIsponsored
study were to: (1) describe and summarize previous and current remediation activities; (2) conduct a
field evaluation to assess the performance of remediation activities with regard to removal of contami-
nants associated with the subsurface solid particles and oily materials; and (3) perform a laboratory
evaluation to assess the microbial metabolic potential of subsurface aquifer materials to accomplish
bioremediation of target chemicals under various management conditions.
With regard to the objectives of the evaluation of in situ bioremediation in the Upper Aquifer,
conclusions included:
(1) With regard to objective 1: describe and summarize previous and current remediation
activities, site characterization and remediation activities undertaken by the PRP indicated that concen-
trations of target chemicals in water in monitoring wells decreased in response to the addition of oxy-
gen and nutrients that were added for the purpose of enhancing microbial activity. This evidence for in
situ bioremediation was based upon field-scale pilot studies and demonstration studies conducted by
the PRP.
As a result of site characterization activities, long-term sources of ground-water contamination
were attributed to the presence of contaminants in aquifer nonaqueous phases that included sediments
and nonaqueous phase liquids (NAPLs). Contamination occurred during the downward movement of
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creosote, a dense nonaqueous phase liquid (DNAPL), through the Upper Aquifer sediments. NAPLs
and sediments provide a continuous source of contaminants to the water phase through diffusion, des-
orption, and solubilization processes, and therefore represent a challenge for bioremediation of the
Upper Aquifer.
The heterogeneous nature of the subsurface and preferential pathways for water through more
permeable layers were indicated as a result of a field pilot-scale study undertaken by the PRP where
one site responded to injection of hydrogen peroxide into the ground water by demonstrating reduced
contaminant concentration at a downgradient monitoring well, while one site did not respond to treat-
ment, as determined in a different downgradient monitoring well.
(2) With regard to objective 2: conduct a field evaluation to assess the performance ofremediation
activities with regard to removal of contaminants associated with the subsurface solid particles and
oily materials, field performance evaluation activities executed as part of this BFI study demonstrated
that, with respect to the ground-water phase, total polycyclic aromatic hydrocarbon (TPAH) com-
pounds and pentachlorophenol (PCP) were present at lower, nondetectable, concentrations in wells
under the influence of the treatment injection system consisting of nutrients and hydrogen peroxide,
while TPAH and PCP were present at higher concentrations in wells outside of the influence of the
injection system. Therefore, treatment appears to have occurred in the water phase under the influence
of the treatment injection system.
An evaluation of the water phase in monitoring wells located in contaminated and uncontami-
nated areas demonstrated the presence of reduced inorganic compounds, including ferrous iron and
manganous manganese in both sets of wells. Concentrations of reduced chemicals were inversely
related to dissolved oxygen concentrations. These chemicals may exert a demand on the oxygen sup-
plied by the hydrogen peroxide. Although oxygen concentrations in several wells downgradient from
the injection system exceeded 20 mg/L, the presence of reduced inorganic species tiiat could be oxi-
dized by the injected hydrogen peroxide has the potential to reduce the mass of injected hydrogen
peroxide that is available for use by microorganisms.
With respect to the NAPL phase, both TPAH and PCP were found in the highest concentrations in
the light nonaqueous phase liquids (LNAPLs), greater than 10,000 and 1,000 mg/L, respectively, than
in any other phase at the Libby Site. These results indicated that there is contamination of the Upper
Aquifer remaining in the form of a pure phase that represents significant potential contamination by
transfer of contaminants from the NAPL phase to the water phase.
There was an observed difference between low levels of contaminants in monitoring well water
and high levels in aquifer NAPL/sediment samples. TPAH and total petroleum hydrocarbons (TPH)
were present within the NAPL/sediment associated phases of the aquifer under the influence of the
treatment injection system at concentrations of 5 to 687 mg/Kg and 70 to 2,525 mg/Kg, respectively.
PCP, the most water soluble contaminant, was present in the lowest concentrations (0.1 to 7.9 mg/Kg).
The occurrance of the three contaminants together, PAH, PCP, and TPH was highly correlated. The
heterogeneous distribution of TPAH, PCP, and TPH contaminants was consistent among all three bore-
holes evaluated from the water table to the deepest sampling point. NAPL/sediment phases are often
expected to be more difficult to bioremediate in situ than the aqueous phase due to limitations of mass
transport of oxygen and nutrients from the water phase to the nonaqueous phases that contain the target
chemicals.
Because this project was initiated five years after pilot injection wells were installed, initial adsorbed
contaminant concentrations before treatment were not available to compare with contaminant concen-
trations at the time of sampling. However, the detection of high concentrations of polycyclic aromatic
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hydrocarbons (PAHs) and TPH associated with NAPL/sediment phases below the water table in the
area of influence of the treatment (injection) wells after approximately three years (full-scale injection
system) and five years (pilot injection wells) of treatment may indicate a lack of rapid response of parts
of the site to the stimulation of in situ bioremediation. The delay in response is related to the nature of
the source (NAPL and sediment) and the subsurface heterogeneity that provides areas of high conduc-
tivity and areas of low conductivity for water carrying nutrients and oxygen.
Information obtained through the field sampling conducted as part of this BFI study and through
previous site characterization activities by the PRP demonstrates the vertical heterogeneous stratigra-
phy of the subsurface as well as the heterogeneous distribution of contaminants. This heterogeneous
nature of the subsurface results in preferential pathways through permeable layers that may be respon-
sible for carrying large volumes of injected water containing nutrients and oxygen. However, the
permeable layers may not coincide with the layers containing the highest degree of contamination. Tn
addition, even where subsurface areas are hydrodynamically connected and therefore received nutri-
ents and oxygen from the injection system, the presence of immiscible NAPL in these areas results in
the presence of NAPL-associated contaminants (TPAH, PCP, and TPH) that are less susceptible to
injection system influence than contaminants in the water phase.
An evaluation of the gas phase in selected areas near an injection well used to introduce hydrogen
peroxide and nutrients into the subsurface indicated that hydrogen peroxide was degassing and passing
into the overlaying unsaturated zone. The concentrations of oxygen gas in the vadose zone pore space
at 5 and 7 feet below ground surface (bgs) were 48 and 54 percent, respectively. This degassing
represents an abiotic loss pathway for oxygen in the subsurface. Therefore, some of the hydrogen
peroxide that is injected may not be available for microbial stimulation due to escape of peroxide into
the vadose zone and the atmosphere, thus reducing the oxygen available for microbial utilization.
Although oxygen concentrations in several wells downgradient from the injection system exceeded 20
mg/L, the degassing of hydrogen peroxide into the overlaying unsaturated zone acts to reduce the mass
of injected hydrogen peroxide that is available for use by aquifer microorganisms.
An evaluation of in situ bioremediation activity in the water phase, by measuring oxygen utiliza-
tion based upon differences in oxygen concentrations in injected and recovered water using a push
(injection)/pull (recovery) test, was conducted. However, high flow rates (greater than 50 feet per day)
prevented injected water from being naturally contained long enough for microbial activity to decrease
the oxygen concentration of the injected water and for the water to be recovered for measurement.
Therefore, the use of push/pull tests at this site for measuring subsurface microbial activity was not
successful, due to site characteristics related to average high hydraulic conductivities and average high
ground-water flow velocities.
(3) With regard to objective 3: perform a laboratory evaluation to assess the microbial metabolic
potential of subsurface aquifer materials to accomplish bioremediation of target chemicals under vari-
ous conditions, an evaluation of the microbial metabolic potential of aquifer samples indicated that
aquifer materials contain indigenous microorganisms that have the ability to mineralize PAH com-
pounds that can serve as a metabolic source of cell carbon, as indicated by the mineralization of the
PAH compound, phenanthrene. There was no significant mineralization observed in poisoned aquifer
samples. PCP mineralization, however, was insignificant (less than two percent) with results similar
for non-poisoned and poisoned samples.
Chemical mass balance experiments for phenanthrene and PCP assisted in the evaluation of field
results. Results demonstrated that up to 30 percent of phenanthrene was mineralized and up to 70
percent became incorporated into the aquifer matrix and was non-solvent extractable, while less than
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six percent was volatilized. With regard to POP, mineralization was less than two percent in all evalu-
ations and incorporation into the aquifer matrix of up to 40 percent (non-solvent extractable) was lower
than that observed for phenanthrene. Volatilization of PCP was less than two percent. Therefore
significant mineralization and reaction with the solid phase aquifer matrix into non-solvent extractable
residue was observed with phenanthrene, while little mineralization and some reaction with solid
phase aquifer matrix into non-solvent extractable residue was observed with PCP.
Temperature, oxygen, and nutrient addition were evaluated, as potential management variables,
with regard to effects on treatment of phenanthrene and PCP. In non-poisoned samples, temperature
and oxygen influenced rate and extent of mineralization of phenanthrene. Addition of nutrients did not
have a significant effect on rate or extent of mineralization of phenanthrene or PCP. An acclimation
period was consistently indicated by the presence of a lag phase in the occurrence of mineralization.
Mineralization of PAH compounds in the aquifer samples appears to be primarily related to biological
processes and is influenced by temperature and oxygen levels.
Results of the laboratory evaluation provided information concerning major treatment pathways
for phenanthrene and PCP within the aquifer material taken from the site. Major pathways for phenan-
threne were biological mineralization and incorporation into aquifer material such that phenanthrene
became non-extractable. The major pathway for PCP was incorporation into the aquifer material such
that PCP became non-extractable. Biological processes were less evident with PCP transformation in
aquifer samples and were more evident with phenanthrene transformation.
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Table of Contents
Page
Notice ii
Foreword iii
Executive Summary iv
List of Figures x
List of Tables xiv
Acknowledgements xvi
Chapter 1. Introduction 1
1.0 Bioremediation Field Initiative 1
1.1 Project Objectives 1
Chapter 2. Conclusions 2
Chapter 3. Recommendations 5
Chapter 4. Site Characteristics and Remediation Activities 6
4.0 BFI Study Objective 1: Previous and Current Remediation Activities 6
4.1 Site Description, History and Extent of Contamination 6
4.2 Target Remediation Levels 15
4.3 Full-Scale System 15
4.4 Pilot-Scale Study of the Intermediate Injection System 22
4.5 Demonstration Study 24
4.6 Cost Estimates for the In Situ Bioremediation Program for
the Upper Aquifer 35
Chapter 5. Field Performance Evaluation of In Situ Bioremediation of the Upper Aquifer 37
5.0 BFI Study Objective 2: Field Evaluation to Assess Performance
of In Situ Bioremediation of the Upper Aquifer 37
5.1 Phase I - Assessment of Potential for In Situ Biodegradation
in the Upper Aquifer 37
5.1.1 Performance of Push/Pull (Single-Well Injection) Tests to
Measure Subsurface Microbial Activity 38
5.1.1.1 Experimental Approach and Methods for the
Performance of Push/Pull Tests 38
5.1.1.2 Results of Push/Pull Tests 38
5.1.2 Ground-Water Analyses to Evaluate the
Oxidative-Reductive Status of the Upper Aquifer 40
5.1.2.1 Experimental Approach and Methods for the Evaluation
of the Oxidative-Reductive Status of the Upper Aquifer 40
5.1.2.2 Results of the Evaluation of the Oxidative-Reductive
Status of the Upper Aquifer 40
5.2 Phase II - Performance of a Field Evaluation to Assess the Performance of
Remediation Activities with Regard to Removal of Contaminants
Associated with the Subsurface Solid Particles and Oily Materials 44
5.2.1 Task 1: Collection of Aquifer Core Samples from Background
Areas and from Contaminated Areas Undergoing Treatment
with Hydrogen Peroxide and Nutrients for Use in Laboratory
Studies and for Analysis of Residual Contamination 46
5.2.1.1 Experimental Approach and Methods for Aquifer
Core Sampling 46
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5.2.1.2 Results of Aquifer Core Sampling 46
5.2.2 Task 2; Analysis of Dissolved Oxygen Concentrations and
Temperature in Selected Ground-Water Wells 48
5,2.2, i Experimental Methods for Measurement of Temperature
and Oxygen Concentrations 48
5.2.2.2 Results of Measurement of Temperature and Oxygen
Concentrations 48
5.2.3 Task 3: Analysis of Ground-Water Samples Collected from
Selected Wells to Determine Hydrogen Peroxide
Concentrations ..... 54
5.2.3.1 Experimental Method for Measurement of Hydrogen
Peroxide Concentrations 54
5.2.3.2 Results of Measurement of Hydrogen Peroxide
Concentrations 55
5.2.4 Task 4: Analysis of Soil Gas at Selected Sites Near an Injection
Well to Determine Concentration of Oxygen in the Soils Above the
Site of Injection of Hydrogen Peroxide in Order to Assess
Whether Degassing of Hydrogen Peroxide from the Aquifer was
Occurring 55
5.2,4.1 Experimental Method for the Analysis of Soil Gas
to Assess Degassing of Hydrogen Peroxide 55
52.4.2 Results of the Analysis of Soil Gas to Assess
Degassing of Hydrogen Peroxide 55
5.2.5 Analysis of Ground-Water Samples Collected from Selected
Wells for the Presence of Compounds that Indicate the
Oxidative-Reductive Status of the Upper Aquifer 55
5.2.5.1 Experimental Methods for the Analysis of Compounds
that Indicate the Oxidative-Reductive Status of the
Upper Aquifer 56
5.2.5.2 Results of Analyses for the Presence of Compounds
that Indicate the Oxidative-Reductive Status of
the Upper Aquifer 57
5.2.6 Task 6: Determination of Aqueous Phase Concentrations of
PAH Compounds and PCP in Ground-Water Samples
Collected from Wells Within and Not Within the Influence
of the Intermediate Injection Area and from a Well in an
Uncontaminated Background Area 57
5.2.6.1 Experimental Methods for the Analysis of
Ground-Water Samples for PAH Compounds and PCP 57
5.2.6.2 Results of the Analysis of Ground-Water Samples
for PAH Compounds and PCP 57
5.2.7 Task 7: Determination of Concentrations of PAH Compounds
and PCP in an LNAPL Sample Collected from a Well
Downgradient from the Intermediate Injection Area 59
5.2.7.1 Experimental Methods for the Analysis of PAH
Compounds and PCP in An LNAPL Sample 59
5.2.7.2 Results of the Determination of PAH Compounds and
PCP in an LNAPL Sample from a Ground-Water
Monitoring Well 59
5.2.8 Task 8: Determination of Solid Phase Concentrations of PAH
Compounds, PCP and TPH in Aquifer Core Samples in
Contaminated Areas Receiving Nutrients and Oxygen 60
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5.2.8.1 Experimental Methods for the Determination of the
Vertical Distribution of PAH Compounds, PCP, and TPH in
Aquifer Core Samples 60
5.2.8.2 Results of the Determination of the Vertical Distribution
of Contamination 60
5.3 Phase HI - Performance of a Field Evaluation to Investigate the Role of
Preferential Flow Pathways in the Intermediate Injection Area of the
Upper Aquifer 67
5.3.1 Purpose of Investigation 67
5.3.2 Experimental Methods and Materials 67
5.3.3 Results of the Investigation of the Role of Flow Preferential
Pathways in the Intermediate Injection Area 69
5.3.3.1 Inorganic Compounds as Indicators of Preferential
Flow Pathways 69
5.3.3.2 Organic Compounds as Indicators of Preferential
Flow Pathways 73
Chapter 6. Laboratory Performance Evaluation of In Situ Bioremediation of the
Upper Aquifer 75
6.0 BFI Study Objective 3; Laboratory Evaluation to Assess Performance
of In Situ Bioremediation of the Upper Aquifer 75
6.1 Objectives of Laboratory Study 76
6.2 Experimental Design, Materials, and Methods 76
6.3 Results of the Laboratory Evaluation to Assess Performance of In Situ
Bioremediation of the Upper Aquifer 82
6.3.1 Mineralization of Phenanthrene 82
6.3.2 Mineralization of Pentachlorophenol 82
6.3.3 Volatilization of Phenanthrene and Pentachlorophenol 83
6.3.4 Soil Incorporation of Phenanthrene 83
6.3.5 Soil Incorporation of Pentachlorophenol 85
Chapter7. References 95
Appendix A. Preliminary Cost Estimates for the In Situ Bioremediation Program
for the Upper Aquifer (Woodward-Clyde Consultants, 1990) A-l
Table A-l Cost Estimate Assumptions A-l
Table A-2 Preliminary Cost Estimate for In-Situ Bioremediation Program A-2
Table A-3 Preliminary Cost Estimate for In-Situ Bioremediation Program A-3
Table A-4 Preliminary Cost Estimate for In-Situ Bioremediation Program A-4
Table A-5 Preliminary Cost Estimate for Ih-Situ Bioremediation Program A-5
Table A-6 Preliminary Cost Estimate for In-Situ Bioremediation Program A-6
Table A-7 Preliminary Cost Estimate for In-Situ Bioremediation Program A-7
Table A-8 Preliminary Cost Estimate for In-Situ Bioremediation Program A-8
Appendix B. Analytical Methods and Quality Assurance/Quality Control
Procedures B-l
B-l Extraction of Aquifer Solid and Ground-Water Samples and
Moisture Determination of Aquifer Solids B-l
B-2 Analysis of PCP using Gas Chromatography B-4
B-3 Analysis of PAH Compounds using HPLC B-6
B-4 Analysis ofTPII using Gas Chromatography B-7
B-5 Analysis of PAH Compounds and PCP by ManTech Environmental
Technology B-8
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Appendix C, Analytical Results torn Phase II and Phase HI Field Investigations C-1
Table C-I Analysis of Aquifer Solids from Borehole No. 2(31 feet SW of
Monitoring Well 3026): November, 1992 .. C-l
Table C-2 Analysis of Aquifer Solids from Borehole No. 3 (58 feet NW of
Injection Well 3007) November, 1992 C-l
Table C-3 Analysis of Aquifer Solids from Borehole No. 4 (51 feet N of
Injection Well Cluster 9500/9501): November, 1992 C-2
Table C-4 Inorganic Compounds in Ground Water from Injection and
Monitoring Wells: March, 1993 C-3
Table C-5 Sample Number Nomenclature and Depth Interval for Sample Results
Presented in Table C-4 C-4
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List of Figures
Page
Figure 4.1 Location of Libby Project 7
Figure 4.2 Libby Site 7
Figure 4.3 An Example of the Stratigraphy of the Upper Aquifer (Woodward-Clyd
Consultants, 1990) 8
Figure 4.4 DNAPL Transport in the Subsurface (Huling and Weaver, 1991) 14
Figure 4.5 Source Area, Intermediate, and Boundary Injection Systems
(Piotrowski, 1991) 17
Figure 4.6 Source Area Injection System (Woodward-Clyde Consultants, 1990) 19
Figure 4.7 Intermediate Injection System (Woodward-Clyde Consultants, 1990) 20
Figure 4.8 Boundary Injection System (Woodward-Clyde Consultants, 1990) 21
Figure 4.9 Pilot-Scale Injection System in the Intermediate Injection
Area (Piotrowski, 1991) 23
Figure 4.10 Development of an Oxic Zone in the Intermediate Injection
Area During the Pilot-Scale Study (Piotrowski, 1991) 24
Figure 4.11 Location of Injection Wells and Monitoring Wells in the
Intermediate Injection Area During the Demonstration Program
(Woodward-Clyde Consultants, 1990) 25
Figure 4.12 Drilling Log for Injection Well No. 9500 (Woodward-Clyde
Consultants, 1990) 26
Figure 4.13 Drilling Log for Injection Well No. 9501 (Woodward-Clyde
Consultants, 1990) 28
Figure 4.14 Drilling Log for Monitoring Well No. 3029 (Woodward-Clyde
Consultants, 1990) 29
Figure 4.15 Drilling Log for Monitoring Wells Nos. 3031.1 and 3031.2
(Woodward-Clyde Consultants, 1990) 30
Figure 4.16 Drilling Log for Monitoring Wei 1 No. 3032 (Woodward-Clyde
Consultants, 1990) 31
Figure 4.17 Geologic Section of the Upper Aquifer through Injection
Well No. 9500 and Monitoring Well Nos. 3015, 3031, and 3017
(Woodward-Clyde Consultants, 1990) 32
Figure5.1 Bromide Tracer Push/Pull Test for Well No. 3014.1: September, 1991 39
Figure 5.2 Bromide Tracer Push/Pull Test for Well No. 3017.1: September, 1991 39
Figure 5.3 Bromide Tracer Push/Pull Test for Well No. 3003.2: October, 1991 41
Figure5.4 Bromide Tracer Push/Pull Test for Well No. 3010.1: October, 1991 41
Figure 5.5 Bromide Tracer Push/Pull Test for Well No. 3017.1: October, 1991 42
Figure 5.6 Bromide Tracer Push/Pull Test for Well No. 3014.1: October, 1991 42
Figure 5.7 Bromide Tracer Push/Pull Test for Well No. 3034: October, 1991 43
Figure 5.8 Number of Bailings Required to Achieve a Constant Bromide
Concentration in Well No. 3010.1: October, 1991 43
Figure 5.9 Schematic of Site Showing Locations of Injection
Wells, Monitoring Wells, and Aquifer Drilling Core Locations 47
Figure 5.10 Location of Core Nos. 2 and 3 and Depths of Injection Well Screens
(I.W. = Injection Well and M.W. = Monitoring Well) 49
Figure 5.11 Drilling Log for Core No. 1 (Background) 50
Figure 5.12 Drilling Log for Core No. 2 (31 Feet SE of Monitoring Well No. 3026) 51
Figure 5.13 Drilling Log for Core No. 3 (58 Feet NW of Injection Well No. 3007 52
Figure 5.14 Drilling Log for Core No. 4(51 FeetN of Injection Well Cluster 9500/9501).... 53
Figure 5.15 Total Polycyclic Aromatic Hydrocarbon Concentrations with Depth
in Borehole 2 62
Figure 5.16 Pentachlorophenol Concentrations with Depth in Borehole 2 62
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Figure 5.37 Total Petroleum Hydrocarbon Concentrations with Depth in
Borehole 2 63
Figure 5.18 Total Polycyclic Aromatic Hydrocarbon Concentrations with Depth
in Borehole 3 63
Figure 5.19 Pentachlorophenol Concentrations with Depth in Borehole 3 64
Figure 5.20 Total Petroleum Hydrocarbon Concentrations with Depth in
Borehole 3 64
Figure 5.21 Total Polycyclic Aromatic Hydrocarbon Concentrations with Depth
in Borehole 4 65
Figure 5.22 Pentachlorophenol Concentrations with Depth in Borehole 4 65
Figure 5.23 Total Petroleum Hydrocarbon Concentrations with Depth in
Borehole 4 66
Figure 5.24 Screened Intervals and Sampling Depths for Well Nos. 3025,
3026, and 3032 68
Figure 5.25 Vertical Profile of Dissolved Oxygen in the Ground Water: March, 1993 70
Figure 5.26 Vertical Profile of Ground-Water Temperature: March, 1993 70
Figure 5.27 Vertical Profile of Nitrate/Nitrite in the Ground Water: March, 1993 71
Figure 5.28 Vertical Profile of Ammonia in the Ground Water: March, 1993 71
Figure 5.29 Vertical Profile of Chloride in the Ground Water March, 1993 72
Figure 5.30 Vertical Profile of Total Phosphorus in the Ground Water: March, 1993 72
Figure 6.1 Temperature Effects Study Design 77
Figure 6.2 Oxygen/Nutrient Effects Study Design 77
Figure 6.3 Schematic of a Laboratory Microcosm and Gas Trapping Apparatus 80
Figure 6.4 Interaction of Temperature, Aquifer Material Sample, and
Biotic/Abiotic Treatment on the Time-Averaged Cumulative
Mineralization of 14C-Phenanthrene in the Laboratory Microcosms 84
Figure 6.5 Effects of the Interaction of Poisoning and Incubation Time on
the Average Cumulative l4C02 Evolved from the Mineralization
of i4C-Phenanthrene in the Laboratory Microcosms 84
Figure 6.6 Effects of the Interaction of Sample, Biotic/Abiotic Treatment, and
Temperature on the Volatilization of l^C-Phenanthrene in the
Temperature Effects Study 88
Figure 6.7 Effects of the Interaction of Temperature, Sample, and Biotic/Abiotic
Treatment on the Amount of Solvent-Extractablc 14C-Phenanthrene
from the Aquifer Materials .used in the Temperature Effects Study 90
Figure 6.8 Effects of the Interaction of Temperature, Sample, and Biotic/Abiotic
Treatment on the Soil-Binding of i4C-Phenanthrcne in the Temperature
Effects Study 90
Figure 6.9 Temperature x Biotic/Abiotic Treatment Interaction Effects on the
Solvent-Extractable 14C-PCP Following 56 Days Incubation in the
Temperature Effects Study 92
Figure 6.10 14C-PCP Bound to Aquifer Materials Following 56 Days Incubation
in the Temperature Effects Study 92
Figure 6.11 Sample x Biotic/Abiotic Treatment Interaction Effects on the
Solvent Extractability of HC-PCP Following 56 Days Incubation in the
Temperature Effects Study 93
Figure 6.12 Effects of Oxygen on Soil-Binding of14C-PCP Following 56 Days
Incubation in the Oxygen/Nutrients Effects Study 93
Figure 6.13 Effects of the Interaction of Biotic/Abiotic Conditions, Nitrogen
Addition, and Oxygen on the Solvent-Extractability of MC-PCP
Following 56 Days Incubation in the Oxygen/Nutrient Study 94
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List of Tables
Page
Table 4.1 Properties of 16 Priority Pollutant PAH Compounds
(Sims etal., 1986) 9
Table 4.2 Physical Properties of PCP (McGinnis et al., 1991) 12
Table 4.3 Screened Intervals of Monitoring Wells (Woodward-Clyde
Consultants, 1990) 27
Table 4.4 PCP, Total Noncarcinogenic PAH, and Total Carcinogenic
PAH in Monitoring Wells During the Demonstration Program
(Woodward-Clyde Consultants, 1990) 35
Table 4.5 Cost Estimates for the Upper Aquifer In Situ Bioremediation
Program (Woodward-Clyde Consultants, 1990)
Table 5.1 Concentrations of Compounds that Indicate the Oxidative-Reductive
Status of the Upper Aquifer: October, 1991 45
Table 5.2 Concentrations of Compounds that Indicate the Oxidative-Reductive
Status of the Upper Aquifer April, 1992 45
Table 5.3 Aquifer Core Drilling Locations: November, 1992 48
Table 5.4 Temperature, Oxygen, and Hydrogen Peroxide Measurements for
Ground Water in Selected Wells: November 19, 1992 54
Table 5.5 Chemical Analysis of Soil Gas for Oxygen Concentrations Near
Injection Well Cluster 9500/9501: November 21, 1992 56
Table 5.6 Concentrations of Compounds that Indicate the Oxidative-Reductive
Status of the Upper Aquifer: November, 1992 57
Table 5.7 Concentrations of PCP and PAH Compounds in Ground
Water: November, 1992 58
Table 5.8 Concentrations of PAH Compounds and PCP in LNAPL
Collected from Monitoring Well No. 3031: November, 1992 60
Table 5.9 Ranges of Concentrations of Contaminants Associated with
Aquifer Solids: November, 1992 66
Table 5.10 Details of Construction for Well Nos. 3025,3026, and 3032 67
Table 5.11 Inorganic Compounds in Injection Water: March, 1993 69
Table 5.12 Hydrogen Peroxide Concentrations in Well No. 3032: March, 1993 73
Table 5.13 Concentrations of PCP and PAH Compounds in Ground Water
Collected from Well No. 3025: March 1993 74
Table 6.1 Experimental Variables in the Laboratory Studies 76
Table 6.2 Concentrations of PAH Compounds and PCP in Borehole
Samples Selected for the Laboratory Studies 78
Table 6.3 Principal Cations and Anions in a Libby Aquifer Sample and the
Artificial Aquifer Water 79
Table 6.4 Salts used to Prepare Simulated Water 79
Table 6.5 Mean and Standard Deviation of Cumulative Percent i^C-Phenanthrene
Mineralization in Duplicate Experimental Microcosms During the
Temperature Effects Study 83
Table 6.6 Mean and Standard Deviation of Cumulative Percent nC-Pentachlorophenol
Mineralization in Duplicate Microcosms During the Temperature
Effects Study 85
Table 6.7 Mean and Standard Deviation of Cumulative Percent ,4C-Pentachlorophenol
Mineralization in Duplicate Microcosms in the Oxygen/Nutrient
Effects Study 86
Table 6.8 Mean and Standard Deviation of Cumulative Percent nC-Phenanthrene
Volatilization During the Temperature Effects Study 87
Table 6.9 Mean and Standard Deviation of Cumulative Percent i4C-Pentachlorophenol
Volatilization in Duplicate Microcosms in the Temperature
Effects Study 88
xiv
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Table 6.10 Mean and Standard Deviation of Cumulative Percent' 4C Pentachlorophcnol
Volatilization in Duplicate Microcosms in the Oxygen/Nutrient
Effects Study 89
Table 6.11 14C-C Phenanthrene Mass Balance for Each of the Temperature Effects
Experimental Microcosms after 56 Days of Incubation , 89
Table 6.12 ' *c-C Pentachlorophenol Mass Balance for Each of the Temperature Effects
Experimental Microcosms after 56 Days of Incubation 91
Table 6,13 i tc-C Pentachlorophenol Mass Balance for Each of the Oxygen/Nutrient
Effects Experimental Microcosms after 56 Days of Incubation 91
Table A-1 Cost Estimate Assumptions J A-1
Table A-2 Preliminary Cost Estimate for In-Situ Bioremediation Program A-2
Table A-3 Preliminary Cost Estimate for In-Situ Bioremediation Program A-3
Table A-4 Preliminary Cost Estimate for In-Situ Bioremediation Program A-4
Table A-5 Preliminary Cost Estimate for In-Situ Bioremediation Program A-5
Tabic A-6 Preliminary Cost Estimate for In-Situ Bioremediation Program A-6
Table A-7 Preliminary Cost Estimate for In-Situ Bioremediation Program... A-7
Table A-8 Preliminary Cost Estimate for In-Situ Bioremediation Program A-8
Table C-l Analysis of Aquifer Solids from Borehole No. 2 (31 feet SW of
Monitoring Well 3026): November, 1992 C-l
Table C-2 Analysis of Aquifer Solids from Borehole No. 3 (58 feet NW of
Injection Well 3007) November, 1992 C-l
Table C-3 Analysis of Aquifer Solids from Borehole No. 4 (51 feet N of
Injection Well Cluster 9500/9501): November, 1992 C-2
Table C-4 Inorganic Compounds in Ground Water from Injection and
Monitoring Wells: March, 1993 C-3
Table C-5 Sample Number Nomenclature and Depth Interval for Sample Results
Presented in Table C-4..... C-4
XV
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Acknowledgements
We wish to acknowledge and thank Dr. Ronald Drake, on-site contract manager, and Dr. Daniel
Pope, Research Scientist, Dynamac Corporation, Ada, Oklahoma, for their efforts in helping us com-
plete the Libby Site Bioremediation Performance Evaluation. We would also like to thank Dr. Scott
Huling and Mr. Bert Bledsoe, U.S. EPA project officers, Robert S. Kerr Environmental Research Labo-
ratory (RSKERL), Ada, Oklahoma as well as Mr. John Matthews and Dr. Mary Randolph of the RSKERL,
for their invaluable technical and managerial assistance.
The cooperation of Champion International and Woodward-Clyde Consultants was essential to
the successful completion of this project. We are grateful to all who helped us conduct sampling activi-
ties, as well as provide technical review of our activities: Ralph Heinert, Jim Davidson, Dave Cosgriff,
and Jerry Cosgriffof Champion International and Dr. Mike Piotrowski, independent consultant (for-
merly of Woodward-Clyde Consultants).
We would also like to thank the following technical staff at Utah State University for their assis-
tance in field sampling activities and laboratory analyses and for their technical review activities: Jim
Herrick, Pamela Hole, Joan McLean, Brett Barney, Linda Krywy, Jon Ginn, Chad Ellis, James Kerrigan,
Boyd Welch, Allan Cooley, Scott Korom, and Michael McFarland.
We would also like to thank Mohammed Saleem, Graduate Research Assistant in the Department
of Civil and Environmnetal Engineering at Utah State Universisity, for conducting the laboratory evalu-
ation studies.
xvi
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Chapter 1
Introduction
1.0 Bioremediation Field Initiative
The Office of Solid Waste and Emergency Response (OSWER) and the Office of Research and
Development (ORD) of the U.S. Environmental Protection Agency (U.S. EPA) jointly established the
Bioremediation Field Initiative (BFI) in 1990 as part of a strategy to develop bioremediation as an
effective alternative remediation technology. The BFI was designed to address the need for additional
field experience concerning the implementation of bioremediation techniques, including the collection
and dissemination of performance data from field experiences.
Specifically, the BFI has three primary objectives: (1) to document more fully the performance of
full-scale bioremediation field applications in terms of treatment effectiveness and operational reliabil-
ity; (2) to provide technical assistance to U.S. EPA and State remediation managers responsible for
overseeing or considering use of bioremediation as a remedial alternative for hazardous waste sites;
and (3) to develop biotreatability data bases that will be available through the U.S. EPA's Alternative
Treatment Technology Information Center (ATTIC). This report focuses on Objective 1 by providing
an evaluation of a full-scale field application of bioremediation at a specific site, the Champion Inter-
national Supcrfund Site in Libby, Montana.
The first step in the implementation of Objective 1 of the BFI involved the identification of sites
where bioremediation was currently being planned, demonstrated, or implemented as an alternative
remediation technology. The Champion International Superfiind Site, a former wood preserving facil-
ity in Libby, Montana (referred to as the Libby Site), was nominated by the Robert S. Kerr Environ-
mental Research Center (RSKERC), Ada, Oklahoma, as a candidate site for bioremediation perfor-
mance evaluation. The Libby Site was subsequently selected for study during implementation of the
initial set of bioremediation field performance evaluations. The potentially responsible party (PRP),
Champion International, agreed to cooperate with the RSKERC in conducting the proposed
bioremediation performance evaluation studies for biological treatment processes in operation at the
Libby Site.
The Libby Site uses three distinct biological processes in the site remediation scenario: (1) surface
soil biological treatment in a prepared-bed, lined land treatment unit; (2) oil-water separation of ex-
tracted ground water, followed by aqueous phase treatment in an above-grade, fixed-film bioreactor,
and (3) in situ bioremediation of the Upper Aquifer. Results of the evaluation of in situ bioremediation
of the Upper Aquifer are presented in this report
1.1 Project Objectives
Objectives of the evaluation of the in situ bioremediation of the Upper Aquifer in this BFIsponsored
study were to: (1) describe and summarize previous and current remediation activities; (2) conduct a
field evaluation to assess the performance of remediation activities with regard to removal of contami-
nants associated with the subsurface solid particles and oily materials; and (3) perform a radiolabeled
chemical mass balance laboratory evaluation to assess the microbial metabolic potential of subsurface
aquifer materials to accomplish bioremediation of target chemicals under different management con-
ditions and to evaluate major fate mechanisms of target chemicals.
1
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Chapter 2
Conclusions
2.0 Conclusions
"With regard to the objectives of the evaluation of in situ bioremediation of the Upper
Aquifer identified in Section 1.1, conclusions include:
(1) With regard to objective 1, described in Chapter 4: describe and summarize previous and
current remediation activities, site characterization and remediation activities undertaken by the PRP
indicated that some in situ bioremediation could be accomplished at the site. Evidence for in situ
bioremediation was based upon field-scale pilot studies and demonstration studies conducted by the
PRP. The conclusion that bioremediation was occurring was based upon information generated that
indicated that concentrations of target chemicals in water from monitoring wells decreased in response
to the addition of oxygen and nutrients that were added for the purpose of enhancing microbial activity.
As a result of site characterization activities, long-term sources of ground-water contamination
were attributed to the presence of contaminants in aquifer nonaqueous phases, including nonaqueous
phase liquids (NAPLs) and sediments. Contamination occurred during the downward movement of
creosote, a dense nonaqueous phase liquid (DNAPL), through the Upper Aquifer sediments. NAPLs
and sediments provide a continuous source of contaminants to the water phase through diffusion, des-
orption, and solubilization processes, and therefore represent a challenge for bioremediation of the
Upper Aquifer.
The heterogeneous nature of the subsurface and preferential pathways for water flow through
more permeable layers was indicated as a result of a field pilot-scale study undertaken by the PRP. One
pilot-scale site responded to injection of hydrogen peroxide into the ground water by demonstrating
reduced contaminant concentration at a downgradient monitoring well, while another site did not re-
spond to treatment (Piotrowski, 1991), as determined in a different downgradient monitoring well.
Results observed during a 1990 evaluation by the PRP showed several additional wells with persistent
high oxygen and non-detectable dissolved contaminant concentrations (Piotrowski, 1991).
(2) With regard to objective 2, described in Chapter 5: conduct a field evaluation to assess the
performance of remediation activities with regard to removal of contaminants associated with the
subsurface solid particles and oily materials, field performance evaluation activities executed as part
of this BFI study demonstrated that, with respect to the water phase, total polycyclic aromatic hydro-
carbon (TPAH) compounds and pentachlorophenol (PCP) were present at lower concentrations in wells
under the influence of the treatment injection system that included nutrients and hydrogen peroxide,
while TPAH and PCP were present at higher concentrations in wells outside of the influence of the
injection system. Therefore, treatment appears to have occurred in the water phase under the influence
of the treatment injection system.
An evaluation of the water phase in monitoring wells locatfed in contaminated and uncontami-
nated areas demonstrated the presence of reduced inorganic compounds, including ferrous iron and
manganous manganese in both sets of wells. Concentrations of reduced chemicals were inversely
related to dissolved oxygen concentrations. These chemicals may exert a demand on the oxygen sup-
plied by the hydrogen peroxide and reduce the oxygen available for microbial utilization.
2
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With respect to the NAPL phase, both TPAH and PCP were found in the highest concentrations in
the LNAPL, greater than 10,000 and 1,000 mg/L, respectively, than in any other phase at the Libby
Site. These results indicated that there is contamination of the Upper Aquifer remaining in the form of
a NAPL phase that represents significant potential contamination by transfer of contaminants from the
NAPL phase to the water phase.
There was an observed difference between low levels of contaminants in monitoring well water
and high levels in aquifer NAPL/sediment samples. TPAH and total petroleum hydrocarbons (TPH)
were present within the NAPL/sedimcnt associated phases of the aquifer under the influence of the
treatment injection system at concentrations of 5 to 687 mg/Kg and 70 to 2,525 mg/Kg, respectively.
Pentachlorophenol (PCP), the most water soluble contaminant, was present in the lowest concentra-
tions (0.1 to 7.9 mg/Kg). The heterogeneous distribution of TPAH, PCP, and TPH contaminants in the
aquifer solid phase was consistent among all three boreholes evaluated from the water table to the
deepest sampling point. NAPL/sediment phases are often expected to be more difficult to bioremediate
in situ than the aqueous phase due to limitations of mass transport of oxygen and nutrients from the
water phase to the nonaqueous phases that contain the target chemicals.
The detection of such high concentrations of TPAH and TPH associated with NAPL/sediment
phases below the water table in the area of influence of the treatment (injection) wells after approxi-
mately five years of treatment indicates a lack of rapid response of the site to the stimulation of in situ
bioremediation. The delay in response is related to the nature of the source (NAPL and sediment) and
the subsurface heterogeneity that provides areas of high conductivity and areas of low conductivity for
water carrying nutrients and oxygen.
Information obtained through the field sampling conducted as part of this BFI study and through
previous site characterization activities by the PRP demonstrates the vertical heterogeneous stratigra-
phy of the subsurface as well as the heterogeneous distribution of contaminants. This heterogeneous
nature of the subsurface results in preferential pathways through permeable layers that may be respon-
sible for canying large volumes of injected water containing nutrients and oxygen. However, the
permeable layers may not coincide with the layers containing the highest degree of contamination. In
addition, even where subsurface areas are hydrodynamically connected, and therefore received nutri-
ents and oxygen from the injection system, the presence of immiscible NAPL in these areas results in
the presence of NAPL associated contaminants (TPAH, PCP, and TPH) that are less susceptible to
injection system influence than contaminants in the water phase.
An evaluation of the gas phase in selected areas near an injection well used to introduce hydrogen
peroxide and nutrients into the subsurface indicated that hydrogen peroxide was degassing and passing
into the overlaying unsaturated zone. The concentrations of oxygen in the soil gas in the vadose zone
pore space at 5 and 7 feet below ground surface (bgs) were 48 and 54 percent, respectively. This
degassing represents a pathway for abiotic loss of oxygen in the subsurface, thus reducing oxygen
available for microbial utilization in the saturated zone.
An evaluation of in situ bioremediation activity in the water phase was conducted by measuring
oxygen utilization as determined by differences in oxygen concentrations in injected and recovered
water using a push (injection)/pull (recovery) test However, high flow rates (greater than 50 feet
per day) prevented injected water from being naturally contained long enough for microbial activity to
decrease the oxygen concentration of the injected water and for the water to be recovered for measure-
ment. Therefore, push/pull tests at this site were not successful for measuring subsurface microbial
activity, due to site characteristics related to average high hydraulic conductivities and average high
subsurface ground-water flow velocities.
3
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(3) With regard to objective 3, described in Chapter 6: perform a Iradiollabeled chemical mass
balance aboratory evaluation to assess the microbial metabolic potential of subsurface aquifer mate-
rials to accomplish bioremediation of target chemicals under various conditions and to evaluate majro
fate mechanisms of target chemicals, an evaluation of the microbial metabolic potential of aquifer
samples indicated that aquifer materials contain indigenous microorganisms that have the ability to
mineralize PAH compounds that can serve as a metabolic source of cell carbon, as indicated by the
mineralization of the PAH compound, phenanthrene. There was no significant mineralization ob-
served in poisoned aquifer samples. PCP mineralization, however, was insignificant (less than two
percent) with results similar for nonpoisoned and poisoned samples.
Chemical mass balance experiments for phenanthrene and PCP assisted in the evaluation of field
results. Results demonstrated that up to 30 percent of phenanthrene was mineralized and up to 70 per-
cent became incorporated into the aquifer matrix and was non-solvent extractable, while less than six
percent was volatilized. With regard to PCP, mineralization was less than two percent in all evaluations
and incorporation into the aquifer matrix of up to 40 percent (non-solvent extractable) was lower than
that observed for phenanthrene. Volatilization of PCP was less than two percent. Therefore significant
mineralization and reaction with the solid phase aquifer matrix into non-solvent extractable residue
was observed with phenanthrene, while little mineralization and some reaction with solid phase aqui-
fer matrix into non-solvent extractable residue was observed with PCP.
Temperature, oxygen, and nutrient addition were evaluated with regard to their influence on the
treatment of phenanthrene and PCP- In non-poisoned samples, temperature and oxygen influenced rate
and extent of mineralization for phenanthrene. Addition of nutrients did not have a significant effect on
rate or extent of mineralization of phenanthrene or PCP. An acclimation period was consistently indi-
cated by the presence of a lag phase in the occurrence of mineralization. Therefore, mineralization of
PAH compounds in the aquifer samples appears to be primarily related to biological processes.
Results of the radiolabeled chemical mass balance laboratory evaluation were used to demon-
strate major treatment pathways for phenanthrene and PCP within the aquifer material taken from the
site. The major treatment pathway for phenanthrene was biological degradation and incorporation into
aquifer material. The major pathway for PCP was incorporation into the aquifer material. Biological
processes were more evident with phenanthrene transformation than with PCP transformation.
4
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Chapter 3
Recommendations
3.0 Recommendations
Based upon the information generated in the execution of the objectives of this evaluation of
field-scale in situ bioremediation of ground water at the Libby Site, several recommendations are pre-
sented.
(1) Because the free product NAPL present in the subsurface may represent a long-term source
of contamination to ground water, source removal technologies and techniques should be evaluated.
Large sources as well as dispersed sources of NAPL within the aquifer should be identified. Areas with
the largest masses of source material should be removed in order to enhance the efficiency and effec-
tiveness of in situ bioremediation. Therefore, the use of a treatment train, which would include more
emphasis on free product removal methods, in addition to the existing treatment technologies that
include above-ground treatment of the water phase and in situ treatment of PAH compounds sorbed to
the solid phase as well as treatment of residual saturation of PAH compounds in the soil pores, may be
appropriate.
(2) Because hydrogen peroxide reacts with reduced iron to create highly oxidizing agents, (e.g.,
Fenton's reagent) the combination of chemical and biological treatment may be possible by optimizing
the addition of ferrous iron and hydrogen peroxide to the subsurface. The chemical oxidation may
transform residual NAPL to make it more bioavailable through oxidation processes that render the
components more water soluble. Preliminary studies should be conducted to evaluate effectivenss and
to identify the processes occurring in the reactions involving ferrous iron and hydrogen peroxide in the
subsurface environment present of the Upper Aquifer.
(3) An evaluation of mixing effectiveness for hydrogen peroxide and nutrients within the sub-
surface should be conducted for the area under treatment, since field-scale sampling results indicate a
heterogeneous stratigraphy with large differences in chemical contaminant concentrations with depth,
and pilot-scale studies performed by the PRP indicated differential responses to the addition of hydro-
gen peroxide. Mixing effectiveness will be influenced by properties of the injected fluid (water) and
properties of the aquifer, including stratigraphy and heterogeneity. Identification of areas where mix-
ing is inadequate and where desorption and/or dissolution of contaminants result in threats to offsite
contamination would indicate that management techniques should be developed to enhance mixing in
those specific areas. Potential measures to enhance mixing include tighter well spacings and multiple
vertically-oriented injection intervals.
(4) Based upon results obtained for solid and NAPL phases at the Libby Site, the Upper Aqui-
fer solid phase and NAPL phase should be monitored to determine the effectiveness of treatment of
PAHs and PCP at the site. Although determination of attainment of cleanup standards requires ground-
water monitoring, solid phase and NAPL monitoring would help elucidate impacts of bioremediation
on long-term groundwater quality. Characteristics of the water phase cannot be used to indicate the
extent of a NAPL phase at this site.
(5) Reactions of reduced manganese, identified at the site, and hydrogen peroxide should be
evaluated for their effect on target contaminants. Abiotic treatment may occur whereby reduced man-
ganese, oxidized by hydrogen peroxide, reacts with PAH transformation products and PCP.
5
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Chapter 4
Site Characteristics and Remediation Activities
4.0 BFI Study Objective 1: Previous and Current Remediation Activities
As part of the field performance evaluation of in situ bioremediation of the Upper Aquifer at the
Libby Site, information concerning remediation activities was summarized in order to understand the
purpose and design of the remedial system. However, Champion International operates the in situ
bioremediation system in a dynamic capacity. To improve or optimize the system, modifications to
system operations are implemented as required. Therefore, the activities and plans summarized here
were current at the time of the study. Several of the operational procedures used at the time of the study
have been changed. For example, hydrogen peroxide injection has been changed to injection of com-
pressed oxygen gas.
4.1 Site Description, History and Extent of Contamination
The Libby Site is an active lumber mill located southeast of the town of Libby in northwest
Montana (Figures 4.1 and 4.2) (Piotrowski, 1991). The site is located in an alluvial valley adjacent to
the Kootenai River. Surface soils vary from clays to gravels. Due to alluvial processes and past glacia-
tion, the stratigraphy beneath the site is complex, consisting of interbedded layers of highly coarse
deposits with lenses and layers of lower permeability. The intermingled deposits include clays, silts,
sands, gravels, cobbles, and boulders (Figure 4.3). The lateral extent of the deposits are usually lim-
ited. The deposits can typically be correlated from borehole to borehole in the subsurface over very
short distances (Woodward-Clyde Consultants, 1990).
Two ground-water bearing units underlie the site (Piotrowski, 1991). The shallowest unit (re-
ferred to as the Upper Aquifer) extends approximately 12 to 70 feet bgs. The sediments are generally
coarse-grained, composed of laterally discontinuous, interbedded sequences of gravel and sand, clayey
gravels, and sand, silt and clay, and have few confining layers. The depth of the water table surface
varies seasonally. Regional ground-water flow is primarily to the northwest, although the complex
stratigraphy of the aquifer results in flow paths of variable directions on a micro-scale. The complex
geology of the aquifer also results in broad ranges of aquifer characteristics such as transmissivity and
conductivity. Transmissivities have been estimated as high as about 2,000,000 gallons per day per
square foot (gpd/ft2), based on pumping tests. Additional information on the Upper Aquifer is provided
in Section 4.5 (see Figure 4.17).
Beneath the Upper Aquifer is a discontinuous, semi-permeable, fine-grained layer composed of
clays, silts, fine sands, etc. that restricts, but does not preclude, vertical migration of ground-water
(middle aquitard) (Piotrowski, 1991). The layer is approximately 30 feet thick and ranges from about
70 to 100 feet bgs. The second water-bearing unit (referred to as the Lower Aquifer) lies below the
fine-grained layer and extends from 100 to approximately 180 feet bgs. Regional ground-water flow in
this aquifer unit is to the north. This aquifer appears to be a more consolidated water-bearing unit than
the Upper Aquifer.
6
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Figure 4.1. Location of Llbby Project,
Fi gure 4.2. Llbby Site
7
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Grouod Surface
Sand, SQry
- 10
Gravel. Sandy
and Clayey
_ 20 Clay, Saodv
and Gravelly
iJaad. Oayey
and Gravelly
- JO
1
laterbedded Sand
aod Clay
-40
s
Upper Aquifer
... Gravels, Sandy
and Clayey
- 70
Middle Aquitard City, Sandy
L to
Figure 4.3. An Example of the Stratigraphy of the Upper Aquifer (Woodward-Clyde Consultants, 1990)
Wood preservative wastes (including creosote, PCP at 5 percent in a dicsel fuel-like carrier, and
waste sludges) were released into the soil environment at the site. Creosote is a complex mixture of
over two hundred organic compounds derived from coal tar (McGinnjs et al., 1991). Creosote consists
primarily of neutral fractions containing single- to multiple-ring compounds. Tar acids, such as phenol
and cresols, and tar bases, such as quinoiines, pyridines, and acridines, constitute a small percentage of
the total weight of creosote. Chemical and physical properties of specific creosote products are influ-
enced by the characteristics of the tar from which it originates, the type of equipment used in the
distillation process, and the particular process used for preserving wood
Primary contaminants of concern in creosote are PAH compounds, which are found in the neutral
fraction. PAH compounds consist of two or more fused benzene rings, with each ring sharing two
carbon atoms. Sixteen PAH compounds have been designated as priority pollutants by the U.S. EPA
due to their toxic, mutagenic, carcinogenic, teratogenic, and/or fetotoxic properties (40 Code of Fed-
eral Regulations (CFR) Part 423, Appendix A) and have also been listed as hazardous constituents by
the U.S EPA (40 CFR Part 261, Appendix XIII and IX). Properties of these priority pollutant com-
pounds are presented in Table 4.1. The major PAH compounds present in creosote include two-, three-
, and four-ring compounds and their methyl derivatives (Sims et al., 1986). Creosote also contains
smaller amounts of five- and six-ring PAH compounds.
Two- and three-ring PAH compounds can be utilized by soil microorganisms as sole carbon sources
and are usually easily degraded (Sims and Overcash, 1983; Sims et al., 1986). PAH compounds with
a greater number of rings are not known to be utilized as sole carbon sources but can be cometabolized
with other organic compounds (Keck et al., 1989). Cometabolism involves concurrent metabolism of
a carbon source capable of sustaining growth with a compound that the microorganism is unable to use
as a sole source of energy.
8
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Table 4.1 Properties of 16 Priority Pollutant PAH Compounds (Sims et al., 1986).
Vapor Pressure
Aqueous Melting Boiling @ 20°C
Molecular Solubility Point Point torr
Weight ug/L °C X LowK»w
Length of
Molecule
A Kqc
i. Two Rings
Naphthalene
2. Three Rings
Acenaphthylene
Acenaphthene
128
31,700
152 3,470
154 3,930
80
92
96
218
265
279
4.92x10-2 , 3.37
2.9 x 10-2
2.0x10-2
4.07
•.33
8.0 1,300
Fluorene
Anthracene
166 1,980 116 293 1.3x10-2 4.18
178 73 216 340 1.96 xl(H 4.45 10.5 2,600
Phenanthrene
178 1,290
101
340 6.80x10-4 4.46
9.5 23,000
3. F
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Table 4.1 (Continued)
Vapor Pressure
Aqueous Melting Boiling @ 20*C Length of
Molecular Solubility Point Point torr Molecule
Weight ue/L 'C 'C Low K.w A* IU.
Benz(a)anthracene
Chrysene
4. Five Ring
Benzo(b)fluoranthene
228 14 158 400 5.0x10-9 5.61 11.8
228
255
252 1.2 16:
6.3x10-7 5.61 11.8
5.0x10-7 6.57
Benzo(k)fluoranthene
Benzo(a)pyrene
Dibenz(a,h)anthracene
0.55 217 480 5.0x 10-7 6.84
3.8 179 496 5.0x10-7 6.04
4,510,651
278 2.49 262 — 1.0x10-10 5.97 13.5 2,029,000
-------
Table 4.1 (Continued)
Vapor Pressure
Aqueous Melting Boiling @ 20*C Length of
Molecular Solubility Point Point torr Molecule
Weight ng/L °C °C LowKnw A' K«,
5.
Benzo(g,h,i)perylene
276 0.26 222
1.0x10-10 7.23
Indeno( 1,2,3-Cd)pyrene
276 62 163
1.0x10-10 7.66
-------
PAH compounds are nonionic, nonpolar compounds that do not ionize significantly in aqueous
systems. Sorption of nonionic compounds is primarily a function of solubility. PAH compounds
participate in hydrophobic sorption in a soil Systran, where the nonpolar PAH compounds partition out
of the polar water phase onto hydrophobic surfaces of the soil matrix. Hydrophobic sites include fats,
Table 4.2. Physical Properties of PCP (McGlnnls et aL, 1991)
Property
Value
Empirical formula
C6C150H
Molecular weight
255.36
Melting point
190° C
Boiling point
293° €
Density
1.85 g/cm3
pKA(25°C)
4.70 -4.80
Partition coefficient (Kp), 25° C
Octanol-water
1760
Hexane-water
1.03 x 105
Vapor pressure, torr (mm Hg)
0°C
1.7 x 10-5
20e C
1.7 x 10-4
50° C
3.1 x 10-3
100° C
0.14
200° C
25.6
300° C
758.4
Solubility in water (g/L)
0°C
0.005
20° C
0.014
30° C
0.020
50° C
0.035
70° C
0.085
Solubility in water (25C)* pH (mg/L) (Std Dev)
4.2
13.2 2.2
5.0
21.6 1.5
6.3
147 25
7.7
1460 8
9.0
8130 98
Solubility in organic solvents (g/100 g solvent)
in methanol, 20° C
57
in diethylether, 20° C
53
in ethanol, 20° C
47
in acetone, 20° C
21
in xylene, 20° C
14
in benzene, 20° C
11
in carbon tetrachloride, 20° C
2
* Data from A. Ramaprasad (1994)
12
-------
waxes, and resins of the soil organic matter. The organic matter content of the soil or aquifer system is,
therefore, more important in determining the extent of sorption of PAH compounds than substrate pH,
cation exchange capacity, texture, or clay mineralogy (Means et al., 1979). Most PAH compounds tend
to be nonvolatile, with acenaphthalene and naphthalene being the most volatile.
Technical-grade PCP (4% - 8%) dissolved in a diesel fuel-like carrier was also used as a wood
preservative at the site. Physical properties of PCP are presented in Table 4.2. Technicalgrade PCP
usually contains 85 to 90 percent PCP, while the remaining materials are 2,3,4,6tetrachlorophenol (4 to
8 percent), "higher chlorophenols" (2 to 6 percent), and chlorinated dioxins and furans (0.1 percent)
(McGinnis et al., 1991). Tetrachlorophenol is added to PCP to increase the rate of solubilization, while
the other compounds are formed as contaminant by-products during manufacture. PCP is manufac-
tured from phenol using a catalytic chlorination process. PCP, a highly chlorinated, exceptionally toxic
compound, has been listed as a 40 Code of Federal Regulations (CFR) Part 261, Appendix IX hazard-
ous constituent by the U.S EPA; wastes containing PCP are classified as hazardous.
PCP is stable and considered to be chemically inert. Though the chlorinated ring structure of PCP
increases its stability, the polar hydroxyl group facilitates biological degradation (Renberg, 1974;
McGinnis et al., 1991). The transport of PCP is related to the pH of the environment, since the proto-
nated (phenolic) form is practically insoluble in water, while monovalent alkali metal salts of PCP are
soluble in water. The pKa of PCP at 25° C is 4.7 to 4.8; therefore, sorption of PCP significantly
increases with decreased pH. Greatest sorption occurs at a soil pH between 4.6 and 5.1. Little sorption
occurs above a soil pH of 6.8, which is the near thepH of the Upper Aquifer at the Libby site, therefore
PCP would be expected to be present in the water phase.
The wastes were released in three primary areas of the site; (1) an unlined waste pit that received
waste sludges and other organic residues from wood-treating operations and wood preservative liquids
that did not meet user specifications; (2) a former tank farm area that had been contaminated during
chemical transfer operations; and (3) an unlined butt dip area, where wood preservatives were released
directly to an unlined excavation and were used to treat the ends of telephone poles (Piotrowski, 1991).
The quantities of wood preservatives released in each area were not recorded.
The released contaminants migrated downward through the soils from the source areas into the
Upper Aquifer. LNAPLs spread out over the surface of the water table in the Upper Aquifer, were
dispersed by ground-water flow, and are still present in some areas of the site (Piotrowski, 1991).
DNAPLs moved down through the Upper Aquifer, passed through the more permeable regions of the
fine-grained intervening layer, and entered the Lower Aquifer, where they may have accumulated in
pools and/or began to migrate horizontally. During the downward movement of the DNAPLs, sedi-
ments in the Upper Aquifer, the fine-grained intervening layer, and the Lower Aquifer became con-
taminated by both sorption of organic compounds and residual saturation of the DNAPL (residual
saturation describes the saturation level at which the DNAPLs become discontinuous and are immobi-
lized by capillary forces within soil pores; the DNAPLs under low moisture conditions in the unsatur-
ated zone may exist as a wetting fluid around the contact points of adjacent grains; under higher mois-
ture conditions in the unsaturated zone and in the saturated zone, the DNAPLs may exist as isolated
droplets in the open pores (Huling and Weaver, 1991). These sorbed and residual contaminants are
serving as long-term sources of ground water contamination. A conceptual schematic of possible flow
scenarios of the DNAPLs at the Libby Site, as illustrated in Figure 4.4, demonstrates the complexity of
contamination at the site.
Ground-water flow in the Upper Aquifer distributed the wood-treating fluids downgradient from
the points of release, and by 1986, the plume of contaminated ground water in the Upper Aquifer was
about two kilometers long and encompassed 94 hectares (Piotrowski, 1991; Piotrowski and Doyle,
13
-------
Groundwater
How
Fractured
Clay or Rock
Groundwater
Row
Sand
Sand
V////777777/77^
,7777777777777777777?
/ Impermeable Boundary
Figure 4.4. DNAPL Transport in the Subsurface (Huling and Weaver, 1991)
1990; Woodward-Clyde Consultants, 1986b). Contaminant concentrations in the Upper Aquifer ground-
water plume range from percent levels in the waste pit area to partsper-billion (ppb) levels at the
downgradient edge of the plume. The Upper Aquifer also contains mobile NAPL as well as residually-
trappedNAPL.
Off-site, private drinking and irrigation wells became contaminated by the plume. Complaints by
the residents of Libby with wells affected by the contamination led to an investigation by the U.S. EPA
and placement of the site in 1983 on the National Priority List (NPL) tor cleanup (Piotrowski, 1991).
Remedial investigations were initiated and conducted through 1986 (Woodward-Clyde Consultants,
1986a,b). In 1985, the feasibility study (FS) process was initiated to evaluate remedial options for
treatment of the site. During the FS process, on-site, feasibility studies were conducted that indicated
that biological treatment could result in appreciable reductions in contaminants in the Upper Aquifer.
These studies demonstrated that as ground water passed through the contaminated zone of the aquifer,
the concentrations of dissolved oxygen and other electron acceptors (i.e., nitrate, nitrite, and sulfate)
were reduced (Piotrowski and Doyle, 1990; Woodward-Clyde Consultants, 1986a, b). These observa-
tions suggested than the presence of contaminants in the Upper Aquifer was stimulating in situ biologi-
cal activity. These results also suggested that lack of oxygen may have been limiting the microbial
degradation of the wood preserving contaminants, since the major contaminants present were known
to degrade more rapidly under oxic conditions than under anoxic conditions.
In 1986, a "Buy Water" plan was implemented in which Libby residents with contaminated wells
were reimbursed for using municipally-supplied water in place of using contaminated water from their
private wells. Also, there was a prohibition placed on new well installation within Libby City Limits.
This plan was initially implemented by the owner of the lumber mill and the City of Libby in the spring
14
-------
of 1986 and was later mandated by the U.S. EPA in the fall of 1986 (U.S. EPA, 1986a). The "Buy
Water" plan resulted in the elimination of human exposure to the contaminated ground water. How-
ever, due to the potential risks associated with the contaminant plume and the potential for contamina-
tion of additional private off-site wells, target remedial (cleanup) levels and remedial plans for the
Upper Aquifer were developed.
In 1988, following a pilot-scale study conducted in 1987-1988 (see Sec. 4.4), the U.S. EPA pro-
mulgated the Record of Decision (ROD) for the site that stipulated that in situ enhanced biological
restoration would be used for treatment of the Upper Aquifer. The remedial action plan (RAP) for
treatment of the site was prepared (Woodward-Clyde Consultants, 1989) and approved by the U.S.
Department of Justice and the U.S. EPA in October 1989 by consent decree (Civil Action No. CV 89-
127-M-CCL).
The extent of contamination in the Lower Aquifer is not as well understood as in the Upper Aqui-
fer (U.S. EPA, 1990). There are no residential or irrigation wells in the Lower Aquifer downgradient
from the site. A study has been initiated to assess the potential for bioremediation of the Lower Aqui-
fer. A combined approach of bioremediation and oil recovery techniques will also be studied.
4.2 Target Remediation Levels
The final target remediation levels in the Upper Aquifer, as specified in the ROD (U.S. EPA,
1988), were defined as:
(1) 40 ng/L (part per trillion, or ppt) of total carcinogenic PAH compounds;
(2) 400 ng/L (ppt) of total PAH compounds;
(3) 1.05 mg/L of PCP;
(4) 5 mg/L of benzene;
(5) 50 mg/L of arsenic; and
(6) a human health threat of no greater than 105 for ground-water concentrations of other
organic and/or inorganic compounds.
Existing U.S. EPA analytical methodology has limits of detection for total carcinogenic PAH
compounds in ground water of greater than 1 part per billion (ppb). Therefore, the determination as to
whether target remediation levels are being achieved is beyond the capability of existing accepted
analytical methods. In addition, although background PAH levels in ground water at the site are gen-
erally below detection limits, whether these concentrations are also below remediation levels has not
been established (Woodward-Clyde Consultants, 1990).
43 Full-Scale System
The objectives of the in situ bioremediation program are to achieve, to the fullest extent possible,
removal of PCP and PAH compounds from the ground water in the Upper Aquifer. A combination of
treatment technologies is being used to achieve this goal, including: (1) in situ bioremediation of the
aquifer; and (2) extraction of contaminated ground water and treatment in an above-ground, fixed film
bioreaetor. An evaluation of the first technology is presented in this report; a second report is available
that includes evaluation of the bioreaetor system (Stevens et al., 1994). The objective of the bioreaetor
system is to recover and treat highly contaminated ground water associated with the waste pit source
area so that subsequent in situ bioremediation of this area of the Upper Aquifer will result in more
15
-------
efficient removal of residual contamination. The bioreactor system consists of three components:
ground water extraction wells, ground-water bioreactor unit with equalization tank, and infiltration
trench for reinjection of treated ground water (Woodward-Clyde Consultants, 1990).
Design of the full-scale in situ bioremediation system proposed for the site will be implemented
and installed in a sequence of phases (Woodward-Clyde Consultants, 1990; Piotrowski, 1991). The
initial phases of study included pilot-scale and demonstration studies. After the demonstration study,
Phase I of the remedial activity was initiated. Design and implementation of Phase II will be initiated
after information from Phase I concerning the performance of the injection wells and their effects on
the aquifer is evaluated.
The variable nature of contamination at the site complicates the ability to remediate the site.
Since aqueous phase contamination has been transported along tortuous pathways within the complex
stratigraphy of the site, delivery of oxygen and nutrients to the contaminants is difficult to achieve.
DNAPL contaminants are also likely to have sorbed to and/or formed areas of residual contamination
in fine-grained strata; such areas are difficult to treat rapidly in situ because of the slow diffusion of
nutrients and oxygen into areas of residual saturation. Because of these factors, the final design will be
implemented in phases so that the ability of the system to degrade contamination in this heterogenous
aquifer can be properly assessed and modified as necessary. A phased implementation should also
allow for better design of the final system since additional data collected during the initial remedial
actions can be used in the final design. Specific data that are being collected during the initial phases
include: (1) interactions between adjacent injection wells; (2) long-term effectiveness of the in situ
program; and (3) efficiency of the system to remediate low levels of PAH compounds.
The full-scale, in situ system was originally conceived to consist of three separate injection sys-
tems. The locations of the injection systems (illustrated in Figure 4.5) include: (1) the waste pit source
area, which is at the head of the contaminant plume; this injection system (referred to as the source area
or upgradient injection system) will be installed to treat the most heavily contaminated region of the
Upper Aquifer; (2) in the vicinity of the existing pilot-scale system in an intermediate location (in the
tank farm source area) in the contaminant plume (referred to as the intermediate injection system; this
system was the primary focus of this BFI study, since it has been operated the longest and more data
were available at the beginning of the study); and (3) along the downgradient boundary of the lumber
mill site to treat off-site plume areas (referred to as the boundary injection system). The upgradient and
intermediate systems are designed to remediate their respective source areas. The boundary injection
system is located approximately 1,000 to 2,000 feet downgradient of the intermediate system and
1,000 to 2,000 feet upgradient from the boundary of the contaminated plume. At the time of this
investigation, however, not enough information was available to elaborate on the Phase II remedial
design with additional detail.
The effectiveness of the in situ bioremediation program will be assessed by periodic monitoring
of the ground water through a network of monitoring wells (Woodward-Clyde, 1990). Each well will
be monitored monthly for dissolved oxygen, water level, and temperature, and quarterly for PCP and
PAH compounds during operation of the injection systems. The injection and extraction rates for each
well will be measured weekly.
Each injection system consists or will consist of injection sites connected by subsurface piping for
year-round use of surface water amendment facilities, which are currently used to add hydrogen perox-
ide and nutrients to the injection water. The addition of an oxygen source (/.e,hydrogen peroxide) and
nutrients is expected to stimulate biodegradation of PCP and PAH compounds in the ground water as
well as those sorbed and trapped in the aquifer sediments. Each injection well has been or will be
16
-------
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Figure 4.5. Source Area, intermediate, and Boundary Injection Systems (Piotrowski, 1991).
completed and screened to a depth that fully penetrates the Upper Aquifer (Woodward-Clyde Consult-
ants, 1990). The well screen is a 4-inch stainless steel (to withstand the corrosive effects of hydrogen
peroxide) screen with 0.03 inch slots. Selection of the slot size was based on gradational analyses of
the formation material. Above the well screen, 4inch steel casing is used to the ground surface. The
sand pack for the wells is either a natural pack or an approximate 8 to 12 grade sand pack.
17
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Each new injection well is tested before use (Woodward-Clyde Consultants, 1990). In addition,
a bromide tracer test is performed in each new injection well. The test consists of injecting bromide in
the injection well and monitoring the appearance of bromide in downgradient monitoring wells for
approximately five days. These tests provide information concerning aquifer properties such as aqui-
fer flow patterns and hydraulic properties that can be used in the design of Phase II injection systems.
The source of the injection water is the fire protection system for the facility, which includes the
fire pond and water mains throughout the site. Inj ection water is filtered through a sand filter to remove
particulate matter (solids greater than 0.45 mm in diameter) that could clog injection well screens.
After filtering, hydrogen peroxide and nutrients are added to the water from storage tanks. The inter-
mediate injection system operates at nearly 100 gallons per minute (gpm) and the boundary injection
system operates at 245 gpm total. This injection rate is divided into the different injection wells within
each system. Operational monitoring requirements include monthly measurements of water depth in
injection wells (to check for clogging), periodic backwashing of sand filters, periodic recharging of the
hydrogen peroxide and nutrient tanks, and routine visual inspections. If clogging of the injection wells
does occur, high concentrations of hydrogen peroxide or low concentrations of acids will be added to
remove accumulations of microorganisms or chemical precipitates that may have formed around the
injection well screens.
The source area injection system will consist of injection sites located around the head of the
contaminant plume (Figure 4.6) (Piotrowski, 1991). Hydrogen peroxide and nutrients will be added to
the aquifer region that underlies the former waste pit area to stimulate biodegradation. When this area
of the aquifer is remediated, the major source of ground-water contamination at the site will have been
removed. No injection wells will be installed in this area during Phase I so that the ground-water flow
in the area can be further investigated (Woodward-Clyde Consultants, 1990). This area has a complex
flow pattern due to: (1) mounding from the fire pond, which can cause seasonal variations in the
ground-water flow pattern; and (2) operation of the ground-water infiltration trench and extraction
wells, which are a part of the bioreactor system for treatment of ground water. Monitoring of ground-
water levels will be conducted during Phase I in order to characterize hydraulic head distribution and
ground-water flow patterns in the area as affected by the infiltration trench and extraction wells. These
data are required to define well placement, spacing, and flow rates so that oxygen and nutrients can be
effectively delivered to this area of the Upper Aquifer during Phase II.
The injection sites of the intermediate and boundary injection systems will be located along transects
that run perpendicular to the direction of regional ground-water flow (i.e., across the contaminant
plume) (Piotrowski, 1991). In Phase I, the intermediate system will consist of all the wells used in the
pilot-scale and demonstration studies (referred to as Well Nos. 3004, 3007, 9500, and 9501) (Fig-
ure 4.7). This system is designed to provide oxygen and nutrients to the middle part of the contami-
nated ground-water plume and to the tank farm area. In the intermediate injection system, hydrogen
peroxide is used as the oxygen source. Approximately 50 gpm of hydrogen peroxide will be injected in
the full-scale injection well and 10 to 40 gpm in the existing pilot-scale/demonstration study wells
(Woodward-Clyde Consultants, 1990).
The monitoring wells to assess the performance of the intermediate injection system will consist
of the wells used for the demonstration program as well as two new wells (Well Nos. 3038 and 3039).
The location of the new wells was selected to provide data for determining the lateral and downgradient
effects near the northeast end of the intermediate injection system.
The boundary injection system, designed to enhance degradation in the off-site portion of the
contaminated ground-water plume, is located along the property boundary (Figure 4.8). Two injection
wells are being installed during Phase I so that the effects of the in situ injection system in this area can
18
-------
Figure 4.6. Source Area Injection System (Woodward-Clyde Consultants, 1990).
be better defined (Woodward-Clyde, 1990). Data collected during Phase I will be used to design the
remaining part of the boundary injection system in Phase II. The use of an oxygen generator to provide
oxygen (95 percent pure) will be investigated to determine if sufficient oxygen can be provided for
microbial activity while reducing operational costs. The levels of contaminants in this region of the
plume are relatively low compared to upgradient regions of the plume, and less oxygen may be re-
quired for remediation. Oxygen injection rates using the generator will be set to deliver oxygen con-
centrations of approximately 40 mg/L (WoodwardClyde Consultants, 1990). The injection wells will
be operated at rates ranging from 50 to 100 gpm. These higher injection rates, as compared to the rates
used in the intermediate injection system, were selected due to higher transmissivity estimated to exist
in this area. The higher injection rates are required to affect the same area affected during the demon-
stration study.
The monitoring network for the boundary injection system during Phase I consists of onsite and
offsite monitoring wells and privately owned offsite wells (Woodward-Clyde Consultants, 1990). Prior
to initiating the injection program in this system, these monitoring wells will be sampled for PAH
compounds, PCP, dissolved oxygen, and nutrient concentrations to establish baseline conditions.
19
-------
Figure 4.7. Intermediate Injection System (Woodward-Clyde Consultants, 1990).
Ideally, as injection of nutrients and an oxygen source continue in the injection areas and as con-
taminants are degraded, oxygen consumption rates in the immediate vicinity of the injection wells
should decline, and zones of elevated dissolved oxygen (D.O.) (i.e., oxic zones) should form and ex-
tend further down gradient. The formation and expansion of the oxic zones produced at each injection
site should eventually create elongated oxic zones in the Upper Aquifer that are perpendicular to the
direction of regional ground-water flow (i.e., across the contaminant plume). These extended oxic
zones should be biologically active zones that will result in the degradation of PCP and PAH com-
pounds passing into the zones from upgradient aquifer regions (Piotrowski, 1991).
20
-------
Figure 4.8. Boundary Injection System (Woodward-Clyde Consultants, 1990).
21
-------
4.4 Pilot-Scale Study of the Intermediate Injection System
A pilot-scale in situ bioremediation system was designed and installed in July 1987 at the
site of the intermediate injection system (Piotrowski, 1991). The study, using smaller injection wells
and lower injection rates than those planned for full-scale operation, was conducted for over one year.
A preliminary feasibility assessment had indicated that dissolved oxygen was a primary limiting factor
for aerobic contaminant biodegradation within the aquifer. The pilot-scale study involved operation of
an injection system to supply dissolved oxygen to the contaminated plume, located approximately
750 feet downgradient from the waste pit area.
Hydrogen peroxide (H202) was selected to serve as the oxygen source. Hydrogen peroxide de-
composes to dissolved oxygen in the environment at a ratio of two peroxide molecules to one oxygen
molecule. Some oxygen can be lost via Fenton's reaction and other oxidative processes that can be
facilitated by the presence of H202. Hydrogen peroxide was injected into the aquifer at 100 mg/L,
therefore, calculation indicates an oxygen concentration of approximately 50 mg/L in the groundwater
ideally.
The pilot design utilized two injection sites (Well Nos. 3004 and 3007) located within the con-
taminant plume approximately 600 feet downgradient of the waste pit area (Figure 4.9). The two well
sites were approximately 250 feet apart perpendicular to the direction of ground-water flow. Each site
consisted of paired wells constructed so that water was injected at depths approximately 15 and 30 feet
bgs in each well. The injection sites were connected by subsurface piping to an injection system that
delivered filtered fire pond water containing hydrogen peroxide at a total flow rate of 40 gpm. Injec-
tion was conducted under atmospheric pressure and gravity.
Two 4-inch diameter monitoring wells (Well Nos. 3025 and 3026) were installed approximately
200 feet downgradient from the two injection sites. Each well had an extended vertical screen (15 or 20
feet in length) that was located at such depths as to sample the aquifer region under the influence of the
injection system (i.e., the treatment zone). A monitoring well (Well No. 3012) located upgradient of
the injection system was sampled to provide information on water quality characteristics of the ground
water entering the treatment zone.
An initial bromide tracer study was conducted to evaluate ground-water flow conditions during
operation of the injection system and to verify that the downgradient monitoring wells were hydrauli-
cally connected to the injection system (Piotrowski, 1991). Results of the tracer study indicated that
the injection system produced a ground-water flow rate greater than 100 feet per day in the Upper
Aquifer immediately downgradient from the injection system. In addition, the injected water was
reaching the monitoring wells 200 feet downgradient in a period of less than two days.
Injection of tihe hydrogen peroxide began in July 1987. The three monitoring wells were purged
and sampled bi-weekly for D.O. concentrations. Nutrient concentrations and total microbial densities
were also measured periodically. For the first four months of the study, D.O. concentrations in the
upgradient monitoring well and in the two downgradient monitoring wells remained below 1 mg/L
(Piotrowski, 1991). Approximately 150 days after the initiation of the injection program, the D.O.
concentrations in one of the primary downgradient monitoring wells initially increased to approxi-
mately 12 mg/L and continued to increase and remain between 15 and 20 mg/L for over one year.
These results suggested that injection of the hydrogen peroxide solution created a zone of elevated
D.O. (an oxic zone) within the contaminant plume that extended at least 200 feet downgradient from
one of the injection sites (Figure 4.10). At oxygen breakthrough, however, there still may exist flow
paths between injection and extraction wells that are not receiving proportional groundwater and oxy-
gen.
22
-------
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Ground-water samples collected from within this zone indicated lower concentrations of total
hydrocarbon contaminants compared to the untreated region of the contaminant plume. During the
first four months of the study, PAH and PCP concentrations were similar to levels observed in the
upgradient control well (greater than 1000 mg/L total contaminant concentration (Piotrowski, 1989).
However, once the D.O. concentration in the monitoring well increased, dissolved contaminant con-
centrations decreased to less than 20 mg/L. Contaminant concentrations continued to decrease so that
454 days after hydrogen peroxide injection, PAH compounds were not detectable in a sample collected
from the monitoring well with increased D.O. levels, while the PCP concentration was 1 mg/L. How-
23
-------
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1991).
ever, only one of the two monitoring wells exhibited oxygen breakthrough and produced ground-water
samples containing reduced contaminant concentrations, indicating that the subsurface influence of the
injection system varied across the treatment zone in the Upper Aquifer. Preferential pathways through
permeable layers may be responsible for carrying relatively large volumes of injected water, but the
permeable layers may not coincide with the layers with the highest degree of contamination,
4,5 Demonstration Study
A demonstration program for remediation of the Upper Aquifer using full-scale inj ection wells (in
contrast to the smaller wells used in the pilot-scale study) was designed, constructed, and operated
from January to June, 1990. Because the stratigraphy of the site is complex and the hydraulic charac-
teristics of the Upper Aquifer vary considerably over short distances, the demonstration program was
conducted to gain additional information on full-scale system performance for enhancing biodegrada-
tion and to evaluate the operational performance of the injection system before implementation of full-
scale operations in Phase I (Piotrowski, 1991). Data obtained from the demonstration program were
24
-------
used to: (1) further evaluate the effectiveness of the injection of an oxygen source into the Upper
Aquifer; (2) investigate the potential for the addition of a nutrient injection program to further enhance
subsurface microbial activities; (3) acquire more information on the zone of influence of the fiill-scale
injection wells to use in final design; and (4) gain more knowledge about the operational components
of the system (WoodwardClyde Consultants, 1990).
For the demonstration study, one full-scale injection system was installed at a location in the
intermediate injection system area midway between the two injection sites used in the pilot-scale study
(Piotrowski, 1991). The location was selected to be near the center of the contaminated ground-water
plume, in proximity to several downgradient monitoring wells, and close to the injection building,
where the hydrogen peroxide and nutrients are mixed with the injection water. The site consisted of
two adjacent injection wells (Well Nos. 9500 and 9501) (Figures 4.7 and 4.11), each 4 inches in diam-
eter with a 20 foot wire-wrap screen section. Well No. 9500 was installed with a screen interval of 45
to 65 feet bgs in an interval where the sediments have moderate permeability (Figure 4.12). Well No.
9501 was screened at a shallower depth, with its screen interval at depths ranging from 18 to 38 feet bgs
in sediments that have higher permeabilities than those in Well No. 9500 (Figure 4.13). These depths
were selected to distribute the injected water across the thickness of the Upper Aquifer so that oxygen
and nutrients could be applied evenly over (he Upper Aquifer zone. The two existing pilot-scale injec-
tion wells (Well Nos. 3004 and 3007) were not used during the demonstration study since the purpose
Figure 4.11. Location of Injection Wells and Monitoring Wells in the Immediate Area during the Demostration
Program (Woodward-Clyde Consultants, 1990).
25
-------
PROJECT NAME CHAMPION-LIBBY HOLE NO. 9500
BOO NO LOCATION CHAMPION-LIBBY, MONTANA
ELEVATION AM) DATUM
ohiunOaoenCY B&B DRILLING DRlL£B DAVE ILIFP
bsi»> m,
DRLUNOeOUIPMENT
COMPLETION DEPTH g-j.
SAUPlfcH
OHUjw,«t=iw^IR R0TARY w/CASING ADVANCE I UHIX ""
§S4vi|Ses
UNUOI.
SIOIWDIKIH* "S™ 4« STEEL
WATER '
ELEV.
MWST
CSM7L 24 HIS.
TYPE OF perforation 4» STAINLESS 0.03" j FH0M 45 T0 65
L
OGQED BV
BILL TURNER
CHECKEOBY
KAREN PHILLIPS
SZEAMHYPEOfPWX SAND PACK ; FROM 42 TO 67
WHU-UUL BENTONITE SLURRY j""" 15 '« 40
11
DEsaunioN
OTAPHC103
li
UJ
t
5
§
SWPUE8
REMARKS
(Ml Rae. Fluid Bis,Odor.BC.)
Llhoiosy
Plezotrotor
tnttattiofl
6
Z
t
£
ti
i
&
5—
I Brown, Silty, Gravelly, Fine to Medium
¦ Sand, Occasional Cobbles
l :
L-M
M •
M-H
M~
M-H
L-H-
«:
0
.5
5
J
5ppm
lOppn
20ppn
Sppm
13ppn
2ppm
8ppm
_10'-I3.5'Rocky
and Very Slow
Drilling
- Inc. Contamination
in Discharge
- Further Inc. in Cont.
in Discharge,
Drilling Faster
- Low Cont. in
Disharge
- Inc. Drilling Rate
- Fast Drill Rate
- Slight Sheen in
Discharge
- Mod. Drilling ConL
Inc. in Discharge
NOTE: Mostly low
contamination noted
during drilling
!
fN
I
~o
1
atu
>ac
!
ir
10-
15-
20-
25-
30-
35-
40-
45-
50-
55-
60-
65-
70-
¦ GraveL Brown, Green and Gray, Coarse
I Sand, Occasional Cobbles, Subangular to
1_ Subrounded
I Boulder
1_ Silty Sandy Gravel with Cobbles, Brown-
- Green and Gray
1- Gravel, Brown, Green and Gray Coarse
; Sand, Occasional Cobbles, Subangular
—Tight Formation
I Inc. Silty Sand
— Gravel, Brown, Highly Sandy, Fine to
; Coarse With Occasional Cobbles
: Rocky Zone
~ Decreasing Sand
- T.D. 67'
Figure 4.12. Drilling Log for Injection Well No. 9500 (Woodward-Clyde Consultants, 1990).
26
-------
of the study was to determine the zone of influence for a single injection well. During Phase I of the
remediation program, the cumulative effects of multiple injection wells are being investigated
(WoodwardClyde Consultants, 1990).
Four monitoring wells were installed in locations to expand the existing downgradient network of
monitoring wells. The monitoring wells used in the demonstration study had screened intervals that
allowed an evaluation of the effects of the full-scale injection site on hydrogeological aspects
downgradient from the injection wells and at different depths in the Upper Aquifer (Table 4.3). Ex-
amples of the drilling logs for three of the monitoring wells are presented in Figures 4.14 and 4.15. In
addition, one well (Well No. 3032) was installed approximately 25 feet from the injection wells to
provide an evaluation of the extent of ground-water mounding induced by injection (Figure 4.16)
(Woodward-Clyde Consultants, 1990).
A geologic cross-section of the Upper Aquifer through Well Nos. 9500, 3015, 3031, and 3017 in
the demonstration area is shown in Figure 4.17 (Woodward-Clyde Consultants, 1990). This cross-
section illustrates the lenticular nature of the sediments and the lack of correlation of individual layers
among well locations. The most continuous layers are the three sand and gravel units.
After installation of the injection wells, a bromide tracer test was conducted to determine the
hydraulic interconnections between the injection wells and the monitoring wells (Woodward-Clyde
Consultants, 1990; Piotrowski, 1991). A bromide tracer solution (2.8 percent sodium bromide) was
introduced into the injection wells, and the downgradient wells were monitored for bromide over four
days. Results of the tracer test indicated that the downgradient monitoring wells were hydrauiically
connected to the full-scale injection well (Woodward-Clyde Consultants, 1990), with some wells more
connected than others in the near-field region. The tracer arrived at wells closest to the injection wells
at relatively high concentrations in two to three days, followed by its detection at lower concentrations
further downgradient in three to four days. The area affected by the bromide injection was approxi-
mately 500 feet wide lateral and 1,000 feet downgradient. However, there was relatively poor hydrau-
lic connection observed between Injection Well Nos. 9500/9501 and Monitoring Well Nos. 3026/3029.
Table 4.3. Screened Intervals of Monitoring Wells (Woodward-Clyde Consultants, 1990)
Monitoring Well Screen Interval
No. (feet bgs)
3003.1
3003.2
3008.1
3008.2
3012.1
3015.1
3016.1
3017.1
3017.2
3017.3
3025.1
3026.1
3029.1
3031.1
3031.2
3032
21.5-23.5
31-34
27-30
70-73
77-83
68-71
66-69
31-34
49-52
75-78
14-34
18-33
51-71
16-31
37-52
10.5-20.5
27
-------
PROJECT NAME CHAMPION-LTBBY HOLE NO. 9501
BCRNQ location CHAMPION-LIBBY, MONTANA
ELEVATION AND DATUM
ORIilNQAOENCY b&B DRILLING I Df,lLER DAVE ILIFF
DATERNBHED
0«UJNOEQUIPM6Nr
COMPLETION DEPTH
38'
SAMPLER
OHiuwoMt.w^iR ROTARy w/CASING ADVANCE I ""
NO. Of >
6AMPIE8 |
UNUST.
uuk Muawrtw uasnu DJA gj-EEL
W
E
i
FIRST
12'
COMPL W WB.
12 S
TWEOFPenronAHON WIRE WRAPPED j fhom Ig
TO 38
LOGGED BY
CHECKED BY
scemwfeofpkk natural pack !mCM 15
TO 38
BILL TURNER
KAREN PHILLIPS
ivtwsuu. BENTONITE PELLETS j H1a" 9
to i5
afucHicLoa
8
SAMPLES
I
DEScnpncN
Uthoiogy
Pteomaw
Im&Eatton
if
2
$
X
Q
i
i
i
ii
REMARKS
(Ml R«e. Fluid Odor. ec.)
I Brown, Silty, Gravelly, Pine to
- Medium Sand, Occasional Cobbles
L '
i
\
10J
15-
; Gravel, Brown, Green and Gray Coarse
- Sand, Occasional Cobbles, Subangular to
—Subrounded
I
~V~
LM
- Slight Sheen On
Samples
20-
25-
- Silty, Sandy Gravel with Cobbles
rBrown-Green and Gray
M
8
GL.
m :
I
30-
Ippin
35-
- Gravel, Brown, Green and Gray Coarse
- Sand, Occasional Cobbles, Subanguiar
40-
1. T.D. 38"
45-
50-
55-
60-
65 ~
70-
Figure 4.13. Drilling Log for Injection Well No. 9501 (Woodward-Clyde Consultants, 1990).
28
-------
PROJECT NAME CHAMPION-LIBBY HOLE NO. 3029
BOBNQ location CHAMPION-LIBBY, MONTANA
ElEVATCN AND DATUM
~RUINGAGENCY B & B DRILLING DRU-ER DAVE ILIFF
DATE STATED
OAlf FINSHSO
9128/89
I0/V8<>
DRLUNGEQUJPMENT
COMPLETION DEPTH
71'
SWPlER
UHUJNUMfc R0TARy w/cas jNG ADVANC£ | -I, an
8 1/4"
SAMPLES x
0
UNUBT.
m ANiJoHArbUr CASING ... A tvrccI
4 DIA. STEEL
Et£V.
rm&i
12'
cumpl 24 HHJ.
TYPE OF PERFORATUM ^ 0y | ^ 71
TO
51
LOGGEOBY
CHECKEOBY
see andtypeof pao< NATURAL PACK S FB0M 71.5
TO
48.5
BILL TURNER
KAREN PHILLIPS
ivpt u- itAL BENTONrrE SLURRY AND CEMENT ! 48.5
!U
Surf
OfiAPHCLOQ
ill
SAMtt£S
DESCFUPTION
LShotofly
Ptezc
Inato
MT1
Eat
ner
on
sf
i
Typo No.
i
REMARKS
(W1 R4«, RUd k»8. Odor. efc.)
5-
; Gravel, Sandy with Cobbles, Very
¦ Angular, Tan and Brown
Cement I
Cement |
0 ppmHNU
10J
—
—
Drilling Slower
15-
20-
- Gravel, Coarse to Fine, Green, Brown and
LBlack, Subangular
L -
25pfon
25pjur
Rocky Drilling
Making Little WTR
Faster Drilling
25-
30-
35-
; Gravel, Sandy Brown, Black and Green
; Subrounded, Slight Amount of Silty Clay
—Gravel, Loose, Coarse Grained, Sandy,
- Clayey, Brown with Sheen
u
+
&
s
55
V
'S
0
1
+
35
V
3
o
5
6
5ppm
1 ipprr:
25pfim
Increased Discharge
in Well 3026
Little Returns
33'-38* Very Fast
Drilling
H ;
40-
45-
; Gravel, with Boulders and Cobbles,
- Subangular to Subrounded with Sheen
; Gravel, Medium to Coarse Sand, Occasional
- Cobbles, Subangular with Sheen
1
1
L-
13.5|>pi
20ppir
-
Very Slow Drilling
42,-44'
Note: Lost a lot of
cement slurry in hole
addea 440 gal. to
raise annuius seal
from 48* to T bgs.
50-
lOppc
.Hid] Contamination
in Discharge
55-
7"Inc. Sands
M
u
HJ
20bw
60-
at
C
a
1
9ppm
-1
Fast Drilling
• Slow Drilling
65-
2ln»i:
Mod. Discharge
70-
—Inc. Sands
—
22ppir
T.D. 72'
Figure 4.14. Drilling Log for Monitoring Well No. 3029 (Woodward-Clyde Consultants, 1990).
29
-------
PROJECT NAME CHAMPION-LIBBY
3031-1
hole no. mn
BORNOIOCATON CHAMPION-LIBBY, MONTANA
ELEVATION AND DATUM
onujUOAQENCV B & B DRILLING
DfillER DAVEIUFF
DATE STATED
DAT* WNSHED
DRUINQEOUIPUENr
COM PUs liON DEr k H
SAMPLER
0fRuw»MeiH0^IR R0TARYW/CASING ADVANCE| Urtu-aii 6 1/4.
SAMPLES
UNUfc>l.
2" D1A. STEEL
WAIkH IHTO1
ElEV. : IT
COM PL
TYPEOf PCTF0RAT1CN 2" STAINLESS .03" I FR0M j? 10 si
LOGGED BY
BILL TURNER
CHECKED BY
KAREN PHILLIPS
9 BE AJOTYPE OF PACK NATURAL PACK ! 37 70 52
lYcti^itAL BENTONrrE PELLETS j™" 51 37
DC3CRPT10N
QRAPHC LOG
g
XW
REMARKS
<041 Rate, RuiGlosa, Odor, eft.)
Sand, Fine to Coarse, Brown,
• - Gravelly, Slightly Clayey, Occasional
Cobbles
10.
Gravel, Brown, Green and Gray,
"Sandy, Coarse, Subangular to
Subrounded
15 - — Inc. Sandy Cement
20-
25-
30-
35-
40-
45-
50-
55-
60-
65-
70
Gravel, Brown, Tan and Green, Highly
"Sandy, Coarse, Subrounded
;; Silt, Brown, Clayey C., Occasional Gravel
Gravel, Brown, Green and Gray, Slightly
"Sandy with Cobbles, Subrounded
Sand, Coarse, Gray and Brown, Gravelly,
"Semi-Rounded (Sheen on Sample)
Sheen
T.D. 52'
'i
I
L ¦
L
L-V"
M..
W
mh:
5ppm
Sppm
2ppm
12ppn
6ppm
Ippm
22ppn
!3ppn
Rocky Drilling
Initial HNU
Reading 2 ppm
Low Contamination
Inc. Contamination
at 26"
Highly
Contaminated Oil
on Pit Sheen to
T.D.
Figure 4.15 Drilling Log for Monitoring Well No. 3031.1 and 3031.2 (Woodward-Clyde Consultants, 1990).
30
-------
PROJECT NAME CBAMPIQN-ygBY HOLE NO. 3032
BORWG LOCATION CHAMPION-LIBBY, MONTANA
ELEVATION AND DATUM
DfUJJNG AGENCY B & B DRILLING
DRUER DAVg |L1pp
DATE STATED
DATERNSKED
10/2/89
inn/M
DRLUNQEQUIPMEttT
COMPI&HCN DEPTH
20.5"
tIAWPUR
UfuUNGMk IN^[R R(yrARY W/CAS)NG ADVANCE| UHli ""
8 I/4"
NO. Or j
SAMPLES ;
NONE
UNflfcT.
set ANDSHwtoi- wsnu 2„ D1A STAINLESS steel
WATER
ELEV.
i
HHST ]5,
IAJMHL 2q j, ** *¦#*!•
TYPE CP PERFORATION .02" SLOTTED
W0M 20.5
T0 10.5
LOGGED BY
CHSCKEO BY
SEE AfCTYPEOF pack^j ^ MONT. + NATURAL PACK
prom 20.5
TO g
BILL TURNER
KAREN PHILLIPS
iypt«-btAL BENTONite pellets
WUM g
,u 6
GnAPHCLOG
6awH£S
n
DE6CRPT10N
Uhdogf
Ptozometer
Iralattfion
water
Content
1
5
i
|
1
8
a
§g
i«
REMARKS
(Ml Rae. R lid bSS. Odor, efc.)
5-
; Brown, Silty, Gravelly, Fine to
- Medium Sand, Occasional Cobbles
I
c
10_
15 J
20 :
• Gravel, Brown, Green and Gray,
- Coarse Sand, Occasional Cobbles,
_Subangular to Subrounded
; Boulders Encountered
0
1
SB
I
,v
L-M
m:
l-M
5ppm
Rocky, Slow
Drilling
25 :
I T.D. 20.5'
30:
35 :
40 :
45 :
50 :
55 :
60 ~
65~
70"
Figure 4.16. Drilling Log for Monitoring Well No. 3032 (Woodward-Clyde Consultants, 1990).
31
-------
A*
Injection Well 9500
1
"H.
a
a
10
20
- 30
- 40
SO
60
70
80
3015
3031
30J7 Injection Well
m
Middle
Leaky
Aquitard
Horizontal Scale In Feet
Vertical ExuggeoMd 5X
I Date. 7/11/30
Geologic Cross Section A-A'
Figure 4.17.
Geologic Section of the Upper Aquifer through Injection Well No. 9500 arid Monitoring Wells
No. 3015, 3031, and 3017 (Woodward-Clyde, 1990).
-------
No bromide was detected in Well No. 3029 and Iower-than-expected concentrations were measured in
the adjacent monitoring well (Well No.3026). These results were probably due to heterogenous and
lenticular deposits of finegrained sediments in those areas.
There were only slightly higher concentrations of bromide detected in shallow monitoring wells
compared to the deeper zones. There did not seem to be differences in ground-water flow with depth,
but rather a fairly uniform vertical flow occurred in the Upper Aquifer (WoodwardClyde Consultants,
1990).
Ground-water flow rates, estimated from the bromide tracer test, ranged from 175 feet per day at
Well No. 3003 to 300 feet per day at Well No. 3017 (Woodward-Clyde Consultants, 1990; Piotrowski,
1991). These ground-water flow rates are similar to those estimated in the pilot-scale study.
The approach used in the demonstration program to accomplish in situ bioremediation involved
the addition of hydrogen peroxide as a source of D.O. and inorganic nutrients to stimulate growth of
contaminant-specific populations (Piotrowski, 1991). The hydrogen peroxide injection rates were
designed to maintain a concentration of approximately 100 mg/L of hydrogen peroxide. Inorganic
nutrients in the form of potassium tripolyphosphate and ammonium chloride were continuously added
to achieve concentrations in the injection water of 27 mg/L and 22 mg/L, respectively.
To conduct the full-scale demonstration program in the intermediate injection system area, the
injection water delivery and conditioning system had to be upgraded in order to introduce larger amounts
of both hydrogen peroxide and nutrients into the ground water. The source of injection water was from
the fire pond, which is part of the fire protection system for the lumber mill. Injection water was
filtered to remove particulate matter that could clog injection well screens.
The anticipated maximum capacity of the upgraded injection system was greater than 70 gpm. To
accommodate this increase in flow, the following measures were taken:
(1) the existing sand filter system was upgraded by operating an additional sand filter in parallel
with the original filter to remove particulate matter from the fire pond water;
(2) the existing piping network was continuously monitored to assess corrosion by hydrogen
peroxide;
(3) flow meters were installed in-line for flow rate determinations in each well; and
(4) hydrogen peroxide storage, pumping capacities, and nutrient addition capabilities were ex-
panded.
The flow through the full-scale injection site was started in January 1990 and discontinued in June
1990 (Piotrowski, 1991). The deeper well (Well No. 9500, which was screened lower in the Upper
Aquifer) had a maximum flow rate of approximately 20 gpm; injection rates during the study were
about 13 gpm. The rate of injection was limited by the geological formation, which consisted of
sediments of lower permeability. Mounding in this well reached near the top of the casing during
injection. The shallower well (Well No. 9501) had a maximum rate in excess of 50 gpm; during the
study, the injection rate was about 45 gpm. This rate was considered to be an appropriate flow rate to
provide sufficient oxygen to enhance downgradient biodegradation. Less mounding was noticed in the
shallower well, indicating the presence of more permeable sediments in the upper part of the aquifer.
The total injected flow that could be delivered to the Upper Aquifer was therefore at least 70 gpm;
during the demonstration study, the total flow rate was about 58 gpm. Water was injected at atmo-
spheric pressure. No significant operational problems were encountered during the period of the dem-
onstration study. No evidence of clogging of the well screens was observed.
33
-------
Operational procedures included the periodic recharging of the hydrogen peroxide and nutrient
tanks. The peroxide tank was recharged with 50 percent hydrogen peroxide approximately every two
months, based on continuous operation. The nutrient addition tank was recharged approximately every
two weeks, based on continuous operation. Other operational procedures included periodic backwashing
of the sand filters and routine visual inspections of the system.
The response of the contaminated plume to hydrogen peroxide and nutrient injection was evalu-
ated by monitoring dissolved concentrations of PCP and selected PAH compounds, total bacterial counts,
and Microtox™ toxicity in samples collected in March and May from eight monitoring wells located in
the vicinity and downgradient from the injection wells (WoodwardClyde Consultants, 1990; Piotrowski,
1991). Operational guidelines for the demonstration system also required monthly measurements of
D.O., water depth, and temperature in 15 monitoring wells. Ground-water mounding was evaluated by
monitoring the water levels in the injection wells and in the adjacent Monitoring Well No. 3032. After
injection was completed, water levels in the wells were monitored for 24 hours to determine recovery
curves for the wells. Based on these data, a distance mounding plot was developed to estimate the
lateral distance affected by mounding.
D.O. concentrations in wells located in regions potentially under the influence of the injection site
were compared to oxygen concentrations in wells located upgradient from the site (Woodward-Clyde
Consultants, 1990; Piotrowski, 1991). A well that exhibited a D.O. concentration greater than normal
concentrations (less than 1 mg/L) within the contaminant plume or greater than concentrations within
pristine ground water (approximately 5 mg/L) was considered to be under the biogeochemical influ-
ence of the injection site. Increases in D.O. concentrations were often variable between adjacent wells
and over time within the same well, likely due to variability in sampling and analyses and variability in
the migration of the D.O. downgradient. However, in general, monitoring wells that showed increased
bromide concentrations during the bromide tracer test also showed increase in D.O. concentrations.
The area of increased D.O. levels due to hydrogen peroxide addition, as determined by D.O. monitor-
ing, was estimated to be about 400 feet wide, as measured perpendicular to the general ground-water
flow direction, and approximately 1000 feet downgradient from the injection well.
Increased D.O. concentrations downgradient of the injection wells also seemed to be distributed
vertically within the Upper Aquifer, with monitoring wells screened in both shallow and deep horizons
showing increased D.O. levels (Woodward-Clyde Consultants, 1990). Similar to the results obtained
in the bromide tracer experiment, Well Nos. 3026 and 3029 showed only slight increases in D.O.
concentrations, indicating poor hydraulic connections between these wells and the injection wells.
To determine if degradation was occurring in the aquifer, results of sampling for PAH compounds
and PCP were compared between the March and May sampling dates (Table 4.4) (Woodward-Clyde
Consultants, 1990). Carcinogenic PAH compounds were detected in only a few monitoring wells, so
no overall relationship for degradation of those compounds could be established. For concentrations of
PCP and for total noncarcinogenic PAH compounds, five of the eight wells monitored showed decreas-
ing concentrations, while three wells showed increasing concentrations. The decrease in total noncar-
cinogenic PAH compounds and PCP were 10 percent and 18 percent, respectively, between March and
May, 1990. The results may indicate that enhanced biodegradation was occurring (Woodward-Clyde
Consultants, 1990).
Comparison of the D.O. measurements and the results of the chemical analyses indicated a rea-
sonable but variable and mixed relationship between these factors (Woodward-Clyde Consultants, 1990).
For example, wells that showed a decrease in organic contaminants also showed a trend of increasing
D.O. with time. Another well showed a slight increase in PCP and PAH concentrations and a decrease
34
-------
in D.O. content. Another well showed a substantial increase in total PAH compounds and a slight
decrease in PCP, but little fluctuation in the D.O. concentrations was observed. Based on these results,
the parameter D.O. cannot be used with a high degree of confidence to indicate changes in PAH and
PCP concentrations.
Operation of the full-scale injection site during the six-month demonstration period produced a
mounding of the water table of the Upper Aquifer in the vicinity of the injection site that averaged
approximately three feet in height (Piotrowski, 1991). In addition, some mounding effects may have
occurred at distances over 100 feet on either side (i.e., perpendicular to groundwater flow) of the
injection site. Water table mounding at the site may also have been influenced by infiltration from the
nearby fire pond.
Based on results from the assessment of mounding during the demonstration program of the full-
scale system, it was determined that spacings between adjacent injection sites of the intermediate injec-
tion system should be at least 200 feet (Piotrowski, 1991). Additional final design details for the in situ
bioremediation program are being based on the aquifer properties determined from the bromide injec-
tion tests and the monitoring data from the demonstration program, as well as additional information
being generated as the full-scale system continues to be implemented in phases.
4.6 Cost Estimates for the In Situ Bioremediation Program for the Upper
Aquifer
Table 4.4. PCP, Total Noncarclnogenlc PAH, and Total Carcinogenic PAH in Monitoring Wells During the
Demonstration Program (Woodward-Clyde Consultants, 1990).
March 1990 May 1990
Well
PCP
Total Non- Total
PCP
Total Non-
• Total
Number
Carcinogenic Carcinogenic
Carcinogenic
Carcinogenic
PAH PAH
PAH
PAH
furl 1
3012.1
566
1199
371
764.5
3015.1
267
426
989
600
3025.1
1020
2458 304
528
1657
3026
1321
1147
803
4070
3029.1
2440
8686
2708
7108
3031.1
760
3840
454
2374
3031.2
1060
5006
760
2116
10
3032.1
173
288
205
123.5
57
Totals
7607
23050
68181
188132
1 This represents a 10% decrease from March
2 This represents an 18% decrease from March
35
-------
In 1990, preliminary cost estimates .were prepared-forthe entire in situ bioremediation program
for the Upper Aquifer (Woodward-Clyde Consultants, 1990). A summary of the cost estimates is pre-
sented in Table 4.5. Xhe.low capital costs for the intermediate injection system reflect the presence of
equipment already installed as part of the pilot-scale and demonstration programs that have been
completed. Detailed cost estimates for each injection area and for operations and maintenance activi-
ties are presented in Appendix A.
Table 4.5. Cost Estimates for the Upper Aquifer In Situ Bioremediation Program (WoodwardClyde
Consultants, 1990).
Injection Area Capital Costs Annual Operations and
Maintenance Costs
Intermediate Injection System
(Upgrade) $ 41,900
Boundary Injection System $183,500
Source Area Injection System $ 57.600
Total: $283,000
$ 46,700
S 42,100
S 38.400
$127,200
36
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Chapter 5
Field Performance Evaluation of In Situ Bloremediation of the Upper
Aquifer
5.0 BF1 Study Objective 2: Field Evaluation to Assess Performance of In Situ Bioremediation
of the Upper Aquifer
Previous ground-water studies conducted at the Libby, Montana, wood treating site have focused on bio-
degradation of soluble organic compounds. This approach to evaluating in situ bioremediation may have re-
sulted in over-estimating the rate and extent of biodegradation of organic contaminants at the site. The PAH
compounds of concern at the site have limited solubility in the water phase but have a preference, due to high
octanol-water partition coefficient values (KJ, for nonaqueous phase liquids (NAPLs) that may be located
within the pore space of aquifer solids as a water-immiscible oily phase. Also, the PAH compounds of concern
have a preference to be associated with the solid phase of an aquifer matrix due to high solid-water partition
coefficient values (K,). The hydrophobicity, or "water-hating" characteristics, of PAHs as a class of compounds
has been addressed in detail by Grady and Lim (1980), Sawhney and Brown (1989), and Sims and Overcash
(1983). PCP, however, has increasing water solubility with increasing environmental pH values above 4.75 and,
therefore, has less preference than PAH compounds to be associated with oil and solid phases at the Libby Site,
which has a pH of 6.9. Therefore, an evaluation of the aquifer solid phase and associated NAPL was performed
to evaluate whether PAII compounds as well as PCP have been removed from aquifer solids in subsurface areas
where nutrients and oxygen were injected.
Bioremediation of subsurface environments involves the interaction of four main components: (1) micro-
biology, (2) terminal electron acceptor, (3) nutrients, and (4) the target chemical, which may be a substrate or a
co-substrate (McFarland and Sims, 1991). These components must be present and must interact for biodegrada-
tion to occur. The rate and extent of interaction will be determined primarily by the subsurface stratigraphy. In
addition, there are four phases in the subsurface in which one or more of these components may be present:
(1) solid (aquifer materials, soil), (2) gaseous (oxygen, hydrocarbon vapors), (3) aqueous liquids, and (4) non-
aqueous phase liquids (NAPLs) (Sims, 1990). Because of the tendency of PAH compounds to be associated
with the solid phase and especially the NAPL phase in the subsurface, PAH compounds have limited interaction
with microorganisms, oxygen (terminal electron acceptor), and nutrients due to the water-immiscible nature of
the NAPL as well as the heterogeneous nature of the subsurface at the Libby Site. Therefore, the bioavailability
of the PAH compounds within the aquifer may be limited, and analysis of ground-water samples only may not
provide a clear indication of whether bioremediation is occurring in other phases in the aquifer.
Therefore, the second objective of this BFI study was to conduct a field evaluation to assess the perfor-
mance of remediation activities with regard to the removal of contaminants associated with subsurface solid
particles and oily (NAPL) materials. The field evaluation was conducted in three phases: (I) assessment of
potential for in situ biodegradation in the Upper Aquifer; (II) assessment of the performance of remediation
activities with regard to removal of contaminants associated with the subsurface solid particles and oily materi-
als in the Upper Aquifer; and (III) investigation of the role of preferential flow pathways in the intermediate
injection area of the Upper Aquifer.
5.1 Phase I - Assessment of Potential for In Situ Biodegradation in the Upper Aquifer
Preliminary studies were performed to determine if an in situ assessment of biodegradation in the water
phase could be performed at the Libby Site. These studies consisted of: (1) singlewell injection (push/pull) tests
to measure subsurface microbial activity in the Upper Aquifer, and (2) ground-water analyses to evaluate the
oxidative-reductive status of the Upper Aquifer.
37
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S.LI Performance of Push/Putt (Single-WeU Injection) Tests to Measure Subsurface Microbial
Activity
An evaluation of in situ bioremediation activity in the water phase was conducted by measuring oxygen
utilization based upon differences in oxygen concentrations in injected and recovered water using a push (injec-
tion)/pull (recovery) test (i.e., single-well injection test). As part of push/pull testing, a conservative tracer is
injected to determine the dilution or concentration of various compounds that indicate the presence of biological
transformation activities by comparing the concentrations of the compounds with the concentrations of the
conservative tracer. For example, if biological activity or abiotic oxygen demand is present, concentrations of
added oxygen or nitrate, which, are electron acceptors, should decrease below those concentrations predicted by
dilution.
5.1.1.1 Experimental Approach and Methods for the Performance ofPush/Pull Tests
The first set of push/pull tests was conducted September 16 - 21,1991. Two wells were selected for use in
the testing. Well No. 3014.1 was located outside the contaminant plume, while Well No. 3017.1 was located
within the contaminated plume.
Bromide was used as a conservative tracer to monitor the dilution of the injection plume with native
ground water. Two hundred gallons of fixe pond water used for injection into Well No. 3014.1 was spiked with
40 g of sodium bromide (NaBr) and 400 mL of a 25 percent solution of hydrogen peroxide. For Well No.
3017.1, the injection water was only spiked with 40 g of NaBr. After injection of the spiked water, water
samples were pumped from the wells immediately after injection and six more times over the next 23 hours. The
water samples were analyzed for bromide (Br) and dissolved oxygen (D.G.).
Additional push/pull tests were conducted October 14 - 20,1991. The tests were performed on five wells:
Well Nos. 3014.1 and 3034 (located outside the contaminated plume) and Well Nos. 3003.2,3010.1, and 3017.2
(located within the contaminated plume). Each well was injected with 500 gallons of fire pond water spiked
with 500 g of NaBr for a Br concentration of approximately 205 mg/L, The wells were sampled immediately
after injection and an additional two to four times in the next 24 to 36 hours.
5.1.1.2 Results of Push/Pull Tests
In the first push/pull injection tests, in Well No. 3014.1,as illustrated in Figure 5.1, bromide concen-
tration in the injection plume gradually was reduced to 16.5 percent of its initial value (33.3 mg/L) during the
duration of the test These results were not expected, based on the estimated ground-water velocities of 50 to
300 feet per day. D.O. concentrations increased during the first two hours of the test, due to degradation of
hydrogen peroxide to oxygen. The D.O. appeared to disappear from the plume at a faster rate than bromide was
diluted. In Well No. 3017.1 (Figure 5.2), the bromide concentration decreased at approximately twice the rate as
it decreased in Well No. 3014.1. D.O. appeared to behave as a conservative tracer; i.e., it appeared to be diluted
in the plume at a similar rate as bromide.
The results of the first push/pull injection tests showed that tracer plumes formed by injecting 200 gallons
of spiked water could only be monitored for 12 to 24 hours. Since biodegradation is expected to be a slower
process, this procedure using 200 gallons did not provide sufficient time to evaluate biodegradation in situ.
Therefore, the push/pull tests were repeated using 500 gallons of spiked injection water in the second test.
In the second test, the bromide concentrations also decreased rapidly (Figures 5.3 to 5.7), indicating that
high flow rates (probably greater than 50 feet per day) prevented the injected water from being contained long
enough for microbial activity to decrease measurably the oxygen concentration of the injected water and for the
water to be recovered for measurement. The D.O. was being lost from the plume by dilution, though the reac-
tions that were consuming oxygen (i.e., microbial activity or chemical reactions) are not known.
During sampling of the ground water to determine bromide concentrations, a test was conducted to deter-
mine how many times a well had to be bailed before a constant bromide concentration was achieved in the bai led
38
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samples. As shown in Figure 5.8, a constant value for bromide was not achieved even after 25 bailings (in this
well, one water column in the well was equivalent to eight bailings). The injected plume was probably moving
away from the well screen at a rate too great to obtain constant bromide concentrations.
2.0
Initial Conditions:
Bromide = 33.3 mg/L
j ^ D.O. = 8.1 mg/L
Background Conditions:
_ Bromide = 0.30 mg/L
2 D.O. = 0.5 mg/L
O 1.0
0.5
0.0
0 5 10 15 20 25 30
Time (hours)
Figure 5.2. Bromide Tracer Push/Pull Test tor Well No. 3104.1: September, 1991.
e
U
u
T 1 , , 1 , 1 r
5 10
Time (hours)
Initial Conditions:
Bromide = 31.9 mg/L
D.O. = 9.4 mg/L
Background Conditions:
Bromide = 0.30 mg/L
D.O. = 0.4 mg/L
Figure 5.2. Bromide Tracer Push/Pull Test for Well No. 3107.1: September, 1991.
-------
Therefore, the use of push/pull tests at this site for measuring subsurface microbial: activity was not suc-
cessful, due to site characteristics related to high hydraulic conductivities and high subsurface ground-water
flow velocities.
5.L2 Ground-Water Analyses to Evaluate the Oxidative-Reductive Status of the Upper
Aquifer
In an aquifer that is in a reduced state (i.e., minerals present are in a reduced rather than oxidized form),
there may be competition for the use of oxygen added to the aquifer for remedial purposes. The reduced miner-
als may compete for available oxygen with the microorganisms accomplishing the degradation of organic con-
taminants; thus, the time required for remediation will be much longer than estimated based on oxidation of
organic contaminants present, as well as more expensive, especially when oxidants such as hydrogen peroxide
are used. In a reduced aquifer, ground-water samples would be expected to have lower concentrations of elec-
tron acceptors, such as oxygen, nitrates, and sulfates, and higher concentrations of electron donors, such as
reduced manganese (II) and iron (II), and sulfides. Conversely, ground-water samples from an oxidized aquifer
should have higher levels of electron acceptors and lower levels of electron donors.
5.1.2.1 Experimental Approach and Methods for the Evaluation of the Oxidative-Reductive Status of the
Upper Aquifer
Ground-water samples were collected in October 1991 for analysis of iron (II), manganese (II), and dis-
solved oxygen (D.O.) during the testing period for the push/pull injection experiments. Three to four samples
were collected over a 10 to 24 hour period; results are presented as the average of the replicate samples. During
a sampling trip in April 1992, ground-water samples were collected for analysis of iron (II), manganese (II),
D.O., nitrate (N03 ), and sulfate (SO,, 2).
Wells sampled in October 1991 included: Well Nos. 3014.1 and 3034 (located outside the contaminated
plume) and Well Nos. 3003.2,3010.1, and 3017.2 (located within the contaminated plume). In April 1992, the
following wells inside the contaminated plume were sample± Well Nos. 3002.1,3003.1,3008.1,3010.1,3013.1,
3017.1, and 3018.1. The wells outside the contaminated plume included; Well Nos. 3011.1, 3014.1, 3014.2,
3021,3027,3033,3034,3036, and. 3037. were analyzed in the field immediately after collection for ferrous iron
(FeJ+) using a procedure modified from Lovely and Phillips (1987, 1988). Forty mL of ground water were
placed in a commercially pre-cleancd jar containing 0.5 mL of a 0.5 N HC1 solution. After mixing, 0.2 mL of
this solution was added to 5 mL of a buffered ferrozine solution. The ferrozine solution was prepared by dissolv-
ing 0.5 g of ferrozine in 500 mL of a 50 mM HEPES buffer, which had been prepared by dissolving 13.02 g of
HEPES (N-[2Hydroxyethyl]piperazine-N'-[2-ethanesulfonic acid]) in approximately 800 mL distilled, deion-
ized water (DDW) and diluted to 1 L. The solution with the ferrozine solution was mixed for 15 seconds. The
concentration of Fe2* was determined by measuring the absorbance at 562 nm.
Manganese in the ground-water samples was analyzed at the Utah Water Research Laboratory (UWRL) by
inductively coupled atomic emission spectroscopy (ICP) using U.S EPAMethod 6010 (U.S. EPA, 1986b). The
instrument used for the analysis was a Perkin-EImer ICP/6000 Inductively Coupled Arc Plasma system. Ni-
trates and sulfates were analyzed using ion chromatography (Dionex Ion Chromatograph/HP 3396A Integrator)
according to U.S. EPA Method 300.0: The Determination of Inorganic Ions in Water by Ion Chromatography
(Pfaff et al., 1989).
Dissolved oxygen measurements were performed at the wellhead. Analyses for dissolved oxygen were
performed using a YSI Dissolved Oxygen instrument (YSI, Inc., Yellow Springs, Ohio).
5.1.2.2 Results of the Evaluation of the Chddative-ReducAve Status of the Upper Aquifer
Results of both sampling trips indicate that aquifer materials located in both contaminated and uncontami-
nated areas are in a chemically reduced condition (as indicated by the presence of reduced iron and manganese)
40
-------
Initial Conditions:
Bromide = 200,8 mg/L
D.O, = 9.1 mg/L
Background Conditions:
Bromide = 0.23 mg/L
D.O. = 2.3 mg/L
4 6 8 10
Time (hours)
12 14 16
Figure 5.3. Bromide Tracer Push/Pull Test for Well No. 3003.2: October, 1991.
o
U
u
1.1
I
.9
.8
.7
.6
.5
.4
.3
.2
.1
i
o C/Co
i \ \
i \ \
s w
o C/Co-DO
\\
: f n*
i
: i
!
" I
1
1
~
1—i—i—i—r
2 4 6
Time (hours)
10
Initial Conditions:
Bromide =186.8 mg/L
D.O. = 9.5 mg/L
Background Conditions:
Bromide = 0.22 mg/L
D.O. = 3.0 mg/L
12
Figure S.4. Bromide Tracer Push/Pull Test for Well No. 3010.1: October, 1991.
A-1
-------
Time (hours)
Initial Conditions:
Bromide = 208.5 mg/L
DO. = 9.1 mg/L
Background Conditions:
Bromide = 0.20 mg/L
D.O. = 1.9 mg/L .
Figure 5.S. Bromide Tracer Push/Pull Test for Well No. 3017.1: October, 1991.
Initial Conditions:
Bromide = 203.7 mg/L
D.O. = 8.6 mg/L
Background Conditions:
Bromide = 0.36 mg/L
D.O. = 2.4 mg/L
Figure 5.6. Bromide Tracer Push/Pull Test for Well No. 3014.1: October, 1991.
42
-------
©
V
u
Time (hours)
Initial Conditions;
Bromide = 203.7 mg/L
D.O. = 8,8 mg/L
Background Conditions:
Bromide = 0.23 mg/L
D.O. = 1.9 mg/L
Figure 5.7. Bromide Tracer Push/Pull Test for Well No. 3034: October, 1991.
Figure 5.8, Number of bailings required to achieve a constant Bromide concentration in Well No. 3010.1:
October, 1991.
.da
-------
(Tables 5.1 and 5.2); therefore, the site has an abiotic oxygen demand, in addition' to the. biological oxygen
demand of the organic contamination. In general, concentrations of reduced chemicals were inversely related to
dissolved oxygen concentrations. The presence of the abiotic oxygen demand presents challenges with respect
to the evaluation of uptake of oxygen due to microbial activity. Due to this abiotic oxygen demand, the calcula-
tion of ratios of electron acceptors (oxygen-demanding substances) to electron donors (organic contaminants)
regarding biological activity is not possible. Since both abiotic and biotic demands are occurring simulta-
neously, the amount of oxygen available for microbial degradation of organic contaminants is reduced.
5.2 Phase II - Performance of a Field Evaluation to Assess the Performance of Remediation
Activities with Regard to Removal of Contaminants Associated with the Subsurface Solid Particles
and Oily Materials.
The effectiveness of remedial activities was evaluated by performing the following tasks:
(1) collection of aquifer cote samples from background, areas and from contaminated areas
undergoing treatment with hydrogen peroxide and nutrients for use in laboratory studies and for
analysis for residual contamination;
(2) analysis of dissolved oxygen concentrations and temperature in selected ground-water wells;
(3) analysis of ground-water samples collected from selected wells to determine hydrogen perox-
ide concentrations;
(4) analysis of soil gas at selected sites near an injection well to determine concentration of
oxygen in the soils above the site of injection of hydrogen peroxide in order to assess whether
degassing of hydrogen peroxide from the aquifer was occurring;
(5) analysis of ground-water samples collected from selected wells for the presence of com-
pounds that indicate the oxidative-reductive status of the aquifer;
(6) determination of aqueous phase concentrations of PAH compounds and PCP in ground-water
samples collected from wells within and not within the influence of the intermediate injection area
and from a well in an unconlaminated background area;
(7) determination of nonaqueous phase concentrations of PAH compounds, PCP, and TPH in a
NAPL sample collected from a well downgradient from the intermediate injection area; and
(8) determination of solid phase concentrations of PAH compounds, PCP and TPH in aquifer core
samples in contaminated areas receiving nutrients and oxygen and in a background uncontami-
nated aquifer core sample.
44
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Table 5.1. Concentrations of Compounds that Indicate the Oxidati've-Reductive Status of the Upper
Aquifer: October, 1991.
Well No. Iron (II) Mn (II) D.O.
(mg/L) (mg/L) (mg/L)
Wells Outside the
Plume
3014.1 nd 3.02 2.4
3034 4.89 6.62 1.9
Wells Inside the
Plume
3003.2 1.07 2.13 2.3
3010.1 056 2.76 3.0
3017.1 9.54 6.17 1.9
1 nd = non-detectable
Table 5.2. Concentrations of Compounds that Indicate the Oxidative-Reductive Status of the
UpperAquifer: April, 1992.
Well No.
Iron (II)Mn (II)
(mg/L)
s
-------
5.2.1 Task 1: Collection of Aquifer Core Samples from Background Areas and from
Contaminated Areas Undergoing Treatment with Hydrogen Peroxide and Nutrients for Use in
Laboratory Studies and for Analysis for Residual Contamination
5.2.1.1 Experimental Approach and Methods for Aquifer Core Sampling
Core samples were collected in November 1992, in the following areas: (1) control area (upgradient); and
(2) contaminated areas downgradient of injection wells (Figure 5.9; Table 5.3). This strategy was designed to
allow evaluation of the effect of injection of nutrients and hydrogen peroxide on the biodegradation of PAH
compounds, PCP, and total petroleum hydrocarbons (TPH) associated with aquifer core materials. Ground-
water monitoring data from Well No. 3025 during the pilot-scale study had indicated that contaminants may
have still been present in the pilotscale study area, so the downgradient cores were specifically located within
that area. Collection of a second set of cores was initially planned to evaluate changes in contaminant concen-
trations as a function of time, but due to results from the initial sampling in November 1992, the collection of
additional cores was not conducted.
The depth of sampling was approximately 20-30 feet bgs. The method of drilling used was air rotary with
casing hammer, a technique that has been used at the Libby Site by a local contractor, B&B Drilling. B&B
Drilling performed all drilling for this field evaluation. A sampling procedure developed at the U.S. EPA Robert
S. Kerr Environmental Research Laboratory was used to obtain aquifer core samples (Leach et al., 1988). A 5-
foot long, 4-inch diameter core barrel equipped with a retainer basket and plunger seal was attached to the drill
stem, lowered into the cased hole and driven into the subsurface. The core barrel was extracted from the hole
and a 2-foot section of the core was extruded using a hydraulic jack. The core was laid out on a preparation table
(aluminum foil-lined PVC half pipe) and halved over the length of the core (i.e., split sample). One-half was
quartered and composited into a glass container. The sampling intervals began near the water table and pro-
ceeded at selected depths for approximately 20-30 feet. The core barrel was rinsed off with tap water between
samples, and the water was disposed of in the above-grade bioreactor system. Large rocks and boulders often
hindered penetration of the sampler. These rocks were crushed by the drill hammer to form cuttings. Cuttings
and ground water produced during drilling were contained in a diverter. The diverter was periodically emptied
using a forklift. Each core hole was carefully plugged after drilling to prevent cross-contamination of the
aquifer.
Vertical profiles of each core were characterized on site by Lowell E. Leach, a geological engineer associ-
ated with the RSKERL. Subsamples of each core were taken with depth. Aquifer core (i.e., undisturbed)
samples were taken in unconsolidated sediments, while at depths where large rocks were present, aquifer cut-
tings samples (which represented disturbed samples) were taken. Samples were not collected below the area of
influence of the injection wells (Figure 5.10). Injection well 9500 is screened at the base of the Upper Aquifer
from 45 to 65 feet bgs. Samples were placed and sealed in appropriately labeled, pre-cleaned (rinsed with
solvent and distilled water and autoclaved) 1-quart Mason jars.
After all samples had been collected, the sample jars were wrapped in newspaper and placed in a cooler
with "blue ice." The coolers were secured with filament tape and shipped by express services to the UWRL in
Logan, Utah, for analysis.
All personnel involved in core sample extraction, handling, and packing had received the Hazardous Waste
Operations and Emergency Response training required under OSHA 1910.120. Personnel in the drilling and
core handling areas wore appropriate protective clothing (i.e., Level C).
5.2.1.2 Results of Aquifer Core Sampling
Boring logs were prepared for the boreholes drilled where the samples were collected and are presented in
Figures 5.11 through 5.14. One hole was drilled in an uncontaminated area, while three holes were drilled in the
intermediate injection area where nutrients and hydrogen peroxide were introduced to the aquifer to stimulate
46
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Figure 5.9. Schematic of Site showing locations of Injection Wells, Monitoring Wells, and Aquifer Drilling
Core locations.
microbial activity for in situ bioremediation of target PAH compounds and PCP. Samples taken from the bore-
holes revealed a highly heterogeneous, rocky formation. Very little finer-grained soil materials, as represented
by the sand, silt, and clay size fractions, were present in the samples. Unconsolidated material (cores) and
consolidated material (aquifer cuttings) were subsampled in the field and placed and sealed in glass jars for
measurement of contaminant concentrations and for the performance of laboratory evaluation of microbial meta-
bolic potential to transform the target compounds, including PCP and the PAH compound, phenanthrene.
47
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Table 5.3. Aquifer Core Drilling Locations: November 19SZ
Core Comments Rationale
No.
1
Background: upgradient from
the waste pit area (200 feet south of land
treatment units and approximately 600 yards
south of Core # 3)
Background PCP/PAHs/TPH
2
Downgradient from injection wells
in the intermediate injection area
(pilot study area) (~ 31 feet southeast of
the axis between Injection Site 3007 [~5 yr
operation] and Monitoring Well 3026)
PCP/PAHs/TPH upgradient
from monitoring wells &
downgradient from injection wells
of the intermediate injection system
3
Downgradient from injection wells
in the intermediate injection area
(~ 58 feet northwest of Injection Well
No.3007 directly towards Well No. 3026)
Same as Core # 2, but closer to
injection wells (Core # 2 had
exhibited visual evidences of
contamination, so a core closer
to injection wells was selected)
4
Downgradient from injection wells
in the intermediate injection area
(~ 51 feet north of Injection Wells
No. 9500/9501 [~ 3 yr operation]
directly towards Well No. 3015.1)
Same as Cores # 2 and # 3, but closer
to injection wells and towards the
of the center of the zone of
influence of the intermediate
injection system
5.2.2 Task 2: Analysis of Dissolved Oxygen Concentrations and Temperature in Selected
Ground-water Wells
5.2.2.1 Experimental Methods for Measurement of Temperature and Dissolved Oxygen Concentrations
Dissolved oxygen measurements were performed at the wellhead. Ground-water samples were collected
using either a bladder pump or an air lift evacuation pump connected to a sampling bladder. Analyses for
dissolved oxygen and temperature were performed using a YSI Dissolved Oxygen instrument (YSI, IncYellow
Springs, Ohio). Two to three pore volumes of the well were purged prior to performing the analysis. Monitoring
wells within the influence of the intermediate injection system sampled included: Nos. 3026,3032,3029,3015.1,
and 302S. Monitoring wells outside the influence of the intermediate injection system sampled included: Nos.
3012.1 and 3016.1. If LNAPL was present in a well, it was measured during this sampling event using an ORS
Interface Probe.
5.2.2.2 Results of Measurement of Temperature and Dissolved Oxygen Concentrations
Results of measurements of temperature and dissolved oxygen concentrations for water from selected
wells are presented in Table 5.4. The average temperature of the wells was 9.2° C. In Well No. 3026, the
48
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Figure 5.10. Location of Core Nos. 2 and 3 and depths of Injection Well Screens (I.W. ¦ Injection Well and
M.W. » Monitoring Well).
average yearly temperature in 1992, based on monthly measurements, was 9.9° C (data provided by Champion
International). The monthly measurements were:
1/92: 7.0° C (estimated)
2/92:6.0° C
3/92: 5.8° C
4/92:6.3° C
5/92: 8,1° C
6/92:9.3° C
7/92:11.6° C
8/92: 14.1" C
9/92: 14.1° C
10/92: 15.8° C
11/92:11.8° C
12/92: 9.0° C (estimated).
Seasonal fluctuations in temperature over the year are also evident the data presented above.
an
-------
Drilling Log
Project: Champion International Corp., Libby, Montana
Date Drilled: 11-21-92
Hole No: #1 (Background)
Bot Hole Depth: 20" 5"
Location: ~600 yd. south of hole #3.200' S of land treatment units
No. Of Samples: 1 Core
Type of Drill: Air Rotary with Casing Hammer
Depth to W.T.: 18' 3"
Size of Bit: 5 1/2" Carbide Tip
Driller:
B & B Drilling, Libby, MT„ Dave Iliff
Size of Casing: 6" I.D. Welded
Log Prepared By: Lowell Leach
Type of Sampler: 4" OD. Tbinwall Barrel with Piston
Consulting Engineer, OK, PE 6951
Depth
Scale Ft
Description
Geol
Symbol
Remarks
II II !
II 1 1 i
Tan 10 yellow silty sandstone chips with 10% grey angular
limestone up to 1/2". 2 to 3% black granitic chips
, . . P.
. A. £>.
'A\l\
¦ ¦ ¦ jry«
0-5'drill cuttings
Mil
Mil
50% grey and 50% tan angular chips. Sandstone and
limestone gravels
; ym
m4mjt\
5' -9'drill cuttings
— 10 —
Material continuous mixture of tan sandstone and grey limestone
chips grading to higher % limestone with depth
• js.-
¦ a a ¦ •
¦
¦ • •£>•
9- 0" — 19' 4" drill cuttings
— —
~~ 15 ~~
yt • * ^
First moisture 15' 10"
18' 3" water table
_ —
• Va"
\a
20
Tan and grey medium round sand and limestone
G>
19 4" to 20' 5" core sample
to refusal. 6" recovery
Bottom of Hole 20' 5"
No evidence of Pcntachlorophcnol
25
Gravels 1/4 to 3/4" diameter
Mill
O
on
11 11 1
1 1 1
1 1 1
* Core Samples
Figure 5.11. Drilling Log for Core No. 1 (Background).
50
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Drilling Log
Project: Champion International Corp., Libby, Montana
Date Drilled: 11-18-92
Hole No: #2
Bot. Hole Depth: 33' 8"
Location: Approximately 31' SE of Well 3026
No. Of Samples: 4 Cores
Type of Drill: Air Rotary with Casing Hammer
Depth to W.T.: 16'
Size of Bit: 5 1/2 Carbide Tip
Driller: B & B Drilling, Libby, MT. Dave Iliff
Size of Casing: 6" I.D. Welded
Log Prepared By: Lowell Leach
Type of Sampler: 4" O.D. Tliinwall Barrel with Piston
Consulting Engineer, OK, PB 6951
Depth
Scale Ft
Description
Geol
Symbol
Remarks
1 1 1 1
1 1 1 1
Tan silty sand with tew 1/2" diameter elongated
moderately rounded gravels. Approx. 10% gravels
¦ m n •
«cp. .=i=>
o
'cb*
' # w
" • <=5
0 — 5' drill cuttings
5 - 10' drill cuttings
10 —12' drill cuttings
12—13" drill cuttings ^ .
^ hirst Odor of
! Mil 1 1 I
1 M 1 1 1 1 1
Tan weathered limestone silty texture with green
and black gravels varying in size from BB to
1/2". Granules 20% tan and 10% black and green.
Very angular
J7r_ — &-
Gray angular limestone with light orange brown clay
balls {< 10%)
t37
.~ «== ~
CD • tZD •
Z 15 Z
Z 2° z
25
Weathered tan limestone, subangular with pea size clay balls
'f'T'
i > i ) k
Tan to yellow sandstone. Medium soft with gravels
shot size to 1/4" well ground
• ¦ •
¦-* ¦
Pentachlorophenol
13-16' drill cuttings
16'—W.T. on drill rod
16' 1" — 16' 7" core sample #1 to refused
16' 7"—23' 6" drill cuttings
23' 6" — 24' 9" core sample
recover 13 1/2 sample
24' 9" —26' 6" drill cuttings
26' 0" — 26' 6" core sample
29' 6" — 31' 0" drill cutting sample
31' 0"—32' 6" cuttings sample
32' 0"—33' 8" core sample
Bottom of Hole 33' 8"
Red/gray/green mixture of 1/4" to 3/4" semi round gravel. 9094 grave! 10% sill
•o.
Grey/grccn/black angular gravel 18' to 23' 6" tan
very angular limestone shot size to 1/2" mixed with
black angular granitic chips
• • •
l •
50% course angular gravels. 1/2" to 3/4" dark
grey limestone
i—¦ ^\-r-
•Cy ' o
¦ ¦ 23 m
— —
10% tan silty sand, 50% semiangular cobbles 1/2" to 3*
grey limestone
' '
* Core Samples
Figure 5.12. Drilling Log for Core No. 2 (31 feet SE of Monitoring Well No. 3026).
-------
Drilling Log
Project: Champion International Corp., Libby, Montana
Date Drilled: 11-19-92
Hole No: #3
Bot. Hole Depth: 32' 6"
Location." Approximately 58' NW of [njcction Well 3007
No. Of Samples: 4 Cores
Type of Drill: Air Rotary with Casing Hammer
Depth to W.T.: 13'6"
Size of Bit: 5 \a" Carbide Tip
Driller: B & B Drilling, Libby, MT., Dave llifF
Size of Casing: 6" I.D. Welded
Log Prepared By: Lowell Leach
Type of Sampler: 4" O.D. Thinwall Barrel with Piston
Consulting Engineer, OK, PE 6951
Depth
Scale Ft
Description
Geol
Symbol
Remarks
II II I II I I I!
2
I I I I I I I I I I I
Soil tan silly sandstone with 10% grey angular limestone gravels
up to 1/4" diameter
• • • • •
• a* »5f
.. v .
• • a • •
'Z"
¦ ¦c •<-> •
* °o
0—6'drill cuttings
6 —11' drill cuttings
11'- First moisture 12'First Odor of
^ Pentachlorophenol
—13' drill cutting
50/50 mixture of tan sandstone and grey angular limestone
gravels, B8 to 1/2" size. 10% silty sand
1 1 111 1
• • ty •
.cr. 6 j>
— —
Tan sandstone chips. BB top 1/2" angular
¦ p
¦ -iVa
Z 15 Z
Grey to green mixture of 1/4" to 3/4" limestone gravels. 90%
gravel with 10% tan silty sand. Well rounded
» • • • •
o o
¦ Ca- o
•OO • C
16' 5" - 18' 0" core sample
18' 5" - 20' 0" cutting sample
20' 0"—21' 5" cuttings sample
22'4"-23'3" core sample
23' 3" — 24' 9" cutting sample
25'10"-26'8" core sample
Noted oily sheen on sample
26' 8" — 27' 6" cutting sample
27' 6" - 29' cutting sample
29' — 30" 10" drill cuttings
Strong penta odor
30" 10" — 32' 6" core sample
Rntrnm nfHntr ?'¦ A"
~~ 20 ~~
Tan very angular limestone chips Shot size to 1/2" with black chips
. J=3
• £-J>-
.6 O ¦
1 1 1 1 1 II 1 1 1
o ro
r 111 m M M
Tan & grey angular chips of limestone 1/4" to 3/4". About
10% silty sand
¦ so
¦<%£'
1/4" to 3M gray limestone cobblers, angular 10%. Fine silty sand.
Green to black limestone chips. 1/4" to 1/2" angular. 10% fines
Course well rounded grey limestone gravel 1/4" to 1 i/2".
10% fine tan silts
m m •
urcy and green limestone chips, iz/4" to J/4"
. b. ,'l>
Tan silty sand 10%, grey/red/green angular gravels. 1 12" to 314"
MINI
L
1 II 1 II
DB to 3/4" angular and well rounded pebbles grey and black
limestone & granite
• • l>' •
: n\$
10% tan silty sand, 50% semiangular cobbles 1/2" to 2" grey
limestone
¦ ¦f%o
# Core Samples
Figure 5.13. Drilling Log for Core No. 3 (58 feet NW of InjectionWell No. 3007).
52
-------
Drilling Log
Project: Champion International Corp., Libby, Montana
Date Drilled: 11-20-92
Hole No: #4
Bot. Hole Depth: 31*6"
Location: Approx. 5!' N of Injection Well 9500/9501
No. Of Samples: 3 Cores
Type of Drill: Air Rotary with Casing Hammer
Depth to W.T.: 8' 6"
Size of Bit: 5 1/2" Carbide Tip
Driller: B & B Drilling, Libby, MT., Dave fliff
Size of Casing: 6" I.D. Welded
Log Prepared By: Lowell Leach
Type of Sampler: 4" OX). Thinwall Barrel with Piston
Consulting Engineer, OK, PE 6951
Depth
Scale Ft
Description
Geol
Symbol
Remarks
II II II 1 II 1 II
1 Ml 1 1 M 1 1 1 1
Tan silty sand with few angular grey limestone chips <1/2". 10%
black/grey granitic chips. Small gravels well rounded
• O -o
i • • i t
: .
¦ ¦ • • •
0 — 7" drill cuttings
First moisture in cuttings @ 10'
Water table at 8' 6*
13' 8" to 15' 0" core sample
Recovery 8"
15' 0" to 16' 6" cuttings sample
17' 2" to 18' 8" cuttings sample
18' 8" to 19' 0" core sample
immediate refusal no recovery
18' 6" to 25' 0" 2-cuttings samples,
material same.
25' 0" to 30' 10" drill cuttings
3ff 10" to 31* 6" core sample Recovery 8"
Bottom Hole - 31'6"
* Core Samples
¦ • • • M
.Q . O
Grey angular limestone chips with tan to yellow sandstone.
1/4" to 3/4".
a • a a •
¦ A"
• ¦ ¦ • ¦
•A
II III
Mixture of 1/8 -1/2" angular chips grey to tan limestone with 5%
red and black granitic chips.
• A" •£»
• ¦ •
'¦& ii.""
"&.• • ¦&
¦ -A- "
• a • a •
II 1 II II II 1
III ii T i hi
BB to 3/4" angular grey/brown and few red and green chips.
Approximately 80% limestone mixed with granitic chips.
'A a ;
• ¦ j
.
...
10% silty sand. 1/2 to 2" grey limestone cobbles
•a *b-
Figure 5.14. Drilling Log for Core No. 4 (51 feet N of Injection Well Cluster 9500/9501).
53
-------
Table 5.4. Temperature, Oxygen, and Hydrogen Peroxide Measurements for Ground Water from Selected
Wells: November 19, 1992.
Well No. Temperature D.O. H202
(°C) (mg/L) (mg/L)
Injection Wells:
3004.1 - - 108
3004.2 - - 96
3007.1 - - 97
3007.3 - - 123
9500 - - 110
9501 - - 112
Monitoring Wells
Within the Influence of the Intermediate
Injection System
3026 11.4 >20 2.0
3032 5.8 >20 3.4
3029 7.4 >20
3015.1 9.7 2.7
3025 10.0 2.8
Monitoring Wells
Outside the Influence of the Intermediate
Injection System
3012.1 9.5 0.7 5.0
3016.1 10.5 0.7
Dissolved oxygen concentrations ranged from 0.68 to greater than 20 mg/L, where the higher D.O. con-
centrations indicate the influence of hydrogen peroxide injection. In Well No. 3025, a 0.1 foot layer of LNAPL
was measured on the surface of the water table.
5.2.3 Task 3: Analysis of Hydrogen Peroxide Concentrations in Ground-Water Samples
Collected from Selected Wells
5.23.1 Experimental Method for Measurement of Hydrogen Peroxide Concentrations
Hydrogen peroxide analyses were performed using a titanium sulfate acid colorimetric procedure modi-
fied from the procedure developed by Boltz and Howell (1978). A field spectrophotometer was used to measure
absorbance (ABS) at 407 nanometers. One mL of titanium sulfate/H2S04 reagent was added to ten mL of
sample. A calibration curve was prepared using a Spectronic 20 spectrophotometer in the on-site laboratory.
Linear regression analysis (for 0 to 40 mg/L HjOj) was performed; the regression parameters were as follows:
r2 = 0.999
x coefficient = 0.022232
y intercept = 0
ABS = 0.0222 [HjOJ or [H.OJ = 45.05 ABS
54
-------
5.2.3.2 Results of Measurement of Hydrogen Peroxide Concentrations
Results of measurement of hydrogen peroxide concentrations for water from selected wells are
presented in Table 5.4. Hydrogen peroxide concentrations in the injection wells were approximately
100 mg/L, the target concentrations. Hydrogen peroxide concentrations were low in Monitoring Well
Nos. 3026, 3032, and 3012.1, where loss of hydrogen peroxide may have been due to utilization by
microorganisms and also to reactions with reduced inorganic chemicals such as ferrous iron and man-
ganous manganese. Hydrogen peroxide may also degas upon reaction with mineral surfaces of the
subsurface. Well No. 3032 is located 30 to 35 feet laterally to the 9500/9501 injection cluster. The low
hydrogen peroxide concentration may indicate that a significant rate of hydrogen peroxide decomposi-
tion is occurring in a relatively small area away from these wells.
5.2.4 Task 4: Analysis of Soil Gas at Selected Sites Near an Injection Well to Determine
Concentration of Oxygen in the Soils Above the Site of Injection of Hydrogen Peroxide in
Order to Assess Whether Degassing of Hydrogen Peroxide from the Aquifer was Occurring
5.2.4.1 Experimental Methodfor the Analysis of Soil Gas to Assess Degassing of Hydrogen Peroxide
Soil gas samples were collected in the vicinity of Injection Well Cluster 9500/9501. Soil gas
samples were obtained using a series of (0.5 inch O.D.) galvanized pipe that were coupled together and
driven into the subsurface to the desired depth(s). Several depths were measured to evaluate vertical
concentrations of oxygen within the vadose zone near the Injection Well Cluster 9500/9501. A hand-
held, positive displacement pump was used to pump gas into the sample vessel containing an oxygen
detector.
5.2.4.2 Results of the Analysis of Soil Gas to Assess Degassing of Hydrogen Peroxide
Results of the measurement of soil gas at selected sites near Injection Well Cluster 9500/9501 are
presented in Table 5.5.
Results of soil gas sampling show that hydrogen peroxide was degassing near the injection wells
and entering the overlying vadose zone. The degassing was observed while dissolved oxygen concen-
trations in wells 3026,3032, and 3029 were in excess of 20 mg/L. This degassing represents an abiotic
pathway for loss of oxygen in the subsurface; this pathway accounts for part of the decrease in hydro-
gen peroxide concentrations within the water phase as peroxide moves from an injection well to a
monitoring well within the subsurface at the site.
5.2.5 Task 5: Analysis of Ground-Water Samples Collected from Selected Wells for the
Presence of Compounds that Indicate the Oxidative-Reductive Status of the Upper Aquifer
5.2.5.1 Experimental Methods for the Analysis of Compounds that Indicate the OxidativeReductive Status
of the Upper Aquifer
Ground-water samples were collected from monitoring wells within the influence of the interme-
diate injection area, Well Nos. 3015.1, 3025, 3029, and 3032; wells outside the influence of the inter-
mediate injection area, Well Nos. 3012.1 and 3016.1; and a background well, Well No. 3001. The
methods used for the analysis of iron, manganese, nitrate, and sulfate are presented in Section 5.1.2.1.
Kfi
-------
Table 5.5. Chemical Analysis of Soil Gas for Oxygen Concentrations Near Injection Well Cluster 9500/
9501: November21, 1992.
Sample
Location Relative, to
Injection Well Cluster
9500/9501
Depth
(Feet)
Oxygen Gas Content
(%)
10.4 Feet NW
1
20.2
10.4 Feet NW
2
36.8
13 Feet W
2.6
19.4
13 Feet W
5.0
21.9
13 FeetW
7.4
53.8
10.6 Feet SE
2.6
20.9
10.6 Feet SE
5.0
48.2
13 Feet E
2.1
12.1
5.2.5.2 Results of Analyses for the Presence of Compounds that Indicate the Oxidative-Reductive Status of
the Upper Aquifer
Results of ground-water analyses for inorganic chemicals, including iron, manganese, sulfate, and
nitrate, are presented in Table 5.6. Results indicated that reduced iron and manganese were present in
the ground water, with the highest concentrations associated with Well Nos. 3012.1 and 3016.1. These
wells are outside the influence of the intermediate injection system and therefore, outside of the influ-
ence of the oxidation source, i.e., hydrogen peroxide. Water from these wells also had the lowest D.O.
concentrations, indicating reducing conditions in the ground water. Conversely, reduced iron and man-
ganese concentrations were lowest in ground water under the influence of the intermediate injection
system, where a more oxidizing environment was present, indicated by elevated levels of D.O. due to
the injection of hydrogen peroxide. Reduced iron and manganese may exert an abiotic oxygen demand
on the ground-water environment at the site. Oxidized manganese (TV) has been shown to react abioti-
cally with intermediates of PAH degradation to transform the intermediates and result in the reduction
of manganese IV to manganese II (Whelan, 1992; Whelan and Sims, 1995; Whelan and Sims, 1995).
Although reduced compounds were present, reducing conditions were not sufficient to transform
sulfate to hydrogen sulfide.
56
-------
Table 5.6. Concentrations of Compounds that Indicate the Oxidative-Reductive Status of the Upper
Aquifer: November, 1992.
Well No. Iron (II) Mn (II) SO^ NO/1 DXX
(mg/L) (mg/L) (mg/L) (mg/L) (mg/L)
Wells Within the
Influence of the
Intermediate Injection
System
3029 1.07
3032 0.93
3015.1 1.61
3025 2.49
Wells Outside the
Influence of the
Intermediate Injection
System
3012.1 4.25
3016.1 2.50
Well In Background
Area
3001 0.54
1 nd = non-detectable
2 not measured
5.2.6 Task 6: Determination of Aqueous Phase Concentrations of PAH Compounds and PCP
in Ground-Water Samples Collected from Wells Within and Not Within the Influence of the
Intermediate Injection Area and from a Well in an Uncontaminated Background Area
5.2.6.1 Experimental Methods for the Analysis of Ground-Water Samples for PAH Compounds and PCP
Ground-water samples were collected from two wells under the influence of the intermediate
injection system, Well Nos. 3015.1 and 3025; from two wells outside the influence of the intermediate
injection system, Well Nos. 3012.1 and 3016.1; and from a well in an uncontaminated background
area, Well No. 3001. Well Nos. 3015.1 and 3016.1 were sampled before and after purging. Well Nos.
3001, 3025, and 3012.1 were sampled only after purging. A peristaltic pump was used to obtain the
ground-water samples. Water removed during well evacuation was disposed in the above-ground
bioreactor. The samples were extracted and analyzed for PAH compounds and PCP using the methods
presented in Appendix B.
5.2.6.2 Results of the Analysis of Ground-Water Samples for PAH Compounds and PCP
Concentrations of PAH compounds and PCP found in the aqueous phase in selected samples from
the Upper Aquifer are presented in Table 5.7.
57
3.10
nd'
0.10
0.33
1.994
2.542
2.918
2.173
2.72
4.45
1.073
0.209
nd
4.336
0.032
1.560
0.766
0.443
>20
>20
2.7
2.8
nd
nd
0.7
0.7
0.097
-------
Table 5.7. Concentrations of PCP and Pah Compounds In Ground Water: November, 1992.
Compound
Concentrations (fig/L) in Samples Collected from Well No.:
3015.1 (Prepurge) 3015.1 (Postpurge) 3025 (Postpurge)
Naphthalene
<0.63
<0.63
<0.63
Acenaphthylene
<1.58
<1.58
<1.58
Acenaphthalene
<1,15
<1.15
<1.15
Fluorene
<0.07
<0.07
<0.07
Phenanthrene
<0.06
<0.06
<0.06
Anthracene
<0.04
<0.04
<0.04
Fluoranthene
<0.30
<0.30
118.94
Pyrene
<0.15
<0.15
46.25
6enzo(a)anthracene
<0.07
<0.07
<0.07
Chrysene
<0.05
<0.05
<0.05
Benzo(b)fluoranthene
<0.11
<0.11
6.28
Benzo(k)fluoranthene
<0.21
<0.21
<0.21
Benzo(a)pyrene
<0.10
<0.10
<0.10
Dibenzo(a,h)anthracene
<0.27
<0.27
<0.27
Benzo(g,h,i) perylene
<0.28
<0.28
<0.28
Indeno(l,2,3-cd) pyrene
<2.11
<2.11
<2.11
Pentachlorophenol
10
1
14
Compound Concentrations (ng/L) in Samples Collected from Well No.:
3016.1 (Prepurge) 3016.1 (Postpurge) 3012.1 (Postpurge) 3001 (Postpurge)
Naphthalene
13.65
<0.63
680.04
<0.63
Acenaphthylene
<1.58
<1.58
<1.58
<1.58
Acenaphthalene
<1,15
<1.15
<1.15
<1.15
Fluorene
57.98
185.16
82.57
<0.07
Phenanthrene
53.47
660.86
171.29
<0.06
Anthracene
0.91
27.98
20.54
<0.04
Fluoranthene
33.16
422.52
91.54
<0.30
Pyrene
16.28
244.87
46.28
<0.15
Benzo(a)anthracene
6.17
123.12
15.48
<0.07
Chrysene
1.09
26.32
<0.05
<0.05
Benzo(b)fluoranthene
<0.11
16.82
<0.11
<0.11
Benzo(k)fluoranthene
<0.21
<0.21
<0.21
<0.21
Benzo(a)pyrene
<0.10
<0.10
<0.10
<0.10
Dibenzo(a,h)anthracene
<0.27
<0.27
<0.27
<0.27
Benzo(g,h,i) perylene
<0.28
<0.28
<0.28
<0.28
Indeno(l,2,3-cd) pyrene
<2.11
104.61
<2.11
<2.11
Pentachlorophenol
58
98
446
<3
58
-------
In Well No. 3015.1, downgradient of the intermediate injection system, concentrations of PAH
compounds were low (below detectable limits), and there was little difference between prepurge and
postpurge results. The concentration of PCP was found to decrease after purging. In Well No. 3025,
which is farther downgradient of the injection system than Well No. 3015.1, concentrations of three
PAH compounds, fluoranthene, pyrene, and benzo(b)fluoranthene, and PCP were higher than in Well
No. 3015.1.
Concentrations of PAH compounds and PCP were also evaluated in wells where the ground water
was not under the influence of the intermediate injection system. In Well No. 3016.1, downgradient
but outside the influence of the injection system, concentrations of PAH compounds and PCP were
high. There was a trend towards increasing concentrations of PAH compounds from prepurge to
postpurge for nine PAH compounds in Well No. 3016.1. In Well No. 3012.1, which is upgradient of the
intermediate injection system and within the contaminated plume, concentrations of PAH compounds
and PCP were also high.
No contamination was evident in water collected from a background well located upgradient from
the source area and the contaminated ground-water plume, Well No. 3001. Therefore, in the water
phase as evaluated through the analysis of ground water for the presence of target contaminants,
nondelegable concentrations of PAH compounds and PCP were associated with ground water under
the influence of the intermediate injection system.
5.2.7. Task 7: Determination of Concentrations of PAH Compounds and PCP in an LNAPL
Sample Collected from a Well Downgradient from the Intermediate Injection Area
5.2.7.1 Experimental Methods for the Analysis ofPAH Compounds and PCP in an LNAPL Sample
Using an ORS Interface Probe, a layer of LNAPL measuring. 2.15 ft. deep was detected in Moni-
toring Well No. 3031, located within the vicinity, and assumed to be within the influence, of the inter-
mediate injection system. The top of the LNAPL layer was measured at 16.85 ft. from die top of the
well casing. A sample of the LNAPL was collected and shipped to the U.S. EPA RSKERL in Ada,
Oklahoma, for analysis by GC/MS using modifications of U.S. EPA Method 8270A ((U.S. EPA, 1986b)
- see Appendix B-5).
5.2.7.2 Results of the Determination of PAH Compounds and PCP in an LNAPL Sample from a Ground-
Water Monitoring Well
Both PAH compounds and PCP were found in high concentrations in the LNAPL from Monitor-
ing Well No. 3031, as shown in Table 5.8. The intermittent presence of LNAPL at the Libby site has
been report for over eight years (Piotrowski, personnel communication). These results indicate that
there is contamination of the Upper Aquifer remaining in the form of a pure product phase, which
represents long-term continual significant potential contamination by transfer of contaminants from
the NAPL phase to the water phase.
59
-------
Table 5.8. Concentrations ofPAH Compounds-arid PCPiin LNAPL Collected from Monitoring Well No.
3031: November '1992.
Compound
Concentration (mg/L)
Acenaphthylene
4001
Fluorene
5,080
Phenanthrene
10,080
Anthracene
2,230
Pyrene
3,040
Benzo(a)anthracene
700
Chrysene
720
Benzo(b)fluoranthene
440
Benzo(k)fluoranthene
1,160
Benzo(a)pyrene
830
Indeno(l f'2,3-c,d)pyrene
41
Dibcnzo(a,h)anthracene
36
Benzo(g,h,i)perylene
38
PCP
1,342
1 Results-are -mean of two duplicate -analyses.
5.2.8 Task 8: Determination of Solid Phase Concentrations of PAH Compounds, PCP, and
TPH in Aquifer Core Samples in Contaminated Areas Receiving Nutrients and Oxygen
5.2.8.1 Experimental Methods/or the Determination of the Vertical Distribution ofPAH Compounds,
PCP, and TPH in Aquifer Core Samples
Extraction and analytical methods used for samples of aquifer solids from Borehole Nos. 2,3, and
4 (collected as described in Section 5.2.1.1) are described in Appendix B for: (1) extraction of samples
(U.S. EPA Method 3550 (U.S. EPA, 1986b)) and moisture determinations for the aquifer solids (B-l);
(2) analysis of PCP (U.S. EPA Method 8040 (U.S. EPA, 1986b)) using gas chromatography (B-2); (3)
analysis of PAH compounds using high performance liquid chromatography (HPLC) (U.S. EPAMethod
8310 (U.S. EPA, 1986b)) (B-3); and (4) analysis of TPH using gas chromatography (B-4). The UWRL
Environmental Quality Laboratory is certified by the State of Utah Department of Health, Division of
Laboratory Services, for analyses pertaining to environmental compliance monitoring required by the
Resource Conservation and Recovery Act
5.2.8.2 Results of the Determination of the Vertical Distribution of Contamination
Vertical profiles of chemical contaminants associated with the aquifer solids for Borehole No. 2
are presented in Figure 5.15 for TPAH compounds, in Figure 5.16 for PCP, and in Figure 5.17 for TPH.
Numerical values for each sample are provided in Appendix C. TPAH concentrations ranged from 25
to 416 mg/kg, PCP concentrations ranged from 0.1 to 1.3 mg/kg, and TPH concentrations ranged from
60
-------
184 to 2,910 mg/kg. The highest values for all these contaminants within Borehole No. 2 occurred at
23.5-24.8 feet bgs (7.5 - 8.8 feet below the water table). Profiles for TPAH, PCP, and TPH indicate the
heterogeneous distribution of contaminants over a relatively short distance (16 feet) within the aquifer
in Borehole No. 2. Comparison of contaminant profiles indicates that the contaminants are highly
correlated with each other.
Vertical profiles of chemical contaminants associated with the aquifer solids for Borehole No. 3
are presented in Figure 5.18 for TPAH, in Figure 5.19 for PCP, and in Figure 5.20 for TPH. Numerical
values for each sample are provided in Appendix C. TPAH concentrations ranged from 5.2 to 687 mg/
kg and, therefore, demonstrated a greater spread in TPAH concentrations than that observed for Bore-
hole No. 2. The highest TPAH concentration (687 mg/kg) was observed in the sample at 26.7 - 27.5
feet bgs. Samples containing over 400 mg/kg were also present at depths of 23.3 - 24.8 feet (404 mg/
kg) and at 27.5 - 29 feet (443 mg/kg). PCP concentrations ranged from 0.1 mg/kg to 3.2 mg/kg, and
TPH concentrations ranged from 258 to 1,924 mg/kg. Profiles for TPAH, PCP, and TPH indicate a
heterogeneous distribution of contaminants over a 15 foot depth from the water table within Borehole
No. 3. Comparison of contaminant profiles indicated that the contaminants were highly correlated
with each other, and that the most contaminated interval sampled occurred at 26.7 - 27.5 feet bgs (13.4
- 14.2 feet below the water table) within Borehole No.3.
Vertical profiles of chemical contaminants associated with the solid matrix for Borehole No. 4 are
presented in Figure 5.21 for TPAH, in Figure 5.22 for PCP, and in Figure 5.23 for TPH. Numerical
values for each sample are provided in Appendix C. TPAH concentrations ranged from 5.8 to 216 mg/
kg, with the highest value sample occurring at the sample depth of 17.2 -18.7 feet bgs. PCP concentra-
tions ranged from 0.1 to 7.9 mg/kg, with the high value sample occurring at 15 - 16.5 feet bgs. TPH
concentrations ranged from 70 to 2525 mg/kg, with the highest value also occurring at 15 -16.5 feet
bgs. Profiles for TPAH, PCP, and TPH indicate a heterogenepus distribution of contaminants over a 17
foot interval from the water table within Borehole No. 4 at the site. Comparison of contaminant pro-
files indicates that the contaminants are highly correlated with each other, and that the most contami-
nated interval sampled occurred between 15 and 18.7 feet bgs (6.5 - 10.2 feet below the water table)
within Borehole No. 4.
Comparison of results among Borehole Nos. 2,3, and 4 indicates that concentrations and ranges
of chemical contaminants in each borehole were similar, and that there was no trend of decreasing
contaminant concentrations with increasing proximity to the injection system (i.e., from Borehole No.
2 to No. 3 to No. 4) (Table 5.9). Site vertical physical heterogeneity was associated with a heteroge-
neous vertical distribution of the contaminants, as shown in Figures 5.15 to 5.23. Preferential path-
ways of flow may have resulted in differences in treatment in the subsurface, with some areas more
hydrodynamically connected to the intermediate injection system and some more hydrodynamically
isolated from the injection system. However, even where subsurface areas were hydrodynamically
connected and, therefore, received oxygen and nutrients from the injection system, the presence of
immiscible NAPL in these areas (as identified in the drilling logs (Figures 5.12,5.13, and 5.14)) results
also in the presence of NAPL-associated contaminants (i.e., TPAH, PCP, and TPH) that are less suscep-
tible to the influence of the injection system than contaminants present in the water phase or sorbed to
the surface of rock particles. Therefore, reductions in concentrations of contaminants were not ob-
served in a borehole as related to the distance of the borehole from the injection system, but rather
differences in contaminant concentrations were found to be more closely related to distances below the
water table.
61
-------
Concentration (mg/Kg)
Figure 5,15. Total Poycylic Aromatic HydrocarbonConcentrallons with depth in Borehole 2.
Concentration (mg/Kg)
Figure 5.16. Pentachlorophenol Concentrations with depth in Borehole 2.
62
-------
Ground Surface
£
P.
«
A
-5
-io
-15
-20
-25
-30
-
-
^ Water Table
X7
-
- o—r
—r —
.— —
™r
0
500 1000 1500 2000 2500 3000
Concentration (mg/Kg)
Figure 5.17. Total Petroleum HydrocarbonConcentrations with depth In Borehole 2.
Ground Surface
8
£3*
a
a
1
-5-
!
I
-10-
}
1
Water Table
V
-15-
S
Ir^
-20"
-25"
i° —
1 cr—=
-30-
1
1 o
r—
o .
r . .
-100 0 100 200 300 400 500 600 700 800
Concentration (mg/Kg)
Figure 5.18. Total Polycyclic Aromatic HydrocarbonConcentrations with depth in Borehole 3.
S3
-------
8
fe
<£
0k
V
a
Oi
-5-
-10-
-15-
-20
-25-
-30-
Ground Surface
Water Table
JSZ.
smrnQ.
0
o
-i—i—i—r
.5
i 1—i—i—i—i—i—r
1 1.5 2 2.5
Concentration (mg/Kg)
3.5
Figure 5.19. Pentaehtorophenoi Concentrations with depth in Borehole 3.
o-
-5"
10'
15
O -20
-25'
-30 ¦
0,
V
Ground Surface
Water Table
^7
o
c
200 400 600 800 1000 1200 1400 1600 1800 2000
Concentration (mg/Kg)
Figure 5.20. Total Petroleum Hydrocarbon Concentrations with depth in Borehole 3.
64
-------
g
o.
C
0
-5
-10
-15-
-20
-251
Ground Surface
Water Table
^7
Q
7
25 5 0 75 100 125 150 1 75 200 225
Concentration (mg/Kg)
Figure 5.21. Total Polycyclic Aromatic Hydrocarbon Concentrations with depth In Borehole 4.
Concentration (mg/Kg)
Figure 5.22. Pentachlorophenol Concentrations with depth in Borehole 4.
RK
-------
Concentration (nig/Kg)
Figure 5.23. Total Petroleum HydrocarbonConcentrations with depth In Borehole 4.
Table S.9. Ranges of Concentrations of Contaminants Associated with Aquifer Solids: November 1992.
Chemical Contaminant
Concentrations of Contaminants in
Borehole No.:
(mg/Kg)
3 4
TPAH
PCP
TPH
25 - 416
0.1-0.3
184-2,910
5.2 - 687
0.1-3.2
258 - 1,924
5.8-216
0.1 - 7.9
70 - 2,525
66
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5.3 Phase III - Performance of a Field Evaluation to Investigate the Role of Preferential Flow
Pathways in the Intermediate Injection Area of the Upper Aquifer
5.3.1 Purpose of Investigation
Results from analyses of ground-water samples and aquifer solids, as well as visual inspections of
the aquifer cores during core acquisition, indicated that the effectiveness of bioremediation in the aqui-
fer materials may be affected by the presence of preferential flow pathways that may be conveying
relatively large volumes of injected water; these layers (or layer) may be responsible for enhanced flow
but may not necessarily coincide with zones with high degrees of contamination. When ground-water
samples from a well are collected, two to three well volumes are typically purged from the well before
sampling; this purging may result in the sampling of water that represents a relatively large volume of
ground water from a highly permeable, low contaminated zone and only a small volume of water from
a slowly permeable, highly contaminated zone.
Therefore, in Phase III of the field performance evaluation, an investigation of the role of prefer-
ential flow pathways in the intermediate injection area by means of sampling and analysis of discrete
levels of the ground water was conducted. Data were collected to evaluate effects of preferential flow
pathways on deliveiy of hydrogen peroxide and nutrients and on the concentrations of contaminant
concentrations in downgradient monitoring wells.
5.3.2 Experimental Methods and Materials
Sampling was conducted in March 1993 by personnel from the U.S. EPARSKERL. Three moni-
toring wells in the intermediate injection area were used in the investigation: Well Nos. 3025, 3026,
and 3032. Well No. 3025 is a 5 inch (inner diameter (I.D.)) cased well with a 20 foot stainless steel (4
inch I.D., #30 wire-wrapped, 0.03 inch opening) screen welded to the casing extending from 14 to 34
feet bgs. Well No. 3026 is an 5 inch (I.D.) cased well wife a 15 foot stainless steel (4 inch IX)., #30
wire-wrapped, 0.03 inch opening) screen welded to the casing extending from 18 to 33 feet bgs. Well
No. 3032 is a 2 inch (ID.) well with a 10 foot stainless steel slotted (0.02 inch) screen extending from
10.5 to 20.5 feet bgs. Well construction details are presented in Table 5.10. The depths of these wells
were calculated based on measurements taken during the Phase III sampling trip and do not necessarily
correlate with the depths of the screened intervals provided by Champion International.
Table 5.10. Details of Construction for Well Nos. 3025,3026, and 3032.
Well No. Elevation of
Elevation of
Height of
Screen
Total
Depth
T.O.C.1
Ground Surface
Pipe2
Interval3
Depth4
bgs5
(feet)
(feet)
(feet)
(feet)
(feet)
(feet)
3025 2101.9
2097.4
4.49
14-34
32.1
27.6
3026 2101.6
2097.4
4.20
18-33
35.6
31.4
3032 2104.7
2101.2
3.51
10.5-20.5
24.5
20.99
1 Elevation of top of casing (T.O.C.)
2 Height = (elevation of top of casing - elevation of ground surface)
3 Below ground surface (bgs)
4 Total depth of well from T.O.C.
5 Total depth of well from ground surface
87
-------
The following assumptions were used to determine an appropriate sampling rate in order to col-
lect ground-water samples from discrete levels within the wells: Assuming the ground-water seepage
velocity was greater than 100 feet/day in the injection area (Piotrowski, 1991), the flow of ground
water through a one-foot screened interval (assuming 30% open screen area) was 200 mL/min in a 4
inch (I.D.) well; and 82 mL/min in a 2 inch (I.D.) well (assuming 25% open screen area). Assuming
there was no ambient flow within the well, slow-rate sampling below these rates should provide ground-
water samples from discrete levels within the wells.
Therefore, slow-rate, discrete level ground-water sampling was conducted using a peristaltic pump
attached to Teflon® tubing. The average flow rate of ground-water sampling was 200,184, and 91 mL/
min in Well Nos. 3025,3026, and 3032, respectively. The end of the Teflon® tube was modified with
a weighted T-joint to encourage horizontal ground-water flow so as to collect samples representative of
the interval from which they were obtained. The volume of water in the tubing was removed prior to
sample collection. Ground-water samples were collected at one-foot intervals in Well Nos. 3026 and
3032 and at three-foot intervals in Well No. 3025 (Figure 5.24). In addition, samples of the fire pond
water amended with nutrients and hydrogen peroxide and used for injection into Well Nos. 9500 and
9501 were collected from the pipework inside the injection "houses" prior to injection. Ground water
was also collected from Injection Well Nos. 9500 and 9501.
Ground Surface
Well
3025
Well
3026
Well
3032
Groundwater
Sample
Loctioos
Well Screened Interval
3025 14-34
3025 18-33
3032 10.5-20.5
14
34
18
10.5
20.5
33 Q
Figure 5.24. Screened Intervals and Sampling Depths for Well Nos. 3025, 3026, and 3032.
68
-------
The ground-water samples were analyzed for temperature, dissolved oxygen (D.O.), hydrogen
peroxide, nutrients (total phosphorus, ammonia, and nitrate-nitrite), chlorides, PAH compounds, and
PCP. Injection water sampled prior to injection was analyzed for nutrients, D.O., temperature, and
hydrogen peroxide (R,02). Temperature, D.O., and hydrogen peroxide measurements were performed
at the wellhead, using procedures described in Sections 5.2.2.1 and 5.2.3.1. Samples analyzed for
nutrients and chlorides were acidified in the field and analyzed at the U.S. EPA RSKERL in Ada,
Oklahoma. Ammonia (NH3-N), nitrate/nitrite (N03 /N02 ), chloride (CI"), and total phosphorus (total P)
were analyzed using U.S. EPA Method Nos. 350.1, 353.1, 325.2, and 365.4, respectively (U.S. EPA,
1979). Samples used for analysis of organic compounds (PAH compounds and PCP) were collected
and scaled in 1 L amber glass bottles, stored on ice, and shipped to the U.S. EPA RSKERL for extrac-
tion (using U.S. EPA Methods 3500 and 3510 (U.S. EPA, 1986b)) and analysis by GC/MS (using
modifications of U.S. EPA Method 8270A(U.S. EPA, 1986b) - see Appendix B-5).
5.3.3 Results of the Investigation of the Role of Preferential Flow Pathways in the
Intermediate Injection Area
5.3.3.1 Inorganic Compounds as Indicators of Preferential Flow Pathways
Results of the analyses for inorganic compounds in the fire pond injection water are shown in
Table 5.11. These data represent only one point in time; during on-going injection operations, concen-
trations of the compounds vary with time.
Table 5.11. Inorganic Compounds in Injection Water: March 1993.
Well
No.
D.O.
(mg/L)
Temperature
(°C)
no3/no2-
(mg/L)
nh3-nci-
(mg/L)
Total P
(mg/L)
(mg/L)
(mg/L)
9500
5.1
12.1
0.26
3.32
8.24
1.21
84.4
9501
5.1
12.1
0.26
3.11
8.00
1.40
93.2
Results of analyses for inorganic compounds are shown in Figures 5.25 to 5.30 and in Appendix
Table C-4. The D.O. and nitrate/nitrite concentrations at the second sampling depth in Well No. 3025
(Figures 5.25 and 5.27) indicate the presence of a possible preferential flow pathway. However, in
general, the inorganic nutrient data do not conclusively indicate the presence of preferential flow path-
ways in the intermediate injection area. This observation is based on the absence of a clear, consistent
pattern of vertical profiles of the measured inorganic compounds in downgradient wells. Variability in
the data collected, as well as transformations of some of the compounds in the subsurface, also compli-
cated the evaluation of flow pathways.
-------
Depth (feet below ground surface)
5
30 -
35L ¦—-i ¦ i .1-. . 11 i I...), i •
0 5 10 15 20 25 30 35
Concentration (mg/l)
Well 3025 Well 3026 Well 3032
Figure 5.25. Vertical Profile of Dissolved Oxygen in the Ground Water: March, 1993.
Depth (feet below ground surface)
Concentration (mg/l)
Well 3025 Well 3026 Well 3032
Figure 5.26. Vertical Profile of Ground Water Temperature: March, 1993.
70
-------
Depth (feet below ground surface)
0 0.5 1 1,5 2 2.5
Concentration (mg/1)
Well 3025 Well 3026 Well 3032
Figure 5.27. Vertical Profile of Nitrate/Nitrite in the Ground Water March, 1993.
Depth (feet below ground surface)
0 0.2 0.4 0.6 0.8 i
Concentration (mg/1)
Well 3025 Well 3026 Well 3032
Figure 5.28. Vertical Profile of Ammonia in the Ground Water: March, 1993.
-------
Depth (feet below ground surface)
0 2 4 6 8 10 12
Concentration (mg/1)
Well 3025 Well 3026 Well 3032
Figure 5.29. Vertical Profile of Chloride in the Ground Water: March, 1993.
Depth (feet below ground surface)
Concentration (mg/1)
Well 3025 Well 3026 Well 3032
Figure 5.30. Vertical Profile of Total Phosphorus in the Ground Water: March, 1993.
72
-------
Hydrogen peroxide was not detected in Well Nos. 3025 and 3026, indicating that no preferential
pathway was present that allowed rapid transport of hydrogen peroxide. Hydrogen peroxide is likely to
be unstable in the subsurface and decomposes rapidly, as indicated for Well No. 3032 in Table 5.12. In
this well, hydrogen peroxide concentrations were less than 4 mg/L, representing greater than 95 per-
cent decomposition within only approximately 25 feet from the injection wells. Although Well No.
3032 is located slightly upgradient under non-injection conditions, the ground-water mounding result-
ing from injection into Well Nos. 9500 and 9501 result in Well No. 3032 becoming a downgradient
well. The presence of a preferential pathway to Well No. 3032 is not apparent from the data.
Due to hydrogen peroxide decomposition, with the associated oxygen gas generated from the
decomposition, the concentration of D.O. in the ground water is greater than the concentration at
saturation at 1 atmosphere. The D.O. data indicate the relative impact of the injection system on
nearby wells. D.O. concentrations decrease with increasing distance from the injection wells (i.e.,
Well No. 3025 is located at a greater distance from the injection wells than Well Nos. 3026 and 3032.)
Measurement of the temperature of the ground water is shown in Figure 5.26. Decreasing tem-
perature with depth for the six upper depths in Well No. 3032 may have been due to formation of ice
inside the sampling line; the line had been left in the well overnight. Therefore, some of the tempera-
ture measurements may not have been representative of actual ground-water temperatures.
Nutrient and chloride data are also inconclusive with regard to identifying the presence of prefer-
ential flow pathways (Figures 5.27 to 5.30). Several sinks and sources affect the concentrations of the
nutrients and chloride in the aquifer; a more complex analysis would be required to more thoroughly
assess their fate and transport in this aquifer.
5.3.3.2 Organic Compounds as Indicators of Preferential Flow Pathways
A primary objective of this investigation was to account for the discrepancies between routine
ground-water analyses, which do not show evidences of ground-water contamination remaining after
in situ treatment, and the results of soil core analyses obtained in Phase II of this study, which showed
both physical and analytical evidences of residual contamination. Groundwater samples were obtained
without purging three well volumes prior to collection, in contrast to normal collection procedures, in
order to see if purging results in dilution of contaminated water from aquifer layers of low conductivity.
Table 5.12. Hydrogen Peroxide Concentrations in Well No. 3032: March 1993.
Sample Depth HLp2 Concentration
(ft. bgs) (mg/L)
10.5 3.8
11.5 3.8
12.5 3.6
13.5 3.6
14.5
15.5 2.4
16.5 2.8
17.5 3.8
18.5 3.6
19.5 3.6
73
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However, in Well Nos. 3026 and 3032, PCP and PAH compounds were not detected in the ground
water. The detection limit of the GC/MS method used for analysis was less than 1 mg/L (or 1 ppb).
The discrepancy between field observations of visibly contaminated aquifer core materials (oily ap-
pearance, dark color, and hydrocarbon odor) obtained 30 ft. upgradient from Monitoring Well No. 3026
during the November 1991 sampling trip and the lack of ground-water contamination in Well No. 3026
still exists. One possible explanation for the discrepancy is that boring #2 did not access aquifer
sediments directly under the influence of the injection system (M. Piotrowski, personnel communica-
tion).
PCP and 10 of the 16 PAH compounds were detected in the ground-water samples collected from
Well No. 3025 (Table 5.13). No consistent trend was observed in the concentration of the compounds
with depth. Detection of PAH compounds and PCP in this well may be due to the presence of a thin
film (approximately 0.01 ft.) of LNAPL in the water table in the well.
Therefore, this investigation did not definitely identify any preferential flow pathways. However,
preferential pathways may exist in the aquifer, but, if present, their role in influencing contaminant
concentrations in downgradient monitoring wells is not known.
Table 5.13. Concentrations of PCP and PAH Compounds in Ground Water Collected from Well No. 3025:
March 1993.
Compound Concentrations (jo.g/L) in Samples Collected from Depth (bgs)
13.5 ft
16.5 ft.
19.5 ft.
22.5 ft.
Acenaphthylene
2
1
1
1
Acenaphthalene
33
2
11
<1 ppb
Fluorene
13
1
8
N.F.'
Phenanthrene
3
N.F.
18
N.F.
Anthracene
2
<1 ppb
5
<1 ppb
Fluoranthene
6
N.F.
15
N.F.
Pyrene
5
3
16
1
Benzo(a)anthracene
1
<1 ppb
2
N.F.
Chrysene
<1 ppb
<1 ppb
2
N.F.
Benzo(b)fluoranthene
<1 ppb
<1 ppb
<1 ppb
N.F.
Benzo(k)fluoranthene
N.F.
<1 ppb
<1 ppb
N.F.
Benzo(a)pyrene
<1 ppb
<1 ppb
1
N.F.
Indeno(l,2,3-cd) pyrene
N.F.
N.F.
N.F.
N.F.
Dibenzo(a,h)anthracene
and
Indenopyrene
N.F.
N.F.
N.F.
N.F.
Benzo(g,h,i) perylene
N.F.
N.F.
N.F.
N.F.
Pentachlorophenol
40
26
43
34
1 N.F. = Not found
74
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Chapter 6
Laboratory Performance Evaluation of In Situ Bioremediation of the
Upper Aquifer
6.0 BFI Study Objective 3: Laboratory Evaluation to Assess Performance of In
Situ Bioremediation of the Upper Aquifer
The third objective of this BFI-sponsored study was to perform a laboratory evaluation to assess
the microbial metabolic potential of subsurface aquifer materials to accomplish bioremediation of tar-
get chemicals under various conditions. This laboratory study to provide additional information con-
cerning in situ bioremediation of the Upper Aquifer is consistent with the intent of the U.S. EPA
Bioremediation Field Initiative. While the laboratory study involved tests on aquifer samples ex situ, it
provided direct evidence of biodegradation in situ. Results from the study are used to evaluate the role
of nutrient amendments, abiotic losses/transformations, and abiotic oxygen demand in the subsurface.
Measurement of mineralization of radiolabeled PCP and phenanthrene in aquifer material allowed the
evaluation of biodegradation by indigenous microorganisms. While analyses of ground water and
aquifer material yield information on the presence of important components to biodegradation in the
subsurface, the laboratory study yielded information indicating that indigenous microorganisms have
the metabolic capability to biodegrade the compounds of interest Numerous biotic and abiotic pro-
cesses affect the concentration of contaminants and dissolved oxygen in ground water. In an effort to
more clearly identify the relative role of biotic processes, it is necessary to understand both processes.
The approach used in the laboratory study was to estimate the rate and extent of contaminant
removal in aquifer core materials in laboratory microcosms using a chemical mass balance approach
(Sims, 1990). By performing a chemical mass balance, the fraction of contaminants: 1) biodegraded;
2) sorbed to organic solids; 3) humified (i.e., irreversibly bound); and 4) mineralized was estimated. In
order to accomplish a chemical mass balance, contaminated aquifer cores were spiked with l4C-PCP
and 14C-phenanthrene in the laboratory microcosms.
Since biodegradation potential of a chemical may vary depending on temperature, oxygen avail-
ability, and nutrient availability, the influence of these factors on the rate and extent of mineralization,
volatilization and soil incorporation was also investigated. Contaminant biodegradation at 10° and
20° C, with and without nutrient addition, and with and without atmospheric oxygen, was evaluated.
The lower temperature was selected to simulate the average ground-water temperature at the site (see
Section 5.2.2.2), while the higher temperature was selected to ensure that temperature was not a limit-
ing factor in biodegradation in order to evaluate the effects of the other variables. Nutrients were added
in the form of ammonium chloride. Poisoned microcosms were also evaluated to separate the effects
of biological metabolism from abiotic reactions. Poisoning was accomplished by adding a mercuric
chloride solution to the microcosms. Aerobic microcosms were aerated periodically to maintain oxy-
gen in the headspace atmosphere. Anaerobic microcosms were flushed with an oxygen-free atmo-
sphere. Volatile traps were used to capture compounds removed by volatilization. Carbon dioxide
traps were used to evaluate mineralization of the compounds to carbon dioxide. The aquifer sediment
slurries from the microcosms were analyzed at the end of the incubation period to determine the distri-
bution of the parent compounds and/or their degradation products.
75
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6.1 Objectives of Laboratory Study
The specific objectives of the laboratory study were to:
(1) determine the rate and extent of biodegradation of 14C-phenanthrene and J4C-PCP in contami-
nated aquifer materials as affected by temperature, oxygen, and nutrient addition in two different
core samples; and
(2) determine the fate of I4C-phenanthrene and 14C-PCP in the aquifer materials (solvent- extract-
able and bound residue) and air (mineralization and volatilization) phases using a chemical mass
balance approach.
6.2 Experimental Design, Materials, and Methods
A complete factorial design approach was used for the investigation of the effects of temperature
and biotic/abiotic conditions on degradation of PCP and phenanthrene in two borehole samples, with
every factor at two levels (2k design) and with duplicate sets of each treatment (referred to as the
Temperature Effects Study). A substudy was conducted using one borehole sample to investigate the
effects of oxygen, nutrients, and biotic/abiotic conditions on the degradation of PCP, with each factor at
two levels and with duplicate sets of each treatment (referred to as the Oxygen/Nutrient Effects Study).
The treatments used in the laboratory studies are summarized in Table 6,1 and graphically presented in
Figures 6.1 and 6.2. The borehole samples used in the experiments were collected as described in
Section 5.2.1.1.
Table 6.1. Experimental Variables In the Laboratory Studies.
(a) Temperature Effects Study
Variable Levels of Treatment
Compounds PCP and phenanthrene
Temperature 10° C and 20° C
Sample Sample # 1: Borehole No. 2 at 20-foot depth
Sample # 2: Borehole No. 2 at 29-foot depth
Poisoned Yes (Abiotic) and No (Biotic)
Nutrients Yes
Oxygen Yes
(b) Oxygen/Nutrient Study
Variable Levels of Treatment
Compound PCP
Temperature 10° C
Sample Sample # 2: Borehole No. 2 at 29-foot depth
Poisoned Yes (Abiotic) and No (Biotic)
Nutrients Yes and No
Oxygen Yes and No
76
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TEMPERATURE EFFECTS STUDY DESIGN
Pentachlorophenol
or
Plienanthrene
10* C
Sample #1
Sample # 2
Biotic \ Biotic
Abiotic Abiotic
20° C
Sample #1
Sample # 2
Biotic \ Biotic
Abiotic Abiotic
Figure 6.1. Temperature Effects Study Design (Both samples are from Borehole No. 2. Sample #1 is from
20 feet deep arid Sample #2 Is from 29 feet deep. Duplicate microcosms were used for each
Biotfc and Abiotic treatment).
OXYGEN AND NUTRIENTS EFFECTS STUDY DESIGN
Pentachlorophenol
Nutrients
Biotic
Aerobic
No Nutrients
Biotic
Abiotic
Abiotic
Anaerobic
Nutrients
Biotic
No Nutrients
Biotic
Abiotic
Abiotic
Figure 6.2. Oxygen/Nutrient Effects Study Design (A sample from Borehole No. 2; 29-foot depth was used
for all of the microcosms. Incubation temperature was 10* C. Duplicate microcosms were used
for each Biotic and Abiotic treatment).
77
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This design resulted in the use of 32microcosms (2 contaminants x 2 temperatures x 2 samples x
2 poisoned levels x 2 replicates = 32) for the Temperature Effects Study.
The Oxygen/Nutrient Effects Study consisted of 16 microcosms (2 oxygen levels x 2 nutrients x 2
poisoned levels x 2 replicates = 16). Only 12 additional microcosms were set up for this study as 4
microcosms in the Temperature Effects Study had the same treatment factors (i.e., the treatments for
Sample 2, PCP, 10° C, biotic and abiotic, with nutrients, were used in both studies).
Concentrations of PAH compounds and PCP in the borehole samples used in this study are shown
in Table 6.2.
Table 6.2. Concentrations of PAH Compounds and PCP in Borehole Samples Selected for the Laboratory
Studies.
Sample Location
Compound Borehole No. 2: 20 foot depth Borehole No. 2: 29 foot depth
Naphthalene 40.261 8.92
Acenaphthylene 15.35 3.29
Acenaphthene 99.05 21.91
Fluorene 45.14 4.5
Phenanthrene 66.37 6.35
Anthracene 27.07 3.12
Fluoranthene 98.76 16.75
Pyrene 71.36 6.33
Benzo(a)anthracene 31.62 4.82
Chrysene 15.09 2.33
Benzo(b)fluoranthene 7.12 0.51
Benzo(k)fluoranthene 6.47 0.81
Benzo(a)pyrene nd2 nd
Total PAH Compounds 523.66 79.64
Pentachlorophenol 0.137 2.26
• All concentrations are in mg/kg
2 nd = non-detectable
There was not enough water in the samples collected from the field to keep the solid materials
submerged in the microcosms, so a solution containing approximately the same concentration of major
cations and anions as the site ground water was added to ensure that the solid material was submerged.
This addition was done to simulate the aquifer environment at the Libby Site. Analysis of water from
the sample, Borehole No. 1: 19 feet 3 inches depth, to determine principal cations was conducted using
inductively coupled arc plasma (ICP) by the Utah State University Soils Testing Laboratory. Chloride,
sulfate, and phosphate were determined by the Utah Water Research Laboratory using ion chromatog-
raphy. Bicarbonate was determined by titration with standard acid. Data from these analyses and the
principal ion composition of the artificial aquifer water are presented in Table 6.3.
78
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Table 6.3. Principal Cations and Anions in a Libby Aquifer Sample and the Artificial Aquifer Water.
Ion
Natural sample
concentration (mg/L)
Artificial water
concentration (mg/L)1
Na
27
27.1
K
19
19.0
Ca
39
38.7
Mg
14
13.6
CI
13
13.2
SO4
10
10.3
PO4-P
15
15.2
HCO3
197
155.5
i Concentration calculated from composition.
Table 6.4 shows the concentrations of various salts added to deionized water to prepare the artificial
aquifer water. The salts were brought into solution by bubbling the suspension with CO2. The final
pH was adjusted to 7.4 using dilute NaOH.
Table 6.4. Salts Used to Prepare Simulated Water.
Salt Concentration (mg/L)
"NaCI 20
MgS04 12.9
KH2PO4 21.8
NaHC03 67.7
KHCO3 32.6
MgCOs 38.1
CaCCh 96.6
Microcosms were constructed using 250 mL Erlenmeyer flasks with a two-holed rubber stopper.
Teflon®) tubing through this stopper provided an inlet and an outlet (Figure 6.3). The outlet and inlet
were closed using one-way stopcocks, equipped with male Luer Lock adapters. Each microcosm
received 13 grams of the sample slurry material and 12 mL of artificial aquifer water.
Nutrients used in the full-scale field system at the Libby Site are ammonium chloride and dibasic
potassium phosphate. The analysis of the water from Borehole No. 1:19 feet 3 inches indicated that
the ground water contained 15 mg/L P04 -P. The artificial ground water added to the microcosms was
prepared to contain approximately this concentration (Table 6.3). This unexpectedly high concentra-
tion of available phosphorus was considered to be adequate to support biodegradation of the contami-
nants present in the aquifer materials, so no additional phosphorus was added. Ammonium chloride
solution was added to all the microcosms in the Temperature Effects Study and to the "nutrient "
microcosms in the Oxygen/Nutrient Effects Study to increase the concentration of the aqueous phase
by 2.4 mg of NH4-N per L.
79
-------
air
connecting tubes
soil
(13 grams)
vacuum
pump
C02 trap
solution
Figure 6,3. Schematic of a Laboratory Microcosm and Gas Trapping Apparatus.
"Abiotic" microcosms were prepared by adding 1.25 mL of a 5.2 mg/mL solution of HgCl2 to the
appropriate microcosms to achieve a concentration of approximately 2 mM HgCl2 per Kg dry weight
of aquifer materials, as recommended by Wolf et al. (1989).
Uniformly labeled l4C-pentachlorophenol (250 pL; 1.16 x 105 DPM) or '"C-phenanthrene (250
pL; 1.38x10* DPM) was added into the appropriate microcosms. Each radiolabeled compound was
prepared by dissolving the compound in 50 mL of DDW (distilled, deionized water). The solutions
were agitated for 24 hours and then filtered through a 45 pm filter before use. Triplicates of the same
volume of spiking solutions were prepared and measured on a liquid scintillation counter (Bcckman
Corporation, Models LSI 701 or LS6000 SE) to obtain a measurement of the total amount of MC spiked
into the microcosms. These measured values were used to calculate the mass balance obtained in the
experiments.
Aerobic microcosms were placed on shaker tables and gently shaken at 100 rpm to ensure effec-
tive mass transfer of oxygen from the atmosphere. Anaerobic microcosms were incubated at 10° C in
an anaerobic glove box with an atmosphere of 95 percent N2 and 5 percent H,. They were not placed on
a shaker table, but were shaken by hand. To achieve temperature control, microcosms were incubated
in constant temperature rooms at either 10 ± 2° C or 20 ± 2° C.
80
-------
The headspace of the aerobic microcosms was simultaneously purged and aerated once every four
days by applying a vacuum at the outlet of the C02 trap (Figure 6.3). The anaerobic microcosms were
purged with a vacuum pump using the gas in the glove box. At the time of purge, the outlet was
connected to a volatile organics trap and a C02 trap. The outlet of the organic trap was connected to
the inlet of the C02 trap, as shown in Figure 6.3. Gas traps were constructed from 150 mm long gas
washing tubes. The first trap contained 15 mL of ethylene glycol monomethyl ether (EGME) for the
collection of organic compounds. The carbon dioxide trap contained 15 mL of a solution containing 50
percent Ready Gel™ (Beckman). 40 percent methanol and 10 percent monoethanolamine.
The purge rate was slow (<60 mL/min) to keep air bubbles small to effect a greater trapping
efficiency. Each purge lasted 15 minutes. A 1 mL sample from the C02 trap or the volatile organics
trap was counted in the Beckman liquid scintillation counter after mixing the solution with Ready
Gel™. The maximum counting time used was 10 minutes and the maximum counting error allowed
was 10 percent.
At the end of the incubation period, residual phenanthrene and PCP in the solid phase were ex-
tracted using sonication (U.S. EPA Method 3550 (U.S. EPA, 1986b) - see Appendix B-l). The solvent
used for extraction was a 1:1 mixture of methylene chloride and acetone (Baxter HPLC grade). The
aquifer solids from each microcosm were transferred to a beaker. The microcosms were rinsed twice
with about 10 mL of the solvent. The solvent slurry was sonicated using an ultrasonic processor
(Sonicator® Heat Systems, Model XL 2020) after addition of 100 mL of solvent. Pulsed sonication
was applied to the sample for two minutes with the output control maintained at position 5 and the duty
cycle at 50. The sonicator was tuned before starting the extractions and was subsequently checked
after every five extractions. The probe was cleaned with solvent in between extractions. After sonica-
tion, the supernatant was decanted into a diying column filled to three-fourth of its height with crystal-
line, oven-dried anhydrous sodium sulfate. The remaining solids were rinsed with 10 mL of solvent;
this solvent was also passed through the drying column. The solvent was collected in a Kuderna-
Danish (KD) flask by applying pressure to the top of the drying column. Two to three boiling stones
were added to the KD flask, and a Snyder column was fitted to the top. The KD flask was heated over
a water bath to concentrate the sample to about 2 to 4 mL. The concentrate was transferred to a 10 mL
volumetric flask; acetonitrile was added to bring the solution to volume. A I mL sample was removed
and added to scintillation cocktail. The sample was then measured for radioactivity using the Beckman
liquid scintillation counter.
Soil-bound l4C was determined by combusting the solids after extraction in a Biological Oxidizer
(RJ. Harvey Instruments) and trapping the resulting C02 in the carbon dioxide trap. After extraction,
the aquifer solids were air dried under a hood for 24 hours. The solids were then hand-ground in a
porcelain dish. Duplicate 1 g samples of these solids were then combusted in the biological oxidizer.
The temperature of the catalyst zone was 670°-690° C; the temperature of the combustion zone was
about 900° C. The flow of the oxygen and nitrogen gases through the oxidizer was maintained at 350
mL/min. Evolved I4C02 was trapped in a C02 trapping solution. Ready Gel™ was added to the
trapping solution, and the samples were counted in the liquid scintillation counter for 10 minutes. The
maximum error allowed was 2 percent The quench limits were set at a low of 3.8 and a high of 319.3
For quality control, duplicates of a 1.00 g aquifer solid sample were spiked with 250 ^L of die
radiolabeled solutions. The samples were allowed to dry for 30 minutes in a hood and then combusted
for four minutes. The amount of activity recovered was calculated on a percentage basis. Recoveries
were 94 percent and 97 percent.
A mass balance was calculated based on the total l4C-chemicaI added to the microcosms. The
following equation was evaluated for all microcosms:
81
-------
Total amount of 14C-chemical spiked = [amount of 14C mineralized] + [amount 14C volatil-
ized] + [amount of 14C solvent extractable] + [amount 14C soil bound]
Statistical analyses were conducted using the JMP® software package (SAS Institute, Inc.) on a
Macintosh computer. Repeated measures analysis of variance (ANOVA) was used to analyze mineral-
ization and volatilization data, with sampling day as the repeated measure. The solventextractable and
solid-bound data were analyzed with ANOVA. Differences among results were considered to be sig-
nificant at the 95 percent confidence level.
6.3 Results of the Laboratory Evaluation to Assess Performance of In Situ
Bioremediation of the Upper Aquifer
6.3.1 Mineralization of Phenanthrene
Cumulative phenanthrene mineralization in biotic microcosms over the 56-day Temperature Ef-
fects Study ranged from 11.18 to 20.12 percent of the added 14C. The mean and standard deviation of
the percent mineralization in the duplicate microcosms in this experiment are shown in Table 6.5.
Phenanthrene mineralization was significantly affected by the interaction of temperature with the
sample and biotic/abiotic treatment The nature of this interaction is illustrated in Figure 6.4. Averaged
across the period of the experiment, the highest mineralization occurred in the microcosms using the
Borehole No. 2: 29-foot depth sample, without poison, at 10" C. In the Borehole No. 2: 20-foot depth
sample, mineralization was significantly lower than that in the Borehole No. 2: 29-foot depth sample,
but phenanthrene mineralization at 10° C was higher in both samples than it was at 20' C. At 20° C,
there was no significant difference between mineralization in Borehole No. 2: 20-foot depth and Bore-
hole No. 2: 29-foot depth samples.
Average mineralization in the abiotic microcosms was low in comparison to the biotic micro-
cosms. There was no significant difference in mineralization between temperatures or samples. This
low level of activity may have been due to the incomplete destruction of microbial activity by the
HgCl2 poison or may be due to non-biological chemical reactions.
There was a significant difference in average phenanthrene mineralization activity over time be-
tween the biotic and abiotic microcosms from the beginning of the experiment (Figure 6.5).
These data indicate that mineralization of phenanthrene in the Libby aquifer material is microbio-
logically mediated and that the microorganisms responsible for the mineralization activity are adapted
to the lower temperatures of the aquifer. There is no indication that artificially raising the temperature
of the contaminated zone would result in higher rates of mineralization.
6.3.2 Mineralization of Pentachlorophenol
In the Temperature Effects Study, cumulative l4C02 evolved from microcosms amended with ,4C-
pcntachlorophenol ranged from 0.44 to 1.16 percent. The averages and standard deviations of the
cumulative percent pentachlorophenol mineralized from duplicate microcosms are shown in Table 6.6.
The average cumulative PCP mineralized in microcosms in the Oxygen/Nutrient Effects Study did not
exceed 0.46 percent of the added radiolabeled carbon (Table 6.7).
The rates of PCP mineralization in the Libby aquifer material, under aerobic or anaerobic condi-
tions, were very slow. Assuming first order degradation kinetics and 1 percent mineralization in 56
days, the half life for mineralization of PCP would be approximately 10 years.
82
-------
Table 6.5. Mean and Standard Deviation of Cumulative Percent uC-Phenanthrene Mineralization in
Duplicate Experimental Microcosms During the Temperature Effects Study.
Temp. Sample/Type
CO 4
8
12
Day
16 20 24 28 35
|-
-------
15'
10-
nil'
lifSf
ISs
s
i
Bar is 1/2 LSD
10 'C
Core 2:20 ft, Biotic
Core 2:29 ft, Biotic
Core 2: 20 ft. Abiotic
Core 2:29 ft, Abiotic
20 °C
Temperature
Figure 6.4. Interaction of Temperature, Aquifer Material Sample, and Biotic/Abiotic Treatment on the Time-
Averaged, Cumulative Mineralization of 14°-Phenanthrene in the Laboratory Microcosms.
20-
Bar indicates LSD
Abiotic
Biotic
10-
jjC-^rr $ . I $
—!_
40
t-
50
60
Day
Figure 6.5. Effects of the Interaction of Poisoning and Incubation Time on the Average Cumulative 14C02
Evolved from the Mineralization of 14C-Phenanthrene in the Laboratory Microcosms.
84
-------
Table 6.6. Mean and Standard Deviation of Cumulative Percent uC-Pentachtoropbenot Mineralization in
Duplicate Microcosms During the Temperature Effects Study.
Temp. SampleAiype
CO
Day
12 16 20 24 28 35 42
WCO2 (l4C Mineralized, Cumulative %)
49
56
20
20 ft/Biotic
Mean 0.08
0.12
0.13
Std. Dev. 0.04
0.07
0.07
10
20 ftTBiotic
Mean 0.02
0.05
0.06
Std. Dev. 0.00
0.01
0.01
20
20 ft/Abiotic
Mean 0.02
0.03
0.03
Std. Dev. 0.01
0.01
0.01
10
20 ft./Abiotic
Mean 0.02
0.04
0.04
Std. Dev. 0.00
0.00
0.00
20
29 ft./Biotic
Mean 0.04
0.05
0.06
Std. Dev. 0.01
0.02
0.02
10
29 ftTBiotic
Mean 0.03
0.06
0.07
Std. Dev. 0.00
0.01
0.02
20
29 ft./Abiotic
Mean 0.03
0.04
0.05
Std. Dev. 0.00
0.01
0.01
10
29 ft./Abiotic
Mean 0.02
0.03
0.06
Std. Dev. 0.00
0.00
0.02
0.18
0.11
0.10
0.01
0.14
0.13
0.08
0.01
0.15
0.06
0.09
0.01
0.09
0.02
0.07
0.03
0.22
0.17
0.15
0.01
0.24
0.28
0.15
0.05
0.25
0.07
0.11
0.02
0.12
0.07
0.18
0.08
0.28
0.25
0.22
0.02
0.39
0.46
0.19
0.10
0.30
0.13
0.17
0.04
0.16
0.13
0.25
0.05
0.45
0.31
0.39
0.15
0.64
0.64
0.45
0.03
0.52
0.15
0.31
0.00
0.29
0.12
0.45
0.09
0.63
0.45
0.47
0.18
0.81
0.65
0.57
0.02
0.76
0.17
0.38
0.01
039
0.20
0.51
0.09
0.82
0.85
0.85
0.60
0.60
0.60
0.54
0.54
0.54
0.20
0.21
0.21
1.13
1.15
1.16
0.54
0.53
0.54
0.70
0.71
0.72
0.08
0.08
0.09
1.09
1.12
1.12
0.26
0.26
0.26
0.43
0.44
0.44
0.02
0.02
0.02
0.46
0.48
0.48
0.25
0.25
0.25
0.57
0.58
0.58
0.09
0.10
0.10
threne extractable with solvent and the fraction tightly bound to the soil (combustible) were signifi-
cantly affected by the interaction of temperature with the effects of poisoning and the aquifer material
samples used in the microcosms (Figures 6.7 and 6.8). The highest average soil-bound and the lowest
average solvent-extractable phenanthrene was observed in the Borehole No. 2: 20-foot depth sample,
without poison, incubated at 10" C. The next highest, but significantly lower, average amount of soil-
bound phenanthrene was observed in Borehole No. 2: 20-foot depth sample microcosms, without
poison, incubated at 20° C. The lowest average soil binding and the highest average solvent-extract-
ability of phenanthrene was observed with the Borehole No. 2: 29-foot depth sample, poisoned, and
incubated at 20" C. This suggests that the characteristics of the aquifer materials, in combination with
temperature and microbial activity, may be important in immobilizing phenanthrene and its degrada-
tion products on the aquifer materials. Apparently, soil incorporation, as well as mineralization of
phenanthrene in the aquifer material is microbiologically mediated.
63.5 Soil Incorporation of Pentachlorophenol
The distribution and mass balance of l4C-PCP in the Temperature Effects experimental micro-
cosms after 56 days of incubation are shown in Table 6.12. The solvent-extractability of PCP, or its
degradation products, from the aquifer material incubated at either 10° or 20° C, ranged between 51 and
89 percent in all of the treatments. Table 6.13 contains the mass balance data for the Oxygen/Nutrient
Study. Solvent extractability in the Oxygen/Nutrient Study ranged from 50 to 86 percent.
85
-------
Table 6.7. Mean and Standard Deviation of Cumulative Percent'
-------
nitrogen-amended aquifer material in aerobic microcosms was much lower than that from other treat-
ments. The range of 14C-PCP extractability responses to other three-way interactions of this kind was
less than 10 percent. The influence of these differences on the full-scale treatment process would not
be expected to be important
Table 6.8. Mean and Standard Deviation of Cumulative PercentC-Phenanthrene Volatilization During
the Temperature Effects Study.
Temp. Sample/Type Day
CO 4 8 12 16 20 24 28 35 42 49 56
14C Volatilized (Cumulative %)
20 20 ftVBiotic
10 20 ft/Biotic
20 20 ft/Abiotic
10 20 ft/Abiotic
20 29ft/Biotic
10 29 ft./Biotic
20 29 ft/Abiotic
10 29 ft/Abiotic
Mean 0.44
Std. Dev. 0.07
Mean 2.12
Std. Dev. 2.51
Mean 0.27
Std. Dev. 0.08
Mean 0.24
Std. Dev. 0.03
Mean 034
Std. Dev. 0.08
Mean 0.27
Std. Dev. 0.12
Mean 0.32
Std. Dev. 0.03
Mean 0.17
Std. Dev. 0.07
0.68 0.68
0.15 0.15
2.49 2.50
2.73 2.74
0.41 0.43
0.04 0.04
0.32 0.33
0.02 0.03
0.53 0.54
0.03 0.04
0.59 0.63
0.37 0.34
0.49 0.50
0.06 0.05
0.29 0.30
0.02 0.02
0.71 0.71
0.11 0.11
2.50 2.55
2.74 2.80
0.43 0.54
0.04 0.20
0.44 0.44
0.13 0.13
0.55 0.55
0.05 0.05
0.71 0.71
0.44 0.44
0.57 0.57
0.16 0.16
0.48 0.48
0.28 0.28
1.41 2.29
0.72 1.93
2.55 2.72
2.80 3.04
0.54 0.67
0.20 0.03
0.44 0.76
0.13 0.58
0.65 130
0.09 0.48
0.71 1.45
0.44 0.40
0.63 1.25
0.24 0.11
0.48 131
0.28 0.06
2.53 2.70
2.02 2.01
3.02 3.26
2.96 2.87
0.96 1.31
0.10 0.06
1.14 1.32
0.87 1.00
1.52 1.72
0.47 0.36
1.82 2.12
0.33 0.47
1.46 1.70
0.09 0.03
1.62 1.94
0.03 0.09
2.73 2.73
2.06 2.06
3.26 3.26
2.87 2.87
1.35 1.35
0.06 0.06
132 132
0.99 059
239 239
0.19 0.19
2.62 2.62
0.31 031
1.82 1.82
0.06 0.06
2.08 2.08
0.04 0.04
The results from these laboratory experiments indicate that temperature and nitrogen enrichment
effects on the incorporation of PCP into the aquifer material are minor. More PCP may be incorporated
into the aquifer material under anaerobic conditions than under aerobic conditions. There was no
evidence of a significant role of microbial activity in PCP incorporation into the solid phase aquifer
material.
87
-------
3.0
T
y~*
V
g
§ 2.0
-------
Table 6.10. Mean and Standard Deviation of Cumulative Percent 14C-Pentachlorophenol Volatilization in
Duplicate Microcosms in the Oxygen/Nutrient Effects Study.
Oxygen/Type
Nitrogen Status
4
8
12
16
20
Day
24 28 35 42
¦C Volatilized (Cumulative %)
49
56
No Oxygen/Biotic Mean 0.03
o.os
0.06
0.06
0.06
0.06
0.06
0.06
0.06
0.06
0.06
Nitrogen
Std. Dev. 0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
Oxygen/Biotic
Mean 0.02
0.03
0.04
0.04
0.04
0.04
0.04
0.06
0.07
0.07
0.07
Nitrogen
Std. Dev. 0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.01
0.01
0.01
0.01
Oxygen/Biotic
Mean 0.04
0.05
0.06
0.06
0.06
0.06
0.07
0.08
0.09
0.09
0.09
No Nitrogen
Std. Dev. 0.00
0.00
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
No Oxygen/Biotic Mean 0.03
0.05
0:06
0.06
0.06
0.06
0.06
0.06
0.06
0.06
0.06
No Nitrogen
Std. Dev. 0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
No Oxygen/Abiotic Mean 0.03
0.06
0.06
0.06
0.06
0.06
0.06
0.07
0.07
0.07
0.07
Nitrogen
Std. Dev.O.Ol
0.00
0.01
0.01
0.01
0.01
0.01
0.00
0.00
0.00
0.00
Oxygen/Abiotic
Mean 0.02
0.03
0.04
0.04
0.04
0.04
0.05
0.06
0.06
0.08
0.08
Nitrogen
Std. Dev.O.Ol
0.01
0.01
0.01
0.01
0.01
0.01
0.00
0.01
0.03
0.03
Oxygen/Abiotic
Mean 0.02
0.03
0.04
0.04
0.04
0.04
0.05
0.06
0.07
0.07
0.07
No Nitrogen
Std. Dev. 0.0I
0.01
0.01
0.01
0.00
0.00
0.01
0.01
0.01
0.01
0.01
No Oxygco/AbioticMean 0.03
0.04
0.05
0.05
0.05
0.05
0.05
0.05
0.05
0.05
0.05
No Nitrogen
Std. Dev. 0.00
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
Table 6.11. uC-Phenanthrene Mass Balance for each of the Temperature Effects Experimental Microcosms
after 56 Days of Incubation.
14C
Temperature Sample/
Volatilized
Mineralized
Solvcnt-
Soil-
Total
CO
Type
(%)
(%)
Extractable
Bound
Recovery
(%)
(%)
(%)
20
Core 2: 20 ft/ Biotic
4.13
19.64
17.95
59.36
101.07
20
Core 2: 20 ft/ Biotic
1.27
3.90
13.04
46.45
64.66
10
Core 2: 20 ft/Biotic
5.29
21.42
11.19
70.24
108.13
10
Core 2: 20 ft/Biotic
1.23
8.39
10.70
60.48
80.81
20
Core 2: 20 ft/Abiotic
. 1.39
2.37
31.52
40.06
75.34
20
Core 2: 20 ft/Abiotic
1.30
2.52
18.08
44.58
66.48
10
Core 2: 20 ft/Abiotic
0.63
7.03
37.16
3535
80.16
10
Core 2: 20 ft/ Abiotic
2.02
3.68
49.79
29.60
85.09
20
Core 2: 29 ft/Biotic
2.26
17.81
35.41
40.07
95 35
20
Core 2: 29 ft/ Biotic
2.52
4.56
41.71
42.49
91.28
10
Core 2: 29 ft/ Biotic
2.40
9.51
44.96
29.38
86.25
10
Core 2: 29 ft/ Biotic
2.84
30.72
32.62
44.72
110.91
20
Core 2: 29 ft/ Abiotic
1.78
2.00
82.04
34.80
120.62
20
Core 2: 29 ft/ Abiotic
1.87
3.40
88.43
25.85
119.55
10
Core 2: 29 ft/Abiotic
2.11
4.38
31.05
42.20
79.74
10
Core 2: 29 ft/Abiotic
2.05
4.64
30.01
40.19
76.89
Average Total
90.16
Standard Deviation 17.58
89
-------
o
a
a
-------
Table 6.12. uC-Pentachlorophenol Mass Balance for each of the Temperature Effects Experimental
Microcosms after 56 Days of Incubation.
I4C
Temperature Sample/
Volatilized
Mineralized
Solvent-
Soil-
Total
cc)
TVpe
(%)
(%)
Extractable
Bound
Recovery
(%)
(%)
(%)
10
Core 2: 20 ft/Biotic
0.19
0.43
61.83
26.96
89.40
10
Core 2: 20 fl/ Biotic
0.14
1.28
65.96
27.55
94.92
20
Core 2: 20 ft/Biotic
0.17
0.40
78.18
14.15
92.89
20
Core 2: 20 ft/ Biotic
0.15
0.69
70.89
28.57
100.30
10
Core 2: 20 ft/Abiotic
0.27
0.78
68.77
29.91
99.72
10
Core 2: 20 ft/ Abiotic
0.19
1.54
62.18
27.00
90.93
20
Core 2: 20 ft/ Abiotic
0.11
0.65
52.20
37.71
90.68
20
Core 2: 20 ft/ Abiotic
0.24
0.78
51.16
32.58
84.75
10
Core 2: 29 ft/ Biotic
0.15
1.30
62.11
29.39
92.95
10
Core 2: 29 ft/ Biotic
0.20
0.93
58.75
18.94
78.82
20
Core 2: 29 ft/Biotic
0.10
0.45
67.61
19.01
87.18
20
Core 2: 29 ft/ Biotic
0.14
0.42
68.41
15.70
84.67
10
Core 2: 29 ft/Abiotic
0.15
0.65
89.32
17.71
107.83
10
Core 2: 29 ft/Abiotic
0.41
0.31
82.09
22.59
105.39
20
Core 2: 29 ft/ Abiotic
0.11
0.65
72.80
18.19
91.75
20
Core 2: 29 fl/Abiotic
0.15
0.51
74.42
17.70
92.77
Average Total 92.81
Standard Deviation 7.62
7ad/e 6.13. uC-Pentachlorophenol Mass Balance for Each of the Oxygen/Nutrient Effects Experimental
Microcosms after 56 Days of Incubation.
MC ¦
Nitrogen Oxygen Volatilization Mineralization Solvent-Extractable Soil-Bound Total
Added Status (%) (%) (%) (%) Recovery
(%)
Yes
No Oxygen
0.06
0.04
76.31
10.49
86.90
Yes
No Oxygen
0.06
0.04
86.04
6.42
92.56
Yes
Oxygen
0.06
0.15
67.61
19.01
86.83
Yes
Oxygen
0.07
0.16
68.41
15.70
84.34
No
Oxygen
0.09
0.26
73.49
15.68
89.51
No
Oxygen
0.10
0.25
69.83
13.12
83.30
No
No Oxygen
0.06
0.04
88.40
8.55
97.04
No
No Oxygen
0.05
0.07
72.25
21.66
94.03
Yes
No Oxygen
0.07
0.36
80.27
8.99
89.69
Yes
No Oxygen
0.06
0.05
71.05
5.38
76.55
Yes
Oxygen
0.10
0.20
72.80
18.19
91.29
Yes
Oxygen
0.06
0.12
74.42
17.70
92.30
No
Oxygen
0.08
0.37
51.65
16.62
68.71
No
Oxygen
0.07
0.55
50.38
17.78
68.78
No
No Oxygen
0.04
0.04
75.06
15.40
90.54
No
No Oxygen
0.05
0.04
80.30
4.99
85.38
Average Total 86.11
Standard Deviation 8.33
91
-------
u
«
ea
u
«
p
£
«
3
Abiotic, 10 Abiotic, 20 Biotic, 10
Type,Temperature (°C)
Biotic, 20
Figure 6.9. Temperature x Biotic/Abiotic Treatment Interaction Effects on the Solvent- Extractability of "C-
PCP Following 56 Days Incubation in the Temperature Effects Study.
3
6
0s
a
«
40
30-
20'
10'
Bar is 1/2 Least Significant Difference
Sample 1 = Core 2: 20 ft
Sample 2 = Core 2: 29 ft
-
n
¦
Sample 1
Sample 2
Sample
Figure 6.10, ,4C-PCP Bound to Aquifer Materials Following 56 Days of Incubation in the Temperature Effects
Study
92
-------
c
£
I
s
I
m
80'
60'
40'
20
Bar is 1/2 Least Significant Difference
Sample 1 = Core 2: 20 ft
Sample2 = Core 2: 29 ft
Sample 1, Abiotic Sample 1, Biotic Sample2, Abiotic Sample2, Biotic
Sample,Type
Figure 6.11. Sample x Biotlc/Abiotic Treatment Interaction Effects on the Solvent Extractabillty of 14C-PCP
Following 58 days of Incubation In the Temperature Effects Study.
I
y
Oxygen No Oxygen
Treatment
Figure 6.12. Effects of Oxygen on Soil-Binding of 14C-PCP Following 56 days of Incubation In the Oxygen/
Nutrient Study.
93
-------
A = Abiotic
B = Biotic
N —N added
NN = NoN
O =• Oxygen
(Aerobic)
NO =No oxygen
A,NN,N0A,NN,0 A,N,NO A,N,0 B,NN,NO B,NN,0 B,N,NO B.N.O
Treatment
Figure 6.13. Effects of the Interaction of Biotic/Abiotic Conditions, Nitrogen Addition, and Oxygen on the
Solvent-Extractahility of 14C-PCP Following 56 Days of Incubation in the Oxygen/Nutrient Study.
94
-------
Chapter 7
References
7.0 References
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Publishers, John Wiley & Sons, New York, NY.
Grady, C.PX. Jr., and H.C. Lim. 1980. Biological Wastewater Treatment: Theory and Applications.
Marcel Dckkor, Inc. New York, NY. 963 pp.
Huling, S.G., and J.W. Weaver. 1991. Dense Nonaqueous Phase Liquids, EPA/540/4-91 -002, Robert
S. Kerr Environmental Research Laboratory, U.S. Environmental Protection Agency, Ada, OK.
Keck, J., R.C. Sims, M. Coover, K. Park, and B. Symons. 1989. Evidence of cooxidation of poly-
nuclear aromatic hydrocarbons in soil. Water Research 23(12):1467-1476.
Leach, L.E., F.P. Beck, J.T. Wilson, and D.H. Kampbell. 1988. Aseptic subsurface sampling tech-
niques for hollow-stem auger drilling. Proceedings, Second National Outdoor Action Conference
on Aquifer Restoration, Ground Water Monitoring, and Geophysical Methods 1:3151.
Lovely, D.R., and E.J.P. Phillips. 1987. Rapid assay for microbially reducible ferric ion in aquatic
sediments. Applied and Environmental Biology 53:1536-1540.
Lovely, D.R., and E.J. P. Phillips. 1988. Novel mode of microbial energy metabolism: Organic
carbon oxidation coupled to dissinulatory reduction of iron or manganese. Applied and Environ-
mental Mictx)biology 54: 1472-1480.
MeFarland, M.J,, and R.C. Sims. 1991. Thermodynamic framework for evaluating PAH degradation
in the subsurface. Ground Water 29(6): 885-896.
McGinnis, G.D., H. Borazjani, D.F Pope, D.A. Strobel, and L.K. MeFarland. 1991. On-site Treat-
ment of Creosote and Pentachlorophenol Sludges and Contaminated Soil. EPA/600/2-91/019,
Robert S. Kerr Environmental Research Laboratory, U.S. Environmental Protection Agency, Ada,
OK.
Means, J.C., G.S. Wood, J.X Hassett, and W.L. Banwarl. 1979. Sorption of polynuclear aromatic
hydrocarbons by sediments and soils. Environmental Science and Technology 14:1524.
Pfaff, J.D., C.A. Brockhofif, and J.W. O'Dell. 1989. Test Method: The Determination of Inorganic
Anions in Water by Ion Chromatography - Method 300.0. Environmental Monitoring and Systems
Laboratory, U.S. Environmental Protection Agency, Cincinnati, OH.
Piotrowski. M.R. 1989. In Situ Biogeochemical Reduction of Hydrocarbon Contamination of
Groundwater by Injecting Hydrogen Peroxide: A Case Study in a Montana Aquifer Contaminated
by Wood Preservatives. Ph.D. Dissertation, Boston University, Boston, MA. UMI No. 8913768.
218 pp.
95
-------
Piotrowski, M.R. 1991. Full-scale in situ bioremediation at a Superfund Site: A progress report.
Paper presented at Second Annual West Coast Conference: Hydrocarbon Contaminated Soils and
Ground Water: Analysis, Fate, Environmental and Public Health Effects, and Remediation.
EPACH Corporation, Newport Beach, CA, March 6.
Piotrowski, M.R., and J.R. Doyle. 1990. U.S. EPA-Approved in-situ bioremediation of a Superfund
aquifer contaminated by wood preservatives: Pilot study and full-scale remedial activities. Pro-
ceedings on the Remediation of Wood Treating Waste in Groundwater, Soil, and Process Streams,
Mississippi Forest Products Laboratory, Mississippi State University, Mississippi State, MS, June
5-6.
Piotrowski, M. R., J.R. Doyle, D. Cosgriff, and M.C. Parsons. 1994. Bioremedial progress at the
Libby, Montana, Superfund site. pp. 240-255. In: Applied Biotechnology for Site Remediation,
R.E. Hinchee, D.B. Anderson, F.B. Metting, Jr., and G.D. Sayles (eds.). CRC Press, Lewis Pub-
lishers, Boca Raton, FL.
Renberg, L. 1974. Ion exchange technique for the determination of chlorinated phenols and phenoxy
acids in organic tissue, soil, and water. Analytical Chemistry 46(3): 459-461.
Sawhney,B.L. and K. Brown (Eds.). 1989. Reactions and Movement of Organic Chemicals in Soils.
SSSA Special Publication Number 22. Soil Science Society of America/ American Society of
Agronomy, Madison, WI.
Sims, R.C. 1990. Soil remediation techniques at uncontrolled hazardous waste sites. Journal of the
Air & Waste Management Association 40(5): 704-732.
Sims, R.C., and M.R. Overcash. 1983. Fate of polynuclear aromatic compounds (PNAs) in soilplant
systems. Residue Reviews 88: 1-68.
Sims, R.C., J.L. Sims, D.L. Sorensen, andL.L. Hastings. 1986. Waste/Soil Treatability Study for
Four Complex Industrial Wastes: Methodology and Results. Volume 1. Literature. Assessment,
Waste/Soil Characterization, Loading Rate Selection. EPA/600/6-86/003a, Robert S. Kerr Envi-
ronmental Research Laboratory, U.S. Environmental Protection Agency, Ada, OK.
Stevens, D.K., M.M. Shah, and R.C. Sims. 1994. Evaluation of the At-Grade Ground Water Treat-
ment System at Champion International, Libby, MT, April 1990 - December 1992. Final Report to
the Robert S. Kerr Environmental Research Laboratory, U.S. Environmental Protection Agency,
Ada, OK.
U.S. EPA. 1979. Methods for Chemical Analysis of Water and Waste. EPA/600/4-79/020, U.S.
Environmental Protection Agency, Washington, DC.
U.S. EPA. 1986a. Record of Decision: Libby Ground Water Superfund Site, Lincoln County, Mon-
tana. Region VIII Montana Operations Office, U.S. Environmental Protection Agency, Helena,
MT.
96
-------
U.S. EPA. 1986b. Test Methods for Evaluating Solid Waste, Physical/Chemical Methods. SW846,
Third Edition. U.S. Environmental Protection Agency, Washington, DC.
U.S. EPA. 1988. Record of Decision: Libby Ground Water Superfund Site, Lincoln County, Montana.
Region VIII Montana Operations Office, U.S. Environmental Protection Agency, Helena, MT.
U.S. EPA. 1990. Libby Superfund Site Update. Region VIII Montana Operations Office, U.S. Envi-
ronmental Protection Agency, Helena, MT.
Whelan, G. 1992. Surface-Induced Oxidation of Multiple-Ringed Diol and Dione Aromatics by
Manganese Dioxide, Ph.D. Dissertation, Department of Civil and Environmental Engineering,
Utah State University, Logan, UT.
Whelan, G. and R.C. Sims. 1995. Mn-Catalyzed oxidation of multiple-ringed aromatics. Hazardous
Waste & Hazardous Materials, 12(3): 243-256.
Whelan, G. and R.C. Sims. 1995. Mn-Catalyzed oxidation of Naphthalenediol. Hazardous Waste &
Hazardous Materials, 12(4): 381-394.
Woodward-Clyde Consultants. 1986a. Phase IVRemedial Investigation Report, Libby, Montana
Ground Water Contamination Site. Woodward-Clyde Consultants, Denver, CO.
Woodward-Clyde Consultants. 1986b. Phase IV, Step 3 Remedial Investigation Report, Libby, Mon-
tana Ground Water Contamination Site. Woodward-Clyde Consultants, Denver, CO.
Woodward-Clyde Consultants. 1989. Work Plan for Remedial Design/Remedial Action, Ground
Water Site, Libby, Montana. Woodward-Clyde Consultants, Denver, CO,
Woodward-Clyde Consultants. 1990. Pre-Final Remedial Design Report: Upper Aquifer Operable
Unit, Libby Ground Water Site, Libby, Montana. Woodward-Clyde Consultants, Denver, CO.
Wolf, D.C., T.H. Dao, H.D. Scott, and T.L. Lavy. 1989. Influence of sterilization methods on se-
lected soil microbiological, physical, and chemical properties. Journal of Environmental Quality
18: 39-44.
97
-------
Appendix A
Preliminary Cost Estimates for the In Situ Bioremediation Program for the
Upper Aquifer
(Woodward-Clyde Consultants, 1990)
A-1. Cost Estimate Assumptions
Costs for the entire in situ remediation system are included, although the program may be phased in over
more than one year.
Lower contaminant concentrations at the Downgradient System (Station 2) allow the use of an air com-
pressor and oxygen generator for the oxygen supply. The existing peroxide system will be used at the Interme-
diate System (Station 1) and a peroxide system will be installed at the Source Area System (Station 3).
The only piece of major purchased equipment required to upgrade the Intermediate System at Station 1 is
a 2,500 gal. storage tank for peroxide. This tank will be housed in a separate structure with a concrete berm to
provide secondary containment. Another 2,500 gal. peroxide storage tank will be installed at Station 3. This
tank also will be surrounded by a concrete berm for secondary containment. These tanks will provide approxi-
mately a 2 month supply of peroxide and will allow the peroxide to be purchased at a lower bulk rate.
The piping trenches are 5-1/2 feet deep. The trenches will be benched, with a width of 2 feet for the
interval 5-1/2 feet to 2-1/2 feet, and a width of 4 feet for the interval 2-1/2 feet to ground surface.
Costs for piping, valves and fittings are only included for the system from the filter out to the injection
wells. Costs are not included for conveyance of fire pond water to each station. There will be no paving over the
pipe trenches. All piping is PVC, except for short lengths within Station 2, as specified on the Conceptual
Arrangement for that station.
Backwash water from the filters at Stations 2 and 3 will be released to a gravel drywell. The dimensions of
the drywell are assumed to be 4 ft. wide x 4 ft long x 6 ft. deep.
Nutrients are mixed in the proportion of 67 lbs. ammonium chloride to 33 lb. potassium tripolyphosphate
per 600 gal. water. Nutrients are metered into the injection system at a rate of275 mLper minute per 100 gpm
of water.
At Station 2, where an oxygen generator is the oxygen source, the water will be saturated with oxygen
(oxygen saturation is 40 mg oxygen per liter of water). At Stations 1 and 3, peroxide is metered into the injection
well system at a rate of 70 mL per minute per 100 gpm of water.
Pipe and earthwork costs are from Means Site Work Cost Data 1990. labor costs have been multiplied by
0.94 (per Means) for work performed in Great Falls, Montana. Costs for earthwork have been converted from $/
yd3 to $/linear foot based on cubic yard calculations for the trench benching described above.
PVC fittings and valve costs are from Harrington Plastics catalog, 7th edition. All prices are multiplied by
0.3 per the Harrington representative to provide a more realistic value.
Costs for housing are from Means Construction Cost Data 1990, and are based on a rate per cubic foot of
building at this stage of the design.
A-1
-------
A-2. Preliminary Cost Estimate for In-Sttu Bioremediatkm Program
CAPITAL COST
STATION 1/INTERMEDIATE SYSTEM UPGRADE
Description
Quantity
Unit
Unit 'Price
Total Cost
Station 1 Major Purchased Equipment (MPE)
Injection Wells
1 well
$9,990.00
$9;900
Monitoring Wells
2 well
$5,500,00
$11*000
Filter
1 each
$0.00*
$0
Air Compressor with Dryer & Filter
0 each
$0
Oxygen Generator
Oeach
$0
Spargers
0 each
$0
Peroxide Storage Tank (2,500 gal)
1 each
$1,300.00
$1,500
Peroxide Pump
1 each
$0.00*
$0
Nutrient Storage Tank
1 each
$0.00*
$0
Nutrient Mixer
1 each
$0.00*
$0
Nutrient Pump
1 each
$0.00*
SO
Housing
1 each
S8,500.00
$8,500
Flow Meters
1 each
$0.00*
$0
Piping & Tubing
$150
Labor
Supervisor
8 hours
$40.00
$320
Pipe Fitter
24 hours
$35.00
$840
Electrician
0 hours
$35.00
$0
Laborer
24 hours
$20.00
$480
Construction Supervisor
Supervisor Labor
201iours
$60.00
$1,200
Per Diem
2 day
$100.00
$200
Airfare
1 RT
$1,500.00
$1,500
SUBTOTAL STATION 1 MAJOR PURCHASED EQUIPMENT
$35,590
~Equipment exists and lis currently operating
A-2
-------
A-3. Preliminary Cost Estimate for In-Situ Bioremedlation Program
CAPITAL COST (Continued)
Description
Quantity
Unit
Materials
Unit Price Amount
Labor and Equipment
Unit Price Amount
Total Cost
Station 1 Pipe, Fittings, Valves
PVC Pipe
2 Inches
30 ft.
$1.31
$39.30
$5.69
$170.70
$210
2 1/2 Inches
500 ft,
$1.87
$935.00
$5.97
$2,985.00
$3,920
4 Inches
Oft.
$3.28
$0.00
$6.96
$0.00
$0
PVC Tee
2-1/2x2-1/2x2
3 ea.
$5.44
$16.32
$0.00
$16
4x4x2
0 ea.
$12.94
$0.00
$0.00
$0
4x4x2-1/2
0 ea.
$12.94
$0.00
$0.00
$0
PVC 45 Degree Braid
2-1/2 inches
0 ea
$4.08
$0.00
$0.00
$0
4 inches
0 ea.
$0.30
$0.00
$0.00
$0
PVC 90 Degree Bend
2-1/2 inches
Oea.
4.07
$0.00
$0.00
$0
PVC Cap
2-1/2 inches
1 ea.
$2.19
$2.19
$0.00
$2
4 inches
Oea.
$5.45
$0.00
$0.00
$0
PVC Butterfly Valve
2 inches
1 ea.
$34.80
$34.80
$0.00
$35
2-1/2 inches
Oea.
$38.10
$0.00
$0.00
$0
SUBTOTAL STATION 1 PIPE, 1-1T
TINGS,
VALVES
$1,027.61
$3,15,5,70
$4,192
Station 1 Earthwork
Excavate
530 If
$0.00
$0.00
$1.73
$916.90
$917
Sand Bedding
530 If
$0.33
SI 74.90
$0.40
$212.00
$387
Backfill/Compact
530 If
$0.00
$0.00
$1.57
$832.10
$832
SUBTOTAL STATION 1 EARTHWORK
$174,90
$1,961,00
$2,136
SUBTOTAL STATION 1 CAPITAL COST
$41,909
A-3
-------
A-4. Preliminary Cost Estimate for ln-SituJ3joremediation -Program
CAPITAL COST
STATION 2/DOWNGRADIENT SYSTEM
Quantity
Description
Unit
Unit Price
Toial Cost
Station 2 MajorTurchased Equipment (MPE)
Injection Wells
.6 .wells
$9,990.00
$59,400
Monitoring Wells
2 wells
15,500.00
$11,000
Filter
1 each
$16,416.00
$16,416
Air Compressor with;Dryer&Filter
leach
:$8,200.00
$8,200
Oxygen Generator
1 each
$11,680.00
$11,680
Spargers
1 each
$3.15,00
$315
Peroxide Storage Tank
O.each
$0
Peroxide Pump
Oeach
$0
Nutrient Storage Tank (2,00 gal)
leach
$1,500.00
$1,500
Nutrient Mixer
1 each
$5,200.00
$5,200
Nutrient Pump
1 each
$1,.936.00
$1,936
Housing
1 each
$26,000.00
$26,000
Flow Meters
1 each
$1,400.00
$1,400
Piping & Tubing
$400
Labor
Supervisor
8 hours
$40.00
$320
Pipe Fitter
40 hours
$35.00
$1,400
Electrician
1.6 hours
$35.00
$560
Laborer
40 hours
$20.00
$800
Construction Supervisor
Supervisor Labor
40 hours
$60.00
$2,400
Per Diem
6 days
$100.00
$600
Airfare
1 RT
$1,500.00
$1,500
SUBTOTAL STATIONS MAJOR PURCHASED EQUIPMENT
$151,027
A - 4
-------
A-S. Preliminary Cost Estimate for In-Situ Biommediation Program
CAPITAL COST (Continued)
Quantjly
Description Unit Materials Labor and Equipment Total Cost
Unit Price Amount Unit Price Amount
Station 2 Pipe, Fittings, Valves
PVC Pipe
2 Inches
10 ft.
$1.31
$13.10
$5.69
$56.90
$70
2 1/2 Inches
50 ft.
$1.87
$93.50
$5.97
$298.50
$392
4 Inches
2,200 ft.
$3.28
$7,216.00
$6.96
$15,312.00
$22,528
PVCTee
2-1/2x2-1/2x2
Oea.
$5.44
so
$0.00
$0
4x4x2
1 ea.
$12.94
$12.94
$0.00
$13
4x4x2-1/2
5 ea.
$12.94
$64.70
$0.00
$65
PVC 45 Degree Bend
2-1/2 inches
Oea
$4.08
$0.00
$0.00
$0
4 inches
1 ea.
$0.30
$0.30
$0.00
$0
PVC 90 Degree Bend
2-1/2 inches
0 ea.
$4.07
$0.00
$0.00
$0
PVC Cap
2-1/2 inches
Oea.
$2.19
$0.00
$0.00
$0
4 inches
2 ea.
$5.45
$10.90
$0.00
$11
PVC Butterfly Valve
2 Inches
1 ea.
$34.80
$34.80
$0.00
$35
2-1/2 inches
5 ea.
$38.10
$190.50
$0.00
$191
SUBTOTAL STATION 2 PIPE, FITTINGS.
VALVES
$7,636,74
$15,667.40
$23,304
Station 2 Earthwork
Excavate
2,260 If
$0.00
$0.00
$1.73
$3,909.80
$3,910
Sand Bedding
2,260 If
$0.33
$745.80
$0.40
$904.00
$1,650
Backfill/Compact
2,260 If
$0.00
$0.00
$1.57
$3,584.20
$3,548
Gravel Drywell
3.63 yd3
$10.55
$37.98
7.98;
$28.73
$9,175
SUBTOTAL STATION 2 EARTHWORK:
%m,n
$3,390.73
$9,175
SUBTOTAL STATION 2 CAPITAL COST
$183,506
A-5
-------
A-6. Preliminary Cost Estimate for In-Situ Bioremediatbn Program
Capital cost
STATION 3/SOURCB AREA SYSTEM
Description
Quantity
Unit
Unit Price.
Total Cost
Station 3 Major Purchased Equipment (MPE)
Injection Wells
2 wells
$9,990.00
$19,800
Filter
1 each
$8,483.00
$8,483
Air Compressor with Dryer & Filter
0 each
$0
Oxygen Generator
0 each
$0
Spargers
0 each
$0
Peroxide Storage Tank
1 each
$1,500.00
$1,500
Peroxide Pump
1 each
S373-.00
$373
Nutrient Storage Tank
1 each
$713.00
$713
Nutrient Mixer
1 each'
$4,800.00
$4,800
Nutrient Pump
1 each
$754.00
$754
Housing
1 each
$25,500.00
Flow Meters
1 each
$1,200,00
$1,200
Piping & Tubing
$150
Labor
Supervisor
8 hours
$40.00
$320
Pipe Fitter
40 hours
$35.00
$1,400
Electrician
16 hours
$35.00
$560
Laborer
40 hours
$20.00
$800
Construction Supervisor
Supervisor Labor
40 hours
$60.00
$2,400
Per Diem
6 days
$100.00
$600
Airfare
1 RT
$1,500.00
$1,500
SUBTOTAL STATION 3 MAJOR PURCHASED EQUIPMENT
$45,353
A-6
-------
A-7. Preliminary Cost Estimate for In-Situ Bbremediation Program
CAPITAL COST (Continued)
Qy^jjy ^ —
Description Unit Materials Labor and Equipment Total Cost
Unit Price Amount Unit Price Amount
Station 3 Pipe, Fittings, Valves
PVC Pipe
2 laches
20 ft
$1.31
$26.20
$5.69
$113.80
$140
2 1/2 Inches
1,000 ft.
SI.87
$1,870.00
$5.97
$5,970.00
$7,840
4 Inches
Oft.
$3.28
$0.00
$6.96
$0.00
$0
PVC Tee
2-1/2 x 2-1/2x2
2 ea.
$5.44
$10.88
$0.00
$11
4x4x2
Oea.
$12.94
$0.00
50.00
$0
4x4x2-1/2
Oea.
$12.94
$0.00
$0.00
$0
PVC 45 Degree Bend
2-1/2 inches
1 ea.
$4.08
$4.08
$0.00
$4
4 inches
0 ea.
$0.30
$0.00
$0.00
$0
PVC 90 Degree Bend
2-1/2 inches
1 ea.
$4.07
$4.07
$0.00
$4
PVC Cap
2-1/2 inches
1 ea.
$2.19
$2.19
$0.00
$2
4 inches
0 ea.
$5.45
$0.00
$0.00
$0
PVC Butterfly Valve
2 inches
2 ea.
$34.80
$69.60
$0.00
$70
2-1/2 inches
0 ea.
$38.10
$0.00
$0.00
$0
SUBTOTAL STATION 3 PIPE, FITTINGS,
VALVES
$1,987,02
$6,083.80
$8,071
Station 3 Earthwork
Excavate
1,020 If
$0.00
$0.00
$1.73
$1,764.60
$1,765
Sand Bedding
1,020 If
$0.33
$336.60
$0.40
$408.00
$745
Backfill/Compact
1,020 If
$0.00
$0.00
$1.57
$1,601.40
$1,601
Gravel Drywell
3.6 yd3
$10.55
$37.98
7.98
$28.73
$67
SUBTOTAL STATION 2 EARTHWORK
$374.,58
$3,802-73
$4,177
SUBTOTAL STATION 3 CAPITAL COST $57.601
TOTAL CAPITAL COST FOR ALL THREE SYSTEM $283.016
A-7
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AS. Preliminary Cost Estimate for In-SItu Bloremediatlon Program
ANNUAL OPERATIONS AND MAINTENANCE (O&M) COST
Description
Quantity
Unit
Unit Price
Total Cost
STATION 1/INTERMEDIATE SYSTEM UPGRADE
Power
$1,000
Peroxide
12,154
gal.
S3..12
$37,922
Nutrients
Almond Chloride
5,475
lb.
$0.33
$1,807
Potassium Tripolyphosphate
(PTP)
2,628
lb.
$1.19
$3,127
Maintenance and Repairs *
,5% MPE of Station.3
$2,268
Operating Supplies
15% Maintenance and Repairs
$340
Well Maintenance
1
well
$200.00
$200
SUBTOTAL STATION 1 ANNUAL O&M
$46,664
STATION 2/DOWNGRADIENT SYSTEM
Power
$10,600
Peroxide
0
gal.
$3.12
$0
Nutrients
Ammonium Chloride
23,360
lb.
$0.33
$7,709
Potassium Ttipolyphosphate
(PTP)
11,680
lb.
$1.19
$13,899
Maintenance and Repairs
5% MPE of Station 2
$7,55.1
15% Maintenance and Repairs
Operating Supplies
$1,133
Well Maintenance
6
well
$200.00
$1,200
SUBTOTAL STATION 2 ANNUAL O&M
$42,092
STATION 3/SOURCE AREA SYSTEM
Power
$1,000
Peroxide
9,709
gal.
$3.12
$30,292
Nutrients
Ammonium Chloride
4,380
lb.
S0.33
$1,445
Potassium Tripolyphosphate
(PTP)
2,190
lb.
$1.19
$2,606
Maintenance and Repairs
5% MPE of Station 3
$2,268
15% Maintenance and Repairs
Operating Supplies
$340
Well Maintenance
2
well
$200.00
$400
SUBTOTAL STATION 3 ANNUAL O&M
$38,351
TOTAL O&M COST FOR ALL THREE SYSTEMS
$127,107
/
~The percentage used tor Maintenance and Repairs for Station 1 is based on the MPE cost for
Station 3. This provides a more reasonable estimate for Station 1 Maintenance and Repairs
because the only MPE needed to complete the Station 1 system is a new tank. The Station 3
system is of similar configuration and flow rate, so the MPE cost for the Station 3 system is
similar to what the MPE would costfor Station 1 if most of the equipment for Station 1 did not
already exist.
A - 8
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APPENDIX B
Analytical Methods and Quality Assurance/Quality Control Procedures
B-l. Extraction of Aquifer Solid and Ground-Water Samples and Moisture
Determination of Aquifer Solids
Upon arrival of samples at the UWRL, the condition of samples was checked and noted. All
samples were logged in by assigning each sample a UWRL log number and by entering appropriate
information in the UWRL log book, including sample type, date sampled, date logged in, field ID, and
type of analyses to be performed. All samples were placed in a refrigerated unit at 4° C. During sample
extraction and analysis, all containers (extraction, storage, GC vials, LC vials, etc.) were labeled with
the UWRL log number. After extraction and analysis, the samples were stored or archived in the 4°
refrigerated unit or in a freezer at -70° C. During data management and analysis, field ID numbers
were re-associated with UWRL log numbers and the concentrations of the target compounds measured
in the samples.
The procedure used for the extraction of contaminated aquifer cores was based on U.S. EPA
Method 3550 using sonication (U.S. EPA, 1986b); the procedure used for the extraction of ground
water was based on U.S. EPA Method 3510 using a separatory funnel (U.S. EPA, 1986b). Samples
were solvent-extracted with methylene chloride/acetone (in a 1:1 mixture by volume) using sonication
or with methylene chloride using separation techniques. Sample extracts were passed through a funnel
containing anhydrous sodium sulfate. Samples were concentrated in a Kuderna-Danish apparatus.
Final volumes were adjusted, and the samples were then ready for analysis. Specifically, the proce-
dures used included the following steps:
The aquifer core samples were prepared for extraction by weighing each sample in the jar as
received using an analytical balance (Sartorius Model B120S) and recording the weight to the nearest
0.01 g. After a sample had been removed from a jar for extraction, the dry weight of the jar was
obtained. The wet weight of the sample was determined by subtracting the dry weight of the jar from
the total weight of the jar and sample. The sample was than transferred to a 2 L glass beaker (labeled
with UWRL sample log number) for extraction. The sample jar was rinsed with solvent, and the
solvent rinse was added to the sample in the beaker.
For the aquifer cuttings samples, approximately 30 g of soil sample was weighed using an analyti-
cal balance (Sartorius Model B120S) into a tared plastic, disposable weighing dish (4 cm x 4 cm), and
the weight was recorded to the nearest 0.01 g. The sample was then transferred to a 125 mL glass jar
with a Teflon®-lined lid (labeled with UWRL sample log number) that had been cleaned with a solvent
rinse or by muffling in a muffle furnace at 550° C for 24 hours.
For the aquifer cuttings samples, at the same time as the portion used for analytical determination
was removed and weighed, 5 to 10 g of the sample was removed and weighed in a tared crucible for
moisture determination. The sample was dried overnight at 105° C and allowed to cool in a desiccator
before re-weighing. For the aquifer core samples, the entire sample after extraction was dried to obtain
the dry weight. The percent moisture of the sample was calculated using the following relationship:
$ of sample (wet weights - e of drv sample x 100 = % moisture (dry weight basis)
g of dry sample
B-1
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For the samples used for analytical determination of contaminant concentrations, 1 mL of a
tribromophenol spiking solution (5000 mg/L, prepared as pure (99% or greater; Aldrich Chemical Co.)
tribromophenol in acetonitrile) was added to the aquifer materials in each extraction jar. For the aqui-
fer cuttings samples, approximately 100 mL of solvent, 1:1 methylene chloride/acetone (pesticide quality)
by volume was then added to the sample in the jar, and the sample and solvent were mixed by swirling.
The sample was then disrupted for 3 minutes with a sonicator (Tekmar Sonic Disrupter Model No.
CV 17, with a 3/4 inch probe) with the output control setting at 10, pulse mode switch set "on," and
percent duty cycle set at 50 %.
After sonication, the solids were allowed to settle. The supernatant (sample extract) was poured
into a 100-mm funnel filled with 2-2.5 inches of anhydrous sodium sulfate and glass wool for removal
of water. The anhydrous sodium sulfate (reagent grade) was prepared by drying in an oven at 105° C
for 12 hours in 600 mL beaker covered with triple layer of aluminum foil, followed by storage in a
desiccator until use. The dried extract was collected in a 500 mL Kuderna-Danish (K-D) flask with a
10 mL graduated concentrator tube attached (the flask was labeled with UWRL sample log number).
One hundred mL of solvent were added to the sample two more times, with sonication of the sample
and separation of supernatant performed after each addition of solvent. After the sample had been
sonicated three times, 5-10 mL of additional solvent were added to the sample, and the sample was
swirled. The solids were allowed to settle and the supernatant was poured through the funnel contain-
ing anhydrous sodium sulfate. This washing procedure of the sample was conducted four more times.
The same procedures were used for the aquifer core samples, except that a total of 1 L of solvent was
used for extraction, rather than 300 mL.
After the sample extract had drained from the funnel, the funnel was rinsed three times with 2-4
mL of solvent. After all the rinses had drained, the funnel was removed from the K-D flask/concentra-
tor, and the tip of the column was rinsed with solvent into the K-D flask.
A small Teflon® boiling chip was added to the K-D flask, and a 3-ball macro Snyder column was
attached. The Snyder column was prewet by adding about 1 mL of methylene chloride to the top of the
column. The K-D apparatus was placed on the steam table (80°-90° C) (concentric ring electric steam-
ing bath, Model No. 66738, Precision Scientific, Chicago, IL) so that the concentrator tube was par-
tially immersed in the hot water, and the entire lower rounded surface of the flask was bathed with hot
vapor. The vertical position of the apparatus and the water temperature, as required, were adjusted to
complete the concentration in 10-15 minutes. At the proper rate of distillation, the balls of the column
actively chattered, but the chambers did not flood with condensed solvent. When the volume of the
liquid reached approximately 5 mL, the K-D apparatus was removed from the steam table and allowed
to drain and cool for at least 10 minutes.
To accomplish solvent exchange, the Snyder column was removed and 15-20 mL of acetonitrile
was added to the flask. The Snyder column was re-attached and the K-D apparatus was placed back on
the steam table. The extract was concentrated to approximately 5 mL. The temperature of the steam
table was raised as necessary to maintain the proper rate of distillation. The K-D apparatus was
removed from the steam table and allowed to cool. The Snyder column was removed, and the flask and
its lower joints were rinsed into the concentrator tube with 1-2 mL acetonitrile.
The final volume was adjusted to 10 mL by transferring the sample to a 10 mL volumetric flask
using a clean disposable Pasteur pipette. The flask was brought to volume with acetonitrile.
Two mL of the extract was transferred to a GC vial (12 x 32 mm (OD x H)) (labeled with UWRL
log number) for PCP analysis using gas chromatography (GC). One mL was. transferred to a 10 mL
volumetric flask and brought to volume with acetonitrile. This sample extract was filtered through a
B - 2
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0.2 micron filter. Two mL of this extract was transferred to a GC vial (labeled with U WRL log number)
for PAH analysis using gas chromatography/mass spectrometry. The samples were stored in the dark at
4° C until analysis.
For extraction of the ground-water samples, each sample was agitated to re-suspend particulates
that settled out. The sample was then filtered through glass fiber filter paper, to remove coarse materi-
als, into a 1000 mL graduated cylinder, and the volume of the sample was recorded. The sample was
then transferred to a 1000 mL separatory funnel and acidified to a pH value below 2 using a 50:50
percent sulfuric acid:water (v:v) solution. Sixty mL of methylene chloride was poured in several
aliquots into the graduated cylinder to transfer quantitatively the remainder of the sample to the separatory
funnel. A one mL aliquot of the tribromophenol spiking solution (5000 mg/L) was added to the sample
in the separatory funnel. The sample was shook vigorously for one minute, with venting several times
to release pressure. The layers were allowed to separate after shaking. If an emulsion was present, it
was broken by putting a pipette through the emulsion, by adding 5 to 10 mL of saturated sodium
chloride solution and agitating gently, or by transferring the emulsion to a centrifuge tube and centri-
fuging for 30 seconds at low speed. The lower layer (methylene chloride) was drained in a funnel filled
with glass wool and two to three inches of sodium sulfate (referred to as the drying funnel), which was
placed over a 250 mL serum bottle. Sixty mL of methylene chloride was added to the separatory funnel
two additional times, and the extraction procedure was repeated. After the final separation, the tip of
the separatory funnel was rinsed into the drying funnel with methylene chloride. The drying funnel was
rinsed twice with methylene chloride, and the tip of the funnel was rinsed into the serum bottle with
methylene chloride. The extract was concentrated using a K-D apparatus and prepared for analysis as
described previously.
Quality control procedures utilized during the extraction procedure included:
1. Duplicate extractions: every fifteenth to seventeenth sample was extracted in duplicate to check
for reproducibility of the extraction procedure. Each duplicate sample was analyzed for PCP and
PAHs.
2. Procedural blanks: With each set of extractions (i.e., every 9-10 samples), a solvent sample
(containing no soil) was run through the extraction procedure to detect contamination associated
with the extraction procedure. The procedural blanks were analyzed with the set of samples with
which they were extracted.
3. Spikes: With every set of extractions (i.e., every 9-10 samples), duplicate samples were spiked
with PCP and tribromophenol. Thirty g aliquots of a sample were weighed into two containers.
Before adding the solvent to the two containers, 250 mL of the PCP spiking solution, and 1 mL of
the tribromophenol spiking solution were added directly to the soil. Samples in both containers were
extracted. The spiked samples were analyzed and the results were recorded, including percent recov-
ery of the spiking solutions.
Stock solutions of the compounds used for spiking the samples were prepared in the following
manner:
a) PCP spiking solution: The spiking solution was prepared by dissolving 0.200 g PCP (reagent
grade) into 100 mL of methanol (pesticide quality);
b) Tribromophenol spiking solution: The spiking solution was prepared at a concentration of 5000
mg/L by dissolving the appropriate amount of pure (99% or greater; Aldrich) tribromophenol in
acetonitrile (pesticide quality).
B-3
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After preparation, the stock spiking solutions were stored at -20° C in the dark until use.
As part of the quality assurance/quality control program, a technician certification procedure was
used. Before a laboratory technician was allowed to perform extractions, he/she was required to ex-
tract duplicate spiked, clean sand samples. Recovery efficiencies of the spiked samples had to be
greater than or equal to 95% and equal to or less than 105% before the technician was allowed to
extract project samples.
B-2. Analysis of PCP using Gas Chromatography
An adaptation of U.S. EPAMethod 8040 (U.S.EPA, 1986b) was used to determine the concentra-
tion of pentachlorophenol (PCP) in the aquifer core and cuttings sample extracts. Gas chromatography
with an electron capture detector was used to detect PCP in the sample extracts. Prior to use of this
method, samples were extracted using sonication as the extraction technique.
Samples were analyzed using a Shimadzu Gas Chromatograph 14A-GC with a Shimadzu Auto-
matic Sample Injector AOC-1400, an R.TX-5 column, and a Shimadzu C-R501 Chromatopac integra-
tor (Shimadzu Instruments, Columbia, MD).
Before every analysis run, the GC column was brought to its highest allowable operating tempera-
ture for five hours. During this time, a solvent was injected every hour in order to achieve better
conditioning of the column. After conditioning, without any injection, the GC was operated for twice
the length of time of a normal run. If a steady baseline was not achieved, the column was re-condi-
tioned.
The temperature program for the analysis was: initial column temperature set at 110° C, held for
2 minutes, followed by 2.5°/min temperature rise to 240° C, held for 6 minutes; a 4° C/min temperature
rise to 285° C; and a 20° C/min temperature rise to 325° C, held for 4 minutes. The injector and detector
temperatures were set at 270° C. Nitrogen was used as the carrier gas.
For each GC run, a log sheet was prepared containing sample identification, name(s) of persons
performing the analyses, type of samples being analyzed, instrument set-up parameters, and identifica-
tion of standard solutions. Also recorded on the log sheet were the date the samples were analyzed, the
file name that data were stored in, and any comments specific to the samples and/or data. Also re-
corded were instrument operating conditions and changes (e.g., if N2 cylinder was changed, column
was reconditioned, or any changes were made in operating conditions).
Once a week, seven PCP and four tribromophenol (TBP) calibration standards were injected to
prepare the linear range of the analytical system for PCP. TBP was analyzed because it had been added
as an internal standard to each sample during the extraction procedure. The standard curves generated
were compared to previous standard curves. During each daily run, three PCP standards and one TBP
calibration standard were injected. Results had to agree within 10 % of values calculated from the
weekly standard curve.
To develop the standard curves for PCP and TBP, peak areas, retention times, and corresponding
calibration concentrations were transferred from the chromatograms to a spreadsheet. Regression equa-
tions were calculated based on peak areas and corresponding concentrations. Control charts were
maintained for slope, y-intercept, and r2 for PCP. A standard curve was rejected if the r2 was less than
0.993.
For preparation of the PCP standard calibration curve, a PCP stock standard solution was prepared
at a concentration of 1000 mg/1 by dissolving the appropriate amount of pure (99.5% or greater) solid
B - 4
-------
PCP (Sigma) in methanol. The stock standard solution was stored at 4° C in an amber bottle to protect
the solution from light. A new stock standard solution was prepared at least every four months. The
PCP calibration standards (at a minimum of seven concentration levels) were prepared by dilution of
the stock standard solution with acetonitrile. Concentration levels corresponded to the range of con-
centrations expected in samples. The calibration standards were stored at 4° C and were protected from
light New calibration standards were prepared weekly.
For preparation of the TBP standard calibration curve, a TBP stock solution was prepared at a
concentration of 5000 mg/L by dissolving the appropriate amount of pure (99% or greater, Aldrich)
TBP in acetonitrile. The stock solution was stored at -20° C in the dark until use. A new stock standard
solution was prepared at least eveiy four months. TBP calibration standards (at a minimum of 4 con-
centration levels) were prepared by dilution of stock standard solution with acetonitrile. Concentration
levels corresponded to the range of concentrations expected in the samples. The calibration standards
were stored at 4° C and were protected from light. New calibration standards were prepared weekly.
For each run, a solvent blank was injected, followed by the injection of 10 - 12 samples; the run
was completed with the injection of another solvent blank. Atypical injection volume was 1 mL. After
each run, the GC glass injection sleeve was replaced with a clean sleeve. Before starting the next run,
the sleeve in the injector port was heated to the maximum injection temperature allowable for one hour.
The used glass sleeve was cleaned according to a procedure that utilized sulfuric acid and methanol as
cleaning solutions, followed by immersion in a silonizing solution and methanol.
PCP and TBP in samples were identified by matching their respective retention times with reten-
tion times of PCP and TBP obtained using calibration standards. If the peak area exceeded the linear
calibration range of the system for a sample, the extract was diluted or concentrated and re-analyzed.
Using an EXCEL spreadsheet, the peak area of PCP or TBP in a sample was converted to concentration
by using the slope and y-intercept of the corresponding calibration standard curve for the specific run
of samples. The formula used was:
concentration (mg/L) = (peak area - y intercept)/slope
The concentration was converted to mg/kg (wet weight) by dividing the concentration in mg/L by
the weight of the soil extracted and then multiplying by the dilution factor. The concentration was
converted to dry weight concentration by dividing the wet weight concentration by the percent dry
weight x 100.
Quality control samples analyzed included:
(1) analysis of duplicate extraction samples to check reproducibility of extraction procedure (every
twentieth sample was extracted in duplicate);
(2) analysis of procedural blanks to determine if any contamination was associated with the ex-
traction procedure (procedural blanks were run through the extraction procedure every 9-10 samples);
(3) analysis of TBP in every sample to determine recovery of TBP (TBP was added to every sample
before extraction);
(4) analysis of samples spiked with PCP to determine recovery of PCP in the spiked samples (du-
plicate samples were spiked every 9-10 samples); and
(5) analysis of solvent blanks to determine if carryover of PCP was occurring during an analytical
run.
B - 5
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B-3. Analysis of PAH Compounds using HPLC
An adaptation of U.S. EPA Method 8310 (U.S. EPA, 1986b) was used to determine the concentra-
tion of 16 polynuclear aromatic hydrocarbons (PAHs) in water and soil samples. The 16 PAHs include:
Acenaphthene Cbrysene
Acenaphthylene Dibenzo(aJj)anthracene
Anthracene Fluoranthene
Benzo(a)antbracene Fluorene
Benzo(a)pyrene Indeno( 1,2,3-cd)pyrene
Benzo(b)fluoranthene Naphthalene
Benzo(ghi)perylene Phenanthrene
Benzo(k)fluoranthene Pyrene
High performance liquid chromatography (HPLC) was used to detect the PAH compounds. Prior
to use of this method, the sonication extraction technique was used to prepare sample extracts for
analysis.
The HPLC systems for analysis used consisted of (1) a Shimad/u SCL-6B system controller, a
SIL-6B auto injector, LC-6A pumps, a Perkin-Elmer LC 90 UV spectrophptometric detector, and a
CR601 Chromatopac integrator (primary system used); and (2) a Shimadzu SCL6A system controller,
a SIL-6A auto injector, LC-6A pumps, an SPD-6A UV spectrophotometric detector, and a C-R3A
Chromatopac integrator. The column used for analysis was a reverse phase column: Supelcolsil™ LC-
PAH, 5 mm particle size diameter, in a 25 cm x 4.61.D. (1/4" O.D) stainless steel column (Supelco 5-
8229).
Before analysis was begun for a set of samples, the column was flushed for 1.5 to 3 hours with
acetonitrile/double deionized water (40:60). The acetonitrile used was HPLC grade, filtered through
Costar filters manufactured by Nuclepore with a 47 mm 0.2 mm polycarbonate membrane. During
analysis, the column conditions were as follows: isocratic elution for 2 minutes using acetonitrile/
DDW (distilled, deionized water) (40:60) (v/v), then linear gradient elution to 70:30 acetonitrile/DDW
over 15 minutes, then linear gradient elution to 100 % acetonitrile over 13 minutes, hold at 100%
acetonitrile for 9 minutes, and then linear gradient elution to 40:60 acetonitrile/DDW over 6 minutes at
a flow rate of 1.0 mL/min. The gradient pumping system was constant flow.
Calibration standards were injected to prepare the linear range of the analytical system for each
PAH compound. The peaks of the individual compounds were labeled for each calibration standard
run. The peak areas, retention times, and corresponding calibration concentrations were transferred to
an EXCEL 4.0 spreadsheet. Regression equations based on peak areas and corresponding concentra-
tions were prepared. Control charts for slope, y-intercept, and r2 were prepared and maintained for all
16 PAH compounds.
For preparation of standard curves for each PAH compound, calibration standards at five concen-
tration levels were prepared using volumetric pipettes and volumetric flasks through dilutions of the
stock standard solution 610-M with acetonitrile (Supelco Mixture 610-M (methanol methylene chlo-
ride used as solvent in the mixture) (Catalog no. 4-8743). Concentrations of PAHs in this mixture in
mg/ml, in order of elution in HPLC analysis, are: naphthalene, 1000; acenaphthylene, 2000;
acenaphthene, 1000; fluorene, 200; phenanthrene, 100; anthracene, 100; fluoranthene, 200; pyrene,
100; benzo(a)anthracene, 100; chrysene (93%), 100; benzo(b)fluoranthene, 200; benzo(a)pyrene, 100;
benzo(ghi)peiylene, 200; dibenzo(ah)anthracene; and indeno(l,2,3-cd)pyrene, 100). Dilutions used
include 1:10,1:50,1:100, 1:250, and 1:500. Mixture 610-M and the calibration standards were stored
at 4° C in the dark in a secured area. Standards were replaced every three months or when difficulties
were observed with the linearity of the standard curve.
B-6
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For each HPLC run, a log sheet was prepared that contained sample identification, name(s) of
persons performing the analyses, type of samples being analyzed, instrument set-up parameters, and
date of samples. The log sheet was stored with the chromatograms generated during an HPLC run. Also
recorded on the log sheet were the date the samples were analyzed, the file name that data were stored
in, and any comments specific to the samples and/or data.
Several samples in each run were spiked to aid in the identification of specific compounds. By
spiking several samples in each run, the range of variability in the matrices of soil/waste contamination
was included. Unspiked sample chromatograms were overlain on the spiked sample chromatograms
on a light table and peaks were identified and labeled, i.e., specific PAH compounds in samples were
identified by matching their respective retention times with retention times of the compounds obtained
in the spiked samples. The spiked samples served as "templates" for the identification of peaks.
If the peak area exceeded the linear calibration range of the system for a sample, the extract was
diluted or concentrated and re-analyzed. Using an EXCEL 4.0 spreadsheet (Macintosh), the peak area
of each PAH compound in a sample was converted to concentration by using the slope and y-intercept
of the corresponding calibration standard curve for the specific run of samples. The formula used was:
concentration (mg/L) = (peak area - y intercept)/slope
The concentration was converted to mg/kg (wet weight) by dividing the concentration in mg/L by
the weight of the soil extracted and then multiplying by the dilution factor. The concentration was
converted to dry weight concentration by dividing the wet weight concentration by the percent dry
weight x 100.
Quality control samples analyzed included:
(1) analysis of duplicate extraction samples to check reproducibility of extraction procedure (every
twentieth sample was extracted in duplicate);
(2) analysis of procedural blanks to determine if any contamination was associated with the extrac-
tion procedure (procedural blanks were run through the extraction procedure every 9-10 samples);
(3) analysis of samples spiked with PAH compounds to determine recovery of PAHs in the spiked
samples (duplicate samples were spiked every 9-10 samples); and
(4) analysis of calibration standards randomly during a sample run to check for instrument drift;
and
(5) analysis of solvent blanks to determine if any carryover of PAH was occurring during an ana-
lytical run.
B-4 Analysis of TPH using Gas Chromatography
To prepare a sample extract (for the sonication procedure see Appendix B-1) for analysis for TPH,
400 mL was removed from the extract storage vial (after thorough shaking) using a syringe and added
to a 5 mL volumetric flask. Two hundred (200) mL of the internal standard, oterphenyl diphenyl
benzene (from a stock solution prepared with a concentration of 1250 mg/L ) was also added to the
flask, resulting in a concentration of 50 mg/L. The flask was brought to volume with acetone. One mL
of this diluted sample extract was placed in a GC vial for analysis.
For preparation of standard curves for TPH, calibration standards at five concentration levels
were prepared using volumetric pipettes and 100 mL volumetric flasks through dilutions of pure diescl
fuel with acetone. The source and date of acquisition of the diesel fuel was recorded. Standard concen-
B - 7
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trations used were: 0.01%, 0.05%, 0.1%, 0.5%, and 1%. Dilutions used include 1:10, 1:50, 1:100,
1:250, and 1:500. The calibration standards were stored at 4° C in brown bottles in the dark in a
secured area. Standards were replaced every three months or when difficulties were observed with the
linearity of the standard curve.
Acheck standard at 0.4% was prepared using pure diesel fuel from a separate source. The calibra-
tion check standard was used to check the standard curve periodically during analyses.
The internal standard o-terphenyl diphenyl benzene was added to both the calibration and check
standards to achieve a final concentration of 50 mg/L.
GC analyses were conducted using a Shimadzu gas chromatograph (Shimadzu Instruments, Co-
lumbia, MD) equipped with an FID detector and a 10 m long, 0.75 mm i.d. small bore Petrocol 3710
(Supelco, Inc., Bellefonte, PA) fused silica capillary column. Solvent extracts were injected directly
into the GC. The system operating conditions were as follows:
Injector temperature: 250° C
Detector temperature: 250° C
Carrier gas: Nitrogen
Carrier Flow: 15 mL/min
Temperature program: 30° C to 280° C at 20° C/min
B-5 Analysis of PAH Compounds and PCP by ManTech Environmental
Technology
An LNAPL sample collected from a monitoring well during the Phase II investigation and ground-
water samples collected during the Phase III investigation were extracted and analyzed by ManTech
Environmental Technology, Ada, Oklahoma, a support laboratory for the U.S. EPA RSKERL.
Five mL of the LNAPL sample was added to 995 mL of GC/MS grade methylene chloride. A 10
mL aliquot of an internal standard mixture containing 1,4-dichlorobenzene-d4, naphthalened8,
acenaphthalene-d)0, phenanthrene-d-10, chrysene-d]2, andperylene-d)2, each at 4000 ppm, was added to
the diluted NAPL sample.
Base/neutral and acid extraction of the ground-water samples was performed according to U.S.
EPA Methods 3500 and 3510 (U.S. EPA, 1986b). Before the extraction, 1.0 mL of 100 ppm base/
neutral surrogates and 1.0 mL of200 ppm acid surrogates were added to each of the 1 L water samples
and to 1.0 L of the method blank water. After the pH of one liter of each water sample was adjusted to
slightly above 11.0 with 10 N NaOH, the water sample was extracted three times with 60 mL of meth-
ylene chloride. After the methylene chloride fraction was passed through a Na2S04 column, it was
concentrated using an evaporative concentrator (Turbo-Vap) to a final volume of 1.0 mL. The water
fraction was then acidified to a pH just below 2.0 using 1:1 H2S04. The acidified water sample was
then extracted three times with 60 mL methylene chloride. The 180 mL of methylene chloride extract
was dried using the Na2S04 and was then concentrated to 1.0 mL using the Turbo-Vap. The acid and
base/neutral extracts were combined, the final volume was reduced to 1.0 mL with the Turbo-Vap, and
the extract was placed in a vial and crimp capped.
For the semi-quantitative analysis, a 20 mL aliquot of an internal standard mixture containing 1,4-
dichlorobenzene-d2, naphthalene-d8, acenaphthalene-d10, phenanthrene-d10, chrysene-d,2, and perylene-
d|2, each at 2000 ppm, was added to 1.0 mL of the base/neutral or acid extract
B - 8
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For both the LNAPL sample and the ground-water samples, the Hewlett Packard 7673 autoinjector
delivered 1.0 mL of this sample under spiitless conditions to a 30 meter, 0.32 mm DB5-MS capillary
column with 1.0 mm film thickness. The column was temperature programmed from 40° to 300° at 8°
C/'min. The Finmgan 4500 GC/MS was scanned from 45 to 450 m/z in 0.5 seconds. The U.S. EPA
tuning criteria for 50 ng of decafluorotriphenylphosphine (DFTPP) was met before starting the analy-
sis.
For the LNAPL sample, standard curves consisting of 1,5,12.5,25,50, and 100 ppm of PCP and
thirteen PAH compounds were established before sample analysis. Ten ppm U.S. EPA quality control
standards containing 35 base/neutral and 11 phenolic priority pollutants including 12 PAH compounds
were analyzed to provide confirmation of compounds present in the extracts and to provide quality
control for the calibration curves.
For the ground-water samples, quality control standards containing 15 PAH compounds and PCP
were analyzed to provide quantitation and confirmation of compounds present in the extracts. Calibra-
tion standards were run at 1.0, 5.0, 10.0, 25.0, 50.0, and 100 ppm for each of the 15 PAH compounds.
Calibration for PCP was obtained at 5.0, 10.0,25.0, 50.0 and 100 ppm.
B - 9
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Appendix C
Analytical Results from Phase II and Phase III Field Investigations
Table C-1. Analysis of Aquifer Solids from Borehole No. 2 (31 feet SW of Monitoring Well No. 3026):
November 1992.
Depth Below TPAH' PCP2 TPH3
Surface
(ft) (mg/Kg) (mg/Kg) (mg/Kg)
16.1 89
0.1
561
23.5 416
1.3
2910
26.0 32
0.2
238
29.5 85
0.4
594
31.0 39
0.2
990
32.0 116
0.8
184
' TPAH = total polycyclic aromatic hydrocarbons; sum of the 16 priority pollutant PAH compounds
2 PCP = pentachlorophenol
3 TPH = total petroleum hydrocarbons
Table C-2. Analysis of Aquifer Solids from Borehole No. 3 (58 feet NW of Injection Well No. 3007):
November 1992.
Depth Below Surface
(ft)
TPAH' PCP2
(mg/Kg) (mg/Kg)
TPH3
(mg/Kg)
16.5
122 0.7
360 .
18.4
22 0.1
258
20.0
5.2 0.2
275
22.3
25 0.1
281
23.3
404 2.8
929
25.8
43 0.1
505
26.7
687 3.2
1924
27.5
443 1.3
1105
30.8
115 1.0
1265
1 TPAH ~ total polycyclic aromatic hydrocarbons; sum of the 16 priority pollutant PAH compounds
2 PCP = pentachlorophenol
3 TPH = total petroleum hydrocarbons
C-1
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Table C-3, Analysisof Aquifer SolidSL from Boretroie No, 4.(5.1 fm N.af Injection Wsll.CJuster 95Q0/9501):
November-1992.
Depth Below Surface
(ft)
TFAH*
(mg/Kg)
pcpz
(mg/Kg)
TPH3.
(mg/Kg)
13.7
24.
0.5
702
15.0
171
7.9
2525
17.2
216
2.0
691
18.7
28.
0.3
70
20.0
47
0.3
132
30.8
5.8.
0.1.
109
1 TPAH = total polycyclic aromatic hydrocarbons sum of tho 16 priority pollute PAH compounds
2 PCP =pentachlorophenol
3 TPH = total petroleum.hydrocarbons
C - 2
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Table C-4.
Inorganic Compounds In Injection and Monitoring Wells: March, 1993
Mg/1
Mg/1
Mg/1
Mg/1
Sample1
NO 7 + NCHfN)
NH3(N)
CL-
T-P
Inj. Well 9500
.26
3.32
8.24
1.21
Inj, Well 9500/9501
.26
3.11
8.00
1.40
25-1
.66
.10
9.81
.30
25-1 Dup
.67
.11
25-2
,69
.06
7.38
.69
25-2 Rep
.40
25-3
1.36
.09
8.19
.35
25-4
.48
.12
9.58
.37
26 1
1,96
<.05
4.17
1.59
26-2
2.08
<.05
5.98
.97
26-2 Dup
2.05
<.05
5.70
26-3
1.85
<.05
7.85
.93
26-4
1.80
<.05
1.68
1.14
26-5
1.71
<.05
4.64
.61
26-5 Dup
.61
2 6-6
1.74
<.05
6.35
1.17
2 6-6 Dup
.91
26-7
1.72
<.05
5.88
.96
26-8
1.71
<.05
6.52
.96
26-9
1.76
<.05
5.58
.73
26-10
1.78
<.05
6.21
.91
26-11
1.84
<.05
5.31
.90
26-12
1.84
<.05
72,5
.92
26-13
1.86
<.05
6.28
1.02
26-13 Dup
1.85
<.05
5.88
26-14
1.89
.06
5.77
.86
26-15
1,86
.05
8.45
.79
32-1
1.90
.70
7.62
1.03
32-2
2.20
.50
9.20
1.25
32-3
1.97
.53
5.71
1.25
32-4
1.99
.55
10,3
1.20
32-5
2.02
.63
9.16
1.25
32-6
2.04
.63
8.31
1.43
32-7
1.90
.78
9.33
1.26
32-8
1.78
.92
8.67
1.29
32-8 Dup
1.77
.91
32-9
1.78
.92
9.22
1.53
32-9 Rep
1.39
32-10
1.77
.94
9.92
1.31
32-10 Dup
1.50
AQCWP029
1.24
.27
31.2
.86
1.03
True Value
1.30
.35
33.3
.94
Spike Recovery
104%
103%
97%
104%
102%
•Sample number nomenclature and depth interval given in Table B-5.
0 ¦ 3
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Table OS. Sample Number Nomenclature and Depth Interval tor Sample Results Presented inTgble C-4.
Well No. Field Sample No.O) Report Sample No. Sample Depth (2)
1
SH251
22.5
2
SH352
19.5
3
SH253
16-5
4
SH254
13.5
1
SH261
29.8
2
broken
28.8
3
SB263
27.8
4
SH264
26.8
5
SH265
25.8
6
broken
24.8
7
SH267
23.8
8
SH268
22.8
9
broken
21.8
10
broken
20.8
11
SH2611
19.8
12
SH2612
18.8
13
SH2613
17.8
14
SH2614
16.8
15
SH2615
15.8
1
SH321
19,5
2
SH322
18.5
3
SH323
17.5
4
SH324
16.5
5
SH325
35.5
6
SH326
14.5
7
SH327
13,5
8
SH328
12.5
9
SH329
11.5
10
SH3210
10.5
(1)Sample number used in the field when collecting samples.
(2)Depth at which sample was collected, below ground surface.
C-4
•ftUA COVERNMOTT FBIMINC OFTICFj 1M7
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